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authorH. Peter Anvin <hpa@zytor.com>2007-09-13 14:16:37 -0700
committerH. Peter Anvin <hpa@zytor.com>2007-09-20 11:06:58 -0700
commit91c4b8cb5ab8cc3e8352739e35699c0487a6b6f3 (patch)
treed0a73e97ddb5c4ab8de7d5cb89517ff7f29f467f /arch/x86_64
parent3f662b3f6e422a15fefcbaf4bdd21f97e6bcf32d (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.S47
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