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@@ -394,30 +394,21 @@ default_entry:
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jz 1f # Did we do this already?
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call *%eax
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1:
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-
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-/* check if it is 486 or 386. */
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+
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/*
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- * XXX - this does a lot of unnecessary setup. Alignment checks don't
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- * apply at our cpl of 0 and the stack ought to be aligned already, and
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- * we don't need to preserve eflags.
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+ * Check if it is 486
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*/
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movl $-1,X86_CPUID # -1 for no CPUID initially
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- movb $3,X86 # at least 386
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+ movb $4,X86 # at least 486
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pushfl # push EFLAGS
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popl %eax # get EFLAGS
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movl %eax,%ecx # save original EFLAGS
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- xorl $0x240000,%eax # flip AC and ID bits in EFLAGS
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+ xorl $0x200000,%eax # flip ID bit in EFLAGS
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pushl %eax # copy to EFLAGS
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popfl # set EFLAGS
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pushfl # get new EFLAGS
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popl %eax # put it in eax
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xorl %ecx,%eax # change in flags
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- pushl %ecx # restore original EFLAGS
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- popfl
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- testl $0x40000,%eax # check if AC bit changed
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- je is386
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-
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- movb $4,X86 # at least 486
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testl $0x200000,%eax # check if ID bit changed
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je is486
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@@ -445,10 +436,7 @@ default_entry:
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movl %edx,X86_CAPABILITY
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is486: movl $0x50022,%ecx # set AM, WP, NE and MP
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- jmp 2f
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-
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-is386: movl $2,%ecx # set MP
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-2: movl %cr0,%eax
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+ movl %cr0,%eax
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andl $0x80000011,%eax # Save PG,PE,ET
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orl %ecx,%eax
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movl %eax,%cr0
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