You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
136 lines
3.2 KiB
136 lines
3.2 KiB
title "CPUID support functions"
|
|
;++
|
|
;
|
|
; Copyright (c) 1999 Microsoft Corporation
|
|
;
|
|
; Module Name:
|
|
;
|
|
; cpuidsup.asm
|
|
;
|
|
; Abstract:
|
|
;
|
|
; Implements functions to detect whether or not the CPUID instruction
|
|
; is supported on this processor and to provide a simple method to use
|
|
; CPUID from a C program.
|
|
;
|
|
; Author:
|
|
;
|
|
; Peter Johnston (peterj) July 14, 1999
|
|
;
|
|
; Environment:
|
|
;
|
|
; Any mode.
|
|
;
|
|
; Revision History:
|
|
;
|
|
;--
|
|
.586p
|
|
|
|
.xlist
|
|
include ks386.inc
|
|
include callconv.inc ; calling convention macros
|
|
.list
|
|
|
|
_TEXT$01 SEGMENT DWORD PUBLIC 'CODE'
|
|
ASSUME DS:FLAT, ES:FLAT, SS:NOTHING, FS:NOTHING, GS:NOTHING
|
|
|
|
page
|
|
subttl "IsCpuidPresent"
|
|
;++
|
|
;
|
|
; BOOLEAN
|
|
; IsCpuidPresent(
|
|
; VOID
|
|
; )
|
|
;
|
|
; Routine Description:
|
|
;
|
|
; If bit 21 of the EFLAGS register is writable, CPUID is supported on
|
|
; this processor. If not writable, CPUID is not supported.
|
|
;
|
|
; Note: It is expected that this routine is "locked" onto a single
|
|
; processor when run.
|
|
;
|
|
; Arguments:
|
|
;
|
|
; None.
|
|
;
|
|
; Return Value:
|
|
;
|
|
; TRUE if CPUID is supported,
|
|
; FALSE otherwise.
|
|
;
|
|
;--
|
|
|
|
EFLAGS_ID equ 200000h ; bit 21
|
|
|
|
|
|
cPublicProc _IsCpuidPresent ,0
|
|
pushfd ; save EFLAGS
|
|
pop ecx ; get current value
|
|
xor ecx, EFLAGS_ID ; flip bit 21
|
|
push ecx ; set flipped value in EFLAGS
|
|
popfd
|
|
pushfd ; read it back again
|
|
pop eax
|
|
xor eax, ecx ; if new value is what we set
|
|
shr eax, 21 ; then these two are the same
|
|
and eax, 1 ; isolate bit 21 (in bit 0)
|
|
xor eax, 1 ; and flip it
|
|
|
|
stdRET _IsCpuidPresent
|
|
|
|
stdENDP _IsCpuidPresent
|
|
|
|
page
|
|
subttl "ExecuteCpuidFunction"
|
|
;++
|
|
;
|
|
; VOID
|
|
; ExecuteCpuidFunction(
|
|
; ULONG Function,
|
|
; PULONG Results
|
|
; )
|
|
;
|
|
; Routine Description:
|
|
;
|
|
; Execute the CPUID instruction, using the Function handed in and
|
|
; return the 4 DWORD result.
|
|
;
|
|
; Note: It is expected that this routine is "locked" onto a single
|
|
; processor when run.
|
|
;
|
|
; Arguments:
|
|
;
|
|
; Function Integer function number to be the input argument for
|
|
; the CPUID instruction.
|
|
; Results Pointer to the 4 DWORD array where the results are to
|
|
; be returned.
|
|
;
|
|
; Return Value:
|
|
;
|
|
; None.
|
|
;
|
|
;--
|
|
|
|
|
|
cPublicProc _ExecuteCpuidFunction ,2
|
|
mov eax, [esp+4] ; set CPUID function
|
|
push esi ; save esi
|
|
mov esi, [esp+12] ; get Results address
|
|
push ebx ; save ebx
|
|
cpuid ; execute
|
|
mov [esi+0], eax ; eax -> Results[0]
|
|
mov [esi+4], ebx ; ebx -> Results[1]
|
|
mov [esi+8], ecx ; ecx -> Results[2]
|
|
mov [esi+12], edx ; edx -> Results[3]
|
|
|
|
pop ebx ; restore ebx, esi
|
|
pop esi
|
|
|
|
stdRET _ExecuteCpuidFunction
|
|
|
|
stdENDP _ExecuteCpuidFunction
|
|
|
|
_TEXT$01 ends
|
|
end
|