56 lines
1.3 KiB
ArmAsm
Executable file
56 lines
1.3 KiB
ArmAsm
Executable file
! getprocessor() - determine processor type Author: Kees J. Bot
|
|
! 26 Jan 1994
|
|
|
|
.sect .text; .sect .rom; .sect .data; .sect .bss
|
|
.sect .text
|
|
|
|
! int getprocessor(void);
|
|
! Return 386, 486, 586, ...
|
|
|
|
.define _getprocessor
|
|
|
|
_getprocessor:
|
|
push ebp
|
|
mov ebp, esp
|
|
and esp, 0xFFFFFFFC ! Align stack to avoid AC fault
|
|
mov ecx, 0x00040000 ! Try to flip the AC bit introduced on the 486
|
|
call flip
|
|
mov eax, 386 ! 386 if it didn't react to "flipping"
|
|
jz gotprocessor
|
|
mov ecx, 0x00200000 ! Try to flip the ID bit introduced on the 586
|
|
call flip
|
|
mov eax, 486 ! 486 if it didn't react
|
|
jz gotprocessor
|
|
pushf
|
|
pusha ! Save the world
|
|
mov eax, 1
|
|
.data1 0x0F, 0xA2 ! CPUID instruction tells the processor type
|
|
andb ah, 0x0F ! Extract the family (5, 6, ...)
|
|
movzxb eax, ah
|
|
cmp eax, 15 ! 15: extended family
|
|
jne direct
|
|
mov eax, 6 ! Make it 686
|
|
direct:
|
|
imul eax, 100 ! 500, 600, ...
|
|
add eax, 86 ! 586, 686, ...
|
|
mov 7*4(esp), eax ! Pass eax through
|
|
popa
|
|
popf
|
|
gotprocessor:
|
|
leave
|
|
ret
|
|
|
|
flip:
|
|
pushf ! Push eflags
|
|
pop eax ! eax = eflags
|
|
mov edx, eax ! Save original eflags
|
|
xor eax, ecx ! 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
|
|
xor eax, edx ! See if the bit changed
|
|
test eax, ecx
|
|
ret
|