dlls/krnl386.exe16/int25.c

   1 /*
   2  * DOS interrupt 25h handler
   3  *
   4  * Copyright 1997 Andreas Mohr
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #include "config.h"
  22
  23 #include <stdlib.h>
  24 #include <stdio.h>
  25 #include <string.h>
  26 #include <fcntl.h>
  27 #ifdef HAVE_UNISTD_H
  28 # include <unistd.h>
  29 #endif
  30 #include "dosexe.h"
  31 #include "wine/debug.h"
  32
  33 WINE_DEFAULT_DEBUG_CHANNEL(int);
  34
  35
  36 /***********************************************************************
  37  *           DOSVM_RawRead
  38  *
  39  * Read raw sectors from a device.
  40  */
  41 BOOL DOSVM_RawRead(BYTE drive, DWORD begin, DWORD nr_sect, BYTE *dataptr, BOOL fake_success)
  42 {
  43     WCHAR root[] = {'\\','\\','.','\\','A',':',0};
  44     HANDLE h;
  45
  46     TRACE( "abs diskread, drive %d, sector %d, "
  47            "count %d, buffer %p\n",
  48            drive, begin, nr_sect, dataptr );
  49
  50     root[4] += drive;
  51     h = CreateFileW(root, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING,
  52                     FILE_FLAG_BACKUP_SEMANTICS, NULL);
  53     if (h != INVALID_HANDLE_VALUE)
  54     {
  55         DWORD r;
  56         SetFilePointer(h, begin * 512, NULL, SEEK_SET );
  57         /* FIXME: check errors */
  58         ReadFile(h, dataptr, nr_sect * 512, &r, NULL );
  59         CloseHandle(h);
  60     }
  61     else
  62     {
  63         memset( dataptr, 0, nr_sect * 512 );
  64         if (fake_success)
  65         {
  66             /* FIXME: explain what happens here */
  67             if (begin == 0 && nr_sect > 1) *(dataptr + 512) = 0xf8;
  68             if (begin == 1) *dataptr = 0xf8;
  69         }
  70         else
  71             return FALSE;
  72     }
  73
  74     return TRUE;
  75 }
  76
  77
  78 /**********************************************************************
  79  *          DOSVM_Int25Handler
  80  *
  81  * Handler for int 25h (absolute disk read).
  82  */
  83 void WINAPI DOSVM_Int25Handler( CONTEXT86 *context )
  84 {
  85     WCHAR drivespec[4] = {'A', ':', '\\', 0};
  86     BYTE *dataptr = CTX_SEG_OFF_TO_LIN( context, context->SegDs, context->Ebx );
  87     DWORD begin;
  88     DWORD length;
  89
  90     drivespec[0] += AL_reg( context );
  91
  92     if (GetDriveTypeW( drivespec ) == DRIVE_NO_ROOT_DIR ||
  93         GetDriveTypeW( drivespec ) == DRIVE_UNKNOWN)
  94     {
  95         SET_CFLAG( context );
  96         SET_AX( context, 0x0201 ); /* unknown unit */
  97         return;
  98     }
  99
 100     if (CX_reg( context ) == 0xffff)
 101     {
 102         begin   = *(DWORD *)dataptr;
 103         length  = *(WORD *)(dataptr + 4);
 104         dataptr = (BYTE *)CTX_SEG_OFF_TO_LIN( context,
 105                                               *(WORD *)(dataptr + 8),
 106                                               *(DWORD *)(dataptr + 6) );
 107     }
 108     else
 109     {
 110         begin  = DX_reg( context );
 111         length = CX_reg( context );
 112     }
 113
 114     DOSVM_RawRead( AL_reg( context ), begin, length, dataptr, TRUE );
 115     RESET_CFLAG( context );
 116 }