sphinx.addnodesdocument)}( rawsourcechildren]( translations LanguagesNode)}(hhh](h pending_xref)}(hhh]docutils.nodesTextChinese (Simplified)}parenthsba attributes}(ids]classes]names]dupnames]backrefs] refdomainstdreftypedoc reftarget!/translations/zh_CN/arch/x86/bootmodnameN classnameN refexplicitutagnamehhh ubh)}(hhh]hChinese (Traditional)}hh2sbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget!/translations/zh_TW/arch/x86/bootmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hItalian}hhFsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget!/translations/it_IT/arch/x86/bootmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hJapanese}hhZsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget!/translations/ja_JP/arch/x86/bootmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hKorean}hhnsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget!/translations/ko_KR/arch/x86/bootmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hPortuguese (Brazilian)}hhsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget!/translations/pt_BR/arch/x86/bootmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hSpanish}hhsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget!/translations/sp_SP/arch/x86/bootmodnameN classnameN refexplicituh1hhh ubeh}(h]h ]h"]h$]h&]current_languageEnglishuh1h hh _documenthsourceNlineNubhcomment)}(h SPDX-License-Identifier: GPL-2.0h]h SPDX-License-Identifier: GPL-2.0}hhsbah}(h]h ]h"]h$]h&] xml:spacepreserveuh1hhhhhh;/var/lib/git/docbuild/linux/Documentation/arch/x86/boot.rsthKubhsection)}(hhh](htitle)}(hThe Linux/x86 Boot Protocolh]hThe Linux/x86 Boot Protocol}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhhhhhKubh paragraph)}(hXOn the x86 platform, the Linux kernel uses a rather complicated boot convention. This has evolved partially due to historical aspects, as well as the desire in the early days to have the kernel itself be a bootable image, the complicated PC memory model and due to changed expectations in the PC industry caused by the effective demise of real-mode DOS as a mainstream operating system.h]hXOn the x86 platform, the Linux kernel uses a rather complicated boot convention. This has evolved partially due to historical aspects, as well as the desire in the early days to have the kernel itself be a bootable image, the complicated PC memory model and due to changed expectations in the PC industry caused by the effective demise of real-mode DOS as a mainstream operating system.}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubh)}(hGCurrently, the following versions of the Linux/x86 boot protocol exist.h]hGCurrently, the following versions of the Linux/x86 boot protocol exist.}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubhtable)}(hhh]htgroup)}(hhh](hcolspec)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKBuh1jhjubhtbody)}(hhh](hrow)}(hhh](hentry)}(hhh]h)}(h Old kernelsh]h Old kernels}(hj*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj'ubah}(h]h ]h"]h$]h&]uh1j%hj"ubj&)}(hhh]h)}(hXzImage/Image support only. Some very early kernels may not even support a command line.h]hXzImage/Image support only. Some very early kernels may not even support a command line.}(hjAhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj>ubah}(h]h ]h"]h$]h&]uh1j%hj"ubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.00h]h Protocol 2.00}(hjahhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj^ubah}(h]h ]h"]h$]h&]uh1j%hj[ubj&)}(hhh]h)}(h(Kernel 1.3.73) Added bzImage and initrd support, as well as a formalized way to communicate between the boot loader and the kernel. setup.S made relocatable, although the traditional setup area still assumed writable.h]h(Kernel 1.3.73) Added bzImage and initrd support, as well as a formalized way to communicate between the boot loader and the kernel. setup.S made relocatable, although the traditional setup area still assumed writable.}(hjxhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjuubah}(h]h ]h"]h$]h&]uh1j%hj[ubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.01h]h Protocol 2.01}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h-(Kernel 1.3.76) Added a heap overrun warning.h]h-(Kernel 1.3.76) Added a heap overrun warning.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.02h]h Protocol 2.02}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hX(Kernel 2.4.0-test3-pre3) New command line protocol. Lower the conventional memory ceiling. No overwrite of the traditional setup area, thus making booting safe for systems which use the EBDA from SMM or 32-bit BIOS entry points. zImage deprecated but still supported.h]hX(Kernel 2.4.0-test3-pre3) New command line protocol. Lower the conventional memory ceiling. No overwrite of the traditional setup area, thus making booting safe for systems which use the EBDA from SMM or 32-bit BIOS entry points. zImage deprecated but still supported.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.03h]h Protocol 2.03}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK#hjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hf(Kernel 2.4.18-pre1) Explicitly makes the highest possible initrd address available to the bootloader.h]hf(Kernel 2.4.18-pre1) Explicitly makes the highest possible initrd address available to the bootloader.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK#hjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.04h]h Protocol 2.04}(hj=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK&hj:ubah}(h]h ]h"]h$]h&]uh1j%hj7ubj&)}(hhh]h)}(h7(Kernel 2.6.14) Extend the syssize field to four bytes.h]h7(Kernel 2.6.14) Extend the syssize field to four bytes.}(hjThhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK&hjQubah}(h]h ]h"]h$]h&]uh1j%hj7ubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.05h]h Protocol 2.05}(hjthhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK(hjqubah}(h]h ]h"]h$]h&]uh1j%hjnubj&)}(hhh]h)}(hq(Kernel 2.6.20) Make protected mode kernel relocatable. Introduce relocatable_kernel and kernel_alignment fields.h]hq(Kernel 2.6.20) Make protected mode kernel relocatable. Introduce relocatable_kernel and kernel_alignment fields.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK(hjubah}(h]h ]h"]h$]h&]uh1j%hjnubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.06h]h Protocol 2.06}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK+hjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hN(Kernel 2.6.22) Added a field that contains the size of the boot command line.h]hN(Kernel 2.6.22) Added a field that contains the size of the boot command line.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK+hjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.07h]h Protocol 2.07}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK.hjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h(Kernel 2.6.24) Added paravirtualised boot protocol. Introduced hardware_subarch and hardware_subarch_data and KEEP_SEGMENTS flag in load_flags.h]h(Kernel 2.6.24) Added paravirtualised boot protocol. Introduced hardware_subarch and hardware_subarch_data and KEEP_SEGMENTS flag in load_flags.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK.hjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.08h]h Protocol 2.08}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK2hjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h(Kernel 2.6.26) Added crc32 checksum and ELF format payload. Introduced payload_offset and payload_length fields to aid in locating the payload.h]h(Kernel 2.6.26) Added crc32 checksum and ELF format payload. Introduced payload_offset and payload_length fields to aid in locating the payload.}(hj0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK2hj-ubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.09h]h Protocol 2.09}(hjPhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK6hjMubah}(h]h ]h"]h$]h&]uh1j%hjJubj&)}(hhh]h)}(hd(Kernel 2.6.26) Added a field of 64-bit physical pointer to single linked list of struct setup_data.h]hd(Kernel 2.6.26) Added a field of 64-bit physical pointer to single linked list of struct setup_data.}(hjghhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK6hjdubah}(h]h ]h"]h$]h&]uh1j%hjJubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.10h]h Protocol 2.10}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK9hjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h(Kernel 2.6.31) Added a protocol for relaxed alignment beyond the kernel_alignment added, new init_size and pref_address fields. Added extended boot loader IDs.h]h(Kernel 2.6.31) Added a protocol for relaxed alignment beyond the kernel_alignment added, new init_size and pref_address fields. Added extended boot loader IDs.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK9hjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.11h]h Protocol 2.11}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK=hjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hK(Kernel 3.6) Added a field for offset of EFI handover protocol entry point.h]hK(Kernel 3.6) Added a field for offset of EFI handover protocol entry point.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK=hjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.12h]h Protocol 2.12}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK@hjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h(Kernel 3.8) Added the xloadflags field and extension fields to struct boot_params for loading bzImage and ramdisk above 4G in 64bit.h]h(Kernel 3.8) Added the xloadflags field and extension fields to struct boot_params for loading bzImage and ramdisk above 4G in 64bit.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK@hj ubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.13h]h Protocol 2.13}(hj,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKDhj)ubah}(h]h ]h"]h$]h&]uh1j%hj&ubj&)}(hhh]h)}(hu(Kernel 3.14) Support 32- and 64-bit flags being set in xloadflags to support booting a 64-bit kernel from 32-bit EFIh]hu(Kernel 3.14) Support 32- and 64-bit flags being set in xloadflags to support booting a 64-bit kernel from 32-bit EFI}(hjChhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKDhj@ubah}(h]h ]h"]h$]h&]uh1j%hj&ubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.14h]h Protocol 2.14}(hjchhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKHhj`ubah}(h]h ]h"]h$]h&]uh1j%hj]ubj&)}(hhh]h)}(hBURNT BY INCORRECT COMMIT ae7e1238e68f2a472a125673ab506d49158c1889 ("x86/boot: Add ACPI RSDP address to setup_header") DO NOT USE!!! ASSUME SAME AS 2.13.h]hBURNT BY INCORRECT COMMIT ae7e1238e68f2a472a125673ab506d49158c1889 (“x86/boot: Add ACPI RSDP address to setup_header”) DO NOT USE!!! ASSUME SAME AS 2.13.}(hjzhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKHhjwubah}(h]h ]h"]h$]h&]uh1j%hj]ubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol 2.15h]h Protocol 2.15}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKMhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hB(Kernel 5.5) Added the kernel_info and kernel_info.setup_type_max.h]hB(Kernel 5.5) Added the kernel_info and kernel_info.setup_type_max.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKMhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubeh}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]colsKuh1jhhubah}(h]h ]h"]h$]h&]uh1hhhhhhhhNubhnote)}(hX^The protocol version number should be changed only if the setup header is changed. There is no need to update the version number if boot_params or kernel_info are changed. Additionally, it is recommended to use xloadflags (in this case the protocol version number should not be updated either) or kernel_info to communicate supported Linux kernel features to the boot loader. Due to very limited space available in the original setup header every update to it should be considered with great care. Starting from the protocol 2.15 the primary way to communicate things to the boot loader is the kernel_info.h]h)}(hX^The protocol version number should be changed only if the setup header is changed. There is no need to update the version number if boot_params or kernel_info are changed. Additionally, it is recommended to use xloadflags (in this case the protocol version number should not be updated either) or kernel_info to communicate supported Linux kernel features to the boot loader. Due to very limited space available in the original setup header every update to it should be considered with great care. Starting from the protocol 2.15 the primary way to communicate things to the boot loader is the kernel_info.h]hX^The protocol version number should be changed only if the setup header is changed. There is no need to update the version number if boot_params or kernel_info are changed. Additionally, it is recommended to use xloadflags (in this case the protocol version number should not be updated either) or kernel_info to communicate supported Linux kernel features to the boot loader. Due to very limited space available in the original setup header every update to it should be considered with great care. Starting from the protocol 2.15 the primary way to communicate things to the boot loader is the kernel_info.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKQhjubah}(h]h ]h"]h$]h&]uh1jhhhhhhhNubh)}(hhh](h)}(h Memory Layouth]h Memory Layout}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjhhhhhK]ubh)}(hjThe traditional memory map for the kernel loader, used for Image or zImage kernels, typically looks like::h]hiThe traditional memory map for the kernel loader, used for Image or zImage kernels, typically looks like:}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK_hjhhubh literal_block)}(hXB | | 0A0000 +------------------------+ | Reserved for BIOS | Do not use. Reserved for BIOS EBDA. 09A000 +------------------------+ | Command line | | Stack/heap | For use by the kernel real-mode code. 098000 +------------------------+ | Kernel setup | The kernel real-mode code. 090200 +------------------------+ | Kernel boot sector | The kernel legacy boot sector. 090000 +------------------------+ | Protected-mode kernel | The bulk of the kernel image. 010000 +------------------------+ | Boot loader | <- Boot sector entry point 0000:7C00 001000 +------------------------+ | Reserved for MBR/BIOS | 000800 +------------------------+ | Typically used by MBR | 000600 +------------------------+ | BIOS use only | 000000 +------------------------+h]hXB | | 0A0000 +------------------------+ | Reserved for BIOS | Do not use. Reserved for BIOS EBDA. 09A000 +------------------------+ | Command line | | Stack/heap | For use by the kernel real-mode code. 098000 +------------------------+ | Kernel setup | The kernel real-mode code. 090200 +------------------------+ | Kernel boot sector | The kernel legacy boot sector. 090000 +------------------------+ | Protected-mode kernel | The bulk of the kernel image. 010000 +------------------------+ | Boot loader | <- Boot sector entry point 0000:7C00 001000 +------------------------+ | Reserved for MBR/BIOS | 000800 +------------------------+ | Typically used by MBR | 000600 +------------------------+ | BIOS use only | 000000 +------------------------+}hjsbah}(h]h ]h"]h$]h&]hhuh1jhhhKbhjhhubh)}(hX|When using bzImage, the protected-mode kernel was relocated to 0x100000 ("high memory"), and the kernel real-mode block (boot sector, setup, and stack/heap) was made relocatable to any address between 0x10000 and end of low memory. Unfortunately, in protocols 2.00 and 2.01 the 0x90000+ memory range is still used internally by the kernel; the 2.02 protocol resolves that problem.h]hXWhen using bzImage, the protected-mode kernel was relocated to 0x100000 (“high memory”), and the kernel real-mode block (boot sector, setup, and stack/heap) was made relocatable to any address between 0x10000 and end of low memory. Unfortunately, in protocols 2.00 and 2.01 the 0x90000+ memory range is still used internally by the kernel; the 2.02 protocol resolves that problem.}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKxhjhhubh)}(hXuIt is desirable to keep the "memory ceiling" -- the highest point in low memory touched by the boot loader -- as low as possible, since some newer BIOSes have begun to allocate some rather large amounts of memory, called the Extended BIOS Data Area, near the top of low memory. The boot loader should use the "INT 12h" BIOS call to verify how much low memory is available.h]hX}It is desirable to keep the “memory ceiling” -- the highest point in low memory touched by the boot loader -- as low as possible, since some newer BIOSes have begun to allocate some rather large amounts of memory, called the Extended BIOS Data Area, near the top of low memory. The boot loader should use the “INT 12h” BIOS call to verify how much low memory is available.}(hj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjhhubh)}(hXUnfortunately, if INT 12h reports that the amount of memory is too low, there is usually nothing the boot loader can do but to report an error to the user. The boot loader should therefore be designed to take up as little space in low memory as it reasonably can. For zImage or old bzImage kernels, which need data written into the 0x90000 segment, the boot loader should make sure not to use memory above the 0x9A000 point; too many BIOSes will break above that point.h]hXUnfortunately, if INT 12h reports that the amount of memory is too low, there is usually nothing the boot loader can do but to report an error to the user. The boot loader should therefore be designed to take up as little space in low memory as it reasonably can. For zImage or old bzImage kernels, which need data written into the 0x90000 segment, the boot loader should make sure not to use memory above the 0x9A000 point; too many BIOSes will break above that point.}(hjChhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjhhubh)}(hqFor a modern bzImage kernel with boot protocol version >= 2.02, a memory layout like the following is suggested::h]hpFor a modern bzImage kernel with boot protocol version >= 2.02, a memory layout like the following is suggested:}(hjQhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjhhubj)}(hX ~ ~ | Protected-mode kernel | 100000 +------------------------+ | I/O memory hole | 0A0000 +------------------------+ | Reserved for BIOS | Leave as much as possible unused ~ ~ | Command line | (Can also be below the X+10000 mark) X+10000 +------------------------+ | Stack/heap | For use by the kernel real-mode code. X+08000 +------------------------+ | Kernel setup | The kernel real-mode code. | Kernel boot sector | The kernel legacy boot sector. X +------------------------+ | Boot loader | <- Boot sector entry point 0000:7C00 001000 +------------------------+ | Reserved for MBR/BIOS | 000800 +------------------------+ | Typically used by MBR | 000600 +------------------------+ | BIOS use only | 000000 +------------------------+ ... where the address X is as low as the design of the boot loader permits.h]hX ~ ~ | Protected-mode kernel | 100000 +------------------------+ | I/O memory hole | 0A0000 +------------------------+ | Reserved for BIOS | Leave as much as possible unused ~ ~ | Command line | (Can also be below the X+10000 mark) X+10000 +------------------------+ | Stack/heap | For use by the kernel real-mode code. X+08000 +------------------------+ | Kernel setup | The kernel real-mode code. | Kernel boot sector | The kernel legacy boot sector. X +------------------------+ | Boot loader | <- Boot sector entry point 0000:7C00 001000 +------------------------+ | Reserved for MBR/BIOS | 000800 +------------------------+ | Typically used by MBR | 000600 +------------------------+ | BIOS use only | 000000 +------------------------+ ... where the address X is as low as the design of the boot loader permits.}hj_sbah}(h]h ]h"]h$]h&]hhuh1jhhhKhjhhubeh}(h] memory-layoutah ]h"] memory layoutah$]h&]uh1hhhhhhhhK]ubh)}(hhh](h)}(hThe Real-Mode Kernel Headerh]hThe Real-Mode Kernel Header}(hjxhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuhhhhhKubh)}(hIn the following text, and anywhere in the kernel boot sequence, "a sector" refers to 512 bytes. It is independent of the actual sector size of the underlying medium.h]hIn the following text, and anywhere in the kernel boot sequence, “a sector” refers to 512 bytes. It is independent of the actual sector size of the underlying medium.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjuhhubh)}(hX@The first step in loading a Linux kernel should be to load the real-mode code (boot sector and setup code) and then examine the following header at offset 0x01f1. The real-mode code can total up to 32K, although the boot loader may choose to load only the first two sectors (1K) and then examine the bootup sector size.h]hX@The first step in loading a Linux kernel should be to load the real-mode code (boot sector and setup code) and then examine the following header at offset 0x01f1. The real-mode code can total up to 32K, although the boot loader may choose to load only the first two sectors (1K) and then examine the bootup sector size.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjuhhubh)}(hThe header looks like:h]hThe header looks like:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjuhhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhjubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhjubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthK,uh1jhjubhthead)}(hhh]j!)}(hhh](j&)}(hhh]h)}(h Offset/Sizeh]h Offset/Size}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hProtoh]hProto}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hNameh]hName}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hMeaningh]hMeaning}(hj.hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj+ubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h01F1/1h]h01F1/1}(hjWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjTubah}(h]h ]h"]h$]h&]uh1j%hjQubj&)}(hhh]h)}(hALL(1)h]hALL(1)}(hjnhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjkubah}(h]h ]h"]h$]h&]uh1j%hjQubj&)}(hhh]h)}(h setup_sectsh]h setup_sects}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjQubj&)}(hhh]h)}(h The size of the setup in sectorsh]h The size of the setup in sectors}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjQubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h01F2/2h]h01F2/2}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hALLh]hALL}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h root_flagsh]h root_flags}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h$If set, the root is mounted readonlyh]h$If set, the root is mounted readonly}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h01F4/4h]h01F4/4}(hj!hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h2.04+(2)h]h2.04+(2)}(hj8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj5ubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hsyssizeh]hsyssize}(hjOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjLubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h,The size of the 32-bit code in 16-byte parash]h,The size of the 32-bit code in 16-byte paras}(hjfhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjcubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h01F8/2h]h01F8/2}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hALLh]hALL}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hram_sizeh]hram_size}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h$DO NOT USE - for bootsect.S use onlyh]h$DO NOT USE - for bootsect.S use only}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h01FA/2h]h01FA/2}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hALLh]hALL}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hvid_modeh]hvid_mode}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hVideo mode controlh]hVideo mode control}(hj0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj-ubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h01FC/2h]h01FC/2}(hjPhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjMubah}(h]h ]h"]h$]h&]uh1j%hjJubj&)}(hhh]h)}(hALLh]hALL}(hjghhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjdubah}(h]h ]h"]h$]h&]uh1j%hjJubj&)}(hhh]h)}(hroot_devh]hroot_dev}(hj~hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj{ubah}(h]h ]h"]h$]h&]uh1j%hjJubj&)}(hhh]h)}(hDefault root device numberh]hDefault root device number}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjJubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h01FE/2h]h01FE/2}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hALLh]hALL}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h boot_flagh]h boot_flag}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h0xAA55 magic numberh]h0xAA55 magic number}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0200/2h]h0200/2}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj1 hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj. ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(hjumph]hjump}(hjH hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjE ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(hJump instructionh]hJump instruction}(hj_ hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj\ ubah}(h]h ]h"]h$]h&]uh1j%hj ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0202/4h]h0202/4}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj| ubah}(h]h ]h"]h$]h&]uh1j%hjy ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hjy ubj&)}(hhh]h)}(hheaderh]hheader}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hjy ubj&)}(hhh]h)}(hMagic signature "HdrS"h]hMagic signature “HdrS”}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hjy ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0206/2h]h0206/2}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(hversionh]hversion}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(hBoot protocol version supportedh]hBoot protocol version supported}(hj) hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj& ubah}(h]h ]h"]h$]h&]uh1j%hj ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0208/4h]h0208/4}(hjI hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjF ubah}(h]h ]h"]h$]h&]uh1j%hjC ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj` hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj] ubah}(h]h ]h"]h$]h&]uh1j%hjC ubj&)}(hhh]h)}(hrealmode_swtchh]hrealmode_swtch}(hjw hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjt ubah}(h]h ]h"]h$]h&]uh1j%hjC ubj&)}(hhh]h)}(hBoot loader hook (see below)h]hBoot loader hook (see below)}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hjC ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h020C/2h]h020C/2}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h start_sys_segh]h start_sys_seg}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h(The load-low segment (0x1000) (obsolete)h]h(The load-low segment (0x1000) (obsolete)}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h020E/2h]h020E/2}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj* hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj' ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(hkernel_versionh]hkernel_version}(hjA hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj> ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h Pointer to kernel version stringh]h Pointer to kernel version string}(hjX hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjU ubah}(h]h ]h"]h$]h&]uh1j%hj ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0210/1h]h0210/1}(hjx hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhju ubah}(h]h ]h"]h$]h&]uh1j%hjr ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hjr ubj&)}(hhh]h)}(htype_of_loaderh]htype_of_loader}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hjr ubj&)}(hhh]h)}(hBoot loader identifierh]hBoot loader identifier}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hjr ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0211/1h]h0211/1}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h loadflagsh]h loadflags}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(hBoot protocol option flagsh]hBoot protocol option flags}(hj" hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0212/2h]h0212/2}(hjB hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj? ubah}(h]h ]h"]h$]h&]uh1j%hj< ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hjY hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjV ubah}(h]h ]h"]h$]h&]uh1j%hj< ubj&)}(hhh]h)}(hsetup_move_sizeh]hsetup_move_size}(hjp hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjm ubah}(h]h ]h"]h$]h&]uh1j%hj< ubj&)}(hhh]h)}(h*Move to high memory size (used with hooks)h]h*Move to high memory size (used with hooks)}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj< ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0214/4h]h0214/4}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h code32_starth]h code32_start}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(hBoot loader hook (see below)h]hBoot loader hook (see below)}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0218/4h]h0218/4}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj# hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h ramdisk_imageh]h ramdisk_image}(hj: hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj7 ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h(initrd load address (set by boot loader)h]h(initrd load address (set by boot loader)}(hjQ hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjN ubah}(h]h ]h"]h$]h&]uh1j%hj ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h021C/4h]h021C/4}(hjq hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjn ubah}(h]h ]h"]h$]h&]uh1j%hjk ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hjk ubj&)}(hhh]h)}(h ramdisk_sizeh]h ramdisk_size}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hjk ubj&)}(hhh]h)}(h initrd size (set by boot loader)h]h initrd size (set by boot loader)}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hjk ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0220/4h]h0220/4}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(hbootsect_kludgeh]hbootsect_kludge}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h$DO NOT USE - for bootsect.S use onlyh]h$DO NOT USE - for bootsect.S use only}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hj ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0224/2h]h0224/2}(hj;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj8ubah}(h]h ]h"]h$]h&]uh1j%hj5ubj&)}(hhh]h)}(h2.01+h]h2.01+}(hjRhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjOubah}(h]h ]h"]h$]h&]uh1j%hj5ubj&)}(hhh]h)}(h heap_end_ptrh]h heap_end_ptr}(hjihhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjfubah}(h]h ]h"]h$]h&]uh1j%hj5ubj&)}(hhh]h)}(hFree memory after setup endh]hFree memory after setup end}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj}ubah}(h]h ]h"]h$]h&]uh1j%hj5ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0226/1h]h0226/1}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h2.02+(3)h]h2.02+(3)}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hext_loader_verh]hext_loader_ver}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hExtended boot loader versionh]hExtended boot loader version}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0227/1h]h0227/1}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h2.02+(3)h]h2.02+(3)}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hext_loader_typeh]hext_loader_type}(hj3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj0ubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hExtended boot loader IDh]hExtended boot loader ID}(hjJhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjGubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0228/4h]h0228/4}(hjjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjgubah}(h]h ]h"]h$]h&]uh1j%hjdubj&)}(hhh]h)}(h2.02+h]h2.02+}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj~ubah}(h]h ]h"]h$]h&]uh1j%hjdubj&)}(hhh]h)}(h cmd_line_ptrh]h cmd_line_ptr}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjdubj&)}(hhh]h)}(h)32-bit pointer to the kernel command lineh]h)32-bit pointer to the kernel command line}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjdubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h022C/4h]h022C/4}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h2.03+h]h2.03+}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hinitrd_addr_maxh]hinitrd_addr_max}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hHighest legal initrd addressh]hHighest legal initrd address}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0230/4h]h0230/4}(hj4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj1ubah}(h]h ]h"]h$]h&]uh1j%hj.ubj&)}(hhh]h)}(h2.05+h]h2.05+}(hjKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjHubah}(h]h ]h"]h$]h&]uh1j%hj.ubj&)}(hhh]h)}(hkernel_alignmenth]hkernel_alignment}(hjbhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj_ubah}(h]h ]h"]h$]h&]uh1j%hj.ubj&)}(hhh]h)}(h+Physical addr alignment required for kernelh]h+Physical addr alignment required for kernel}(hjyhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjvubah}(h]h ]h"]h$]h&]uh1j%hj.ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0234/1h]h0234/1}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h2.05+h]h2.05+}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hrelocatable_kernelh]hrelocatable_kernel}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h$Whether kernel is relocatable or noth]h$Whether kernel is relocatable or not}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0235/1h]h0235/1}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h2.10+h]h2.10+}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h min_alignmenth]h min_alignment}(hj,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj)ubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h$Minimum alignment, as a power of twoh]h$Minimum alignment, as a power of two}(hjChhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj@ubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0236/2h]h0236/2}(hjchhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj`ubah}(h]h ]h"]h$]h&]uh1j%hj]ubj&)}(hhh]h)}(h2.12+h]h2.12+}(hjzhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjwubah}(h]h ]h"]h$]h&]uh1j%hj]ubj&)}(hhh]h)}(h xloadflagsh]h xloadflags}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hj]ubj&)}(hhh]h)}(hBoot protocol option flagsh]hBoot protocol option flags}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hj]ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0238/4h]h0238/4}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h2.06+h]h2.06+}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h cmdline_sizeh]h cmdline_size}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h'Maximum size of the kernel command lineh]h'Maximum size of the kernel command line}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h023C/4h]h023C/4}(hj-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj*ubah}(h]h ]h"]h$]h&]uh1j%hj'ubj&)}(hhh]h)}(h2.07+h]h2.07+}(hjDhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjAubah}(h]h ]h"]h$]h&]uh1j%hj'ubj&)}(hhh]h)}(hhardware_subarchh]hhardware_subarch}(hj[hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjXubah}(h]h ]h"]h$]h&]uh1j%hj'ubj&)}(hhh]h)}(hHardware subarchitectureh]hHardware subarchitecture}(hjrhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjoubah}(h]h ]h"]h$]h&]uh1j%hj'ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0240/8h]h0240/8}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h2.07+h]h2.07+}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hhardware_subarch_datah]hhardware_subarch_data}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hSubarchitecture-specific datah]hSubarchitecture-specific data}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0248/4h]h0248/4}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h2.08+h]h2.08+}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hpayload_offseth]hpayload_offset}(hj%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj"ubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hOffset of kernel payloadh]hOffset of kernel payload}(hj<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj9ubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h024C/4h]h024C/4}(hj\hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjYubah}(h]h ]h"]h$]h&]uh1j%hjVubj&)}(hhh]h)}(h2.08+h]h2.08+}(hjshhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjpubah}(h]h ]h"]h$]h&]uh1j%hjVubj&)}(hhh]h)}(hpayload_lengthh]hpayload_length}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjVubj&)}(hhh]h)}(hLength of kernel payloadh]hLength of kernel payload}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjVubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0250/8h]h0250/8}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h2.09+h]h2.09+}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h setup_datah]h setup_data}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h;64-bit physical pointer to linked list of struct setup_datah]h;64-bit physical pointer to linked list of struct setup_data}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0258/8h]h0258/8}(hj&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj#ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h2.10+h]h2.10+}(hj=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj:ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h pref_addressh]h pref_address}(hjThhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjQubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(hPreferred loading addressh]hPreferred loading address}(hjkhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjhubah}(h]h ]h"]h$]h&]uh1j%hj ubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0260/4h]h0260/4}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h2.10+h]h2.10+}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h init_sizeh]h init_size}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h,Linear memory required during initializationh]h,Linear memory required during initialization}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0264/4h]h0264/4}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h2.11+h]h2.11+}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hhandover_offseth]hhandover_offset}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hOffset of handover entry pointh]hOffset of handover entry point}(hj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj2ubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h0268/4h]h0268/4}(hjUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjRubah}(h]h ]h"]h$]h&]uh1j%hjOubj&)}(hhh]h)}(h2.15+h]h2.15+}(hjlhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjiubah}(h]h ]h"]h$]h&]uh1j%hjOubj&)}(hhh]h)}(hkernel_info_offseth]hkernel_info_offset}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjOubj&)}(hhh]h)}(hOffset of the kernel_infoh]hOffset of the kernel_info}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1j%hjOubeh}(h]h ]h"]h$]h&]uh1j hjNubeh}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]colsKuh1jhjubah}(h]h ]h"]h$]h&]uh1hhjuhhhhhNubj)}(hX?(1) For backwards compatibility, if the setup_sects field contains 0, the real value is 4. (2) For boot protocol prior to 2.04, the upper two bytes of the syssize field are unusable, which means the size of a bzImage kernel cannot be determined. (3) Ignored, but safe to set, for boot protocols 2.02-2.09.h]henumerated_list)}(hhh](h list_item)}(hWFor backwards compatibility, if the setup_sects field contains 0, the real value is 4. h]h)}(hVFor backwards compatibility, if the setup_sects field contains 0, the real value is 4.h]hVFor backwards compatibility, if the setup_sects field contains 0, the real value is 4.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hFor boot protocol prior to 2.04, the upper two bytes of the syssize field are unusable, which means the size of a bzImage kernel cannot be determined. h]h)}(hFor boot protocol prior to 2.04, the upper two bytes of the syssize field are unusable, which means the size of a bzImage kernel cannot be determined.h]hFor boot protocol prior to 2.04, the upper two bytes of the syssize field are unusable, which means the size of a bzImage kernel cannot be determined.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(h7Ignored, but safe to set, for boot protocols 2.02-2.09.h]h)}(hjh]h7Ignored, but safe to set, for boot protocols 2.02-2.09.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]enumtypearabicprefix(suffix)uh1jhjubah}(h]h ]h"]h$]h&]uh1jhjuhhhNhNubh)}(hIf the "HdrS" (0x53726448) magic number is not found at offset 0x202, the boot protocol version is "old". Loading an old kernel, the following parameters should be assumed::h]hIf the “HdrS” (0x53726448) magic number is not found at offset 0x202, the boot protocol version is “old”. Loading an old kernel, the following parameters should be assumed:}(hj+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjuhhubj)}(hUImage type = zImage initrd not supported Real-mode kernel must be located at 0x90000.h]hUImage type = zImage initrd not supported Real-mode kernel must be located at 0x90000.}hj9sbah}(h]h ]h"]h$]h&]hhuh1jhhhKhjuhhubh)}(hOtherwise, the "version" field contains the protocol version, e.g. protocol version 2.01 will contain 0x0201 in this field. When setting fields in the header, you must make sure only to set fields supported by the protocol version in use.h]hOtherwise, the “version” field contains the protocol version, e.g. protocol version 2.01 will contain 0x0201 in this field. When setting fields in the header, you must make sure only to set fields supported by the protocol version in use.}(hjGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjuhhubeh}(h]the-real-mode-kernel-headerah ]h"]the real-mode kernel headerah$]h&]uh1hhhhhhhhKubh)}(hhh](h)}(hDetails of Header Fieldsh]hDetails of Header Fields}(hj`hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhMubh)}(hFor each field, some are information from the kernel to the bootloader ("read"), some are expected to be filled out by the bootloader ("write"), and some are expected to be read and modified by the bootloader ("modify").h]hFor each field, some are information from the kernel to the bootloader (“read”), some are expected to be filled out by the bootloader (“write”), and some are expected to be read and modified by the bootloader (“modify”).}(hjnhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj]hhubh)}(hAll general purpose boot loaders should write the fields marked (obligatory). Boot loaders who want to load the kernel at a nonstandard address should fill in the fields marked (reloc); other boot loaders can ignore those fields.h]hAll general purpose boot loaders should write the fields marked (obligatory). Boot loaders who want to load the kernel at a nonstandard address should fill in the fields marked (reloc); other boot loaders can ignore those fields.}(hj|hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj]hhubh)}(hGThe byte order of all fields is little endian (this is x86, after all.)h]hGThe byte order of all fields is little endian (this is x86, after all.)}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM hj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h setup_sectsh]h setup_sects}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hreadh]hread}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj&ubah}(h]h ]h"]h$]h&]uh1j%hj#ubj&)}(hhh]h)}(h0x1f1/1h]h0x1f1/1}(hj@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj=ubah}(h]h ]h"]h$]h&]uh1j%hj#ubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj`hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj]ubah}(h]h ]h"]h$]h&]uh1j%hjZubj&)}(hhh]h)}(hALLh]hALL}(hjwhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjtubah}(h]h ]h"]h$]h&]uh1j%hjZubeh}(h]h ]h"]h$]h&]uh1j hjubeh}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]colsKuh1jhjubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubh block_quote)}(hThe size of the setup code in 512-byte sectors. If this field is 0, the real value is 4. The real-mode code consists of the boot sector (always one 512-byte sector) plus the setup code. h]h)}(hThe size of the setup code in 512-byte sectors. If this field is 0, the real value is 4. The real-mode code consists of the boot sector (always one 512-byte sector) plus the setup code.h]hThe size of the setup code in 512-byte sectors. If this field is 0, the real value is 4. The real-mode code consists of the boot sector (always one 512-byte sector) plus the setup code.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjubah}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhjubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h root_flagsh]h root_flags}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hmodify (optional)h]hmodify (optional)}(hj/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj,ubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjLubah}(h]h ]h"]h$]h&]uh1j%hjIubj&)}(hhh]h)}(h0x1f2/2h]h0x1f2/2}(hjfhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjcubah}(h]h ]h"]h$]h&]uh1j%hjIubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hALLh]hALL}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubeh}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]colsKuh1jhjubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hIf this field is nonzero, the root defaults to readonly. The use of this field is deprecated; use the "ro" or "rw" options on the command line instead. h]h)}(hIf this field is nonzero, the root defaults to readonly. The use of this field is deprecated; use the "ro" or "rw" options on the command line instead.h]hIf this field is nonzero, the root defaults to readonly. The use of this field is deprecated; use the “ro” or “rw” options on the command line instead.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM hjubah}(h]h ]h"]h$]h&]uh1jhhhM hj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthK/uh1jhjubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM%hjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hsyssizeh]hsyssize}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM%hjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM&hj9ubah}(h]h ]h"]h$]h&]uh1j%hj6ubj&)}(hhh]h)}(hreadh]hread}(hjShhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM&hjPubah}(h]h ]h"]h$]h&]uh1j%hj6ubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjshhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM'hjpubah}(h]h ]h"]h$]h&]uh1j%hjmubj&)}(hhh]h)}(h/0x1f4/4 (protocol 2.04+) 0x1f4/2 (protocol ALL)h]h/0x1f4/4 (protocol 2.04+) 0x1f4/2 (protocol ALL)}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM'hjubah}(h]h ]h"]h$]h&]uh1j%hjmubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM(hjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h2.04+h]h2.04+}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM(hjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubeh}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]colsKuh1jhjubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hThe size of the protected-mode code in units of 16-byte paragraphs. For protocol versions older than 2.04 this field is only two bytes wide, and therefore cannot be trusted for the size of a kernel if the LOAD_HIGH flag is set. h]h)}(hThe size of the protected-mode code in units of 16-byte paragraphs. For protocol versions older than 2.04 this field is only two bytes wide, and therefore cannot be trusted for the size of a kernel if the LOAD_HIGH flag is set.h]hThe size of the protected-mode code in units of 16-byte paragraphs. For protocol versions older than 2.04 this field is only two bytes wide, and therefore cannot be trusted for the size of a kernel if the LOAD_HIGH flag is set.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM+hjubah}(h]h ]h"]h$]h&]uh1jhhhM+hj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM1hj&ubah}(h]h ]h"]h$]h&]uh1j%hj#ubj&)}(hhh]h)}(hram_sizeh]hram_size}(hj@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM1hj=ubah}(h]h ]h"]h$]h&]uh1j%hj#ubeh}(h]h ]h"]h$]h&]uh1j hj ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj`hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM2hj]ubah}(h]h ]h"]h$]h&]uh1j%hjZubj&)}(hhh]h)}(hkernel internalh]hkernel internal}(hjwhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM2hjtubah}(h]h ]h"]h$]h&]uh1j%hjZubeh}(h]h ]h"]h$]h&]uh1j hj ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM3hjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h0x1f8/2h]h0x1f8/2}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM3hjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hj ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM4hjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hALLh]hALL}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM4hjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1jhj ubeh}(h]h ]h"]h$]h&]colsKuh1jhjubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hThis field is obsolete. h]h)}(hThis field is obsolete.h]hThis field is obsolete.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM7hjubah}(h]h ]h"]h$]h&]uh1jhhhM7hj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj-ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj-ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM:hjJubah}(h]h ]h"]h$]h&]uh1j%hjGubj&)}(hhh]h)}(hvid_modeh]hvid_mode}(hjdhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM:hjaubah}(h]h ]h"]h$]h&]uh1j%hjGubeh}(h]h ]h"]h$]h&]uh1j hjDubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM;hjubah}(h]h ]h"]h$]h&]uh1j%hj~ubj&)}(hhh]h)}(hmodify (obligatory)h]hmodify (obligatory)}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM;hjubah}(h]h ]h"]h$]h&]uh1j%hj~ubeh}(h]h ]h"]h$]h&]uh1j hjDubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM<hjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h0x1fa/2h]h0x1fa/2}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM<hjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjDubeh}(h]h ]h"]h$]h&]uh1jhj-ubeh}(h]h ]h"]h$]h&]colsKuh1jhj*ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(h8Please see the section on SPECIAL COMMAND LINE OPTIONS. h]h)}(h7Please see the section on SPECIAL COMMAND LINE OPTIONS.h]h7Please see the section on SPECIAL COMMAND LINE OPTIONS.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM?hjubah}(h]h ]h"]h$]h&]uh1jhhhM?hj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhjubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMBhj7ubah}(h]h ]h"]h$]h&]uh1j%hj4ubj&)}(hhh]h)}(hroot_devh]hroot_dev}(hjQhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMBhjNubah}(h]h ]h"]h$]h&]uh1j%hj4ubeh}(h]h ]h"]h$]h&]uh1j hj1ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjqhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMChjnubah}(h]h ]h"]h$]h&]uh1j%hjkubj&)}(hhh]h)}(hmodify (optional)h]hmodify (optional)}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMChjubah}(h]h ]h"]h$]h&]uh1j%hjkubeh}(h]h ]h"]h$]h&]uh1j hj1ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMDhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h0x1fc/2h]h0x1fc/2}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMDhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hj1ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMEhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hALLh]hALL}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMEhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hj1ubeh}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]colsKuh1jhjubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hThe default root device device number. The use of this field is deprecated, use the "root=" option on the command line instead. h]h)}(hThe default root device device number. The use of this field is deprecated, use the "root=" option on the command line instead.h]hThe default root device device number. The use of this field is deprecated, use the “root=” option on the command line instead.}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMHhj#ubah}(h]h ]h"]h$]h&]uh1jhhhMHhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj>ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj>ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj^hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMLhj[ubah}(h]h ]h"]h$]h&]uh1j%hjXubj&)}(hhh]h)}(h boot_flagh]h boot_flag}(hjuhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMLhjrubah}(h]h ]h"]h$]h&]uh1j%hjXubeh}(h]h ]h"]h$]h&]uh1j hjUubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMMhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hreadh]hread}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMMhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjUubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMNhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h0x1fe/2h]h0x1fe/2}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMNhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjUubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMOhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hALLh]hALL}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMOhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjUubeh}(h]h ]h"]h$]h&]uh1jhj>ubeh}(h]h ]h"]h$]h&]colsKuh1jhj;ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hVContains 0xAA55. This is the closest thing old Linux kernels have to a magic number. h]h)}(hUContains 0xAA55. This is the closest thing old Linux kernels have to a magic number.h]hUContains 0xAA55. This is the closest thing old Linux kernels have to a magic number.}(hjKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMRhjGubah}(h]h ]h"]h$]h&]uh1jhhhMRhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjbubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhjbubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMVhjubah}(h]h ]h"]h$]h&]uh1j%hj|ubj&)}(hhh]h)}(hjumph]hjump}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMVhjubah}(h]h ]h"]h$]h&]uh1j%hj|ubeh}(h]h ]h"]h$]h&]uh1j hjyubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMWhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hreadh]hread}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMWhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjyubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMXhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(h0x200/2h]h0x200/2}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMXhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjyubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMYhj$ubah}(h]h ]h"]h$]h&]uh1j%hj!ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj>hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMYhj;ubah}(h]h ]h"]h$]h&]uh1j%hj!ubeh}(h]h ]h"]h$]h&]uh1j hjyubeh}(h]h ]h"]h$]h&]uh1jhjbubeh}(h]h ]h"]h$]h&]colsKuh1jhj_ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hContains an x86 jump instruction, 0xEB followed by a signed offset relative to byte 0x202. This can be used to determine the size of the header. h]h)}(hContains an x86 jump instruction, 0xEB followed by a signed offset relative to byte 0x202. This can be used to determine the size of the header.h]hContains an x86 jump instruction, 0xEB followed by a signed offset relative to byte 0x202. This can be used to determine the size of the header.}(hjohhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM\hjkubah}(h]h ]h"]h$]h&]uh1jhhhM\hj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhjubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMahjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hheaderh]hheader}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMahjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMbhjubah}(h]h ]h"]h$]h&]uh1j%hjubj&)}(hhh]h)}(hreadh]hread}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMbhjubah}(h]h ]h"]h$]h&]uh1j%hjubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMchj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(h0x202/4h]h0x202/4}(hj+ hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMchj( ubah}(h]h ]h"]h$]h&]uh1j%hj ubeh}(h]h ]h"]h$]h&]uh1j hjubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hjK hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMdhjH ubah}(h]h ]h"]h$]h&]uh1j%hjE ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hjb hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMdhj_ ubah}(h]h ]h"]h$]h&]uh1j%hjE ubeh}(h]h ]h"]h$]h&]uh1j hjubeh}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]colsKuh1jhjubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(h/Contains the magic number "HdrS" (0x53726448). h]h)}(h.Contains the magic number "HdrS" (0x53726448).h]h2Contains the magic number “HdrS” (0x53726448).}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMghj ubah}(h]h ]h"]h$]h&]uh1jhhhMghj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMjhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(hversionh]hversion}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMjhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubeh}(h]h ]h"]h$]h&]uh1j hj ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj!hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMkhj ubah}(h]h ]h"]h$]h&]uh1j%hj ubj&)}(hhh]h)}(hreadh]hread}(hj!hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMkhj!ubah}(h]h ]h"]h$]h&]uh1j%hj ubeh}(h]h ]h"]h$]h&]uh1j hj ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj8!hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMlhj5!ubah}(h]h ]h"]h$]h&]uh1j%hj2!ubj&)}(hhh]h)}(h0x206/2h]h0x206/2}(hjO!hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMlhjL!ubah}(h]h ]h"]h$]h&]uh1j%hj2!ubeh}(h]h ]h"]h$]h&]uh1j hj ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hjo!hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMmhjl!ubah}(h]h ]h"]h$]h&]uh1j%hji!ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj!hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMmhj!ubah}(h]h ]h"]h$]h&]uh1j%hji!ubeh}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1jhj ubeh}(h]h ]h"]h$]h&]colsKuh1jhj ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hContains the boot protocol version, in (major << 8) + minor format, e.g. 0x0204 for version 2.04, and 0x0a11 for a hypothetical version 10.17. h]h)}(hContains the boot protocol version, in (major << 8) + minor format, e.g. 0x0204 for version 2.04, and 0x0a11 for a hypothetical version 10.17.h]hContains the boot protocol version, in (major << 8) + minor format, e.g. 0x0204 for version 2.04, and 0x0a11 for a hypothetical version 10.17.}(hj!hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMphj!ubah}(h]h ]h"]h$]h&]uh1jhhhMphj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj!ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj!ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj!hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMuhj!ubah}(h]h ]h"]h$]h&]uh1j%hj!ubj&)}(hhh]h)}(hrealmode_swtchh]hrealmode_swtch}(hj"hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMuhj"ubah}(h]h ]h"]h$]h&]uh1j%hj!ubeh}(h]h ]h"]h$]h&]uh1j hj!ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj%"hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMvhj""ubah}(h]h ]h"]h$]h&]uh1j%hj"ubj&)}(hhh]h)}(hmodify (optional)h]hmodify (optional)}(hj<"hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMvhj9"ubah}(h]h ]h"]h$]h&]uh1j%hj"ubeh}(h]h ]h"]h$]h&]uh1j hj!ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj\"hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMwhjY"ubah}(h]h ]h"]h$]h&]uh1j%hjV"ubj&)}(hhh]h)}(h0x208/4h]h0x208/4}(hjs"hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMwhjp"ubah}(h]h ]h"]h$]h&]uh1j%hjV"ubeh}(h]h ]h"]h$]h&]uh1j hj!ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj"hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMxhj"ubah}(h]h ]h"]h$]h&]uh1j%hj"ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj"hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMxhj"ubah}(h]h ]h"]h$]h&]uh1j%hj"ubeh}(h]h ]h"]h$]h&]uh1j hj!ubeh}(h]h ]h"]h$]h&]uh1jhj!ubeh}(h]h ]h"]h$]h&]colsKuh1jhj!ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(h9Boot loader hook (see ADVANCED BOOT LOADER HOOKS below.) h]h)}(h8Boot loader hook (see ADVANCED BOOT LOADER HOOKS below.)h]h8Boot loader hook (see ADVANCED BOOT LOADER HOOKS below.)}(hj"hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM{hj"ubah}(h]h ]h"]h$]h&]uh1jhhhM{hj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj"ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj"ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj#hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM~hj#ubah}(h]h ]h"]h$]h&]uh1j%hj #ubj&)}(hhh]h)}(h start_sys_segh]h start_sys_seg}(hj)#hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM~hj&#ubah}(h]h ]h"]h$]h&]uh1j%hj #ubeh}(h]h ]h"]h$]h&]uh1j hj #ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjI#hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjF#ubah}(h]h ]h"]h$]h&]uh1j%hjC#ubj&)}(hhh]h)}(hreadh]hread}(hj`#hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj]#ubah}(h]h ]h"]h$]h&]uh1j%hjC#ubeh}(h]h ]h"]h$]h&]uh1j hj #ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj#hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj}#ubah}(h]h ]h"]h$]h&]uh1j%hjz#ubj&)}(hhh]h)}(h0x20c/2h]h0x20c/2}(hj#hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj#ubah}(h]h ]h"]h$]h&]uh1j%hjz#ubeh}(h]h ]h"]h$]h&]uh1j hj #ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj#hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj#ubah}(h]h ]h"]h$]h&]uh1j%hj#ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj#hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj#ubah}(h]h ]h"]h$]h&]uh1j%hj#ubeh}(h]h ]h"]h$]h&]uh1j hj #ubeh}(h]h ]h"]h$]h&]uh1jhj"ubeh}(h]h ]h"]h$]h&]colsKuh1jhj"ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(h*The load low segment (0x1000). Obsolete. h]h)}(h)The load low segment (0x1000). Obsolete.h]h)The load low segment (0x1000). Obsolete.}(hj#hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj#ubah}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj$ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj$ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj6$hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj3$ubah}(h]h ]h"]h$]h&]uh1j%hj0$ubj&)}(hhh]h)}(hkernel_versionh]hkernel_version}(hjM$hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjJ$ubah}(h]h ]h"]h$]h&]uh1j%hj0$ubeh}(h]h ]h"]h$]h&]uh1j hj-$ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjm$hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjj$ubah}(h]h ]h"]h$]h&]uh1j%hjg$ubj&)}(hhh]h)}(hreadh]hread}(hj$hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj$ubah}(h]h ]h"]h$]h&]uh1j%hjg$ubeh}(h]h ]h"]h$]h&]uh1j hj-$ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj$hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj$ubah}(h]h ]h"]h$]h&]uh1j%hj$ubj&)}(hhh]h)}(h0x20e/2h]h0x20e/2}(hj$hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj$ubah}(h]h ]h"]h$]h&]uh1j%hj$ubeh}(h]h ]h"]h$]h&]uh1j hj-$ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj$hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj$ubah}(h]h ]h"]h$]h&]uh1j%hj$ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj$hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj$ubah}(h]h ]h"]h$]h&]uh1j%hj$ubeh}(h]h ]h"]h$]h&]uh1j hj-$ubeh}(h]h ]h"]h$]h&]uh1jhj$ubeh}(h]h ]h"]h$]h&]colsKuh1jhj$ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hXYIf set to a nonzero value, contains a pointer to a NUL-terminated human-readable kernel version number string, less 0x200. This can be used to display the kernel version to the user. This value should be less than (0x200 * setup_sects). For example, if this value is set to 0x1c00, the kernel version number string can be found at offset 0x1e00 in the kernel file. This is a valid value if and only if the "setup_sects" field contains the value 15 or higher, as:: 0x1c00 < 15 * 0x200 (= 0x1e00) but 0x1c00 >= 14 * 0x200 (= 0x1c00) 0x1c00 >> 9 = 14, So the minimum value for setup_secs is 15. h](h)}(hIf set to a nonzero value, contains a pointer to a NUL-terminated human-readable kernel version number string, less 0x200. This can be used to display the kernel version to the user. This value should be less than (0x200 * setup_sects).h]hIf set to a nonzero value, contains a pointer to a NUL-terminated human-readable kernel version number string, less 0x200. This can be used to display the kernel version to the user. This value should be less than (0x200 * setup_sects).}(hj#%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%ubh)}(hFor example, if this value is set to 0x1c00, the kernel version number string can be found at offset 0x1e00 in the kernel file. This is a valid value if and only if the "setup_sects" field contains the value 15 or higher, as::h]hFor example, if this value is set to 0x1c00, the kernel version number string can be found at offset 0x1e00 in the kernel file. This is a valid value if and only if the “setup_sects” field contains the value 15 or higher, as:}(hj1%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%ubj)}(h0x1c00 < 15 * 0x200 (= 0x1e00) but 0x1c00 >= 14 * 0x200 (= 0x1c00) 0x1c00 >> 9 = 14, So the minimum value for setup_secs is 15.h]h0x1c00 < 15 * 0x200 (= 0x1e00) but 0x1c00 >= 14 * 0x200 (= 0x1c00) 0x1c00 >> 9 = 14, So the minimum value for setup_secs is 15.}hj?%sbah}(h]h ]h"]h$]h&]hhuh1jhhhMhj%ubeh}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjV%ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhjV%ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjv%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjs%ubah}(h]h ]h"]h$]h&]uh1j%hjp%ubj&)}(hhh]h)}(htype_of_loaderh]htype_of_loader}(hj%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%ubah}(h]h ]h"]h$]h&]uh1j%hjp%ubeh}(h]h ]h"]h$]h&]uh1j hjm%ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%ubah}(h]h ]h"]h$]h&]uh1j%hj%ubj&)}(hhh]h)}(hwrite (obligatory)h]hwrite (obligatory)}(hj%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%ubah}(h]h ]h"]h$]h&]uh1j%hj%ubeh}(h]h ]h"]h$]h&]uh1j hjm%ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%ubah}(h]h ]h"]h$]h&]uh1j%hj%ubj&)}(hhh]h)}(h0x210/1h]h0x210/1}(hj%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%ubah}(h]h ]h"]h$]h&]uh1j%hj%ubeh}(h]h ]h"]h$]h&]uh1j hjm%ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj&ubah}(h]h ]h"]h$]h&]uh1j%hj&ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj2&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj/&ubah}(h]h ]h"]h$]h&]uh1j%hj&ubeh}(h]h ]h"]h$]h&]uh1j hjm%ubeh}(h]h ]h"]h$]h&]uh1jhjV%ubeh}(h]h ]h"]h$]h&]colsKuh1jhjS%ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hXQIf your boot loader has an assigned ID (see table below), enter 0xTV here, where T is an identifier for the boot loader and V is a version number. Otherwise, enter 0xFF here. For boot loader IDs above T = 0xD, write T = 0xE to this field and write the extended ID minus 0x10 to the ext_loader_type field. Similarly, the ext_loader_ver field can be used to provide more than four bits for the bootloader version. For example, for T = 0x15, V = 0x234, write:: type_of_loader <- 0xE4 ext_loader_type <- 0x05 ext_loader_ver <- 0x23 Assigned boot loader IDs: ==== ======================================= 0x0 LILO (0x00 reserved for pre-2.00 bootloader) 0x1 Loadlin 0x2 bootsect-loader (0x20, all other values reserved) 0x3 Syslinux 0x4 Etherboot/gPXE/iPXE 0x5 ELILO 0x7 GRUB 0x8 U-Boot 0x9 Xen 0xA Gujin 0xB Qemu 0xC Arcturus Networks uCbootloader 0xD kexec-tools 0xE Extended (see ext_loader_type) 0xF Special (0xFF = undefined) 0x10 Reserved 0x11 Minimal Linux Bootloader 0x12 OVMF UEFI virtualization stack 0x13 barebox ==== ======================================= Please contact if you need a bootloader ID value assigned. h](h)}(hIf your boot loader has an assigned ID (see table below), enter 0xTV here, where T is an identifier for the boot loader and V is a version number. Otherwise, enter 0xFF here.h]hIf your boot loader has an assigned ID (see table below), enter 0xTV here, where T is an identifier for the boot loader and V is a version number. Otherwise, enter 0xFF here.}(hjc&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj_&ubh)}(hFor boot loader IDs above T = 0xD, write T = 0xE to this field and write the extended ID minus 0x10 to the ext_loader_type field. Similarly, the ext_loader_ver field can be used to provide more than four bits for the bootloader version.h]hFor boot loader IDs above T = 0xD, write T = 0xE to this field and write the extended ID minus 0x10 to the ext_loader_type field. Similarly, the ext_loader_ver field can be used to provide more than four bits for the bootloader version.}(hjq&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj_&ubh)}(h-For example, for T = 0x15, V = 0x234, write::h]h,For example, for T = 0x15, V = 0x234, write:}(hj&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj_&ubj)}(hGtype_of_loader <- 0xE4 ext_loader_type <- 0x05 ext_loader_ver <- 0x23h]hGtype_of_loader <- 0xE4 ext_loader_type <- 0x05 ext_loader_ver <- 0x23}hj&sbah}(h]h ]h"]h$]h&]hhuh1jhhhMhj_&ubh)}(hAssigned boot loader IDs:h]hAssigned boot loader IDs:}(hj&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj_&ubj)}(hX@==== ======================================= 0x0 LILO (0x00 reserved for pre-2.00 bootloader) 0x1 Loadlin 0x2 bootsect-loader (0x20, all other values reserved) 0x3 Syslinux 0x4 Etherboot/gPXE/iPXE 0x5 ELILO 0x7 GRUB 0x8 U-Boot 0x9 Xen 0xA Gujin 0xB Qemu 0xC Arcturus Networks uCbootloader 0xD kexec-tools 0xE Extended (see ext_loader_type) 0xF Special (0xFF = undefined) 0x10 Reserved 0x11 Minimal Linux Bootloader 0x12 OVMF UEFI virtualization stack 0x13 barebox ==== ======================================= h]h)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj&ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthK'uh1jhj&ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h0x0h]h0x0}(hj&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj&ubah}(h]h ]h"]h$]h&]uh1j%hj&ubj&)}(hhh]h)}(h,LILO (0x00 reserved for pre-2.00 bootloader)h]h,LILO (0x00 reserved for pre-2.00 bootloader)}(hj&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj&ubah}(h]h ]h"]h$]h&]uh1j%hj&ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0x1h]h0x1}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj'ubah}(h]h ]h"]h$]h&]uh1j%hj'ubj&)}(hhh]h)}(hLoadlinh]hLoadlin}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj'ubah}(h]h ]h"]h$]h&]uh1j%hj'ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0x2h]h0x2}(hj>'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;'ubah}(h]h ]h"]h$]h&]uh1j%hj8'ubj&)}(hhh]h)}(h1bootsect-loader (0x20, all other values reserved)h]h1bootsect-loader (0x20, all other values reserved)}(hjU'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjR'ubah}(h]h ]h"]h$]h&]uh1j%hj8'ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0x3h]h0x3}(hju'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjr'ubah}(h]h ]h"]h$]h&]uh1j%hjo'ubj&)}(hhh]h)}(hSyslinuxh]hSyslinux}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj'ubah}(h]h ]h"]h$]h&]uh1j%hjo'ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0x4h]h0x4}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj'ubah}(h]h ]h"]h$]h&]uh1j%hj'ubj&)}(hhh]h)}(hEtherboot/gPXE/iPXEh]hEtherboot/gPXE/iPXE}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj'ubah}(h]h ]h"]h$]h&]uh1j%hj'ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0x5h]h0x5}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj'ubah}(h]h ]h"]h$]h&]uh1j%hj'ubj&)}(hhh]h)}(hELILOh]hELILO}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj'ubah}(h]h ]h"]h$]h&]uh1j%hj'ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0x7h]h0x7}(hj(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj(ubah}(h]h ]h"]h$]h&]uh1j%hj(ubj&)}(hhh]h)}(hGRUBh]hGRUB}(hj1(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj.(ubah}(h]h ]h"]h$]h&]uh1j%hj(ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0x8h]h0x8}(hjQ(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjN(ubah}(h]h ]h"]h$]h&]uh1j%hjK(ubj&)}(hhh]h)}(hU-Booth]hU-Boot}(hjh(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhje(ubah}(h]h ]h"]h$]h&]uh1j%hjK(ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0x9h]h0x9}(hj(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj(ubah}(h]h ]h"]h$]h&]uh1j%hj(ubj&)}(hhh]h)}(hXenh]hXen}(hj(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj(ubah}(h]h ]h"]h$]h&]uh1j%hj(ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0xAh]h0xA}(hj(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj(ubah}(h]h ]h"]h$]h&]uh1j%hj(ubj&)}(hhh]h)}(hGujinh]hGujin}(hj(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj(ubah}(h]h ]h"]h$]h&]uh1j%hj(ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0xBh]h0xB}(hj(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj(ubah}(h]h ]h"]h$]h&]uh1j%hj(ubj&)}(hhh]h)}(hQemuh]hQemu}(hj )hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj )ubah}(h]h ]h"]h$]h&]uh1j%hj(ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0xCh]h0xC}(hj-)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj*)ubah}(h]h ]h"]h$]h&]uh1j%hj')ubj&)}(hhh]h)}(hArcturus Networks uCbootloaderh]hArcturus Networks uCbootloader}(hjD)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjA)ubah}(h]h ]h"]h$]h&]uh1j%hj')ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0xDh]h0xD}(hjd)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhja)ubah}(h]h ]h"]h$]h&]uh1j%hj^)ubj&)}(hhh]h)}(h kexec-toolsh]h kexec-tools}(hj{)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjx)ubah}(h]h ]h"]h$]h&]uh1j%hj^)ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0xEh]h0xE}(hj)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj)ubah}(h]h ]h"]h$]h&]uh1j%hj)ubj&)}(hhh]h)}(hExtended (see ext_loader_type)h]hExtended (see ext_loader_type)}(hj)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj)ubah}(h]h ]h"]h$]h&]uh1j%hj)ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0xFh]h0xF}(hj)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj)ubah}(h]h ]h"]h$]h&]uh1j%hj)ubj&)}(hhh]h)}(hSpecial (0xFF = undefined)h]hSpecial (0xFF = undefined)}(hj)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj)ubah}(h]h ]h"]h$]h&]uh1j%hj)ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0x10h]h0x10}(hj *hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj*ubah}(h]h ]h"]h$]h&]uh1j%hj*ubj&)}(hhh]h)}(hReservedh]hReserved}(hj *hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj*ubah}(h]h ]h"]h$]h&]uh1j%hj*ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0x11h]h0x11}(hj@*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj=*ubah}(h]h ]h"]h$]h&]uh1j%hj:*ubj&)}(hhh]h)}(h=Minimal Linux Bootloader h](hMinimal Linux Bootloader <}(hjW*hhhNhNubh reference)}(h"http://sebastian-plotz.blogspot.deh]h"http://sebastian-plotz.blogspot.de}(hja*hhhNhNubah}(h]h ]h"]h$]h&]refurijc*uh1j_*hjW*ubh>}(hjW*hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMhjT*ubah}(h]h ]h"]h$]h&]uh1j%hj:*ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0x12h]h0x12}(hj*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj*ubah}(h]h ]h"]h$]h&]uh1j%hj*ubj&)}(hhh]h)}(hOVMF UEFI virtualization stackh]hOVMF UEFI virtualization stack}(hj*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj*ubah}(h]h ]h"]h$]h&]uh1j%hj*ubeh}(h]h ]h"]h$]h&]uh1j hj&ubj!)}(hhh](j&)}(hhh]h)}(h0x13h]h0x13}(hj*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj*ubah}(h]h ]h"]h$]h&]uh1j%hj*ubj&)}(hhh]h)}(hbareboxh]hbarebox}(hj*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj*ubah}(h]h ]h"]h$]h&]uh1j%hj*ubeh}(h]h ]h"]h$]h&]uh1j hj&ubeh}(h]h ]h"]h$]h&]uh1jhj&ubeh}(h]h ]h"]h$]h&]colsKuh1jhj&ubah}(h]h ]h"]h$]h&]uh1hhj&ubah}(h]h ]h"]h$]h&]uh1jhhhMhj_&ubh)}(hJPlease contact if you need a bootloader ID value assigned.h](hPlease contact <}(hj +hhhNhNubj`*)}(h hpa@zytor.comh]h hpa@zytor.com}(hj+hhhNhNubah}(h]h ]h"]h$]h&]refurimailto:hpa@zytor.comuh1j_*hj +ubh-> if you need a bootloader ID value assigned.}(hj +hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMhj_&ubeh}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj8+ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj8+ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjX+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjU+ubah}(h]h ]h"]h$]h&]uh1j%hjR+ubj&)}(hhh]h)}(h loadflagsh]h loadflags}(hjo+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjl+ubah}(h]h ]h"]h$]h&]uh1j%hjR+ubeh}(h]h ]h"]h$]h&]uh1j hjO+ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj+ubah}(h]h ]h"]h$]h&]uh1j%hj+ubj&)}(hhh]h)}(hmodify (obligatory)h]hmodify (obligatory)}(hj+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj+ubah}(h]h ]h"]h$]h&]uh1j%hj+ubeh}(h]h ]h"]h$]h&]uh1j hjO+ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj+ubah}(h]h ]h"]h$]h&]uh1j%hj+ubj&)}(hhh]h)}(h0x211/1h]h0x211/1}(hj+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj+ubah}(h]h ]h"]h$]h&]uh1j%hj+ubeh}(h]h ]h"]h$]h&]uh1j hjO+ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj+ubah}(h]h ]h"]h$]h&]uh1j%hj+ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj,ubah}(h]h ]h"]h$]h&]uh1j%hj+ubeh}(h]h ]h"]h$]h&]uh1j hjO+ubeh}(h]h ]h"]h$]h&]uh1jhj8+ubeh}(h]h ]h"]h$]h&]colsKuh1jhj5+ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hXThis field is a bitmask. Bit 0 (read): LOADED_HIGH - If 0, the protected-mode code is loaded at 0x10000. - If 1, the protected-mode code is loaded at 0x100000. Bit 1 (kernel internal): KASLR_FLAG - Used internally by the compressed kernel to communicate KASLR status to kernel proper. - If 1, KASLR enabled. - If 0, KASLR disabled. Bit 5 (write): QUIET_FLAG - If 0, print early messages. - If 1, suppress early messages. This requests to the kernel (decompressor and early kernel) to not write early messages that require accessing the display hardware directly. Bit 6 (obsolete): KEEP_SEGMENTS Protocol: 2.07+ - This flag is obsolete. Bit 7 (write): CAN_USE_HEAP Set this bit to 1 to indicate that the value entered in the heap_end_ptr is valid. If this field is clear, some setup code functionality will be disabled. h](h)}(hThis field is a bitmask.h]hThis field is a bitmask.}(hjE,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjA,ubh)}(hBit 0 (read): LOADED_HIGHh]hBit 0 (read): LOADED_HIGH}(hjS,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjA,ubj)}(hm- If 0, the protected-mode code is loaded at 0x10000. - If 1, the protected-mode code is loaded at 0x100000. h]h bullet_list)}(hhh](j)}(h3If 0, the protected-mode code is loaded at 0x10000.h]h)}(hjl,h]h3If 0, the protected-mode code is loaded at 0x10000.}(hjn,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjj,ubah}(h]h ]h"]h$]h&]uh1jhjg,ubj)}(h5If 1, the protected-mode code is loaded at 0x100000. h]h)}(h4If 1, the protected-mode code is loaded at 0x100000.h]h4If 1, the protected-mode code is loaded at 0x100000.}(hj,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj,ubah}(h]h ]h"]h$]h&]uh1jhjg,ubeh}(h]h ]h"]h$]h&]bullet-uh1je,hhhMhja,ubah}(h]h ]h"]h$]h&]uh1jhhhMhjA,ubh)}(h#Bit 1 (kernel internal): KASLR_FLAGh]h#Bit 1 (kernel internal): KASLR_FLAG}(hj,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjA,ubj)}(h- Used internally by the compressed kernel to communicate KASLR status to kernel proper. - If 1, KASLR enabled. - If 0, KASLR disabled. h]jf,)}(hhh]j)}(hUsed internally by the compressed kernel to communicate KASLR status to kernel proper. - If 1, KASLR enabled. - If 0, KASLR disabled. h](h)}(hVUsed internally by the compressed kernel to communicate KASLR status to kernel proper.h]hVUsed internally by the compressed kernel to communicate KASLR status to kernel proper.}(hj,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj,ubj)}(h/- If 1, KASLR enabled. - If 0, KASLR disabled. h]jf,)}(hhh](j)}(hIf 1, KASLR enabled.h]h)}(hj,h]hIf 1, KASLR enabled.}(hj,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj,ubah}(h]h ]h"]h$]h&]uh1jhj,ubj)}(hIf 0, KASLR disabled. h]h)}(hIf 0, KASLR disabled.h]hIf 0, KASLR disabled.}(hj,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj,ubah}(h]h ]h"]h$]h&]uh1jhj,ubeh}(h]h ]h"]h$]h&]j,j,uh1je,hhhMhj,ubah}(h]h ]h"]h$]h&]uh1jhhhMhj,ubeh}(h]h ]h"]h$]h&]uh1jhj,ubah}(h]h ]h"]h$]h&]j,j,uh1je,hhhMhj,ubah}(h]h ]h"]h$]h&]uh1jhhhMhjA,ubh)}(hBit 5 (write): QUIET_FLAGh]hBit 5 (write): QUIET_FLAG}(hj"-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjA,ubj)}(h- If 0, print early messages. - If 1, suppress early messages. This requests to the kernel (decompressor and early kernel) to not write early messages that require accessing the display hardware directly. h]jf,)}(hhh](j)}(hIf 0, print early messages.h]h)}(hj9-h]hIf 0, print early messages.}(hj;-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj7-ubah}(h]h ]h"]h$]h&]uh1jhj4-ubj)}(hIf 1, suppress early messages. This requests to the kernel (decompressor and early kernel) to not write early messages that require accessing the display hardware directly. h](h)}(hIf 1, suppress early messages.h]hIf 1, suppress early messages.}(hjR-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjN-ubj)}(hThis requests to the kernel (decompressor and early kernel) to not write early messages that require accessing the display hardware directly. h]h)}(hThis requests to the kernel (decompressor and early kernel) to not write early messages that require accessing the display hardware directly.h]hThis requests to the kernel (decompressor and early kernel) to not write early messages that require accessing the display hardware directly.}(hjd-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj`-ubah}(h]h ]h"]h$]h&]uh1jhhhMhjN-ubeh}(h]h ]h"]h$]h&]uh1jhj4-ubeh}(h]h ]h"]h$]h&]j,j,uh1je,hhhMhj0-ubah}(h]h ]h"]h$]h&]uh1jhhhMhjA,ubh)}(hBit 6 (obsolete): KEEP_SEGMENTSh]hBit 6 (obsolete): KEEP_SEGMENTS}(hj-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjA,ubj)}(h*Protocol: 2.07+ - This flag is obsolete. h](h)}(hProtocol: 2.07+h]hProtocol: 2.07+}(hj-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj-ubjf,)}(hhh]j)}(hThis flag is obsolete. h]h)}(hThis flag is obsolete.h]hThis flag is obsolete.}(hj-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj-ubah}(h]h ]h"]h$]h&]uh1jhj-ubah}(h]h ]h"]h$]h&]j,j,uh1je,hhhMhj-ubeh}(h]h ]h"]h$]h&]uh1jhhhMhjA,ubh)}(hBit 7 (write): CAN_USE_HEAPh]hBit 7 (write): CAN_USE_HEAP}(hj-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjA,ubj)}(hSet this bit to 1 to indicate that the value entered in the heap_end_ptr is valid. If this field is clear, some setup code functionality will be disabled. h]h)}(hSet this bit to 1 to indicate that the value entered in the heap_end_ptr is valid. If this field is clear, some setup code functionality will be disabled.h]hSet this bit to 1 to indicate that the value entered in the heap_end_ptr is valid. If this field is clear, some setup code functionality will be disabled.}(hj-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj-ubah}(h]h ]h"]h$]h&]uh1jhhhMhjA,ubeh}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj.ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj.ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj .hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj.ubah}(h]h ]h"]h$]h&]uh1j%hj.ubj&)}(hhh]h)}(hsetup_move_sizeh]hsetup_move_size}(hj7.hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj4.ubah}(h]h ]h"]h$]h&]uh1j%hj.ubeh}(h]h ]h"]h$]h&]uh1j hj.ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjW.hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjT.ubah}(h]h ]h"]h$]h&]uh1j%hjQ.ubj&)}(hhh]h)}(hmodify (obligatory)h]hmodify (obligatory)}(hjn.hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjk.ubah}(h]h ]h"]h$]h&]uh1j%hjQ.ubeh}(h]h ]h"]h$]h&]uh1j hj.ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj.hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj.ubah}(h]h ]h"]h$]h&]uh1j%hj.ubj&)}(hhh]h)}(h0x212/2h]h0x212/2}(hj.hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj.ubah}(h]h ]h"]h$]h&]uh1j%hj.ubeh}(h]h ]h"]h$]h&]uh1j hj.ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj.hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj.ubah}(h]h ]h"]h$]h&]uh1j%hj.ubj&)}(hhh]h)}(h 2.00-2.01h]h 2.00-2.01}(hj.hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj.ubah}(h]h ]h"]h$]h&]uh1j%hj.ubeh}(h]h ]h"]h$]h&]uh1j hj.ubeh}(h]h ]h"]h$]h&]uh1jhj.ubeh}(h]h ]h"]h$]h&]colsKuh1jhj-ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hXWhen using protocol 2.00 or 2.01, if the real mode kernel is not loaded at 0x90000, it gets moved there later in the loading sequence. Fill in this field if you want additional data (such as the kernel command line) moved in addition to the real-mode kernel itself. The unit is bytes starting with the beginning of the boot sector. This field is can be ignored when the protocol is 2.02 or higher, or if the real-mode code is loaded at 0x90000. h](h)}(hX When using protocol 2.00 or 2.01, if the real mode kernel is not loaded at 0x90000, it gets moved there later in the loading sequence. Fill in this field if you want additional data (such as the kernel command line) moved in addition to the real-mode kernel itself.h]hX When using protocol 2.00 or 2.01, if the real mode kernel is not loaded at 0x90000, it gets moved there later in the loading sequence. Fill in this field if you want additional data (such as the kernel command line) moved in addition to the real-mode kernel itself.}(hj /hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj /ubh)}(hAThe unit is bytes starting with the beginning of the boot sector.h]hAThe unit is bytes starting with the beginning of the boot sector.}(hj/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj /ubh)}(hpThis field is can be ignored when the protocol is 2.02 or higher, or if the real-mode code is loaded at 0x90000.h]hpThis field is can be ignored when the protocol is 2.02 or higher, or if the real-mode code is loaded at 0x90000.}(hj)/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM hj /ubeh}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj@/ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj@/ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj`/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj]/ubah}(h]h ]h"]h$]h&]uh1j%hjZ/ubj&)}(hhh]h)}(h code32_starth]h code32_start}(hjw/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjt/ubah}(h]h ]h"]h$]h&]uh1j%hjZ/ubeh}(h]h ]h"]h$]h&]uh1j hjW/ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj/ubah}(h]h ]h"]h$]h&]uh1j%hj/ubj&)}(hhh]h)}(hmodify (optional, reloc)h]hmodify (optional, reloc)}(hj/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj/ubah}(h]h ]h"]h$]h&]uh1j%hj/ubeh}(h]h ]h"]h$]h&]uh1j hjW/ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj/ubah}(h]h ]h"]h$]h&]uh1j%hj/ubj&)}(hhh]h)}(h0x214/4h]h0x214/4}(hj/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj/ubah}(h]h ]h"]h$]h&]uh1j%hj/ubeh}(h]h ]h"]h$]h&]uh1j hjW/ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj0ubah}(h]h ]h"]h$]h&]uh1j%hj/ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj0ubah}(h]h ]h"]h$]h&]uh1j%hj/ubeh}(h]h ]h"]h$]h&]uh1j hjW/ubeh}(h]h ]h"]h$]h&]uh1jhj@/ubeh}(h]h ]h"]h$]h&]colsKuh1jhj=/ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hXThe address to jump to in protected mode. This defaults to the load address of the kernel, and can be used by the boot loader to determine the proper load address. This field can be modified for two purposes: 1. as a boot loader hook (see Advanced Boot Loader Hooks below.) 2. if a bootloader which does not install a hook loads a relocatable kernel at a nonstandard address it will have to modify this field to point to the load address. h](h)}(hThe address to jump to in protected mode. This defaults to the load address of the kernel, and can be used by the boot loader to determine the proper load address.h]hThe address to jump to in protected mode. This defaults to the load address of the kernel, and can be used by the boot loader to determine the proper load address.}(hjM0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjI0ubh)}(h,This field can be modified for two purposes:h]h,This field can be modified for two purposes:}(hj[0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjI0ubj)}(h1. as a boot loader hook (see Advanced Boot Loader Hooks below.) 2. if a bootloader which does not install a hook loads a relocatable kernel at a nonstandard address it will have to modify this field to point to the load address. h]j)}(hhh](j)}(h>as a boot loader hook (see Advanced Boot Loader Hooks below.) h]h)}(h=as a boot loader hook (see Advanced Boot Loader Hooks below.)h]h=as a boot loader hook (see Advanced Boot Loader Hooks below.)}(hjt0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjp0ubah}(h]h ]h"]h$]h&]uh1jhjm0ubj)}(hif a bootloader which does not install a hook loads a relocatable kernel at a nonstandard address it will have to modify this field to point to the load address. h]h)}(hif a bootloader which does not install a hook loads a relocatable kernel at a nonstandard address it will have to modify this field to point to the load address.h]hif a bootloader which does not install a hook loads a relocatable kernel at a nonstandard address it will have to modify this field to point to the load address.}(hj0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj0ubah}(h]h ]h"]h$]h&]uh1jhjm0ubeh}(h]h ]h"]h$]h&]jj j!hj#.uh1jhji0ubah}(h]h ]h"]h$]h&]uh1jhhhMhjI0ubeh}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj0ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj0ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM!hj0ubah}(h]h ]h"]h$]h&]uh1j%hj0ubj&)}(hhh]h)}(h ramdisk_imageh]h ramdisk_image}(hj0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM!hj0ubah}(h]h ]h"]h$]h&]uh1j%hj0ubeh}(h]h ]h"]h$]h&]uh1j hj0ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj 1hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM"hj 1ubah}(h]h ]h"]h$]h&]uh1j%hj1ubj&)}(hhh]h)}(hwrite (obligatory)h]hwrite (obligatory)}(hj$1hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM"hj!1ubah}(h]h ]h"]h$]h&]uh1j%hj1ubeh}(h]h ]h"]h$]h&]uh1j hj0ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjD1hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM#hjA1ubah}(h]h ]h"]h$]h&]uh1j%hj>1ubj&)}(hhh]h)}(h0x218/4h]h0x218/4}(hj[1hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM#hjX1ubah}(h]h ]h"]h$]h&]uh1j%hj>1ubeh}(h]h ]h"]h$]h&]uh1j hj0ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj{1hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM$hjx1ubah}(h]h ]h"]h$]h&]uh1j%hju1ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj1hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM$hj1ubah}(h]h ]h"]h$]h&]uh1j%hju1ubeh}(h]h ]h"]h$]h&]uh1j hj0ubeh}(h]h ]h"]h$]h&]uh1jhj0ubeh}(h]h ]h"]h$]h&]colsKuh1jhj0ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hpThe 32-bit linear address of the initial ramdisk or ramfs. Leave at zero if there is no initial ramdisk/ramfs. h]h)}(hoThe 32-bit linear address of the initial ramdisk or ramfs. Leave at zero if there is no initial ramdisk/ramfs.h]hoThe 32-bit linear address of the initial ramdisk or ramfs. Leave at zero if there is no initial ramdisk/ramfs.}(hj1hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM'hj1ubah}(h]h ]h"]h$]h&]uh1jhhhM'hj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj1ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj1ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj1hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM+hj1ubah}(h]h ]h"]h$]h&]uh1j%hj1ubj&)}(hhh]h)}(h ramdisk_sizeh]h ramdisk_size}(hj2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM+hj2ubah}(h]h ]h"]h$]h&]uh1j%hj1ubeh}(h]h ]h"]h$]h&]uh1j hj1ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj12hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM,hj.2ubah}(h]h ]h"]h$]h&]uh1j%hj+2ubj&)}(hhh]h)}(hwrite (obligatory)h]hwrite (obligatory)}(hjH2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM,hjE2ubah}(h]h ]h"]h$]h&]uh1j%hj+2ubeh}(h]h ]h"]h$]h&]uh1j hj1ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjh2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM-hje2ubah}(h]h ]h"]h$]h&]uh1j%hjb2ubj&)}(hhh]h)}(h0x21c/4h]h0x21c/4}(hj2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM-hj|2ubah}(h]h ]h"]h$]h&]uh1j%hjb2ubeh}(h]h ]h"]h$]h&]uh1j hj1ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM.hj2ubah}(h]h ]h"]h$]h&]uh1j%hj2ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM.hj2ubah}(h]h ]h"]h$]h&]uh1j%hj2ubeh}(h]h ]h"]h$]h&]uh1j hj1ubeh}(h]h ]h"]h$]h&]uh1jhj1ubeh}(h]h ]h"]h$]h&]colsKuh1jhj1ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(h[Size of the initial ramdisk or ramfs. Leave at zero if there is no initial ramdisk/ramfs. h]h)}(hZSize of the initial ramdisk or ramfs. Leave at zero if there is no initial ramdisk/ramfs.h]hZSize of the initial ramdisk or ramfs. Leave at zero if there is no initial ramdisk/ramfs.}(hj2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM1hj2ubah}(h]h ]h"]h$]h&]uh1jhhhM1hj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj2ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj2ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM5hj3ubah}(h]h ]h"]h$]h&]uh1j%hj3ubj&)}(hhh]h)}(hbootsect_kludgeh]hbootsect_kludge}(hj53hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM5hj23ubah}(h]h ]h"]h$]h&]uh1j%hj3ubeh}(h]h ]h"]h$]h&]uh1j hj3ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjU3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM6hjR3ubah}(h]h ]h"]h$]h&]uh1j%hjO3ubj&)}(hhh]h)}(hkernel internalh]hkernel internal}(hjl3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM6hji3ubah}(h]h ]h"]h$]h&]uh1j%hjO3ubeh}(h]h ]h"]h$]h&]uh1j hj3ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM7hj3ubah}(h]h ]h"]h$]h&]uh1j%hj3ubj&)}(hhh]h)}(h0x220/4h]h0x220/4}(hj3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM7hj3ubah}(h]h ]h"]h$]h&]uh1j%hj3ubeh}(h]h ]h"]h$]h&]uh1j hj3ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM8hj3ubah}(h]h ]h"]h$]h&]uh1j%hj3ubj&)}(hhh]h)}(h2.00+h]h2.00+}(hj3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM8hj3ubah}(h]h ]h"]h$]h&]uh1j%hj3ubeh}(h]h ]h"]h$]h&]uh1j hj3ubeh}(h]h ]h"]h$]h&]uh1jhj2ubeh}(h]h ]h"]h$]h&]colsKuh1jhj2ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hThis field is obsolete. h]h)}(hThis field is obsolete.h]hThis field is obsolete.}(hj 4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM;hj4ubah}(h]h ]h"]h$]h&]uh1jhhhM;hj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj"4ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj"4ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjB4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM>hj?4ubah}(h]h ]h"]h$]h&]uh1j%hj<4ubj&)}(hhh]h)}(h heap_end_ptrh]h heap_end_ptr}(hjY4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM>hjV4ubah}(h]h ]h"]h$]h&]uh1j%hj<4ubeh}(h]h ]h"]h$]h&]uh1j hj94ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjy4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM?hjv4ubah}(h]h ]h"]h$]h&]uh1j%hjs4ubj&)}(hhh]h)}(hwrite (obligatory)h]hwrite (obligatory)}(hj4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM?hj4ubah}(h]h ]h"]h$]h&]uh1j%hjs4ubeh}(h]h ]h"]h$]h&]uh1j hj94ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM@hj4ubah}(h]h ]h"]h$]h&]uh1j%hj4ubj&)}(hhh]h)}(h0x224/2h]h0x224/2}(hj4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM@hj4ubah}(h]h ]h"]h$]h&]uh1j%hj4ubeh}(h]h ]h"]h$]h&]uh1j hj94ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMAhj4ubah}(h]h ]h"]h$]h&]uh1j%hj4ubj&)}(hhh]h)}(h2.01+h]h2.01+}(hj4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMAhj4ubah}(h]h ]h"]h$]h&]uh1j%hj4ubeh}(h]h ]h"]h$]h&]uh1j hj94ubeh}(h]h ]h"]h$]h&]uh1jhj"4ubeh}(h]h ]h"]h$]h&]colsKuh1jhj4ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hzSet this field to the offset (from the beginning of the real-mode code) of the end of the setup stack/heap, minus 0x0200. h]h)}(hySet this field to the offset (from the beginning of the real-mode code) of the end of the setup stack/heap, minus 0x0200.h]hySet this field to the offset (from the beginning of the real-mode code) of the end of the setup stack/heap, minus 0x0200.}(hj/5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMDhj+5ubah}(h]h ]h"]h$]h&]uh1jhhhMDhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjF5ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhjF5ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjf5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMHhjc5ubah}(h]h ]h"]h$]h&]uh1j%hj`5ubj&)}(hhh]h)}(hext_loader_verh]hext_loader_ver}(hj}5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMHhjz5ubah}(h]h ]h"]h$]h&]uh1j%hj`5ubeh}(h]h ]h"]h$]h&]uh1j hj]5ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMIhj5ubah}(h]h ]h"]h$]h&]uh1j%hj5ubj&)}(hhh]h)}(hwrite (optional)h]hwrite (optional)}(hj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMIhj5ubah}(h]h ]h"]h$]h&]uh1j%hj5ubeh}(h]h ]h"]h$]h&]uh1j hj]5ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMJhj5ubah}(h]h ]h"]h$]h&]uh1j%hj5ubj&)}(hhh]h)}(h0x226/1h]h0x226/1}(hj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMJhj5ubah}(h]h ]h"]h$]h&]uh1j%hj5ubeh}(h]h ]h"]h$]h&]uh1j hj]5ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj 6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMKhj6ubah}(h]h ]h"]h$]h&]uh1j%hj6ubj&)}(hhh]h)}(h2.02+h]h2.02+}(hj"6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMKhj6ubah}(h]h ]h"]h$]h&]uh1j%hj6ubeh}(h]h ]h"]h$]h&]uh1j hj]5ubeh}(h]h ]h"]h$]h&]uh1jhjF5ubeh}(h]h ]h"]h$]h&]colsKuh1jhjC5ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hXvThis field is used as an extension of the version number in the type_of_loader field. The total version number is considered to be (type_of_loader & 0x0f) + (ext_loader_ver << 4). The use of this field is boot loader specific. If not written, it is zero. Kernels prior to 2.6.31 did not recognize this field, but it is safe to write for protocol version 2.02 or higher. h](h)}(hThis field is used as an extension of the version number in the type_of_loader field. The total version number is considered to be (type_of_loader & 0x0f) + (ext_loader_ver << 4).h]hThis field is used as an extension of the version number in the type_of_loader field. The total version number is considered to be (type_of_loader & 0x0f) + (ext_loader_ver << 4).}(hjS6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMNhjO6ubh)}(hKThe use of this field is boot loader specific. If not written, it is zero.h]hKThe use of this field is boot loader specific. If not written, it is zero.}(hja6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMRhjO6ubh)}(hrKernels prior to 2.6.31 did not recognize this field, but it is safe to write for protocol version 2.02 or higher.h]hrKernels prior to 2.6.31 did not recognize this field, but it is safe to write for protocol version 2.02 or higher.}(hjo6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMUhjO6ubeh}(h]h ]h"]h$]h&]uh1jhhhMNhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj6ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthK5uh1jhj6ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMYhj6ubah}(h]h ]h"]h$]h&]uh1j%hj6ubj&)}(hhh]h)}(hext_loader_typeh]hext_loader_type}(hj6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMYhj6ubah}(h]h ]h"]h$]h&]uh1j%hj6ubeh}(h]h ]h"]h$]h&]uh1j hj6ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMZhj6ubah}(h]h ]h"]h$]h&]uh1j%hj6ubj&)}(hhh]h)}(h5write (obligatory if (type_of_loader & 0xf0) == 0xe0)h]h5write (obligatory if (type_of_loader & 0xf0) == 0xe0)}(hj6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMZhj6ubah}(h]h ]h"]h$]h&]uh1j%hj6ubeh}(h]h ]h"]h$]h&]uh1j hj6ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM[hj7ubah}(h]h ]h"]h$]h&]uh1j%hj7ubj&)}(hhh]h)}(h0x227/1h]h0x227/1}(hj+7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM[hj(7ubah}(h]h ]h"]h$]h&]uh1j%hj7ubeh}(h]h ]h"]h$]h&]uh1j hj6ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hjK7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM\hjH7ubah}(h]h ]h"]h$]h&]uh1j%hjE7ubj&)}(hhh]h)}(h2.02+h]h2.02+}(hjb7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM\hj_7ubah}(h]h ]h"]h$]h&]uh1j%hjE7ubeh}(h]h ]h"]h$]h&]uh1j hj6ubeh}(h]h ]h"]h$]h&]uh1jhj6ubeh}(h]h ]h"]h$]h&]colsKuh1jhj6ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hX]This field is used as an extension of the type number in type_of_loader field. If the type in type_of_loader is 0xE, then the actual type is (ext_loader_type + 0x10). This field is ignored if the type in type_of_loader is not 0xE. Kernels prior to 2.6.31 did not recognize this field, but it is safe to write for protocol version 2.02 or higher. h](h)}(hThis field is used as an extension of the type number in type_of_loader field. If the type in type_of_loader is 0xE, then the actual type is (ext_loader_type + 0x10).h]hThis field is used as an extension of the type number in type_of_loader field. If the type in type_of_loader is 0xE, then the actual type is (ext_loader_type + 0x10).}(hj7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM_hj7ubh)}(h?This field is ignored if the type in type_of_loader is not 0xE.h]h?This field is ignored if the type in type_of_loader is not 0xE.}(hj7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMchj7ubh)}(hrKernels prior to 2.6.31 did not recognize this field, but it is safe to write for protocol version 2.02 or higher.h]hrKernels prior to 2.6.31 did not recognize this field, but it is safe to write for protocol version 2.02 or higher.}(hj7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMehj7ubeh}(h]h ]h"]h$]h&]uh1jhhhM_hj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj7ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj7ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMihj7ubah}(h]h ]h"]h$]h&]uh1j%hj7ubj&)}(hhh]h)}(h cmd_line_ptrh]h cmd_line_ptr}(hj7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMihj7ubah}(h]h ]h"]h$]h&]uh1j%hj7ubeh}(h]h ]h"]h$]h&]uh1j hj7ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMjhj8ubah}(h]h ]h"]h$]h&]uh1j%hj8ubj&)}(hhh]h)}(hwrite (obligatory)h]hwrite (obligatory)}(hj48hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMjhj18ubah}(h]h ]h"]h$]h&]uh1j%hj8ubeh}(h]h ]h"]h$]h&]uh1j hj7ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjT8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMkhjQ8ubah}(h]h ]h"]h$]h&]uh1j%hjN8ubj&)}(hhh]h)}(h0x228/4h]h0x228/4}(hjk8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMkhjh8ubah}(h]h ]h"]h$]h&]uh1j%hjN8ubeh}(h]h ]h"]h$]h&]uh1j hj7ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMlhj8ubah}(h]h ]h"]h$]h&]uh1j%hj8ubj&)}(hhh]h)}(h2.02+h]h2.02+}(hj8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMlhj8ubah}(h]h ]h"]h$]h&]uh1j%hj8ubeh}(h]h ]h"]h$]h&]uh1j hj7ubeh}(h]h ]h"]h$]h&]uh1jhj7ubeh}(h]h ]h"]h$]h&]colsKuh1jhj7ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hXSet this field to the linear address of the kernel command line. The kernel command line can be located anywhere between the end of the setup heap and 0xA0000; it does not have to be located in the same 64K segment as the real-mode code itself. Fill in this field even if your boot loader does not support a command line, in which case you can point this to an empty string (or better yet, to the string "auto".) If this field is left at zero, the kernel will assume that your boot loader does not support the 2.02+ protocol. h](h)}(hSet this field to the linear address of the kernel command line. The kernel command line can be located anywhere between the end of the setup heap and 0xA0000; it does not have to be located in the same 64K segment as the real-mode code itself.h]hSet this field to the linear address of the kernel command line. The kernel command line can be located anywhere between the end of the setup heap and 0xA0000; it does not have to be located in the same 64K segment as the real-mode code itself.}(hj8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMohj8ubh)}(hXFill in this field even if your boot loader does not support a command line, in which case you can point this to an empty string (or better yet, to the string "auto".) If this field is left at zero, the kernel will assume that your boot loader does not support the 2.02+ protocol.h]hXFill in this field even if your boot loader does not support a command line, in which case you can point this to an empty string (or better yet, to the string “auto”.) If this field is left at zero, the kernel will assume that your boot loader does not support the 2.02+ protocol.}(hj8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMthj8ubeh}(h]h ]h"]h$]h&]uh1jhhhMohj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj8ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj8ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM{hj9ubah}(h]h ]h"]h$]h&]uh1j%hj9ubj&)}(hhh]h)}(hinitrd_addr_maxh]hinitrd_addr_max}(hj/9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM{hj,9ubah}(h]h ]h"]h$]h&]uh1j%hj9ubeh}(h]h ]h"]h$]h&]uh1j hj9ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjO9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM|hjL9ubah}(h]h ]h"]h$]h&]uh1j%hjI9ubj&)}(hhh]h)}(hreadh]hread}(hjf9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM|hjc9ubah}(h]h ]h"]h$]h&]uh1j%hjI9ubeh}(h]h ]h"]h$]h&]uh1j hj9ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM}hj9ubah}(h]h ]h"]h$]h&]uh1j%hj9ubj&)}(hhh]h)}(h0x22c/4h]h0x22c/4}(hj9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM}hj9ubah}(h]h ]h"]h$]h&]uh1j%hj9ubeh}(h]h ]h"]h$]h&]uh1j hj9ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM~hj9ubah}(h]h ]h"]h$]h&]uh1j%hj9ubj&)}(hhh]h)}(h2.03+h]h2.03+}(hj9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM~hj9ubah}(h]h ]h"]h$]h&]uh1j%hj9ubeh}(h]h ]h"]h$]h&]uh1j hj9ubeh}(h]h ]h"]h$]h&]uh1jhj8ubeh}(h]h ]h"]h$]h&]colsKuh1jhj8ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hXsThe maximum address that may be occupied by the initial ramdisk/ramfs contents. For boot protocols 2.02 or earlier, this field is not present, and the maximum address is 0x37FFFFFF. (This address is defined as the address of the highest safe byte, so if your ramdisk is exactly 131072 bytes long and this field is 0x37FFFFFF, you can start your ramdisk at 0x37FE0000.) h]h)}(hXrThe maximum address that may be occupied by the initial ramdisk/ramfs contents. For boot protocols 2.02 or earlier, this field is not present, and the maximum address is 0x37FFFFFF. (This address is defined as the address of the highest safe byte, so if your ramdisk is exactly 131072 bytes long and this field is 0x37FFFFFF, you can start your ramdisk at 0x37FE0000.)h]hXrThe maximum address that may be occupied by the initial ramdisk/ramfs contents. For boot protocols 2.02 or earlier, this field is not present, and the maximum address is 0x37FFFFFF. (This address is defined as the address of the highest safe byte, so if your ramdisk is exactly 131072 bytes long and this field is 0x37FFFFFF, you can start your ramdisk at 0x37FE0000.)}(hj:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj:ubah}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj:ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhj:ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj<:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj9:ubah}(h]h ]h"]h$]h&]uh1j%hj6:ubj&)}(hhh]h)}(hkernel_alignmenth]hkernel_alignment}(hjS:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjP:ubah}(h]h ]h"]h$]h&]uh1j%hj6:ubeh}(h]h ]h"]h$]h&]uh1j hj3:ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjs:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjp:ubah}(h]h ]h"]h$]h&]uh1j%hjm:ubj&)}(hhh]h)}(hread/modify (reloc)h]hread/modify (reloc)}(hj:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj:ubah}(h]h ]h"]h$]h&]uh1j%hjm:ubeh}(h]h ]h"]h$]h&]uh1j hj3:ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj:ubah}(h]h ]h"]h$]h&]uh1j%hj:ubj&)}(hhh]h)}(h0x230/4h]h0x230/4}(hj:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj:ubah}(h]h ]h"]h$]h&]uh1j%hj:ubeh}(h]h ]h"]h$]h&]uh1j hj3:ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj:ubah}(h]h ]h"]h$]h&]uh1j%hj:ubj&)}(hhh]h)}(h2.05+ (read), 2.10+ (modify)h]h2.05+ (read), 2.10+ (modify)}(hj:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj:ubah}(h]h ]h"]h$]h&]uh1j%hj:ubeh}(h]h ]h"]h$]h&]uh1j hj3:ubeh}(h]h ]h"]h$]h&]uh1jhj:ubeh}(h]h ]h"]h$]h&]colsKuh1jhj:ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hXAlignment unit required by the kernel (if relocatable_kernel is true.) A relocatable kernel that is loaded at an alignment incompatible with the value in this field will be realigned during kernel initialization. Starting with protocol version 2.10, this reflects the kernel alignment preferred for optimal performance; it is possible for the loader to modify this field to permit a lesser alignment. See the min_alignment and pref_address field below. h](h)}(hAlignment unit required by the kernel (if relocatable_kernel is true.) A relocatable kernel that is loaded at an alignment incompatible with the value in this field will be realigned during kernel initialization.h]hAlignment unit required by the kernel (if relocatable_kernel is true.) A relocatable kernel that is loaded at an alignment incompatible with the value in this field will be realigned during kernel initialization.}(hj);hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%;ubh)}(hStarting with protocol version 2.10, this reflects the kernel alignment preferred for optimal performance; it is possible for the loader to modify this field to permit a lesser alignment. See the min_alignment and pref_address field below.h]hStarting with protocol version 2.10, this reflects the kernel alignment preferred for optimal performance; it is possible for the loader to modify this field to permit a lesser alignment. See the min_alignment and pref_address field below.}(hj7;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%;ubeh}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjN;ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhjN;ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjn;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjk;ubah}(h]h ]h"]h$]h&]uh1j%hjh;ubj&)}(hhh]h)}(hrelocatable_kernelh]hrelocatable_kernel}(hj;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;ubah}(h]h ]h"]h$]h&]uh1j%hjh;ubeh}(h]h ]h"]h$]h&]uh1j hje;ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;ubah}(h]h ]h"]h$]h&]uh1j%hj;ubj&)}(hhh]h)}(h read (reloc)h]h read (reloc)}(hj;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;ubah}(h]h ]h"]h$]h&]uh1j%hj;ubeh}(h]h ]h"]h$]h&]uh1j hje;ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;ubah}(h]h ]h"]h$]h&]uh1j%hj;ubj&)}(hhh]h)}(h0x234/1h]h0x234/1}(hj;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;ubah}(h]h ]h"]h$]h&]uh1j%hj;ubeh}(h]h ]h"]h$]h&]uh1j hje;ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj<ubah}(h]h ]h"]h$]h&]uh1j%hj <ubj&)}(hhh]h)}(h2.05+h]h2.05+}(hj*<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj'<ubah}(h]h ]h"]h$]h&]uh1j%hj <ubeh}(h]h ]h"]h$]h&]uh1j hje;ubeh}(h]h ]h"]h$]h&]uh1jhjN;ubeh}(h]h ]h"]h$]h&]colsKuh1jhjK;ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hIf this field is nonzero, the protected-mode part of the kernel can be loaded at any address that satisfies the kernel_alignment field. After loading, the boot loader must set the code32_start field to point to the loaded code, or to a boot loader hook. h]h)}(hIf this field is nonzero, the protected-mode part of the kernel can be loaded at any address that satisfies the kernel_alignment field. After loading, the boot loader must set the code32_start field to point to the loaded code, or to a boot loader hook.h]hIf this field is nonzero, the protected-mode part of the kernel can be loaded at any address that satisfies the kernel_alignment field. After loading, the boot loader must set the code32_start field to point to the loaded code, or to a boot loader hook.}(hj[<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjW<ubah}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjr<ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjr<ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj<ubah}(h]h ]h"]h$]h&]uh1j%hj<ubj&)}(hhh]h)}(h min_alignmenth]h min_alignment}(hj<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj<ubah}(h]h ]h"]h$]h&]uh1j%hj<ubeh}(h]h ]h"]h$]h&]uh1j hj<ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj<ubah}(h]h ]h"]h$]h&]uh1j%hj<ubj&)}(hhh]h)}(h read (reloc)h]h read (reloc)}(hj<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj<ubah}(h]h ]h"]h$]h&]uh1j%hj<ubeh}(h]h ]h"]h$]h&]uh1j hj<ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj<ubah}(h]h ]h"]h$]h&]uh1j%hj<ubj&)}(hhh]h)}(h0x235/1h]h0x235/1}(hj=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj=ubah}(h]h ]h"]h$]h&]uh1j%hj<ubeh}(h]h ]h"]h$]h&]uh1j hj<ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj7=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj4=ubah}(h]h ]h"]h$]h&]uh1j%hj1=ubj&)}(hhh]h)}(h2.10+h]h2.10+}(hjN=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjK=ubah}(h]h ]h"]h$]h&]uh1j%hj1=ubeh}(h]h ]h"]h$]h&]uh1j hj<ubeh}(h]h ]h"]h$]h&]uh1jhjr<ubeh}(h]h ]h"]h$]h&]colsKuh1jhjo<ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hXThis field, if nonzero, indicates as a power of two the minimum alignment required, as opposed to preferred, by the kernel to boot. If a boot loader makes use of this field, it should update the kernel_alignment field with the alignment unit desired; typically:: kernel_alignment = 1 << min_alignment; There may be a considerable performance cost with an excessively misaligned kernel. Therefore, a loader should typically try each power-of-two alignment from kernel_alignment down to this alignment. h](h)}(hXThis field, if nonzero, indicates as a power of two the minimum alignment required, as opposed to preferred, by the kernel to boot. If a boot loader makes use of this field, it should update the kernel_alignment field with the alignment unit desired; typically::h]hXThis field, if nonzero, indicates as a power of two the minimum alignment required, as opposed to preferred, by the kernel to boot. If a boot loader makes use of this field, it should update the kernel_alignment field with the alignment unit desired; typically:}(hj=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj{=ubj)}(h&kernel_alignment = 1 << min_alignment;h]h&kernel_alignment = 1 << min_alignment;}hj=sbah}(h]h ]h"]h$]h&]hhuh1jhhhMhj{=ubh)}(hThere may be a considerable performance cost with an excessively misaligned kernel. Therefore, a loader should typically try each power-of-two alignment from kernel_alignment down to this alignment.h]hThere may be a considerable performance cost with an excessively misaligned kernel. Therefore, a loader should typically try each power-of-two alignment from kernel_alignment down to this alignment.}(hj=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj{=ubeh}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj=ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj=ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj=ubah}(h]h ]h"]h$]h&]uh1j%hj=ubj&)}(hhh]h)}(h xloadflagsh]h xloadflags}(hj=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj=ubah}(h]h ]h"]h$]h&]uh1j%hj=ubeh}(h]h ]h"]h$]h&]uh1j hj=ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj >hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj>ubah}(h]h ]h"]h$]h&]uh1j%hj>ubj&)}(hhh]h)}(hreadh]hread}(hj >hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj>ubah}(h]h ]h"]h$]h&]uh1j%hj>ubeh}(h]h ]h"]h$]h&]uh1j hj=ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj@>hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj=>ubah}(h]h ]h"]h$]h&]uh1j%hj:>ubj&)}(hhh]h)}(h0x236/2h]h0x236/2}(hjW>hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjT>ubah}(h]h ]h"]h$]h&]uh1j%hj:>ubeh}(h]h ]h"]h$]h&]uh1j hj=ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hjw>hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjt>ubah}(h]h ]h"]h$]h&]uh1j%hjq>ubj&)}(hhh]h)}(h2.12+h]h2.12+}(hj>hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj>ubah}(h]h ]h"]h$]h&]uh1j%hjq>ubeh}(h]h ]h"]h$]h&]uh1j hj=ubeh}(h]h ]h"]h$]h&]uh1jhj=ubeh}(h]h ]h"]h$]h&]colsKuh1jhj=ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hXrThis field is a bitmask. Bit 0 (read): XLF_KERNEL_64 - If 1, this kernel has the legacy 64-bit entry point at 0x200. Bit 1 (read): XLF_CAN_BE_LOADED_ABOVE_4G - If 1, kernel/boot_params/cmdline/ramdisk can be above 4G. Bit 2 (read): XLF_EFI_HANDOVER_32 - If 1, the kernel supports the 32-bit EFI handoff entry point given at handover_offset. Bit 3 (read): XLF_EFI_HANDOVER_64 - If 1, the kernel supports the 64-bit EFI handoff entry point given at handover_offset + 0x200. Bit 4 (read): XLF_EFI_KEXEC - If 1, the kernel supports kexec EFI boot with EFI runtime support. h](h)}(hThis field is a bitmask.h]hThis field is a bitmask.}(hj>hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj>ubh)}(hBit 0 (read): XLF_KERNEL_64h]hBit 0 (read): XLF_KERNEL_64}(hj>hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj>ubj)}(h@- If 1, this kernel has the legacy 64-bit entry point at 0x200. h]jf,)}(hhh]j)}(h>If 1, this kernel has the legacy 64-bit entry point at 0x200. h]h)}(h=If 1, this kernel has the legacy 64-bit entry point at 0x200.h]h=If 1, this kernel has the legacy 64-bit entry point at 0x200.}(hj>hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj>ubah}(h]h ]h"]h$]h&]uh1jhj>ubah}(h]h ]h"]h$]h&]j,j,uh1je,hhhMhj>ubah}(h]h ]h"]h$]h&]uh1jhhhMhj>ubh)}(h(Bit 1 (read): XLF_CAN_BE_LOADED_ABOVE_4Gh]h(Bit 1 (read): XLF_CAN_BE_LOADED_ABOVE_4G}(hj?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj>ubj)}(h<- If 1, kernel/boot_params/cmdline/ramdisk can be above 4G. h]jf,)}(hhh]j)}(h:If 1, kernel/boot_params/cmdline/ramdisk can be above 4G. h]h)}(h9If 1, kernel/boot_params/cmdline/ramdisk can be above 4G.h]h9If 1, kernel/boot_params/cmdline/ramdisk can be above 4G.}(hj?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj?ubah}(h]h ]h"]h$]h&]uh1jhj?ubah}(h]h ]h"]h$]h&]j,j,uh1je,hhhMhj?ubah}(h]h ]h"]h$]h&]uh1jhhhMhj>ubh)}(h!Bit 2 (read): XLF_EFI_HANDOVER_32h]h!Bit 2 (read): XLF_EFI_HANDOVER_32}(hj??hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj>ubj)}(h[- If 1, the kernel supports the 32-bit EFI handoff entry point given at handover_offset. h]jf,)}(hhh]j)}(hWIf 1, the kernel supports the 32-bit EFI handoff entry point given at handover_offset. h]h)}(hVIf 1, the kernel supports the 32-bit EFI handoff entry point given at handover_offset.h]hVIf 1, the kernel supports the 32-bit EFI handoff entry point given at handover_offset.}(hjX?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjT?ubah}(h]h ]h"]h$]h&]uh1jhjQ?ubah}(h]h ]h"]h$]h&]j,j,uh1je,hhhMhjM?ubah}(h]h ]h"]h$]h&]uh1jhhhMhj>ubh)}(h!Bit 3 (read): XLF_EFI_HANDOVER_64h]h!Bit 3 (read): XLF_EFI_HANDOVER_64}(hjx?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj>ubj)}(hc- If 1, the kernel supports the 64-bit EFI handoff entry point given at handover_offset + 0x200. h]jf,)}(hhh]j)}(h_If 1, the kernel supports the 64-bit EFI handoff entry point given at handover_offset + 0x200. h]h)}(h^If 1, the kernel supports the 64-bit EFI handoff entry point given at handover_offset + 0x200.h]h^If 1, the kernel supports the 64-bit EFI handoff entry point given at handover_offset + 0x200.}(hj?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj?ubah}(h]h ]h"]h$]h&]uh1jhj?ubah}(h]h ]h"]h$]h&]j,j,uh1je,hhhMhj?ubah}(h]h ]h"]h$]h&]uh1jhhhMhj>ubh)}(hBit 4 (read): XLF_EFI_KEXECh]hBit 4 (read): XLF_EFI_KEXEC}(hj?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj>ubj)}(hF- If 1, the kernel supports kexec EFI boot with EFI runtime support. h]jf,)}(hhh]j)}(hDIf 1, the kernel supports kexec EFI boot with EFI runtime support. h]h)}(hBIf 1, the kernel supports kexec EFI boot with EFI runtime support.h]hBIf 1, the kernel supports kexec EFI boot with EFI runtime support.}(hj?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj?ubah}(h]h ]h"]h$]h&]uh1jhj?ubah}(h]h ]h"]h$]h&]j,j,uh1je,hhhMhj?ubah}(h]h ]h"]h$]h&]uh1jhhhMhj>ubeh}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj?ubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj?ubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj@ubah}(h]h ]h"]h$]h&]uh1j%hj @ubj&)}(hhh]h)}(h cmdline_sizeh]h cmdline_size}(hj*@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj'@ubah}(h]h ]h"]h$]h&]uh1j%hj @ubeh}(h]h ]h"]h$]h&]uh1j hj @ubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjJ@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjG@ubah}(h]h ]h"]h$]h&]uh1j%hjD@ubj&)}(hhh]h)}(hreadh]hread}(hja@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj^@ubah}(h]h ]h"]h$]h&]uh1j%hjD@ubeh}(h]h ]h"]h$]h&]uh1j hj @ubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj~@ubah}(h]h ]h"]h$]h&]uh1j%hj{@ubj&)}(hhh]h)}(h0x238/4h]h0x238/4}(hj@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj@ubah}(h]h ]h"]h$]h&]uh1j%hj{@ubeh}(h]h ]h"]h$]h&]uh1j hj @ubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hj@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj@ubah}(h]h ]h"]h$]h&]uh1j%hj@ubj&)}(hhh]h)}(h2.06+h]h2.06+}(hj@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj@ubah}(h]h ]h"]h$]h&]uh1j%hj@ubeh}(h]h ]h"]h$]h&]uh1j hj @ubeh}(h]h ]h"]h$]h&]uh1jhj?ubeh}(h]h ]h"]h$]h&]colsKuh1jhj?ubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hThe maximum size of the command line without the terminating zero. This means that the command line can contain at most cmdline_size characters. With protocol version 2.05 and earlier, the maximum size was 255. h]h)}(hThe maximum size of the command line without the terminating zero. This means that the command line can contain at most cmdline_size characters. With protocol version 2.05 and earlier, the maximum size was 255.h]hThe maximum size of the command line without the terminating zero. This means that the command line can contain at most cmdline_size characters. With protocol version 2.05 and earlier, the maximum size was 255.}(hjAhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj@ubah}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjAubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthK$uh1jhjAubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj7AhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj4Aubah}(h]h ]h"]h$]h&]uh1j%hj1Aubj&)}(hhh]h)}(hhardware_subarchh]hhardware_subarch}(hjNAhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjKAubah}(h]h ]h"]h$]h&]uh1j%hj1Aubeh}(h]h ]h"]h$]h&]uh1j hj.Aubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjnAhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjkAubah}(h]h ]h"]h$]h&]uh1j%hjhAubj&)}(hhh]h)}(h$write (optional, defaults to x86/PC)h]h$write (optional, defaults to x86/PC)}(hjAhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjAubah}(h]h ]h"]h$]h&]uh1j%hjhAubeh}(h]h ]h"]h$]h&]uh1j hj.Aubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjAhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjAubah}(h]h ]h"]h$]h&]uh1j%hjAubj&)}(hhh]h)}(h0x23c/4h]h0x23c/4}(hjAhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjAubah}(h]h ]h"]h$]h&]uh1j%hjAubeh}(h]h ]h"]h$]h&]uh1j hj.Aubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hjAhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjAubah}(h]h ]h"]h$]h&]uh1j%hjAubj&)}(hhh]h)}(h2.07+h]h2.07+}(hjAhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjAubah}(h]h ]h"]h$]h&]uh1j%hjAubeh}(h]h ]h"]h$]h&]uh1j hj.Aubeh}(h]h ]h"]h$]h&]uh1jhjAubeh}(h]h ]h"]h$]h&]colsKuh1jhjAubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hX>In a paravirtualized environment the hardware low level architectural pieces such as interrupt handling, page table handling, and accessing process control registers needs to be done differently. This field allows the bootloader to inform the kernel we are in one one of those environments. ========== ============================== 0x00000000 The default x86/PC environment 0x00000001 lguest 0x00000002 Xen 0x00000003 Intel MID (Moorestown, CloverTrail, Merrifield, Moorefield) 0x00000004 CE4100 TV Platform ========== ============================== h](h)}(hIn a paravirtualized environment the hardware low level architectural pieces such as interrupt handling, page table handling, and accessing process control registers needs to be done differently.h]hIn a paravirtualized environment the hardware low level architectural pieces such as interrupt handling, page table handling, and accessing process control registers needs to be done differently.}(hj$BhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj Bubh)}(h^This field allows the bootloader to inform the kernel we are in one one of those environments.h]h^This field allows the bootloader to inform the kernel we are in one one of those environments.}(hj2BhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj Bubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjCBubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthK;uh1jhjCBubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h 0x00000000h]h 0x00000000}(hjcBhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj`Bubah}(h]h ]h"]h$]h&]uh1j%hj]Bubj&)}(hhh]h)}(hThe default x86/PC environmenth]hThe default x86/PC environment}(hjzBhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjwBubah}(h]h ]h"]h$]h&]uh1j%hj]Bubeh}(h]h ]h"]h$]h&]uh1j hjZBubj!)}(hhh](j&)}(hhh]h)}(h 0x00000001h]h 0x00000001}(hjBhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjBubah}(h]h ]h"]h$]h&]uh1j%hjBubj&)}(hhh]h)}(hlguesth]hlguest}(hjBhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjBubah}(h]h ]h"]h$]h&]uh1j%hjBubeh}(h]h ]h"]h$]h&]uh1j hjZBubj!)}(hhh](j&)}(hhh]h)}(h 0x00000002h]h 0x00000002}(hjBhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjBubah}(h]h ]h"]h$]h&]uh1j%hjBubj&)}(hhh]h)}(hXenh]hXen}(hjBhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjBubah}(h]h ]h"]h$]h&]uh1j%hjBubeh}(h]h ]h"]h$]h&]uh1j hjZBubj!)}(hhh](j&)}(hhh]h)}(h 0x00000003h]h 0x00000003}(hjChhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjCubah}(h]h ]h"]h$]h&]uh1j%hjCubj&)}(hhh]h)}(h;Intel MID (Moorestown, CloverTrail, Merrifield, Moorefield)h]h;Intel MID (Moorestown, CloverTrail, Merrifield, Moorefield)}(hjChhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjCubah}(h]h ]h"]h$]h&]uh1j%hjCubeh}(h]h ]h"]h$]h&]uh1j hjZBubj!)}(hhh](j&)}(hhh]h)}(h 0x00000004h]h 0x00000004}(hj?ChhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjEhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;Eubah}(h]h ]h"]h$]h&]uh1j%hj8Eubj&)}(hhh]h)}(h0x248/4h]h0x248/4}(hjUEhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjREubah}(h]h ]h"]h$]h&]uh1j%hj8Eubeh}(h]h ]h"]h$]h&]uh1j hjDubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hjuEhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjrEubah}(h]h ]h"]h$]h&]uh1j%hjoEubj&)}(hhh]h)}(h2.08+h]h2.08+}(hjEhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjEubah}(h]h ]h"]h$]h&]uh1j%hjoEubeh}(h]h ]h"]h$]h&]uh1j hjDubeh}(h]h ]h"]h$]h&]uh1jhjDubeh}(h]h ]h"]h$]h&]colsKuh1jhjDubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hX(If non-zero then this field contains the offset from the beginning of the protected-mode code to the payload. The payload may be compressed. The format of both the compressed and uncompressed data should be determined using the standard magic numbers. The currently supported compression formats are gzip (magic numbers 1F 8B or 1F 9E), bzip2 (magic number 42 5A), LZMA (magic number 5D 00), XZ (magic number FD 37), LZ4 (magic number 02 21) and ZSTD (magic number 28 B5). The uncompressed payload is currently always ELF (magic number 7F 45 4C 46). h](h)}(hmIf non-zero then this field contains the offset from the beginning of the protected-mode code to the payload.h]hmIf non-zero then this field contains the offset from the beginning of the protected-mode code to the payload.}(hjEhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM hjEubh)}(hXThe payload may be compressed. The format of both the compressed and uncompressed data should be determined using the standard magic numbers. The currently supported compression formats are gzip (magic numbers 1F 8B or 1F 9E), bzip2 (magic number 42 5A), LZMA (magic number 5D 00), XZ (magic number FD 37), LZ4 (magic number 02 21) and ZSTD (magic number 28 B5). The uncompressed payload is currently always ELF (magic number 7F 45 4C 46).h]hXThe payload may be compressed. The format of both the compressed and uncompressed data should be determined using the standard magic numbers. The currently supported compression formats are gzip (magic numbers 1F 8B or 1F 9E), bzip2 (magic number 42 5A), LZMA (magic number 5D 00), XZ (magic number FD 37), LZ4 (magic number 02 21) and ZSTD (magic number 28 B5). The uncompressed payload is currently always ELF (magic number 7F 45 4C 46).}(hjEhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjEubeh}(h]h ]h"]h$]h&]uh1jhhhM hj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjEubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhjEubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjFhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjEubah}(h]h ]h"]h$]h&]uh1j%hjEubj&)}(hhh]h)}(hpayload_lengthh]hpayload_length}(hjFhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjFubah}(h]h ]h"]h$]h&]uh1j%hjEubeh}(h]h ]h"]h$]h&]uh1j hjEubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj9FhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj6Fubah}(h]h ]h"]h$]h&]uh1j%hj3Fubj&)}(hhh]h)}(hreadh]hread}(hjPFhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjMFubah}(h]h ]h"]h$]h&]uh1j%hj3Fubeh}(h]h ]h"]h$]h&]uh1j hjEubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjpFhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjmFubah}(h]h ]h"]h$]h&]uh1j%hjjFubj&)}(hhh]h)}(h0x24c/4h]h0x24c/4}(hjFhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjFubah}(h]h ]h"]h$]h&]uh1j%hjjFubeh}(h]h ]h"]h$]h&]uh1j hjEubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hjFhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjFubah}(h]h ]h"]h$]h&]uh1j%hjFubj&)}(hhh]h)}(h2.08+h]h2.08+}(hjFhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjFubah}(h]h ]h"]h$]h&]uh1j%hjFubeh}(h]h ]h"]h$]h&]uh1j hjEubeh}(h]h ]h"]h$]h&]uh1jhjEubeh}(h]h ]h"]h$]h&]colsKuh1jhjEubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hThe length of the payload. h]h)}(hThe length of the payload.h]hThe length of the payload.}(hjFhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjFubah}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjGubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhjGubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj&GhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM hj#Gubah}(h]h ]h"]h$]h&]uh1j%hj Gubj&)}(hhh]h)}(h setup_datah]h setup_data}(hj=GhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM hj:Gubah}(h]h ]h"]h$]h&]uh1j%hj Gubeh}(h]h ]h"]h$]h&]uh1j hjGubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hj]GhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM!hjZGubah}(h]h ]h"]h$]h&]uh1j%hjWGubj&)}(hhh]h)}(hwrite (special)h]hwrite (special)}(hjtGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM!hjqGubah}(h]h ]h"]h$]h&]uh1j%hjWGubeh}(h]h ]h"]h$]h&]uh1j hjGubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM"hjGubah}(h]h ]h"]h$]h&]uh1j%hjGubj&)}(hhh]h)}(h0x250/8h]h0x250/8}(hjGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM"hjGubah}(h]h ]h"]h$]h&]uh1j%hjGubeh}(h]h ]h"]h$]h&]uh1j hjGubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hjGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM#hjGubah}(h]h ]h"]h$]h&]uh1j%hjGubj&)}(hhh]h)}(h2.09+h]h2.09+}(hjGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM#hjGubah}(h]h ]h"]h$]h&]uh1j%hjGubeh}(h]h ]h"]h$]h&]uh1j hjGubeh}(h]h ]h"]h$]h&]uh1jhjGubeh}(h]h ]h"]h$]h&]colsKuh1jhjGubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hXpThe 64-bit physical pointer to NULL terminated single linked list of struct setup_data. This is used to define a more extensible boot parameters passing mechanism. The definition of struct setup_data is as follow:: struct setup_data { __u64 next; __u32 type; __u32 len; __u8 data[]; } Where, the next is a 64-bit physical pointer to the next node of linked list, the next field of the last node is 0; the type is used to identify the contents of data; the len is the length of data field; the data holds the real payload. This list may be modified at a number of points during the bootup process. Therefore, when modifying this list one should always make sure to consider the case where the linked list already contains entries. The setup_data is a bit awkward to use for extremely large data objects, both because the setup_data header has to be adjacent to the data object and because it has a 32-bit length field. However, it is important that intermediate stages of the boot process have a way to identify which chunks of memory are occupied by kernel data. Thus setup_indirect struct and SETUP_INDIRECT type were introduced in protocol 2.15:: struct setup_indirect { __u32 type; __u32 reserved; /* Reserved, must be set to zero. */ __u64 len; __u64 addr; }; The type member is a SETUP_INDIRECT | SETUP_* type. However, it cannot be SETUP_INDIRECT itself since making the setup_indirect a tree structure could require a lot of stack space in something that needs to parse it and stack space can be limited in boot contexts. Let's give an example how to point to SETUP_E820_EXT data using setup_indirect. In this case setup_data and setup_indirect will look like this:: struct setup_data { .next = 0, /* or */ .type = SETUP_INDIRECT, .len = sizeof(setup_indirect), .data[sizeof(setup_indirect)] = (struct setup_indirect) { .type = SETUP_INDIRECT | SETUP_E820_EXT, .reserved = 0, .len = , .addr = , }, } h](h)}(hThe 64-bit physical pointer to NULL terminated single linked list of struct setup_data. This is used to define a more extensible boot parameters passing mechanism. The definition of struct setup_data is as follow::h]hThe 64-bit physical pointer to NULL terminated single linked list of struct setup_data. This is used to define a more extensible boot parameters passing mechanism. The definition of struct setup_data is as follow:}(hjHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM&hjHubj)}(hYstruct setup_data { __u64 next; __u32 type; __u32 len; __u8 data[]; }h]hYstruct setup_data { __u64 next; __u32 type; __u32 len; __u8 data[]; }}hj!Hsbah}(h]h ]h"]h$]h&]hhuh1jhhhM+hjHubh)}(hWhere, the next is a 64-bit physical pointer to the next node of linked list, the next field of the last node is 0; the type is used to identify the contents of data; the len is the length of data field; the data holds the real payload.h]hWhere, the next is a 64-bit physical pointer to the next node of linked list, the next field of the last node is 0; the type is used to identify the contents of data; the len is the length of data field; the data holds the real payload.}(hj/HhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM2hjHubh)}(hThis list may be modified at a number of points during the bootup process. Therefore, when modifying this list one should always make sure to consider the case where the linked list already contains entries.h]hThis list may be modified at a number of points during the bootup process. Therefore, when modifying this list one should always make sure to consider the case where the linked list already contains entries.}(hj=HhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM7hjHubh)}(hXLThe setup_data is a bit awkward to use for extremely large data objects, both because the setup_data header has to be adjacent to the data object and because it has a 32-bit length field. However, it is important that intermediate stages of the boot process have a way to identify which chunks of memory are occupied by kernel data.h]hXLThe setup_data is a bit awkward to use for extremely large data objects, both because the setup_data header has to be adjacent to the data object and because it has a 32-bit length field. However, it is important that intermediate stages of the boot process have a way to identify which chunks of memory are occupied by kernel data.}(hjKHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM<hjHubh)}(hUThus setup_indirect struct and SETUP_INDIRECT type were introduced in protocol 2.15::h]hTThus setup_indirect struct and SETUP_INDIRECT type were introduced in protocol 2.15:}(hjYHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMBhjHubj)}(hstruct setup_indirect { __u32 type; __u32 reserved; /* Reserved, must be set to zero. */ __u64 len; __u64 addr; };h]hstruct setup_indirect { __u32 type; __u32 reserved; /* Reserved, must be set to zero. */ __u64 len; __u64 addr; };}hjgHsbah}(h]h ]h"]h$]h&]hhuh1jhhhMEhjHubh)}(hXThe type member is a SETUP_INDIRECT | SETUP_* type. However, it cannot be SETUP_INDIRECT itself since making the setup_indirect a tree structure could require a lot of stack space in something that needs to parse it and stack space can be limited in boot contexts.h]hXThe type member is a SETUP_INDIRECT | SETUP_* type. However, it cannot be SETUP_INDIRECT itself since making the setup_indirect a tree structure could require a lot of stack space in something that needs to parse it and stack space can be limited in boot contexts.}(hjuHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMLhjHubh)}(hLet's give an example how to point to SETUP_E820_EXT data using setup_indirect. In this case setup_data and setup_indirect will look like this::h]hLet’s give an example how to point to SETUP_E820_EXT data using setup_indirect. In this case setup_data and setup_indirect will look like this:}(hjHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMQhjHubj)}(hXstruct setup_data { .next = 0, /* or */ .type = SETUP_INDIRECT, .len = sizeof(setup_indirect), .data[sizeof(setup_indirect)] = (struct setup_indirect) { .type = SETUP_INDIRECT | SETUP_E820_EXT, .reserved = 0, .len = , .addr = , }, }h]hXstruct setup_data { .next = 0, /* or */ .type = SETUP_INDIRECT, .len = sizeof(setup_indirect), .data[sizeof(setup_indirect)] = (struct setup_indirect) { .type = SETUP_INDIRECT | SETUP_E820_EXT, .reserved = 0, .len = , .addr = , }, }}hjHsbah}(h]h ]h"]h$]h&]hhuh1jhhhMThjHubeh}(h]h ]h"]h$]h&]uh1jhhhM&hj]hhubj)}(hSETUP_INDIRECT | SETUP_NONE objects cannot be properly distinguished from SETUP_INDIRECT itself. So, this kind of objects cannot be provided by the bootloaders.h]h)}(hSETUP_INDIRECT | SETUP_NONE objects cannot be properly distinguished from SETUP_INDIRECT itself. So, this kind of objects cannot be provided by the bootloaders.h]hSETUP_INDIRECT | SETUP_NONE objects cannot be properly distinguished from SETUP_INDIRECT itself. So, this kind of objects cannot be provided by the bootloaders.}(hjHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMahjHubah}(h]h ]h"]h$]h&]uh1jhj]hhhhhNubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjHubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjHubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMfhjHubah}(h]h ]h"]h$]h&]uh1j%hjHubj&)}(hhh]h)}(h pref_addressh]h pref_address}(hjHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMfhjHubah}(h]h ]h"]h$]h&]uh1j%hjHubeh}(h]h ]h"]h$]h&]uh1j hjHubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMghjIubah}(h]h ]h"]h$]h&]uh1j%hjIubj&)}(hhh]h)}(h read (reloc)h]h read (reloc)}(hj.IhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMghj+Iubah}(h]h ]h"]h$]h&]uh1j%hjIubeh}(h]h ]h"]h$]h&]uh1j hjHubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjNIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhhjKIubah}(h]h ]h"]h$]h&]uh1j%hjHIubj&)}(hhh]h)}(h0x258/8h]h0x258/8}(hjeIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhhjbIubah}(h]h ]h"]h$]h&]uh1j%hjHIubeh}(h]h ]h"]h$]h&]uh1j hjHubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hjIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMihjIubah}(h]h ]h"]h$]h&]uh1j%hjIubj&)}(hhh]h)}(h2.10+h]h2.10+}(hjIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMihjIubah}(h]h ]h"]h$]h&]uh1j%hjIubeh}(h]h ]h"]h$]h&]uh1j hjHubeh}(h]h ]h"]h$]h&]uh1jhjHubeh}(h]h ]h"]h$]h&]colsKuh1jhjHubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hXGThis field, if nonzero, represents a preferred load address for the kernel. A relocating bootloader should attempt to load at this address if possible. A non-relocatable kernel will unconditionally move itself and to run at this address. A relocatable kernel will move itself to this address if it loaded below this address. h](h)}(hThis field, if nonzero, represents a preferred load address for the kernel. A relocating bootloader should attempt to load at this address if possible.h]hThis field, if nonzero, represents a preferred load address for the kernel. A relocating bootloader should attempt to load at this address if possible.}(hjIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMlhjIubh)}(hA non-relocatable kernel will unconditionally move itself and to run at this address. A relocatable kernel will move itself to this address if it loaded below this address.h]hA non-relocatable kernel will unconditionally move itself and to run at this address. A relocatable kernel will move itself to this address if it loaded below this address.}(hjIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMphjIubeh}(h]h ]h"]h$]h&]uh1jhhhMlhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjIubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjIubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjJhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMuhjJubah}(h]h ]h"]h$]h&]uh1j%hj Jubj&)}(hhh]h)}(h init_sizeh]h init_size}(hj)JhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMuhj&Jubah}(h]h ]h"]h$]h&]uh1j%hj Jubeh}(h]h ]h"]h$]h&]uh1j hj Jubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjIJhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMvhjFJubah}(h]h ]h"]h$]h&]uh1j%hjCJubj&)}(hhh]h)}(hreadh]hread}(hj`JhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMvhj]Jubah}(h]h ]h"]h$]h&]uh1j%hjCJubeh}(h]h ]h"]h$]h&]uh1j hj Jubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjJhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMwhj}Jubah}(h]h ]h"]h$]h&]uh1j%hjzJubj&)}(hhh]h)}(h0x260/4h]h0x260/4}(hjJhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMwhjJubah}(h]h ]h"]h$]h&]uh1j%hjzJubeh}(h]h ]h"]h$]h&]uh1j hj Jubeh}(h]h ]h"]h$]h&]uh1jhjIubeh}(h]h ]h"]h$]h&]colsKuh1jhjIubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hXThis field indicates the amount of linear contiguous memory starting at the kernel runtime start address that the kernel needs before it is capable of examining its memory map. This is not the same thing as the total amount of memory the kernel needs to boot, but it can be used by a relocating boot loader to help select a safe load address for the kernel. The kernel runtime start address is determined by the following algorithm:: if (relocatable_kernel) { if (load_address < pref_address) load_address = pref_address; runtime_start = align_up(load_address, kernel_alignment); } else { runtime_start = pref_address; } h](h)}(hXfThis field indicates the amount of linear contiguous memory starting at the kernel runtime start address that the kernel needs before it is capable of examining its memory map. This is not the same thing as the total amount of memory the kernel needs to boot, but it can be used by a relocating boot loader to help select a safe load address for the kernel.h]hXfThis field indicates the amount of linear contiguous memory starting at the kernel runtime start address that the kernel needs before it is capable of examining its memory map. This is not the same thing as the total amount of memory the kernel needs to boot, but it can be used by a relocating boot loader to help select a safe load address for the kernel.}(hjJhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMzhjJubh)}(hKThe kernel runtime start address is determined by the following algorithm::h]hJThe kernel runtime start address is determined by the following algorithm:}(hjJhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjJubj)}(hif (relocatable_kernel) { if (load_address < pref_address) load_address = pref_address; runtime_start = align_up(load_address, kernel_alignment); } else { runtime_start = pref_address; }h]hif (relocatable_kernel) { if (load_address < pref_address) load_address = pref_address; runtime_start = align_up(load_address, kernel_alignment); } else { runtime_start = pref_address; }}hjJsbah}(h]h ]h"]h$]h&]hhuh1jhhhMhjJubeh}(h]h ]h"]h$]h&]uh1jhhhMzhj]hhubh)}(hZHence the necessary memory window location and size can be estimated by a boot loader as::h]hYHence the necessary memory window location and size can be estimated by a boot loader as:}(hjJhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj]hhubj)}(hDmemory_window_start = runtime_start; memory_window_size = init_size;h]hDmemory_window_start = runtime_start; memory_window_size = init_size;}hjKsbah}(h]h ]h"]h$]h&]hhuh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjKubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhjKubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj7KhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj4Kubah}(h]h ]h"]h$]h&]uh1j%hj1Kubj&)}(hhh]h)}(hhandover_offseth]hhandover_offset}(hjNKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjKKubah}(h]h ]h"]h$]h&]uh1j%hj1Kubeh}(h]h ]h"]h$]h&]uh1j hj.Kubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjnKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjkKubah}(h]h ]h"]h$]h&]uh1j%hjhKubj&)}(hhh]h)}(hreadh]hread}(hjKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjKubah}(h]h ]h"]h$]h&]uh1j%hjhKubeh}(h]h ]h"]h$]h&]uh1j hj.Kubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjKubah}(h]h ]h"]h$]h&]uh1j%hjKubj&)}(hhh]h)}(h0x264/4h]h0x264/4}(hjKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjKubah}(h]h ]h"]h$]h&]uh1j%hjKubeh}(h]h ]h"]h$]h&]uh1j hj.Kubeh}(h]h ]h"]h$]h&]uh1jhjKubeh}(h]h ]h"]h$]h&]colsKuh1jhjKubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hThis field is the offset from the beginning of the kernel image to the EFI handover protocol entry point. Boot loaders using the EFI handover protocol to boot the kernel should jump to this offset. See EFI HANDOVER PROTOCOL below for more details. h](h)}(hThis field is the offset from the beginning of the kernel image to the EFI handover protocol entry point. Boot loaders using the EFI handover protocol to boot the kernel should jump to this offset.h]hThis field is the offset from the beginning of the kernel image to the EFI handover protocol entry point. Boot loaders using the EFI handover protocol to boot the kernel should jump to this offset.}(hjKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjKubh)}(h1See EFI HANDOVER PROTOCOL below for more details.h]h1See EFI HANDOVER PROTOCOL below for more details.}(hjKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjKubeh}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjLubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhjLubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj2LhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj/Lubah}(h]h ]h"]h$]h&]uh1j%hj,Lubj&)}(hhh]h)}(hkernel_info_offseth]hkernel_info_offset}(hjILhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjFLubah}(h]h ]h"]h$]h&]uh1j%hj,Lubeh}(h]h ]h"]h$]h&]uh1j hj)Lubj!)}(hhh](j&)}(hhh]h)}(hType:h]hType:}(hjiLhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjfLubah}(h]h ]h"]h$]h&]uh1j%hjcLubj&)}(hhh]h)}(hreadh]hread}(hjLhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj}Lubah}(h]h ]h"]h$]h&]uh1j%hjcLubeh}(h]h ]h"]h$]h&]uh1j hj)Lubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjLhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjLubah}(h]h ]h"]h$]h&]uh1j%hjLubj&)}(hhh]h)}(h0x268/4h]h0x268/4}(hjLhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjLubah}(h]h ]h"]h$]h&]uh1j%hjLubeh}(h]h ]h"]h$]h&]uh1j hj)Lubj!)}(hhh](j&)}(hhh]h)}(h Protocol:h]h Protocol:}(hjLhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjLubah}(h]h ]h"]h$]h&]uh1j%hjLubj&)}(hhh]h)}(h2.15+h]h2.15+}(hjLhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjLubah}(h]h ]h"]h$]h&]uh1j%hjLubeh}(h]h ]h"]h$]h&]uh1j hj)Lubeh}(h]h ]h"]h$]h&]uh1jhjLubeh}(h]h ]h"]h$]h&]colsKuh1jhjLubah}(h]h ]h"]h$]h&]uh1hhj]hhhhhNubj)}(hThis field is the offset from the beginning of the kernel image to the kernel_info. The kernel_info structure is embedded in the Linux image in the uncompressed protected mode region. h]h)}(hThis field is the offset from the beginning of the kernel image to the kernel_info. The kernel_info structure is embedded in the Linux image in the uncompressed protected mode region.h]hThis field is the offset from the beginning of the kernel image to the kernel_info. The kernel_info structure is embedded in the Linux image in the uncompressed protected mode region.}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjMubah}(h]h ]h"]h$]h&]uh1jhhhMhj]hhubeh}(h]details-of-header-fieldsah ]h"]details of header fieldsah$]h&]uh1hhhhhhhhMubh)}(hhh](h)}(hThe kernel_infoh]hThe kernel_info}(hj>MhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj;MhhhhhMubh)}(hRThe relationships between the headers are analogous to the various data sections::h]hQThe relationships between the headers are analogous to the various data sections:}(hjLMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;Mhhubj)}(h2setup_header = .data boot_params/setup_data = .bssh]h2setup_header = .data boot_params/setup_data = .bss}hjZMsbah}(h]h ]h"]h$]h&]hhuh1jhhhMhj;Mhhubh)}(h3What is missing from the above list? That's right::h]h4What is missing from the above list? That’s right:}(hjhMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;Mhhubj)}(hkernel_info = .rodatah]hkernel_info = .rodata}hjvMsbah}(h]h ]h"]h$]h&]hhuh1jhhhMhj;Mhhubh)}(hXWe have been (ab)using .data for things that could go into .rodata or .bss for a long time, for lack of alternatives and -- especially early on -- inertia. Also, the BIOS stub is responsible for creating boot_params, so it isn't available to a BIOS-based loader (setup_data is, though).h]hX We have been (ab)using .data for things that could go into .rodata or .bss for a long time, for lack of alternatives and -- especially early on -- inertia. Also, the BIOS stub is responsible for creating boot_params, so it isn’t available to a BIOS-based loader (setup_data is, though).}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;Mhhubh)}(hXsetup_header is permanently limited to 144 bytes due to the reach of the 2-byte jump field, which doubles as a length field for the structure, combined with the size of the "hole" in struct boot_params that a protected-mode loader or the BIOS stub has to copy it into. It is currently 119 bytes long, which leaves us with 25 very precious bytes. This isn't something that can be fixed without revising the boot protocol entirely, breaking backwards compatibility.h]hXsetup_header is permanently limited to 144 bytes due to the reach of the 2-byte jump field, which doubles as a length field for the structure, combined with the size of the “hole” in struct boot_params that a protected-mode loader or the BIOS stub has to copy it into. It is currently 119 bytes long, which leaves us with 25 very precious bytes. This isn’t something that can be fixed without revising the boot protocol entirely, breaking backwards compatibility.}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;Mhhubh)}(hboot_params proper is limited to 4096 bytes, but can be arbitrarily extended by adding setup_data entries. It cannot be used to communicate properties of the kernel image, because it is .bss and has no image-provided content.h]hboot_params proper is limited to 4096 bytes, but can be arbitrarily extended by adding setup_data entries. It cannot be used to communicate properties of the kernel image, because it is .bss and has no image-provided content.}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;Mhhubh)}(hXTkernel_info solves this by providing an extensible place for information about the kernel image. It is readonly, because the kernel cannot rely on a bootloader copying its contents anywhere, but that is OK; if it becomes necessary it can still contain data items that an enabled bootloader would be expected to copy into a setup_data chunk.h]hXTkernel_info solves this by providing an extensible place for information about the kernel image. It is readonly, because the kernel cannot rely on a bootloader copying its contents anywhere, but that is OK; if it becomes necessary it can still contain data items that an enabled bootloader would be expected to copy into a setup_data chunk.}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;Mhhubh)}(hXAll kernel_info data should be part of this structure. Fixed size data have to be put before kernel_info_var_len_data label. Variable size data have to be put after kernel_info_var_len_data label. Each chunk of variable size data has to be prefixed with header/magic and its size, e.g.::h]hXAll kernel_info data should be part of this structure. Fixed size data have to be put before kernel_info_var_len_data label. Variable size data have to be put after kernel_info_var_len_data label. Each chunk of variable size data has to be prefixed with header/magic and its size, e.g.:}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;Mhhubj)}(hX kernel_info: .ascii "LToP" /* Header, Linux top (structure). */ .long kernel_info_var_len_data - kernel_info .long kernel_info_end - kernel_info .long 0x01234567 /* Some fixed size data for the bootloaders. */ kernel_info_var_len_data: example_struct: /* Some variable size data for the bootloaders. */ .ascii "0123" /* Header/Magic. */ .long example_struct_end - example_struct .ascii "Struct" .long 0x89012345 example_struct_end: example_strings: /* Some variable size data for the bootloaders. */ .ascii "ABCD" /* Header/Magic. */ .long example_strings_end - example_strings .asciz "String_0" .asciz "String_1" example_strings_end: kernel_info_end:h]hX kernel_info: .ascii "LToP" /* Header, Linux top (structure). */ .long kernel_info_var_len_data - kernel_info .long kernel_info_end - kernel_info .long 0x01234567 /* Some fixed size data for the bootloaders. */ kernel_info_var_len_data: example_struct: /* Some variable size data for the bootloaders. */ .ascii "0123" /* Header/Magic. */ .long example_struct_end - example_struct .ascii "Struct" .long 0x89012345 example_struct_end: example_strings: /* Some variable size data for the bootloaders. */ .ascii "ABCD" /* Header/Magic. */ .long example_strings_end - example_strings .asciz "String_0" .asciz "String_1" example_strings_end: kernel_info_end:}hjMsbah}(h]h ]h"]h$]h&]hhuh1jhhhMhj;Mhhubh)}(h0This way the kernel_info is self-contained blob.h]h0This way the kernel_info is self-contained blob.}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;Mhhubj)}(hEach variable size data header/magic can be any 4-character string, without \0 at the end of the string, which does not collide with existing variable length data headers/magics.h]h)}(hEach variable size data header/magic can be any 4-character string, without \0 at the end of the string, which does not collide with existing variable length data headers/magics.h]hEach variable size data header/magic can be any 4-character string, without 0 at the end of the string, which does not collide with existing variable length data headers/magics.}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjMubah}(h]h ]h"]h$]h&]uh1jhj;MhhhhhNubeh}(h]the-kernel-infoah ]h"]the kernel_infoah$]h&]uh1hhhhhhhhMubh)}(hhh](h)}(h!Details of the kernel_info Fieldsh]h!Details of the kernel_info Fields}(hj NhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjNhhhhhMubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjNubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhjNubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hj:NhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj7Nubah}(h]h ]h"]h$]h&]uh1j%hj4Nubj&)}(hhh]h)}(hheaderh]hheader}(hjQNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjNNubah}(h]h ]h"]h$]h&]uh1j%hj4Nubeh}(h]h ]h"]h$]h&]uh1j hj1Nubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjqNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjnNubah}(h]h ]h"]h$]h&]uh1j%hjkNubj&)}(hhh]h)}(h0x0000/4h]h0x0000/4}(hjNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjNubah}(h]h ]h"]h$]h&]uh1j%hjkNubeh}(h]h ]h"]h$]h&]uh1j hj1Nubeh}(h]h ]h"]h$]h&]uh1jhjNubeh}(h]h ]h"]h$]h&]colsKuh1jhjNubah}(h]h ]h"]h$]h&]uh1hhjNhhhhhNubj)}(h/Contains the magic number "LToP" (0x506f544c). h]h)}(h.Contains the magic number "LToP" (0x506f544c).h]h2Contains the magic number “LToP” (0x506f544c).}(hjNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjNubah}(h]h ]h"]h$]h&]uh1jhhhMhjNhhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjNubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jhjNubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjNubah}(h]h ]h"]h$]h&]uh1j%hjNubj&)}(hhh]h)}(hsizeh]hsize}(hjOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjOubah}(h]h ]h"]h$]h&]uh1j%hjNubeh}(h]h ]h"]h$]h&]uh1j hjNubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hj'OhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj$Oubah}(h]h ]h"]h$]h&]uh1j%hj!Oubj&)}(hhh]h)}(h0x0004/4h]h0x0004/4}(hj>OhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;Oubah}(h]h ]h"]h$]h&]uh1j%hj!Oubeh}(h]h ]h"]h$]h&]uh1j hjNubeh}(h]h ]h"]h$]h&]uh1jhjNubeh}(h]h ]h"]h$]h&]colsKuh1jhjNubah}(h]h ]h"]h$]h&]uh1hhjNhhhhhNubj)}(hX(This field contains the size of the kernel_info including kernel_info.header. It does not count kernel_info.kernel_info_var_len_data size. This field should be used by the bootloaders to detect supported fixed size fields in the kernel_info and beginning of kernel_info.kernel_info_var_len_data. h]h)}(hX'This field contains the size of the kernel_info including kernel_info.header. It does not count kernel_info.kernel_info_var_len_data size. This field should be used by the bootloaders to detect supported fixed size fields in the kernel_info and beginning of kernel_info.kernel_info_var_len_data.h]hX'This field contains the size of the kernel_info including kernel_info.header. It does not count kernel_info.kernel_info_var_len_data size. This field should be used by the bootloaders to detect supported fixed size fields in the kernel_info and beginning of kernel_info.kernel_info_var_len_data.}(hjoOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjkOubah}(h]h ]h"]h$]h&]uh1jhhhMhjNhhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjOubj)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhjOubj)}(hhh](j!)}(hhh](j&)}(hhh]h)}(h Field name:h]h Field name:}(hjOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjOubah}(h]h ]h"]h$]h&]uh1j%hjOubj&)}(hhh]h)}(h size_totalh]h size_total}(hjOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjOubah}(h]h ]h"]h$]h&]uh1j%hjOubeh}(h]h ]h"]h$]h&]uh1j hjOubj!)}(hhh](j&)}(hhh]h)}(h Offset/size:h]h Offset/size:}(hjOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjOubah}(h]h ]h"]h$]h&]uh1j%hjOubj&)}(hhh]h)}(h0x0008/4h]h0x0008/4}(hjOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjOubah}(h]h ]h"]h$]h&]uh1j%hjOubeh}(h]h ]h"]h$]h&]uh1j hjOubeh}(h]h ]h"]h$]h&]uh1jhjOubeh}(h]h ]h"]h$]h&]colsKuh1jhjOubah}(h]h ]h"]h$]h&]uh1hhjNhhhhhNubj)}(hwThis field contains the size of the kernel_info including kernel_info.header and kernel_info.kernel_info_var_len_data. h]h)}(hvThis field contains the size of the kernel_info including kernel_info.header and kernel_info.kernel_info_var_len_data.h]hvThis field contains the size of the kernel_info including kernel_info.header and kernel_info.kernel_info_var_len_data.}(hj%PhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj!Pubah}(h]h ]h"]h$]h&]uh1jhhhMhjNhhubh)}(hhh]j)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jhj= 0x0200) { type_of_loader = ; if (loading_initrd) { ramdisk_image = ; ramdisk_size = ; } if (protocol >= 0x0202 && loadflags & 0x01) heap_end = 0xe000; else heap_end = 0x9800; if (protocol >= 0x0201) { heap_end_ptr = heap_end - 0x200; loadflags |= 0x80; /* CAN_USE_HEAP */ } if (protocol >= 0x0202) { cmd_line_ptr = base_ptr + heap_end; strcpy(cmd_line_ptr, cmdline); } else { cmd_line_magic = 0xA33F; cmd_line_offset = heap_end; setup_move_size = heap_end + strlen(cmdline) + 1; strcpy(base_ptr + cmd_line_offset, cmdline); } } else { /* Very old kernel */ heap_end = 0x9800; cmd_line_magic = 0xA33F; cmd_line_offset = heap_end; /* A very old kernel MUST have its real-mode code loaded at 0x90000 */ if (base_ptr != 0x90000) { /* Copy the real-mode kernel */ memcpy(0x90000, base_ptr, (setup_sects + 1) * 512); base_ptr = 0x90000; /* Relocated */ } strcpy(0x90000 + cmd_line_offset, cmdline); /* It is recommended to clear memory up to the 32K mark */ memset(0x90000 + (setup_sects + 1) * 512, 0, (64 - (setup_sects + 1)) * 512); }h]hX#unsigned long base_ptr; /* base address for real-mode segment */ if (setup_sects == 0) setup_sects = 4; if (protocol >= 0x0200) { type_of_loader = ; if (loading_initrd) { ramdisk_image = ; ramdisk_size = ; } if (protocol >= 0x0202 && loadflags & 0x01) heap_end = 0xe000; else heap_end = 0x9800; if (protocol >= 0x0201) { heap_end_ptr = heap_end - 0x200; loadflags |= 0x80; /* CAN_USE_HEAP */ } if (protocol >= 0x0202) { cmd_line_ptr = base_ptr + heap_end; strcpy(cmd_line_ptr, cmdline); } else { cmd_line_magic = 0xA33F; cmd_line_offset = heap_end; setup_move_size = heap_end + strlen(cmdline) + 1; strcpy(base_ptr + cmd_line_offset, cmdline); } } else { /* Very old kernel */ heap_end = 0x9800; cmd_line_magic = 0xA33F; cmd_line_offset = heap_end; /* A very old kernel MUST have its real-mode code loaded at 0x90000 */ if (base_ptr != 0x90000) { /* Copy the real-mode kernel */ memcpy(0x90000, base_ptr, (setup_sects + 1) * 512); base_ptr = 0x90000; /* Relocated */ } strcpy(0x90000 + cmd_line_offset, cmdline); /* It is recommended to clear memory up to the 32K mark */ memset(0x90000 + (setup_sects + 1) * 512, 0, (64 - (setup_sects + 1)) * 512); }}hjTsbah}(h]h ]h"]h$]h&]hhuh1jhhhMlhjRhhubeh}(h]sample-boot-configurationah ]h"]sample boot configurationah$]h&]uh1hhhhhhhhMUubh)}(hhh](h)}(hLoading The Rest of The Kernelh]hLoading The Rest of The Kernel}(hjThhhNhNubah}(h]h ]h"]h$]h&]uh1hhjThhhhhMubh)}(hThe 32-bit (non-real-mode) kernel starts at offset (setup_sects + 1) * 512 in the kernel file (again, if setup_sects == 0 the real value is 4.) It should be loaded at address 0x10000 for Image/zImage kernels and 0x100000 for bzImage kernels.h]hThe 32-bit (non-real-mode) kernel starts at offset (setup_sects + 1) * 512 in the kernel file (again, if setup_sects == 0 the real value is 4.) It should be loaded at address 0x10000 for Image/zImage kernels and 0x100000 for bzImage kernels.}(hjThhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjThhubh)}(hsThe kernel is a bzImage kernel if the protocol >= 2.00 and the 0x01 bit (LOAD_HIGH) in the loadflags field is set::h]hrThe kernel is a bzImage kernel if the protocol >= 2.00 and the 0x01 bit (LOAD_HIGH) in the loadflags field is set:}(hjThhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjThhubj)}(hhis_bzImage = (protocol >= 0x0200) && (loadflags & 0x01); load_address = is_bzImage ? 0x100000 : 0x10000;h]hhis_bzImage = (protocol >= 0x0200) && (loadflags & 0x01); load_address = is_bzImage ? 0x100000 : 0x10000;}hjTsbah}(h]h ]h"]h$]h&]hhuh1jhhhMhjThhubj)}(hImage/zImage kernels can be up to 512K in size, and thus use the entire 0x10000-0x90000 range of memory. This means it is pretty much a requirement for these kernels to load the real-mode part at 0x90000. bzImage kernels allow much more flexibility.h]h)}(hImage/zImage kernels can be up to 512K in size, and thus use the entire 0x10000-0x90000 range of memory. This means it is pretty much a requirement for these kernels to load the real-mode part at 0x90000. bzImage kernels allow much more flexibility.h]hImage/zImage kernels can be up to 512K in size, and thus use the entire 0x10000-0x90000 range of memory. This means it is pretty much a requirement for these kernels to load the real-mode part at 0x90000. bzImage kernels allow much more flexibility.}(hjThhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjTubah}(h]h ]h"]h$]h&]uh1jhjThhhhhNubeh}(h]loading-the-rest-of-the-kernelah ]h"]loading the rest of the kernelah$]h&]uh1hhhhhhhhMubh)}(hhh](h)}(hSpecial Command Line Optionsh]hSpecial Command Line Options}(hjUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjUhhhhhMubh)}(hXIf the command line provided by the boot loader is entered by the user, the user may expect the following command line options to work. They should normally not be deleted from the kernel command line even though not all of them are actually meaningful to the kernel. Boot loader authors who need additional command line options for the boot loader itself should get them registered in Documentation/admin-guide/kernel-parameters.rst to make sure they will not conflict with actual kernel options now or in the future.h]hXIf the command line provided by the boot loader is entered by the user, the user may expect the following command line options to work. They should normally not be deleted from the kernel command line even though not all of them are actually meaningful to the kernel. Boot loader authors who need additional command line options for the boot loader itself should get them registered in Documentation/admin-guide/kernel-parameters.rst to make sure they will not conflict with actual kernel options now or in the future.}(hj#UhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjUhhubj)}(hXvga= here is either an integer (in C notation, either decimal, octal, or hexadecimal) or one of the strings "normal" (meaning 0xFFFF), "ext" (meaning 0xFFFE) or "ask" (meaning 0xFFFD). This value should be entered into the vid_mode field, as it is used by the kernel before the command line is parsed. mem= is an integer in C notation optionally followed by (case insensitive) K, M, G, T, P or E (meaning << 10, << 20, << 30, << 40, << 50 or << 60). This specifies the end of memory to the kernel. This affects the possible placement of an initrd, since an initrd should be placed near end of memory. Note that this is an option to *both* the kernel and the bootloader! initrd= An initrd should be loaded. The meaning of is obviously bootloader-dependent, and some boot loaders (e.g. LILO) do not have such a command. h]hdefinition_list)}(hhh](hdefinition_list_item)}(hX<vga= here is either an integer (in C notation, either decimal, octal, or hexadecimal) or one of the strings "normal" (meaning 0xFFFF), "ext" (meaning 0xFFFE) or "ask" (meaning 0xFFFD). This value should be entered into the vid_mode field, as it is used by the kernel before the command line is parsed. h](hterm)}(h vga=h]h vga=}(hjBUhhhNhNubah}(h]h ]h"]h$]h&]uh1j@UhhhMhj here is either an integer (in C notation, either decimal, octal, or hexadecimal) or one of the strings "normal" (meaning 0xFFFF), "ext" (meaning 0xFFFE) or "ask" (meaning 0xFFFD). This value should be entered into the vid_mode field, as it is used by the kernel before the command line is parsed.h]hX< here is either an integer (in C notation, either decimal, octal, or hexadecimal) or one of the strings “normal” (meaning 0xFFFF), “ext” (meaning 0xFFFE) or “ask” (meaning 0xFFFD). This value should be entered into the vid_mode field, as it is used by the kernel before the command line is parsed.}(hjUUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjRUubah}(h]h ]h"]h$]h&]uh1jPUhj is an integer in C notation optionally followed by (case insensitive) K, M, G, T, P or E (meaning << 10, << 20, << 30, << 40, << 50 or << 60). This specifies the end of memory to the kernel. This affects the possible placement of an initrd, since an initrd should be placed near end of memory. Note that this is an option to *both* the kernel and the bootloader! h](jAU)}(h mem=h]h mem=}(hjsUhhhNhNubah}(h]h ]h"]h$]h&]uh1j@UhhhMhjoUubjQU)}(hhh]h)}(hXs is an integer in C notation optionally followed by (case insensitive) K, M, G, T, P or E (meaning << 10, << 20, << 30, << 40, << 50 or << 60). This specifies the end of memory to the kernel. This affects the possible placement of an initrd, since an initrd should be placed near end of memory. Note that this is an option to *both* the kernel and the bootloader!h](hXN is an integer in C notation optionally followed by (case insensitive) K, M, G, T, P or E (meaning << 10, << 20, << 30, << 40, << 50 or << 60). This specifies the end of memory to the kernel. This affects the possible placement of an initrd, since an initrd should be placed near end of memory. Note that this is an option to }(hjUhhhNhNubj;Q)}(h*both*h]hboth}(hjUhhhNhNubah}(h]h ]h"]h$]h&]uh1j:QhjUubh the kernel and the bootloader!}(hjUhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMhjUubah}(h]h ]h"]h$]h&]uh1jPUhjoUubeh}(h]h ]h"]h$]h&]uh1j:UhhhMhj7Uubj;U)}(hinitrd= An initrd should be loaded. The meaning of is obviously bootloader-dependent, and some boot loaders (e.g. LILO) do not have such a command. h](jAU)}(h initrd=h]h initrd=}(hjUhhhNhNubah}(h]h ]h"]h$]h&]uh1j@UhhhMhjUubjQU)}(hhh]h)}(hAn initrd should be loaded. The meaning of is obviously bootloader-dependent, and some boot loaders (e.g. LILO) do not have such a command.h]hAn initrd should be loaded. The meaning of is obviously bootloader-dependent, and some boot loaders (e.g. LILO) do not have such a command.}(hjUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjUubah}(h]h ]h"]h$]h&]uh1jPUhjUubeh}(h]h ]h"]h$]h&]uh1j:UhhhMhj7Uubeh}(h]h ]h"]h$]h&]uh1j5Uhj1Uubah}(h]h ]h"]h$]h&]uh1jhhhMhjUhhubh)}(h\In addition, some boot loaders add the following options to the user-specified command line:h]h\In addition, some boot loaders add the following options to the user-specified command line:}(hjUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjUhhubj)}(hBOOT_IMAGE= The boot image which was loaded. Again, the meaning of is obviously bootloader-dependent. auto The kernel was booted without explicit user intervention. h]j6U)}(hhh](j;U)}(htBOOT_IMAGE= The boot image which was loaded. Again, the meaning of is obviously bootloader-dependent. h](jAU)}(hBOOT_IMAGE=h]hBOOT_IMAGE=}(hjVhhhNhNubah}(h]h ]h"]h$]h&]uh1j@UhhhMhjVubjQU)}(hhh]h)}(haThe boot image which was loaded. Again, the meaning of is obviously bootloader-dependent.h]haThe boot image which was loaded. Again, the meaning of is obviously bootloader-dependent.}(hjVhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjVubah}(h]h ]h"]h$]h&]uh1jPUhjVubeh}(h]h ]h"]h$]h&]uh1j:UhhhMhjUubj;U)}(h?auto The kernel was booted without explicit user intervention. h](jAU)}(hautoh]hauto}(hj3VhhhNhNubah}(h]h ]h"]h$]h&]uh1j@UhhhMhj/VubjQU)}(hhh]h)}(h9The kernel was booted without explicit user intervention.h]h9The kernel was booted without explicit user intervention.}(hjDVhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjAVubah}(h]h ]h"]h$]h&]uh1jPUhj/Vubeh}(h]h ]h"]h$]h&]uh1j:UhhhMhjUubeh}(h]h ]h"]h$]h&]uh1j5UhjUubah}(h]h ]h"]h$]h&]uh1jhhhMhjUhhubh)}(hIf these options are added by the boot loader, it is highly recommended that they are located *first*, before the user-specified or configuration-specified command line. Otherwise, "init=/bin/sh" gets confused by the "auto" option.h](h^If these options are added by the boot loader, it is highly recommended that they are located }(hjjVhhhNhNubj;Q)}(h*first*h]hfirst}(hjrVhhhNhNubah}(h]h ]h"]h$]h&]uh1j:QhjjVubh, before the user-specified or configuration-specified command line. Otherwise, “init=/bin/sh” gets confused by the “auto” option.}(hjjVhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMhjUhhubeh}(h]special-command-line-optionsah ]h"]special command line optionsah$]h&]uh1hhhhhhhhMubh)}(hhh](h)}(hRunning the Kernelh]hRunning the Kernel}(hjVhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjVhhhhhMubh)}(hThe kernel is started by jumping to the kernel entry point, which is located at *segment* offset 0x20 from the start of the real mode kernel. This means that if you loaded your real-mode kernel code at 0x90000, the kernel entry point is 9020:0000.h](hPThe kernel is started by jumping to the kernel entry point, which is located at }(hjVhhhNhNubj;Q)}(h *segment*h]hsegment}(hjVhhhNhNubah}(h]h ]h"]h$]h&]uh1j:QhjVubh offset 0x20 from the start of the real mode kernel. This means that if you loaded your real-mode kernel code at 0x90000, the kernel entry point is 9020:0000.}(hjVhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMhjVhhubh)}(hXZAt entry, ds = es = ss should point to the start of the real-mode kernel code (0x9000 if the code is loaded at 0x90000), sp should be set up properly, normally pointing to the top of the heap, and interrupts should be disabled. Furthermore, to guard against bugs in the kernel, it is recommended that the boot loader sets fs = gs = ds = es = ss.h]hXZAt entry, ds = es = ss should point to the start of the real-mode kernel code (0x9000 if the code is loaded at 0x90000), sp should be set up properly, normally pointing to the top of the heap, and interrupts should be disabled. Furthermore, to guard against bugs in the kernel, it is recommended that the boot loader sets fs = gs = ds = es = ss.}(hjVhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjVhhubh)}(h(In our example from above, we would do::h]h'In our example from above, we would do:}(hjVhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjVhhubj)}(hXt/* * Note: in the case of the "old" kernel protocol, base_ptr must * be == 0x90000 at this point; see the previous sample code. */ seg = base_ptr >> 4; cli(); /* Enter with interrupts disabled! */ /* Set up the real-mode kernel stack */ _SS = seg; _SP = heap_end; _DS = _ES = _FS = _GS = seg; jmp_far(seg + 0x20, 0); /* Run the kernel */h]hXt/* * Note: in the case of the "old" kernel protocol, base_ptr must * be == 0x90000 at this point; see the previous sample code. */ seg = base_ptr >> 4; cli(); /* Enter with interrupts disabled! */ /* Set up the real-mode kernel stack */ _SS = seg; _SP = heap_end; _DS = _ES = _FS = _GS = seg; jmp_far(seg + 0x20, 0); /* Run the kernel */}hjVsbah}(h]h ]h"]h$]h&]hhuh1jhhhMhjVhhubh)}(hX"If your boot sector accesses a floppy drive, it is recommended to switch off the floppy motor before running the kernel, since the kernel boot leaves interrupts off and thus the motor will not be switched off, especially if the loaded kernel has the floppy driver as a demand-loaded module!h]hX"If your boot sector accesses a floppy drive, it is recommended to switch off the floppy motor before running the kernel, since the kernel boot leaves interrupts off and thus the motor will not be switched off, especially if the loaded kernel has the floppy driver as a demand-loaded module!}(hjVhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjVhhubeh}(h]running-the-kernelah ]h"]running the kernelah$]h&]uh1hhhhhhhhMubh)}(hhh](h)}(hAdvanced Boot Loader Hooksh]hAdvanced Boot Loader Hooks}(hjWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjWhhhhhMubh)}(hXqIf the boot loader runs in a particularly hostile environment (such as LOADLIN, which runs under DOS) it may be impossible to follow the standard memory location requirements. Such a boot loader may use the following hooks that, if set, are invoked by the kernel at the appropriate time. The use of these hooks should probably be considered an absolutely last resort!h]hXqIf the boot loader runs in a particularly hostile environment (such as LOADLIN, which runs under DOS) it may be impossible to follow the standard memory location requirements. Such a boot loader may use the following hooks that, if set, are invoked by the kernel at the appropriate time. The use of these hooks should probably be considered an absolutely last resort!}(hjWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjWhhubh)}(h^IMPORTANT: All the hooks are required to preserve %esp, %ebp, %esi and %edi across invocation.h]h^IMPORTANT: All the hooks are required to preserve %esp, %ebp, %esi and %edi across invocation.}(hj"WhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjWhhubj)}(hXrealmode_swtch: A 16-bit real mode far subroutine invoked immediately before entering protected mode. The default routine disables NMI, so your routine should probably do so, too. code32_start: A 32-bit flat-mode routine *jumped* to immediately after the transition to protected mode, but before the kernel is uncompressed. No segments, except CS, are guaranteed to be set up (current kernels do, but older ones do not); you should set them up to BOOT_DS (0x18) yourself. After completing your hook, you should jump to the address that was in this field before your boot loader overwrote it (relocated, if appropriate.) h]j6U)}(hhh](j;U)}(hrealmode_swtch: A 16-bit real mode far subroutine invoked immediately before entering protected mode. The default routine disables NMI, so your routine should probably do so, too. h](jAU)}(hrealmode_swtch:h]hrealmode_swtch:}(hj;WhhhNhNubah}(h]h ]h"]h$]h&]uh1j@UhhhMhj7WubjQU)}(hhh]h)}(hA 16-bit real mode far subroutine invoked immediately before entering protected mode. The default routine disables NMI, so your routine should probably do so, too.Zh]hA 16-bit real mode far subroutine invoked immediately before entering protected mode. The default routine disables NMI, so your routine should probably do so, too.}(hjLWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjIWubah}(h]h ]h"]h$]h&]uh1jPUhj7Wubeh}(h]h ]h"]h$]h&]uh1j:UhhhMhj4Wubj;U)}(hXcode32_start: A 32-bit flat-mode routine *jumped* to immediately after the transition to protected mode, but before the kernel is uncompressed. No segments, except CS, are guaranteed to be set up (current kernels do, but older ones do not); you should set them up to BOOT_DS (0x18) yourself. After completing your hook, you should jump to the address that was in this field before your boot loader overwrote it (relocated, if appropriate.) h](jAU)}(h code32_start:h]h code32_start:}(hjjWhhhNhNubah}(h]h ]h"]h$]h&]uh1j@UhhhM*hjfWubjQU)}(hhh](h)}(hXA 32-bit flat-mode routine *jumped* to immediately after the transition to protected mode, but before the kernel is uncompressed. No segments, except CS, are guaranteed to be set up (current kernels do, but older ones do not); you should set them up to BOOT_DS (0x18) yourself.h](hA 32-bit flat-mode routine }(hj{WhhhNhNubj;Q)}(h*jumped*h]hjumped}(hjWhhhNhNubah}(h]h ]h"]h$]h&]uh1j:Qhj{Wubh to immediately after the transition to protected mode, but before the kernel is uncompressed. No segments, except CS, are guaranteed to be set up (current kernels do, but older ones do not); you should set them up to BOOT_DS (0x18) yourself.}(hj{WhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhM!hjxWubh)}(hAfter completing your hook, you should jump to the address that was in this field before your boot loader overwrote it (relocated, if appropriate.)h]hAfter completing your hook, you should jump to the address that was in this field before your boot loader overwrote it (relocated, if appropriate.)}(hjWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM'hjxWubeh}(h]h ]h"]h$]h&]uh1jPUhjfWubeh}(h]h ]h"]h$]h&]uh1j:UhhhM*hj4Wubeh}(h]h ]h"]h$]h&]uh1j5Uhj0Wubah}(h]h ]h"]h$]h&]uh1jhhhMhjWhhubeh}(h]advanced-boot-loader-hooksah ]h"]advanced boot loader hooksah$]h&]uh1hhhhhhhhMubh)}(hhh](h)}(h32-bit Boot Protocolh]h32-bit Boot Protocol}(hjWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjWhhhhhM-ubh)}(hFor machine with some new BIOS other than legacy BIOS, such as EFI, LinuxBIOS, etc, and kexec, the 16-bit real mode setup code in kernel based on legacy BIOS can not be used, so a 32-bit boot protocol needs to be defined.h]hFor machine with some new BIOS other than legacy BIOS, such as EFI, LinuxBIOS, etc, and kexec, the 16-bit real mode setup code in kernel based on legacy BIOS can not be used, so a 32-bit boot protocol needs to be defined.}(hjWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM/hjWhhubh)}(hXIn 32-bit boot protocol, the first step in loading a Linux kernel should be to setup the boot parameters (struct boot_params, traditionally known as "zero page"). The memory for struct boot_params should be allocated and initialized to all zero. Then the setup header from offset 0x01f1 of kernel image on should be loaded into struct boot_params and examined. The end of setup header can be calculated as follow::h]hXIn 32-bit boot protocol, the first step in loading a Linux kernel should be to setup the boot parameters (struct boot_params, traditionally known as “zero page”). The memory for struct boot_params should be allocated and initialized to all zero. Then the setup header from offset 0x01f1 of kernel image on should be loaded into struct boot_params and examined. The end of setup header can be calculated as follow:}(hjWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM4hjWhhubj)}(h$0x0202 + byte value at offset 0x0201h]h$0x0202 + byte value at offset 0x0201}hjWsbah}(h]h ]h"]h$]h&]hhuh1jhhhM<hjWhhubh)}(hIn addition to read/modify/write the setup header of the struct boot_params as that of 16-bit boot protocol, the boot loader should also fill the additional fields of the struct boot_params as described in chapter Documentation/arch/x86/zero-page.rst.h]hIn addition to read/modify/write the setup header of the struct boot_params as that of 16-bit boot protocol, the boot loader should also fill the additional fields of the struct boot_params as described in chapter Documentation/arch/x86/zero-page.rst.}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM>hjWhhubh)}(hAfter setting up the struct boot_params, the boot loader can load the 32/64-bit kernel in the same way as that of 16-bit boot protocol.h]hAfter setting up the struct boot_params, the boot loader can load the 32/64-bit kernel in the same way as that of 16-bit boot protocol.}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMChjWhhubh)}(hIn 32-bit boot protocol, the kernel is started by jumping to the 32-bit kernel entry point, which is the start address of loaded 32/64-bit kernel.h]hIn 32-bit boot protocol, the kernel is started by jumping to the 32-bit kernel entry point, which is the start address of loaded 32/64-bit kernel.}(hj XhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMFhjWhhubh)}(hXAt entry, the CPU must be in 32-bit protected mode with paging disabled; a GDT must be loaded with the descriptors for selectors __BOOT_CS(0x10) and __BOOT_DS(0x18); both descriptors must be 4G flat segment; __BOOT_CS must have execute/read permission, and __BOOT_DS must have read/write permission; CS must be __BOOT_CS and DS, ES, SS must be __BOOT_DS; interrupt must be disabled; %esi must hold the base address of the struct boot_params; %ebp, %edi and %ebx must be zero.h]hXAt entry, the CPU must be in 32-bit protected mode with paging disabled; a GDT must be loaded with the descriptors for selectors __BOOT_CS(0x10) and __BOOT_DS(0x18); both descriptors must be 4G flat segment; __BOOT_CS must have execute/read permission, and __BOOT_DS must have read/write permission; CS must be __BOOT_CS and DS, ES, SS must be __BOOT_DS; interrupt must be disabled; %esi must hold the base address of the struct boot_params; %ebp, %edi and %ebx must be zero.}(hj.XhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMJhjWhhubeh}(h]bit-boot-protocolah ]h"]32-bit boot protocolah$]h&]uh1hhhhhhhhM-ubh)}(hhh](h)}(h64-bit Boot Protocolh]h64-bit Boot Protocol}(hjGXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDXhhhhhMSubh)}(hoFor machine with 64bit cpus and 64bit kernel, we could use 64bit bootloader and we need a 64-bit boot protocol.h]hoFor machine with 64bit cpus and 64bit kernel, we could use 64bit bootloader and we need a 64-bit boot protocol.}(hjUXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMUhjDXhhubh)}(hXIn 64-bit boot protocol, the first step in loading a Linux kernel should be to setup the boot parameters (struct boot_params, traditionally known as "zero page"). The memory for struct boot_params could be allocated anywhere (even above 4G) and initialized to all zero. Then, the setup header at offset 0x01f1 of kernel image on should be loaded into struct boot_params and examined. The end of setup header can be calculated as follows::h]hXIn 64-bit boot protocol, the first step in loading a Linux kernel should be to setup the boot parameters (struct boot_params, traditionally known as “zero page”). The memory for struct boot_params could be allocated anywhere (even above 4G) and initialized to all zero. Then, the setup header at offset 0x01f1 of kernel image on should be loaded into struct boot_params and examined. The end of setup header can be calculated as follows:}(hjcXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMXhjDXhhubj)}(h$0x0202 + byte value at offset 0x0201h]h$0x0202 + byte value at offset 0x0201}hjqXsbah}(h]h ]h"]h$]h&]hhuh1jhhhM`hjDXhhubh)}(hIn addition to read/modify/write the setup header of the struct boot_params as that of 16-bit boot protocol, the boot loader should also fill the additional fields of the struct boot_params as described in chapter Documentation/arch/x86/zero-page.rst.h]hIn addition to read/modify/write the setup header of the struct boot_params as that of 16-bit boot protocol, the boot loader should also fill the additional fields of the struct boot_params as described in chapter Documentation/arch/x86/zero-page.rst.}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMbhjDXhhubh)}(hAfter setting up the struct boot_params, the boot loader can load 64-bit kernel in the same way as that of 16-bit boot protocol, but kernel could be loaded above 4G.h]hAfter setting up the struct boot_params, the boot loader can load 64-bit kernel in the same way as that of 16-bit boot protocol, but kernel could be loaded above 4G.}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMghjDXhhubh)}(hIn 64-bit boot protocol, the kernel is started by jumping to the 64-bit kernel entry point, which is the start address of loaded 64-bit kernel plus 0x200.h]hIn 64-bit boot protocol, the kernel is started by jumping to the 64-bit kernel entry point, which is the start address of loaded 64-bit kernel plus 0x200.}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMkhjDXhhubh)}(hX1At entry, the CPU must be in 64-bit mode with paging enabled. The range with setup_header.init_size from start address of loaded kernel and zero page and command line buffer get ident mapping; a GDT must be loaded with the descriptors for selectors __BOOT_CS(0x10) and __BOOT_DS(0x18); both descriptors must be 4G flat segment; __BOOT_CS must have execute/read permission, and __BOOT_DS must have read/write permission; CS must be __BOOT_CS and DS, ES, SS must be __BOOT_DS; interrupt must be disabled; %rsi must hold the base address of the struct boot_params.h]hX1At entry, the CPU must be in 64-bit mode with paging enabled. The range with setup_header.init_size from start address of loaded kernel and zero page and command line buffer get ident mapping; a GDT must be loaded with the descriptors for selectors __BOOT_CS(0x10) and __BOOT_DS(0x18); both descriptors must be 4G flat segment; __BOOT_CS must have execute/read permission, and __BOOT_DS must have read/write permission; CS must be __BOOT_CS and DS, ES, SS must be __BOOT_DS; interrupt must be disabled; %rsi must hold the base address of the struct boot_params.}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMohjDXhhubeh}(h]id1ah ]h"]64-bit boot protocolah$]h&]uh1hhhhhhhhMSubh)}(hhh](h)}(h"EFI Handover Protocol (deprecated)h]h"EFI Handover Protocol (deprecated)}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjXhhhhhMzubh)}(hXThis protocol allows boot loaders to defer initialisation to the EFI boot stub. The boot loader is required to load the kernel/initrd(s) from the boot media and jump to the EFI handover protocol entry point which is hdr->handover_offset bytes from the beginning of startup_{32,64}.h]hXThis protocol allows boot loaders to defer initialisation to the EFI boot stub. The boot loader is required to load the kernel/initrd(s) from the boot media and jump to the EFI handover protocol entry point which is hdr->handover_offset bytes from the beginning of startup_{32,64}.}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM|hjXhhubh)}(hXTThe boot loader MUST respect the kernel's PE/COFF metadata when it comes to section alignment, the memory footprint of the executable image beyond the size of the file itself, and any other aspect of the PE/COFF header that may affect correct operation of the image as a PE/COFF binary in the execution context provided by the EFI firmware.h]hXVThe boot loader MUST respect the kernel’s PE/COFF metadata when it comes to section alignment, the memory footprint of the executable image beyond the size of the file itself, and any other aspect of the PE/COFF header that may affect correct operation of the image as a PE/COFF binary in the execution context provided by the EFI firmware.}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjXhhubh)}(hEThe function prototype for the handover entry point looks like this::h]hDThe function prototype for the handover entry point looks like this:}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjXhhubj)}(hUvoid efi_stub_entry(void *handle, efi_system_table_t *table, struct boot_params *bp);h]hUvoid efi_stub_entry(void *handle, efi_system_table_t *table, struct boot_params *bp);}hjXsbah}(h]h ]h"]h$]h&]hhuh1jhhhMhjXhhubh)}(hX'handle' is the EFI image handle passed to the boot loader by the EFI firmware, 'table' is the EFI system table - these are the first two arguments of the "handoff state" as described in section 2.3 of the UEFI specification. 'bp' is the boot loader-allocated boot params.h]hX ‘handle’ is the EFI image handle passed to the boot loader by the EFI firmware, ‘table’ is the EFI system table - these are the first two arguments of the “handoff state” as described in section 2.3 of the UEFI specification. ‘bp’ is the boot loader-allocated boot params.}(hjYhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjXhhubh)}(hXjXjXj}YjzYj^ZjwYj]ZjZZjHZjEZjUZjRZu nametypes}(jjZjrjZj8MjNjPjQjRjTjUjVjWjWjAXjXj}Yj^Zj]ZjHZjUZuh}(jgZhjojjWjuj5Mj]jNj;MjPjNjQjPjRjQjTjRj UjTjVjUjVjVjWjWj>XjWjXjDXjzYjXjwYjYjZZjYjEZj?ZjRZjLZu footnote_refs} citation_refs} autofootnotes]autofootnote_refs]symbol_footnotes]symbol_footnote_refs] footnotes] citations]autofootnote_startKsymbol_footnote_startK id_counter collectionsCounter}jZKsRparse_messages]transform_messages]hsystem_message)}(hhh]h)}(hhh]h9Hyperlink target "pe-coff-entry-point" is not referenced.}hjZsbah}(h]h ]h"]h$]h&]uh1hhjZubah}(h]h ]h"]h$]h&]levelKtypeINFOsourcehnjlineMuh1jZuba transformerN include_log] decorationNhhub.