如何在VC++6.0中嵌入汇编语句？

[fieldmouse]

本人在VC++6.0中用如下语句读软盘引导扇区：
char a[512];
UINT p=(UINT)a;
_int8 flag=0;
_int16 seg,off;
seg=HIWORD(p);
off=LOWORD(p);
_asm
{
mov AX,seg
mov ES,AX
mov BX,off
mov AH,02H
mov DL,00
mov DH,00
mov CH,0
mov CL,1
mov AL,1
INT 13H
mov flag,CY
}
if(flag)
MessageBox("Read sector ok!");
编译时出错，提示为：
（mov ES,AX句）error C2400:inline assembler syntax error in 'second operand'; found 'newline'
（}句）error C2415: improper operand type
请高手帮忙看看哪儿不对。
谢谢！

[sun2000]

是seg和off的原因你查一下帮助吧

[sxbyl]

CY ？ 有这个寄存器吗？

[sxbyl]

我记得是用AX返回值的吧？还是CX？好几年了，都忘了。

[dingsg]

_asm

[ivefire]

seg在VC++中属于保留字，你用segm就没事了。mov flag,CY应改为mov flag,AH

[kevincheng]

char a[512];
UINT p=(UINT)a;
_int8 flag=0;
_int16 segm,offm;
segm=HIWORD(a);
offm=LOWORD(a);
_asm
{
push es
;
mov ax,segm
pop es
mov ax,0201h
mov bx,offm
mov cx,1
mov dx,0
int 13h
mov flag,ah
;
pop es
}
if(flag)
MessageBox("Read sector ok!");

[kevincheng]

不好意思,错了点.
mov ax,segm
push ax
pop es

[fieldmouse]

kevincheng,谢谢你的帮助。我按你的意见修改程序后，编译能通过，但一执行就非法操作，能再给点建议吗？

[xyzhao]

VC6编译出来的程序运行在3环的32位程序，好像不能直接操作段寄存器ES，还有能不能调用软中断，既不太清楚了，你要是想知道给我发封信我给你查查资料。
又，在Win32程序中调用dos中断有专门的方法，似乎不能直接用汇编调用。你可以自己到msdn里去研究一下相关文档
Platform SDK
Win32 API
Windows 95/98 Programming
Windows 95/98 Overviews
Device I/O Control
About Device I/O Control
Using VWIN32 to Carry Out MS-DOS Functions

[Tasehouny]

想读磁盘的绝对扇区，这个简单，给你一段我用过的代码。
// Bios.h: interface for the CBios class.
//
//////////////////////////////////////////////////////////////////////

#if !defined(AFX_BIOS_H__D25E5BB1_5B1F_11D4_BF46_00E04C800DD8__INCLUDED_)
#define AFX_BIOS_H__D25E5BB1_5B1F_11D4_BF46_00E04C800DD8__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

class CBios
{
public:
int FormatDisk(int head,int track,int sector);
int Virefy(int head,int track,int sec);
int GotoTrack(int track);
int ResetDisk(void);
int WriteSector(unsigned char drive,unsigned char head,unsigned char track,unsigned char sector,unsigned char *buffer);
int ReadSector(unsigned char drive,unsigned char head,unsigned char track,unsigned char sector,unsigned char *buffer);
int MakeSector(unsigned char drive,unsigned char head,unsigned char track,unsigned char sector,unsigned char *buffer);
CBios();
virtual ~CBios();

protected:
int WinBiosDisk(unsigned char command,unsigned char drive,unsigned char head,unsigned char track,unsigned char sector,unsigned char nsectors,void *buffer);
// int WinReadDisk(unsigned char drive,unsigned char sector,unsigned char nsectors,void *buffer);
};

#endif // !defined(AFX_BIOS_H__D25E5BB1_5B1F_11D4_BF46_00E04C800DD8__INCLUDED_)



#include "stdafx.h"
#include "Bios.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
/*本代码用到了 周化同志 写的软盘扇区绝对读取函数 WinBiosDisk()


为了方便, 本函数的参数设计得同 Turbo C 2.0 的 biosdisk() 函数一样.

本函数还有以下两个缺点以待改进：
1.本函数还只能读能读 A: 和 B:,即只能对软盘操作
2.不能改变磁盘扇区大小，只能是标准的 512 个字节。

参数说明:
command 操作:
0 重置磁盘
2 读扇区
3 写扇区
4 校验磁道
5 格式化磁道
8 得到设备参数 (int 1EH)
drive 驱动器 A:=0 B:=1
head 磁头号,范围 0 - 1
track 磁道号,范围 0 - 84 ( 80 - 84 为特殊磁道，通常用来加密 )
sector 扇区号,范围 0 - 255 ( 19 - 255 为非标准扇区编号，通常用来加密)
nsectors 每次读或写的扇区数,不能超出每磁道的最大扇区数
buffer 数据写入或读出的缓冲区，大小为 512 个字节

返回值 ( 同 Int 13H ):

0x0 成功
0x1 无效的命令
0x3 磁盘被写保护
0x4 扇区没有找到
0xa 发现坏扇区
0x80 磁盘没有准备好

******************************************************************/

CBios::CBios()
{

}

CBios::~CBios()
{

}

int CBios::WinBiosDisk(unsigned char command,unsigned char drive,unsigned char head,unsigned char track,unsigned char sector,unsigned char nsectors,void *buffer)
{
HANDLE hd;
DWORD dw;

//int13 寄存器参数块
typedef struct tagPackage
{
void *buffer; // ebx 寄存器

unsigned char drive; // edx 寄存器
unsigned char head; //
unsigned short edx_high; //

unsigned char sector; // ecx 寄存器
unsigned char track; //
unsigned short ecx_high; //

unsigned char number; // eax 寄存器
unsigned char option; //
unsigned short eax_high; //

unsigned int edi; // edi 寄存器

unsigned int esi;
unsigned int eflag;
} PK;

PK pk;
memset(&pk,0,sizeof PK);
pk.buffer=buffer;
pk.drive=drive;
pk.head=head;
pk.sector=sector;
pk.track=track;
pk.option=command;
pk.number=nsectors;

if(command==0x18)pk.edi=(int)buffer;
hd=CreateFile("\\\\.\\vWin32",GENERIC_READ,FILE_SHARE_READ,NULL,OPEN_EXISTING,NULL,NULL);
if(hd==NULL)return 1;
DeviceIoControl(hd,4,&pk,0x1c,&pk,0x1c,&dw,NULL);
if(command==0x8)memcpy(buffer,(unsigned char *)pk.edi,11);
CloseHandle(hd);
return pk.option;

}

/*
int CBios::WinReadDisk(unsigned char drive, unsigned char sector, unsigned char nsectors, void *buffer)
{

}
*/
int CBios::MakeSector(unsigned char drive, unsigned char head, unsigned char track, unsigned char sector, unsigned char *buffer)
{
int i,ret,retry;
unsigned char ctemp[513],cmd[3]={5,3,2};
for(i=0;i<3;i++)
{
retry=5;
while(retry)
{

if(i==0)
{ctemp[0]=track;
ctemp[1]=head;
ctemp[2]=sector;
ctemp[3]=2;
}
else if(i==1)
memcpy(ctemp,buffer,512);
ret=WinBiosDisk(cmd[i],drive,head,track,sector,1,ctemp);
if(ret==0)break;
else if(ret==0x3)return ret;
WinBiosDisk(2,drive,head,track?track-1:track+1,sector,1,ctemp); //重置磁头
retry--;
}
if(!retry)return ret;
}
ret=memcmp(ctemp,buffer,512);
if(ret)return 0xffff;
else return 0;
}

int CBios::ReadSector(unsigned char drive, unsigned char head, unsigned char track, unsigned char sector, unsigned char *buffer)
{
int i,retry=5;
while(retry)
{
i=WinBiosDisk(2,drive,head,track,sector,1,buffer);
if(i==0)break;
WinBiosDisk(2,drive,head,track?track-1:track+1,sector,1,buffer); //重置磁头
retry--;
}
return i;

}

int CBios::WriteSector(unsigned char drive, unsigned char head, unsigned char track, unsigned char sector, unsigned char *buffer)
{
int i,retry=5;
char *buffer1;
buffer1=new char[8196];
while(retry)
{
i=WinBiosDisk(3,drive,head,track,sector,1,buffer);
if(i==0)break;
WinBiosDisk(2,drive,head,track?track-1:track+1,sector,1,buffer1); //重置磁头
retry--;
}
delete []buffer1;
return i;

}

int CBios::ResetDisk()
{
char *buff;
buff = new char[8196];
int i;
i = WinBiosDisk(0,0,1,1,1,1,buff);
delete []buff;
return i;
}

int CBios::GotoTrack(int track)
{
char *buff;
buff = new char[8196];
int i,retry = 5;
int h,sec;
while(retry)
{
h = rand()%2;
sec = rand()%18;
i = WinBiosDisk(4,0,h,track,sec,5,buff);
if(i==0)break;
retry--;
}
delete []buff;
return i;
}

int CBios::Virefy(int head, int track, int sec)
{
int i,retry=5;
char *buff;
buff=new char[8196];
while(retry)
{
i=WinBiosDisk(4,0,head,track,sec,1,buff);
if(i==0)break;
WinBiosDisk(2,0,head,track?track-1:track+1,sec,1,buff); //重置磁头
retry--;
}
delete []buff;
return i;
}

int CBios::FormatDisk(int head, int track, int sector)
{
BYTE buf[1024];
for(int i= 0;i<1024;i++)
{
buf[i] = 0xF6;
}
// char *buff =(char*)buf;
int err = MakeSector(0,head,track,sector,buf);
return err;
}

[ivefire]

进入后先要保存各寄存器的值，退出前恢复.

[kevincheng]

这应该是属于对硬件直接读写的操作，系统是禁止的。

[fieldmouse]

多谢各位大哥！！！！！！