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 "miscemu.h"
  10 #include "drive.h"
  11 #include "debugtools.h"
  12
  13 DEFAULT_DEBUG_CHANNEL(int);
  14
  15 /**********************************************************************
  16  *          INT_Int26Handler
  17  *
  18  * Handler for int 26h (absolute disk read).
  19  */
  20 void WINAPI INT_Int26Handler( CONTEXT86 *context )
  21 {
  22     BYTE *dataptr = CTX_SEG_OFF_TO_LIN( context, context->SegDs, context->Ebx );
  23     DWORD begin, length;
  24
  25     if (!DRIVE_IsValid(LOBYTE(context->Eax)))
  26     {
  27         SET_CFLAG(context);
  28         AX_reg(context) = 0x0201;        /* unknown unit */
  29         return;
  30     }
  31
  32     if (LOWORD(context->Ecx) == 0xffff)
  33     {
  34         begin   = *(DWORD *)dataptr;
  35         length  = *(WORD *)(dataptr + 4);
  36         dataptr = (BYTE *)CTX_SEG_OFF_TO_LIN( context,
  37                                         *(WORD *)(dataptr + 8), *(DWORD *)(dataptr + 6) );
  38     }
  39     else
  40     {
  41         begin  = LOWORD(context->Edx);
  42         length = LOWORD(context->Ecx);
  43     }
  44
  45     TRACE("int26: abs diskwrite, drive %d, sector %ld, "
  46                  "count %ld, buffer %p\n",
  47                  AL_reg(context), begin, length, dataptr );
  48
  49         DRIVE_RawWrite(LOBYTE(context->Eax), begin, length, dataptr, TRUE);
  50     RESET_CFLAG(context);
  51 }