2 * DOS interrupt 25h handler
15 /**********************************************************************
18 * Handler for int 25h (absolute disk read).
20 void WINAPI INT_Int25Handler( CONTEXT *context )
22 BYTE *dataptr = CTX_SEG_OFF_TO_LIN( context, DS_reg(context), EBX_reg(context) );
26 if (!DRIVE_IsValid(AL_reg(context)))
29 AX_reg(context) = 0x0101; /* unknown unit */
33 if (CX_reg(context) == 0xffff)
35 begin = *(DWORD *)dataptr;
36 length = *(WORD *)(dataptr + 4);
37 dataptr = (BYTE *)CTX_SEG_OFF_TO_LIN( context,
38 *(WORD *)(dataptr + 8), *(DWORD *)(dataptr + 6) );
42 begin = DX_reg(context);
43 length = CX_reg(context);
45 TRACE(int, "int25: abs diskread, drive %d, sector %ld, "
46 "count %ld, buffer %d\n",
47 AL_reg(context), begin, length, (int) dataptr);
49 if ((fd = DRIVE_OpenDevice( AL_reg(context), O_RDONLY )) != -1)
51 lseek( fd, begin * 512, SEEK_SET );
52 /* FIXME: check errors */
53 read( fd, dataptr, length * 512 );
58 memset(dataptr, 0, length * 512);
59 if (begin == 0 && length > 1) *(dataptr + 512) = 0xf8;
60 if (begin == 1) *dataptr = 0xf8;