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authorH. Peter Anvin <hpa@zytor.com>2008-11-11 16:19:48 -0800
committerH. Peter Anvin <hpa@zytor.com>2008-11-11 16:19:48 -0800
commit14d7ca5c575853664d8fe4f225a77b8df1b7de7d (patch)
tree0d16169c5fde30712109c3a316652d0525646f4f /arch/x86/include/asm/emergency-restart.h
parentd3ec5cae0921611ceae06464ef6291012dd9849f (diff)
x86: attempt reboot via port CF9 if we have standard PCI ports
Impact: Changes reboot behavior. If port CF9 seems to be safe to touch, attempt it before trying the keyboard controller. Port CF9 is not available on all chipsets (a significant but decreasing number of modern chipsets don't implement it), but port CF9 itself should in general be safe to poke (no ill effects if unimplemented) on any system which has PCI Configuration Method #1 or #2, as it falls inside the PCI configuration port range in both cases. No chipset without PCI is known to have port CF9, either, although an explicit "pci=bios" would mean we miss this and therefore don't use port CF9. An explicit "reboot=pci" can be used to force the use of port CF9. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/include/asm/emergency-restart.h')
-rw-r--r--arch/x86/include/asm/emergency-restart.h4
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/include/asm/emergency-restart.h b/arch/x86/include/asm/emergency-restart.h
index 94826cf87455..cc70c1c78ca4 100644
--- a/arch/x86/include/asm/emergency-restart.h
+++ b/arch/x86/include/asm/emergency-restart.h
@@ -8,7 +8,9 @@ enum reboot_type {
BOOT_BIOS = 'b',
#endif
BOOT_ACPI = 'a',
- BOOT_EFI = 'e'
+ BOOT_EFI = 'e',
+ BOOT_CF9 = 'p',
+ BOOT_CF9_COND = 'q',
};
extern enum reboot_type reboot_type;