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authorH. Peter Anvin <hpa@zytor.com>2012-06-20 21:18:14 -0700
committerH. Peter Anvin <hpa@zytor.com>2012-06-20 21:18:14 -0700
commit2b1b712f050eaf0ac576591281446dc960c0afc5 (patch)
tree44ef6a4039cd0a1f4aa20bdd8d236f95b98bc680 /arch/x86/kernel/reboot.c
parent650513979a437c32d7a0a84f0ed952a55bbb5583 (diff)
x86, reboot: Drop redundant write of reboot_mode
We write reboot_mode to BIOS location 0x472 in native_machine_emergency_restart() (reboot.c:542) already, there is no need to then write it again in machine_real_restart(). This means nothing gets written there for MRR_APM, but the APM call is a poweroff call and doesn't use this memory location. Link: http://lkml.kernel.org/n/tip-3i0pfh44c1e3jv5lab0cf7sc@git.kernel.org Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/kernel/reboot.c')
-rw-r--r--arch/x86/kernel/reboot.c8
1 files changed, 0 insertions, 8 deletions
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 6ddb9cd0ced..6ef559f09ac 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -179,14 +179,6 @@ void __noreturn machine_real_restart(unsigned int type)
write_cr3(real_mode_header->trampoline_pgd);
#endif
- /*
- * Write 0x1234 to absolute memory location 0x472. The BIOS reads
- * this on booting to tell it to "Bypass memory test (also warm
- * boot)". This seems like a fairly standard thing that gets set by
- * REBOOT.COM programs, and the previous reset routine did this
- * too. */
- *((unsigned short *)0x472) = reboot_mode;
-
/* Jump to the identity-mapped low memory code */
#ifdef CONFIG_X86_32
asm volatile("jmpl *%0" : :