freeldr/freeldr/fs/fsrec.c

   1 /*
   2  *  FreeLoader
   3  *  Copyright (C) 1998-2003  Brian Palmer  <brianp@sginet.com>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 #include <freeldr.h>
  21 #include <fs.h>
  22 #include "fsrec.h"
  23 #include "fat.h"
  24 #include "iso.h"
  25 #include "ext2.h"
  26 #include <disk.h>
  27 #include <rtl.h>
  28 #include <arch.h>
  29 #include <debug.h>
  30
  31
  32
  33
  34 /////////////////////////////////////////////////////////////////////////////////////////////
  35 // FUNCTIONS
  36 /////////////////////////////////////////////////////////////////////////////////////////////
  37
  38 /*
  39  *
  40  * BOOL FsRecognizeVolume(U32 DriveNumber, U32 VolumeStartSector, U8* VolumeType);
  41  *
  42  */
  43 BOOL FsRecognizeVolume(U32 DriveNumber, U32 VolumeStartSector, U8* VolumeType)
  44 {
  45
  46         DbgPrint((DPRINT_FILESYSTEM, "FsRecognizeVolume() DriveNumber: 0x%x VolumeStartSector: %d\n", DriveNumber, VolumeStartSector));
  47
  48         if (FsRecIsExt2(DriveNumber, VolumeStartSector))
  49         {
  50                 *VolumeType = PARTITION_EXT2;
  51                 return TRUE;
  52         }
  53         else if (FsRecIsFat(DriveNumber, VolumeStartSector))
  54         {
  55                 *VolumeType = PARTITION_FAT32;
  56                 return TRUE;
  57         }
  58
  59         return FALSE;
  60 }
  61
  62 BOOL FsRecIsIso9660(U32 DriveNumber)
  63 {
  64         PUCHAR Sector = (PUCHAR)DISKREADBUFFER;
  65
  66         if (!DiskReadLogicalSectors(DriveNumber, 16, 1, Sector))
  67         {
  68                 FileSystemError("Failed to read the PVD.");
  69                 return FALSE;
  70         }
  71
  72         return (Sector[0] == 1 &&
  73                 Sector[1] == 'C' &&
  74                 Sector[2] == 'D' &&
  75                 Sector[3] == '0' &&
  76                 Sector[4] == '0' &&
  77                 Sector[5] == '1');
  78 }
  79
  80 BOOL FsRecIsExt2(U32 DriveNumber, U32 VolumeStartSector)
  81 {
  82         PEXT2_SUPER_BLOCK       SuperBlock = (PEXT2_SUPER_BLOCK)DISKREADBUFFER;
  83
  84         if (!DiskReadLogicalSectors(DriveNumber, VolumeStartSector + 2, 2, SuperBlock))
  85         {
  86                 FileSystemError("Failed to read the super block.");
  87                 return FALSE;
  88         }
  89
  90         if (SuperBlock->s_magic == EXT3_SUPER_MAGIC)
  91         {
  92                 return TRUE;
  93         }
  94
  95         return FALSE;
  96 }
  97
  98 BOOL FsRecIsFat(U32 DriveNumber, U32 VolumeStartSector)
  99 {
 100         PFAT_BOOTSECTOR BootSector = (PFAT_BOOTSECTOR)DISKREADBUFFER;
 101
 102         if (!DiskReadLogicalSectors(DriveNumber, VolumeStartSector, 1, BootSector))
 103         {
 104                 FileSystemError("Failed to read the boot sector.");
 105                 return FALSE;
 106         }
 107
 108         if (strncmp(BootSector->FileSystemType, "FAT12   ", 8) == 0 ||
 109                 strncmp(BootSector->FileSystemType, "FAT16   ", 8) == 0 ||
 110                 strncmp(BootSector->FileSystemType, "FAT32   ", 8) == 0)
 111         {
 112                 return TRUE;
 113         }
 114
 115         return FALSE;
 116 }