€•N>      Œsphinx.addnodes”Œdocument”“”)”}”(Œ	rawsource”Œ ”Œchildren”]”(Œtranslations”ŒLanguagesNode”“”)”}”(hhh]”(h Œpending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ
attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ	refdomain”Œstd”Œreftype”Œdoc”Œ	reftarget”Œ:/translations/zh_CN/admin-guide/acpi/initrd_table_override”Œmodname”NŒ	classname”NŒrefexplicit”ˆuŒtagname”hhhubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ:/translations/zh_TW/admin-guide/acpi/initrd_table_override”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ:/translations/it_IT/admin-guide/acpi/initrd_table_override”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ:/translations/ja_JP/admin-guide/acpi/initrd_table_override”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ:/translations/ko_KR/admin-guide/acpi/initrd_table_override”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒSpanish”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ:/translations/sp_SP/admin-guide/acpi/initrd_table_override”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h
hhŒ	_document”hŒsource”NŒline”NubhŒcomment”“”)”}”(hŒ SPDX-License-Identifier: GPL-2.0”h]”hŒ SPDX-License-Identifier: GPL-2.0”…””}”hh£sbah}”(h]”h ]”h"]”h$]”h&]”Œ	xml:space”Œpreserve”uh1h¡hhhžhhŸŒT/var/lib/git/docbuild/linux/Documentation/admin-guide/acpi/initrd_table_override.rst”h KubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒ Upgrading ACPI tables via initrd”h]”hŒ Upgrading ACPI tables via initrd”…””}”(hh»hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hh¶hžhhŸh³h Kubhµ)”}”(hhh]”(hº)”}”(hŒWhat is this about”h]”hŒWhat is this about”…””}”(hhÌhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hhÉhžhhŸh³h KubhŒ	paragraph”“”)”}”(hX  If the ACPI_TABLE_UPGRADE compile option is true, it is possible to
upgrade the ACPI execution environment that is defined by the ACPI tables
via upgrading the ACPI tables provided by the BIOS with an instrumented,
modified, more recent version one, or installing brand new ACPI tables.”h]”hX  If the ACPI_TABLE_UPGRADE compile option is true, it is possible to
upgrade the ACPI execution environment that is defined by the ACPI tables
via upgrading the ACPI tables provided by the BIOS with an instrumented,
modified, more recent version one, or installing brand new ACPI tables.”…””}”(hhÜhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h K
hhÉhžhubhÛ)”}”(hŒWhen building initrd with kernel in a single image, option
ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD should also be true for this
feature to work.”h]”hŒWhen building initrd with kernel in a single image, option
ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD should also be true for this
feature to work.”…””}”(hhêhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h KhhÉhžhubhÛ)”}”(hŒžFor a full list of ACPI tables that can be upgraded/installed, take a look
at the char `*table_sigs[MAX_ACPI_SIGNATURE];` definition in
drivers/acpi/tables.c.”h]”(hŒWFor a full list of ACPI tables that can be upgraded/installed, take a look
at the char ”…””}”(hhøhžhhŸNh NubhŒtitle_reference”“”)”}”(hŒ"`*table_sigs[MAX_ACPI_SIGNATURE];`”h]”hŒ *table_sigs[MAX_ACPI_SIGNATURE];”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j   hhøubhŒ% definition in
drivers/acpi/tables.c.”…””}”(hhøhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h KhhÉhžhubhÛ)”}”(hŒbAll ACPI tables iasl (Intel's ACPI compiler and disassembler) knows should
be overridable, except:”h]”hŒdAll ACPI tables iasl (Intelâ€™s ACPI compiler and disassembler) knows should
be overridable, except:”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h KhhÉhžhubhŒblock_quote”“”)”}”(hŒk- ACPI_SIG_RSDP (has a signature of 6 bytes)
- ACPI_SIG_FACS (does not have an ordinary ACPI table header)
”h]”hŒbullet_list”“”)”}”(hhh]”(hŒ	list_item”“”)”}”(hŒ*ACPI_SIG_RSDP (has a signature of 6 bytes)”h]”hÛ)”}”(hj7  h]”hŒ*ACPI_SIG_RSDP (has a signature of 6 bytes)”…””}”(hj9  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h Khj5  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j3  hj0  ubj4  )”}”(hŒ<ACPI_SIG_FACS (does not have an ordinary ACPI table header)
”h]”hÛ)”}”(hŒ;ACPI_SIG_FACS (does not have an ordinary ACPI table header)”h]”hŒ;ACPI_SIG_FACS (does not have an ordinary ACPI table header)”…””}”(hjP  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h KhjL  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j3  hj0  ubeh}”(h]”h ]”h"]”h$]”h&]”Œbullet”Œ-”uh1j.  hŸh³h Khj*  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j(  hŸh³h KhhÉhžhubhÛ)”}”(hŒ#Both could get implemented as well.”h]”hŒ#Both could get implemented as well.”…””}”(hjr  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h KhhÉhžhubeh}”(h]”Œwhat-is-this-about”ah ]”h"]”Œwhat is this about”ah$]”h&]”uh1h´hh¶hžhhŸh³h Kubhµ)”}”(hhh]”(hº)”}”(hŒWhat is this for”h]”hŒWhat is this for”…””}”(hj‹  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hjˆ  hžhhŸh³h K!ubhÛ)”}”(hŒýComplain to your platform/BIOS vendor if you find a bug which is so severe
that a workaround is not accepted in the Linux kernel. And this facility
allows you to upgrade the buggy tables before your platform/BIOS vendor
releases an upgraded BIOS binary.”h]”hŒýComplain to your platform/BIOS vendor if you find a bug which is so severe
that a workaround is not accepted in the Linux kernel. And this facility
allows you to upgrade the buggy tables before your platform/BIOS vendor
releases an upgraded BIOS binary.”…””}”(hj™  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h K#hjˆ  hžhubhÛ)”}”(hŒThis facility can be used by platform/BIOS vendors to provide a Linux
compatible environment without modifying the underlying platform firmware.”h]”hŒThis facility can be used by platform/BIOS vendors to provide a Linux
compatible environment without modifying the underlying platform firmware.”…””}”(hj§  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h K(hjˆ  hžhubhÛ)”}”(hŒÈThis facility also provides a powerful feature to easily debug and test
ACPI BIOS table compatibility with the Linux kernel by modifying old
platform provided ACPI tables or inserting new ACPI tables.”h]”hŒÈThis facility also provides a powerful feature to easily debug and test
ACPI BIOS table compatibility with the Linux kernel by modifying old
platform provided ACPI tables or inserting new ACPI tables.”…””}”(hjµ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h K+hjˆ  hžhubhÛ)”}”(hŒoIt can and should be enabled in any kernel because there is no functional
change with not instrumented initrds.”h]”hŒoIt can and should be enabled in any kernel because there is no functional
change with not instrumented initrds.”…””}”(hjÃ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h K/hjˆ  hžhubeh}”(h]”Œwhat-is-this-for”ah ]”h"]”Œwhat is this for”ah$]”h&]”uh1h´hh¶hžhhŸh³h K!ubhµ)”}”(hhh]”(hº)”}”(hŒHow does it work”h]”hŒHow does it work”…””}”(hjÜ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hjÙ  hžhhŸh³h K4ubhŒliteral_block”“”)”}”(hX}  # Extract the machine's ACPI tables:
cd /tmp
acpidump >acpidump
acpixtract -a acpidump
# Disassemble, modify and recompile them:
iasl -d *.dat
# For example add this statement into a _PRT (PCI Routing Table) function
# of the DSDT:
Store("HELLO WORLD", debug)
# And increase the OEM Revision. For example, before modification:
DefinitionBlock ("DSDT.aml", "DSDT", 2, "INTEL ", "TEMPLATE", 0x00000000)
# After modification:
DefinitionBlock ("DSDT.aml", "DSDT", 2, "INTEL ", "TEMPLATE", 0x00000001)
iasl -sa dsdt.dsl
# Add the raw ACPI tables to an uncompressed cpio archive.
# They must be put into a /kernel/firmware/acpi directory inside the cpio
# archive. Note that if the table put here matches a platform table
# (similar Table Signature, and similar OEMID, and similar OEM Table ID)
# with a more recent OEM Revision, the platform table will be upgraded by
# this table. If the table put here doesn't match a platform table
# (dissimilar Table Signature, or dissimilar OEMID, or dissimilar OEM Table
# ID), this table will be appended.
mkdir -p kernel/firmware/acpi
cp dsdt.aml kernel/firmware/acpi
# A maximum of "NR_ACPI_INITRD_TABLES (64)" tables are currently allowed
# (see osl.c):
iasl -sa facp.dsl
iasl -sa ssdt1.dsl
cp facp.aml kernel/firmware/acpi
cp ssdt1.aml kernel/firmware/acpi
# The uncompressed cpio archive must be the first. Other, typically
# compressed cpio archives, must be concatenated on top of the uncompressed
# one. Following command creates the uncompressed cpio archive and
# concatenates the original initrd on top:
find kernel | cpio -H newc --create > /boot/instrumented_initrd
cat /boot/initrd >>/boot/instrumented_initrd
# reboot with increased acpi debug level, e.g. boot params:
acpi.debug_level=0x2 acpi.debug_layer=0xFFFFFFFF
# and check your syslog:
[    1.268089] ACPI: PCI Interrupt Routing Table [\_SB_.PCI0._PRT]
[    1.272091] [ACPI Debug]  String [0x0B] "HELLO WORLD"”h]”hX}  # Extract the machine's ACPI tables:
cd /tmp
acpidump >acpidump
acpixtract -a acpidump
# Disassemble, modify and recompile them:
iasl -d *.dat
# For example add this statement into a _PRT (PCI Routing Table) function
# of the DSDT:
Store("HELLO WORLD", debug)
# And increase the OEM Revision. For example, before modification:
DefinitionBlock ("DSDT.aml", "DSDT", 2, "INTEL ", "TEMPLATE", 0x00000000)
# After modification:
DefinitionBlock ("DSDT.aml", "DSDT", 2, "INTEL ", "TEMPLATE", 0x00000001)
iasl -sa dsdt.dsl
# Add the raw ACPI tables to an uncompressed cpio archive.
# They must be put into a /kernel/firmware/acpi directory inside the cpio
# archive. Note that if the table put here matches a platform table
# (similar Table Signature, and similar OEMID, and similar OEM Table ID)
# with a more recent OEM Revision, the platform table will be upgraded by
# this table. If the table put here doesn't match a platform table
# (dissimilar Table Signature, or dissimilar OEMID, or dissimilar OEM Table
# ID), this table will be appended.
mkdir -p kernel/firmware/acpi
cp dsdt.aml kernel/firmware/acpi
# A maximum of "NR_ACPI_INITRD_TABLES (64)" tables are currently allowed
# (see osl.c):
iasl -sa facp.dsl
iasl -sa ssdt1.dsl
cp facp.aml kernel/firmware/acpi
cp ssdt1.aml kernel/firmware/acpi
# The uncompressed cpio archive must be the first. Other, typically
# compressed cpio archives, must be concatenated on top of the uncompressed
# one. Following command creates the uncompressed cpio archive and
# concatenates the original initrd on top:
find kernel | cpio -H newc --create > /boot/instrumented_initrd
cat /boot/initrd >>/boot/instrumented_initrd
# reboot with increased acpi debug level, e.g. boot params:
acpi.debug_level=0x2 acpi.debug_layer=0xFFFFFFFF
# and check your syslog:
[    1.268089] ACPI: PCI Interrupt Routing Table [\_SB_.PCI0._PRT]
[    1.272091] [ACPI Debug]  String [0x0B] "HELLO WORLD"”…””}”hjì  sbah}”(h]”h ]”h"]”h$]”h&]”h±h²uh1jê  hŸh³h K7hjÙ  hžhubhÛ)”}”(hŒYiasl is able to disassemble and recompile quite a lot different,
also static ACPI tables.”h]”hŒYiasl is able to disassemble and recompile quite a lot different,
also static ACPI tables.”…””}”(hjú  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h KahjÙ  hžhubeh}”(h]”Œhow-does-it-work”ah ]”h"]”Œhow does it work”ah$]”h&]”uh1h´hh¶hžhhŸh³h K4ubhµ)”}”(hhh]”(hº)”}”(hŒ!Where to retrieve userspace tools”h]”hŒ!Where to retrieve userspace tools”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hj  hžhhŸh³h KfubhÛ)”}”(hŒKiasl and acpixtract are part of Intel's ACPICA project:
https://acpica.org/”h]”(hŒ:iasl and acpixtract are part of Intelâ€™s ACPICA project:
”…””}”(hj!  hžhhŸNh NubhŒ	reference”“”)”}”(hŒhttps://acpica.org/”h]”hŒhttps://acpica.org/”…””}”(hj+  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”j-  uh1j)  hj!  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h Khhj  hžhubhÛ)”}”(hŒTand should be packaged by distributions (for example in the acpica package
on SUSE).”h]”hŒTand should be packaged by distributions (for example in the acpica package
on SUSE).”…””}”(hj@  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h Kkhj  hžhubhÛ)”}”(hŒvacpidump can be found in Len Browns pmtools:
ftp://kernel.org/pub/linux/kernel/people/lenb/acpi/utils/pmtools/acpidump”h]”(hŒ-acpidump can be found in Len Browns pmtools:
”…””}”(hjN  hžhhŸNh Nubj*  )”}”(hŒIftp://kernel.org/pub/linux/kernel/people/lenb/acpi/utils/pmtools/acpidump”h]”hŒIftp://kernel.org/pub/linux/kernel/people/lenb/acpi/utils/pmtools/acpidump”…””}”(hjV  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”jX  uh1j)  hjN  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h Knhj  hžhubhÛ)”}”(hŒThis tool is also part of the acpica package on SUSE.
Alternatively, used ACPI tables can be retrieved via sysfs in latest kernels:
/sys/firmware/acpi/tables”h]”hŒThis tool is also part of the acpica package on SUSE.
Alternatively, used ACPI tables can be retrieved via sysfs in latest kernels:
/sys/firmware/acpi/tables”…””}”(hjk  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÚhŸh³h Kqhj  hžhubeh}”(h]”Œ!where-to-retrieve-userspace-tools”ah ]”h"]”Œ!where to retrieve userspace tools”ah$]”h&]”uh1h´hh¶hžhhŸh³h Kfubeh}”(h]”Œ upgrading-acpi-tables-via-initrd”ah ]”h"]”Œ upgrading acpi tables via initrd”ah$]”h&]”uh1h´hhhžhhŸh³h Kubeh}”(h]”h ]”h"]”h$]”h&]”Œsource”h³uh1hŒcurrent_source”NŒcurrent_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(h¹NŒ	generator”NŒ	datestamp”NŒsource_link”NŒ
source_url”NŒtoc_backlinks”Œentry”Œfootnote_backlinks”KŒsectnum_xform”KŒstrip_comments”NŒstrip_elements_with_classes”NŒstrip_classes”NŒreport_level”KŒ
halt_level”KŒexit_status_level”KŒdebug”NŒwarning_stream”NŒ	traceback”ˆŒinput_encoding”Œ	utf-8-sig”Œinput_encoding_error_handler”Œstrict”Œoutput_encoding”Œutf-8”Œoutput_encoding_error_handler”j¬  Œerror_encoding”Œutf-8”Œerror_encoding_error_handler”Œbackslashreplace”Œlanguage_code”Œen”Œrecord_dependencies”NŒconfig”NŒ	id_prefix”hŒauto_id_prefix”Œid”Œdump_settings”NŒdump_internals”NŒdump_transforms”NŒdump_pseudo_xml”NŒexpose_internals”NŒstrict_visitor”NŒ_disable_config”NŒ_source”h³Œ_destination”NŒ_config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒfile_insertion_enabled”ˆŒraw_enabled”KŒline_length_limit”M'Œpep_references”NŒpep_base_url”Œhttps://peps.python.org/”Œpep_file_url_template”Œpep-%04d”Œrfc_references”NŒrfc_base_url”Œ&https://datatracker.ietf.org/doc/html/”Œ	tab_width”KŒtrim_footnote_reference_space”‰Œsyntax_highlight”Œlong”Œsmart_quotes”ˆŒsmartquotes_locales”]”Œcharacter_level_inline_markup”‰Œdoctitle_xform”‰Œdocinfo_xform”KŒsectsubtitle_xform”‰Œimage_loading”Œlink”Œembed_stylesheet”‰Œcloak_email_addresses”ˆŒsection_self_link”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œrefids”}”Œnameids”}”(j†  jƒ  j…  j‚  jÖ  jÓ  j  j
  j~  j{  uŒ	nametypes”}”(j†  ‰j…  ‰jÖ  ‰j  ‰j~  ‰uh}”(jƒ  h¶j‚  hÉjÓ  jˆ  j
  jÙ  j{  j  uŒfootnote_refs”}”Œcitation_refs”}”Œautofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ	footnotes”]”Œ	citations”]”Œautofootnote_start”KŒsymbol_footnote_start”K Œ
id_counter”Œcollections”ŒCounter”“”}”…”R”Œparse_messages”]”Œtransform_messages”]”Œtransformer”NŒinclude_log”]”Œ
decoration”Nhžhub.