diff options
| author | Borislav Petkov <bp@suse.de> | 2013-02-11 15:22:15 +0100 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2013-02-12 15:48:40 -0800 |
| commit | 166df91daf38f619d4ca90b58ff90983de6e40d2 (patch) | |
| tree | 6ef1ec7cb0df9988c2db2316b84c099dddbc6da9 /arch/x86/kernel/head_32.S | |
| parent | 8ecba5af948cb58bf6d5eb1537c0df53cbc319c4 (diff) | |
x86, head_32: Remove i386 pieces
Remove code fragments detecting a 386 CPU since we don't support those
anymore. Also, do not do alignment checks because they're done only at
CPL3. Also, no need to preserve EFLAGS.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1360592538-10643-2-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/kernel/head_32.S')
| -rw-r--r-- | arch/x86/kernel/head_32.S | 22 |
1 files changed, 5 insertions, 17 deletions
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index c8932c79e78b..a9c5cc851285 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -394,30 +394,21 @@ default_entry: jz 1f # Did we do this already? call *%eax 1: - -/* check if it is 486 or 386. */ + /* - * XXX - this does a lot of unnecessary setup. Alignment checks don't - * apply at our cpl of 0 and the stack ought to be aligned already, and - * we don't need to preserve eflags. + * Check if it is 486 */ movl $-1,X86_CPUID # -1 for no CPUID initially - movb $3,X86 # at least 386 + movb $4,X86 # at least 486 pushfl # push EFLAGS popl %eax # get EFLAGS movl %eax,%ecx # save original EFLAGS - xorl $0x240000,%eax # flip AC and ID bits in EFLAGS + xorl $0x200000,%eax # flip ID bit in EFLAGS pushl %eax # copy to EFLAGS popfl # set EFLAGS pushfl # get new EFLAGS popl %eax # put it in eax xorl %ecx,%eax # change in flags - pushl %ecx # restore original EFLAGS - popfl - testl $0x40000,%eax # check if AC bit changed - je is386 - - movb $4,X86 # at least 486 testl $0x200000,%eax # check if ID bit changed je is486 @@ -445,10 +436,7 @@ default_entry: movl %edx,X86_CAPABILITY is486: movl $0x50022,%ecx # set AM, WP, NE and MP - jmp 2f - -is386: movl $2,%ecx # set MP -2: movl %cr0,%eax + movl %cr0,%eax andl $0x80000011,%eax # Save PG,PE,ET orl %ecx,%eax movl %eax,%cr0 |