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/* getprocessor() - determine processor type Author: Kees J. Bot */
/* 26 Jan 1994 */
#include <machine/asm.h>
/* int getprocessor(void); */
/* Return 386, 486, 586, ... */
ENTRY(getprocessor)
push %ebp
movl %esp, %ebp
andl $0xFFFFFFFC, %esp /* Align stack to avoid AC fault */
movl $0x00040000, %ecx /* Try to flip the AC bit introduced on the 486 */
call flip
movl $386, %eax /* 386 if it didn't react to "flipping" */
je gotprocessor
movl $0x00200000, %ecx /* Try to flip the ID bit introduced on the 586 */
call flip
movl $486, %eax /* 486 if it didn't react */
je gotprocessor
pushf
pusha /* Save the world */
movl $1, %eax
.byte 0x0F, 0xA2 /* CPUID instruction tells the processor type */
andb $0x0F, %ah /* Extract the family (5, 6, ...) */
movzbl %ah, %eax
cmpl $15, %eax /* 15: extended family */
jne direct
movl $6, %eax /* Make it 686 */
direct:
imull $100, %eax /* 500, 600, ... */
addl $86, %eax /* 586, 686, ... */
movl %eax, 7*4(%esp) /* Pass eax through */
popa
popf
gotprocessor:
leave
ret
flip:
pushf /* Push eflags */
pop %eax /* eax = eflags */
movl %eax, %edx /* Save original eflags */
xorl %ecx, %eax /* Flip the bit to test */
push %eax /* Push modified eflags value */
popf /* Load modified eflags register */
pushf
pop %eax /* Get it again */
push %edx
popf /* Restore original eflags register */
xorl %edx, %eax /* See if the bit changed */
testl %ecx, %eax
ret
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