; JABHACK.ASM
EXTRN LDIV@:far
;============================================================================
DATASEG
EXTRN _intaddr:word
;============================================================================
CODESEG
; Hacked up Juan Jimenez's code a bit to just return 386/not 386
PROC _CheckIs386
PUBLIC _CheckIs386
pushf ; Save flag registers, we use them here
xor ax,ax ; Clear ax and...
push ax ; ...push it onto the stack
popf ; pop 0 into flag registers (all bits to 0),
pushf ; attempting to set bits 12-15 of flags to 0's
pop ax ; Recover the save flags
and ax,08000h ; If bits 12-15 of flags are set to
cmp ax,08000h ; zero then it's 8088/86 or 80188/186
jz not386
mov ax,07000h ; Try to set flag bits 12-14 to 1's
push ax ; Push the test value onto the stack
popf ; pop it into the flag register
pushf ; Push it back onto the stack
pop ax ; pop it into ax for check
and ax,07000h ; if bits 12-14 are cleared then
jz not386 ; the chip is an 80286
mov ax,1 ; We now assume it's a 80386 or better
popf
retf
not386:
xor ax,ax
popf
retf
ENDP
PROC _jabhack2
PUBLIC _jabhack2
jmp @@skip
@@where:
int 060h
retf
@@skip:
push es
mov ax,seg LDIV@
mov es,ax
mov ax,[WORD PTR @@where]
mov [WORD FAR es:LDIV@],ax
mov ax,[WORD PTR @@where+2]
mov [WORD FAR es:LDIV@+2],ax
mov ax,offset @@jabDIV
mov [_intaddr],ax
mov ax,seg @@jabDIV
mov [_intaddr+2],ax
pop es
retf
@@jabDIV:
add sp,4 ;Nuke IRET address, but leave flags
push bp
mov bp,sp ;Save BP, and set it equal to stack
cli
mov eax,[bp+8]
cdq
iDIV [DWORD PTR bp+12]
mov edx,eax
shr edx,16
pop bp ;Restore BP
popf ;Restore flags (from int)
retf 8 ;Return to original caller
ENDP
END