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| author | H. Peter Anvin <hpa@zytor.com> | 2007-05-22 15:46:32 -0700 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2007-05-22 15:46:32 -0700 |
| commit | fff762e1c19c4b684fa4150893196faa2d72743c (patch) | |
| tree | fbebf68294ec7ee2bd7327bd311fb17ab98d6c4e | |
| parent | 66c18ce768b581fd1ace404a070f6bc53ea1b9fe (diff) | |
| download | syslinux-3.50-pre11.tar.gz | |
Fix loading pre-2.00 protocol kernels.syslinux-3.50-pre11
Fix loading pre-2.00 protocol kernels. This is surprisingly important,
since at least memtest86+ mimics such an ancient kernel.
| -rw-r--r-- | runkernel.inc | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/runkernel.inc b/runkernel.inc index 04d3bb11..d11ecb73 100644 --- a/runkernel.inc +++ b/runkernel.inc @@ -208,7 +208,7 @@ cmdline_end: prepare_header: mov dword [RamdiskMax], HIGHMEM_MAX ; Default initrd limit cmp dword [es:su_header],HEADER_ID ; New setup code ID - jne old_kernel ; Old kernel, load low + jne old_kernel ; Old kernel, load low mov ax,[es:su_version] cmp ax,0200h ; Setup code version 2.0 jb old_kernel ; Old kernel, load low @@ -228,8 +228,6 @@ prepare_header: ; new_kernel: mov byte [es:su_loader],my_id ; Show some ID - movzx ax,byte [es:bs_setupsecs] ; Variable # of setup sectors - mov [SetupSecs],ax xor eax,eax mov [es:su_ramdisklen],eax ; No initrd loaded yet @@ -245,6 +243,13 @@ new_kernel: ; jumping to it. ; read_kernel: + movzx ax,byte [es:bs_setupsecs] ; Setup sectors + and ax,ax + jnz .sects_ok + mov al,4 ; 0 = 4 setup sectors +.sects_ok: + mov [SetupSecs],ax + mov si,KernelCName ; Print kernel name part of call cwritestr ; "Loading" message mov si,dotdot_msg ; Print dots @@ -328,8 +333,9 @@ nk_noinitrd: ; the command line to exist in the 9xxxxh range even if the rest of the ; setup doesn't. ; +setup_command_line: cli ; In case of hooked interrupts - mov dx,[fs:su_version] ; cmdline protocol version + mov dx,[KernelVersion] test byte [LoadFlags],LOAD_HIGH jz need_high_cmdline cmp dx,0202h ; Support new cmdline protocol? @@ -494,13 +500,14 @@ HeapEnd equ $-2 ; Self-modifying code! Fun! ; initrd, and are always loaded low. ; old_kernel: - cmp word [InitRDPtr],0 ; Old kernel can't have initrd - je load_old_kernel + xor ax,ax + cmp word [InitRDPtr],ax ; Old kernel can't have initrd + je .load mov si,err_oldkernel jmp abort_load -load_old_kernel: - mov word [SetupSecs],4 ; Always 4 setup sectors - mov byte [LoadFlags],0 ; Always low +.load: + mov byte [LoadFlags],al ; Always low + mov word [KernelVersion],ax ; Version 0.00 jmp read_kernel ; @@ -661,4 +668,5 @@ KernelEnd resd 1 ; Ending address of the kernel image CmdLineLen resw 1 ; Length of command line including null SetupSecs resw 1 ; Number of setup sectors InitRDPtr resw 1 ; Pointer to initrd= option in command line +KernelVersion resw 1 ; Kernel protocol version LoadFlags resb 1 ; Loadflags from kernel |