diff options
| author | H. Peter Anvin <hpa@zytor.com> | 2007-09-13 14:16:37 -0700 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2007-09-20 11:06:58 -0700 |
| commit | 91c4b8cb5ab8cc3e8352739e35699c0487a6b6f3 (patch) | |
| tree | d0a73e97ddb5c4ab8de7d5cb89517ff7f29f467f /arch/x86_64 | |
| parent | 3f662b3f6e422a15fefcbaf4bdd21f97e6bcf32d (diff) | |
[acpi] Correct the decoding of video mode numbers in wakeup.S
wakeup.S looks at the video mode number from the setup header and
looks to see if it is a VESA mode. Unfortunately, the decoding is
done incorrectly and it will attempt to frob the VESA BIOS for any
mode number 0x0200 or larger. Correct this, and remove a bunch of #if
0'd code.
Massive thanks to Jeff Chua for reporting the bug, and suffering
though a large number of experiments in order to track this problem
down.
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86_64')
| -rw-r--r-- | arch/x86_64/kernel/acpi/wakeup.S | 47 |
1 files changed, 13 insertions, 34 deletions
diff --git a/arch/x86_64/kernel/acpi/wakeup.S b/arch/x86_64/kernel/acpi/wakeup.S index 13f1480cbec9..a06f2bcabef9 100644 --- a/arch/x86_64/kernel/acpi/wakeup.S +++ b/arch/x86_64/kernel/acpi/wakeup.S @@ -81,7 +81,7 @@ wakeup_code: testl $2, realmode_flags - wakeup_code jz 1f mov video_mode - wakeup_code, %ax - call mode_seta + call mode_set 1: movw $0xb800, %ax @@ -291,52 +291,31 @@ no_longmode: #define VIDEO_FIRST_V7 0x0900 # Setting of user mode (AX=mode ID) => CF=success + +# For now, we only handle VESA modes (0x0200..0x03ff). To handle other +# modes, we should probably compile in the video code from the boot +# directory. .code16 -mode_seta: +mode_set: movw %ax, %bx -#if 0 - cmpb $0xff, %ah - jz setalias - - testb $VIDEO_RECALC>>8, %ah - jnz _setrec - - cmpb $VIDEO_FIRST_RESOLUTION>>8, %ah - jnc setres - - cmpb $VIDEO_FIRST_SPECIAL>>8, %ah - jz setspc - - cmpb $VIDEO_FIRST_V7>>8, %ah - jz setv7 -#endif - - cmpb $VIDEO_FIRST_VESA>>8, %ah - jnc check_vesaa -#if 0 - orb %ah, %ah - jz setmenu -#endif - - decb %ah -# jz setbios Add bios modes later + subb $VIDEO_FIRST_VESA>>8, %bh + cmpb $2, %bh + jb check_vesa -setbada: clc +setbad: + clc ret -check_vesaa: - subb $VIDEO_FIRST_VESA>>8, %bh +check_vesa: orw $0x4000, %bx # Use linear frame buffer movw $0x4f02, %ax # VESA BIOS mode set call int $0x10 cmpw $0x004f, %ax # AL=4f if implemented - jnz _setbada # AH=0 if OK + jnz setbad # AH=0 if OK stc ret -_setbada: jmp setbada - wakeup_stack_begin: # Stack grows down .org 0xff0 |