Displaying 1 result from an estimated 1 matches for "is_486".
2007 Jan 04
2
Automatically choose between 32-bit and 64-bit kernel
...we're 386. If so, we need to blank out the WBINVD
instruction
;
-%if DO_WBINVD
pushfd ; Save the good flags
pushfd
pop eax
@@ -69,6 +67,47 @@
;
; 386 - Looks like we better blot out the WBINVD instruction
;
+%if DO_WBINVD
mov byte [try_wbinvd],0c3h ; Near RET
-is_486:
%endif ; DO_WBINVD
+ jmp is_32bit
+is_486:
+;
+; Check if this CPU supports the CPUID command
+;
+ pushfd ; Save the flags again
+ pushfd
+ pop eax
+ mov ebx,eax
+ xor eax,(1 << 21) ; CPUID bit
+ push eax
+ popfd
+ pushfd
+ pop eax
+ popfd ; Restore the original flags
+...