非API函数检测操作系统类型

.386
.model flat,stdcall
option casemap:none

include windows.inc
include user32.inc
includelib user32.lib
include kernel32.inc
includelib kernel32.lib

.const

;-- return values from OS_GetOS
OS_UNKNOWN equ -1
OS_WIN95 equ 1
OS_WIN98 equ 2
OS_WINME equ 3
OS_WINNT equ 4
OS_WIN2K equ 5
OS_WINXP equ 6
OS_WIN2K3 equ 7

.data
szCaption db 'xp ',0
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; 代码段
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.code
start:
call OS_GetOS
.if eax==5 ; 在此处加入多个判断，根据eax,得出系统类型
invoke MessageBox,NULL,offset szCaption,offset szCaption,MB_OK
.endif
invoke ExitProcess,NULL

OS_GetOS proc

local _theReturnValue:DWORD

pushad ; store all registers
mov _theReturnValue,OS_UNKNOWN
assume fs:nothing
mov ebx,fs:[18h] ; get self pointer from TEB
mov eax,fs:[30h] ; get pointer to PEB / database
.if eax==7FFDF000h && ebx==7FFDE000h ; WinNT based
mov ebx,[eax+0A8h] ; get OSMinorVersion
mov eax,[eax+0A4h] ; get OSMajorVersion
.if eax==5 && ebx==0 ; is it Windows 2000?
mov _theReturnValue,OS_WIN2K
.elseif eax==5 && ebx==1 ; is it Windows XP?
mov _theReturnValue,OS_WINXP
.elseif eax==5 && ebx==2 ; is it Windows 2003?
mov _theReturnValue,OS_WIN2K3
.elseif eax <=4 ; is it Windows NT?
mov _theReturnValue,OS_WINNT
.endif

.else ; Win9X based

mov edx,00530000h ; the magic value to search
mov eax,fs:[18h] ; get the TEB base address
mov ebx,[eax+58h] ; TEB-base + 58h (W95)
mov ecx,[eax+7Ch] ; TEB-base + 7Ch (WME)
mov eax,[eax+54h] ; TEB-base + 54h (W98)

.if ebx==edx ; is it Windows 95?
mov _theReturnValue,OS_WIN95
.elseif eax==edx ; is it Windows 98?
mov _theReturnValue,OS_WIN98
.elseif ecx==edx ; is it Windows ME?
mov _theReturnValue,OS_WINME
.endif

.endif ; of base check NT/9X

popad ; restore all registers
mov eax,_theReturnValue
ret ; return to caller
OS_GetOS endp

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end start