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驱动牛犊
驱动牛犊
  • 注册日期2002-05-25
  • 最后登录2002-06-16
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阅读:1220回复:0

各位高手能不能帮我解释一下我的两段汇编代码有何作用?

楼主#
更多 发布于:2002-06-15 02:09
是两个函数,它们各有什么用处。

static void __declspec( naked ) NowInRing0()
{
_asm {
push ebp
mov ebp,esp

call ReadIDE

cli
mov ebx, int_idt
mov ax, Entry
mov word ptr [ebx-4], ax
mov eax, Base
shr eax, 16
mov [ebx+2], ax
sti
leave
iretd
}
}

void GetIDEInfo()
{
DWORD dwExcept;

dwExcept = (DWORD)NowInRing0;

_asm {
mov eax, fs:[0]
push eax
sidt [esp-02h]
pop ebx
mov idt, ebx
add ebx, 0x1C
mov int_idt, ebx

mov eax, [ebx]
mov [Base], eax
mov ax, [ebx-4]
mov [Entry], ax

cli
mov esi, dwExcept
push esi
mov [ebx-4], si
shr esi, 16
mov [ebx+2], si
pop esi
sti

int 3
}
}

如果大家还看不懂,下面是整个程序的源代码!用来获取向IDE设备发送IDENTIFY命令以后得到的256个字的程序。

#include <windows.h>
#include <stdio.h>

WORD pw[256];        
static DWORD idt, int_idt;  
static DWORD Base;
static WORD Entry;

#pragma warning (disable:4035)
static int inp(WORD rdx)
{
_asm xor eax, eax
_asm mov dx, rdx
_asm in al, dx
}

static WORD inpw(WORD rdx)
{
_asm xor eax, eax
_asm mov dx, rdx
_asm in ax, dx
}

static void outp(WORD rdx, int ral)
{
_asm mov dx, rdx
_asm mov eax, ral
_asm out dx, al
}

static int WaitIde()
{
int al;

while ((al=inp(0x1F7))>=0x80) ;
return al;
}

static void ReadIDE()
{
int al;
int i;

WaitIde();
outp(0x1F6,0xA0);
al = WaitIde();
if ((al&0x50)!=0x50) return;

outp(0x1F6,0xA0);
outp(0x1F7,0xEC);
al = WaitIde();
if ((al&0x58)!=0x58) return;

for (i=0;i<256;i++) {
pw = inpw(0x1F0);
}
}

static void __declspec( naked ) NowInRing0()
{
_asm {
push ebp
mov ebp,esp

call ReadIDE

cli
mov ebx, int_idt
mov ax, Entry
mov word ptr [ebx-4], ax
mov eax, Base
shr eax, 16
mov [ebx+2], ax
sti
leave
iretd
}
}

void GetIDEInfo()
{
DWORD dwExcept;

dwExcept = (DWORD)NowInRing0;

_asm {
mov eax, fs:[0]
push eax
sidt [esp-02h]
pop ebx
mov idt, ebx
add ebx, 0x1C
mov int_idt, ebx

mov eax, [ebx]
mov [Base], eax
mov ax, [ebx-4]
mov [Entry], ax

cli
mov esi, dwExcept
push esi
mov [ebx-4], si
shr esi, 16
mov [ebx+2], si
pop esi
sti

int 3
}
}

main()
{
char s[80];
register i,j;

GetIDEInfo();

for (i=0,j=0;i<10;i++) {
s[j++]=pw[10+i]>>8;
s[j++]=pw[10+i]&0xFF;
}
s[j] = 0;

printf(\"Serial=%s\\n\", s);

return 0;
}

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