diff options
| author | H. Peter Anvin <hpa@zytor.com> | 2007-11-04 17:50:12 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2007-11-04 19:47:46 -0800 |
| commit | 7ed192906a2144ebc8ca2925a85d27b9c5355668 (patch) | |
| tree | 350af59996f750ae2a2d7d7ccf2ffbb596a571e8 | |
| parent | b55d1b1814c52463c11707f53dbdc223e09b2924 (diff) | |
x86 setup: add a near jump to serialize %cr0 on 386/486
The 386 and 486 needs a jump immediately after setting %cr0 in order
to serialize the pipeline.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| -rw-r--r-- | arch/x86/boot/pmjump.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/boot/pmjump.S b/arch/x86/boot/pmjump.S index 2e559233725..26baeab3a4d 100644 --- a/arch/x86/boot/pmjump.S +++ b/arch/x86/boot/pmjump.S @@ -31,14 +31,14 @@ protected_mode_jump: xorl %ebx, %ebx # Flag to indicate this is a boot movl %edx, %esi # Pointer to boot_params table movl %eax, 2f # Patch ljmpl instruction - jmp 1f # Short jump to flush instruction q. -1: movw $__BOOT_DS, %cx movl %cr0, %edx orb $1, %dl # Protected mode (PE) bit movl %edx, %cr0 + jmp 1f # Short jump to serialize on 386/486 +1: movw %cx, %ds movw %cx, %es |