msdos/int26.c

   1 /*
   2  * DOS interrupt 26h handler
   3  */
   4
   5 #include <stdlib.h>
   6 #include <fcntl.h>
   7 #include <unistd.h>
   8 #include "msdos.h"
   9 #include "ldt.h"
  10 #include "miscemu.h"
  11 #include "drive.h"
  12 #include "debug.h"
  13
  14 /**********************************************************************
  15  *          INT_Int26Handler
  16  *
  17  * Handler for int 26h (absolute disk read).
  18  */
  19 void WINAPI INT_Int26Handler( CONTEXT *context )
  20 {
  21     BYTE *dataptr = CTX_SEG_OFF_TO_LIN( context, DS_reg(context), EBX_reg(context) );
  22     DWORD begin, length;
  23
  24     if (!DRIVE_IsValid(AL_reg(context)))
  25     {
  26         SET_CFLAG(context);
  27         AX_reg(context) = 0x0101;        /* unknown unit */
  28         return;
  29     }
  30
  31     if (CX_reg(context) == 0xffff)
  32     {
  33         begin   = *(DWORD *)dataptr;
  34         length  = *(WORD *)(dataptr + 4);
  35         dataptr = (BYTE *)CTX_SEG_OFF_TO_LIN( context,
  36                                         *(WORD *)(dataptr + 8), *(DWORD *)(dataptr + 6) );
  37     }
  38     else
  39     {
  40         begin  = DX_reg(context);
  41         length = CX_reg(context);
  42     }
  43
  44     TRACE(int,"int26: abs diskwrite, drive %d, sector %ld, "
  45                  "count %ld, buffer %p\n",
  46                  AL_reg(context), begin, length, dataptr );
  47
  48         DRIVE_RawWrite(AL_reg(context), begin, length, dataptr, TRUE);
  49     RESET_CFLAG(context);
  50 }