miscemu/int25.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include "registers.h"
   5 #include "msdos.h"
   6 #include "ldt.h"
   7 #include "wine.h"
   8 #include "miscemu.h"
   9 #include "dos_fs.h"
  10 #include "stddebug.h"
  11 /* #define DEBUG_INT */
  12 #include "debug.h"
  13
  14 int do_int25(struct sigcontext_struct *context)
  15 {
  16         BYTE *dataptr = PTR_SEG_OFF_TO_LIN(DS, BX);
  17         DWORD begin, length;
  18
  19         if(!DOS_ValidDrive(AL))
  20         {
  21             SetCflag;
  22             AX = 0x0101;        /* unknown unit */
  23
  24             /* push flags on stack */
  25             SP -= sizeof(WORD);
  26             setword(PTR_SEG_OFF_TO_LIN(SS,SP), (WORD) EFL);
  27             return 1;
  28         }
  29
  30         if (CX == 0xffff) {
  31                 begin = getdword(dataptr);
  32                 length = getword(&dataptr[4]);
  33                 dataptr = (BYTE *) PTR_SEG_TO_LIN(getdword(&dataptr[6]));
  34
  35         } else {
  36                 begin = DX;
  37                 length = CX;
  38         }
  39         dprintf_int(stdnimp, "int25: abs diskread, drive %d, sector %ld, "
  40         "count %ld, buffer %d\n", AL, begin, length, (int) dataptr);
  41
  42         memset(dataptr, 0, length * 512);
  43
  44         if (begin == 0 && length > 1)
  45                 *(dataptr + 512) = 0xf8;
  46
  47         if (begin == 1)
  48                 *dataptr = 0xf8;
  49
  50         ResetCflag;
  51
  52         /* push flags on stack */
  53         SP -= sizeof(WORD);
  54         setword(PTR_SEG_OFF_TO_LIN(SS,SP), (WORD) EFL);
  55
  56         return 1;
  57 }