Modules/ATA/mbr.c

   1 /*
   2  * Acess2 IDE Harddisk Driver
   3  * - MBR Parsing Code
   4  * mbr.c
   5  */
   6 #define DEBUG   0
   7 #include <acess.h>
   8 #include "common.h"
   9
  10 // == GLOBALS ===
  11
  12 // === CODE ===
  13 /**
  14  * \fn void ATA_ParseMBR(int Disk)
  15  */
  16 void ATA_ParseMBR(int Disk)
  17 {
  18          int    i, j = 0, k = 4;
  19         tMBR    mbr;
  20         Uint64  extendedLBA;
  21
  22         ENTER("iDisk", Disk);
  23
  24         // Read Boot Sector
  25         ATA_ReadDMA( Disk, 0, 1, &mbr );
  26
  27         // Count Partitions
  28         gATA_Disks[Disk].NumPartitions = 0;
  29         extendedLBA = 0;
  30         for( i = 0; i < 4; i ++ )
  31         {
  32                 if( mbr.Parts[i].SystemID == 0 )        continue;
  33                 if(
  34                         mbr.Parts[i].Boot == 0x0 || mbr.Parts[i].Boot == 0x80   // LBA 28
  35                 ||      mbr.Parts[i].Boot == 0x1 || mbr.Parts[i].Boot == 0x81   // LBA 48
  36                         )
  37                 {
  38                         if( mbr.Parts[i].SystemID == 0xF || mbr.Parts[i].SystemID == 5 ) {
  39                                 LOG("Extended Partition");
  40                                 if(extendedLBA != 0) {
  41                                         Warning("Disk %i has multiple extended partitions, ignoring rest", Disk);
  42                                         continue;
  43                                 }
  44                                 extendedLBA = mbr.Parts[i].LBAStart;
  45                                 continue;
  46                         }
  47                         LOG("Primary Partition");
  48
  49                         gATA_Disks[Disk].NumPartitions ++;
  50                         continue;
  51                 }
  52                 // Invalid Partition, so don't count it
  53         }
  54         while(extendedLBA != 0)
  55         {
  56                 if( ATA_ReadDMA( Disk, extendedLBA, 1, &mbr ) != 0 )
  57                         break;  // Stop on Errors
  58
  59                 extendedLBA = 0;
  60
  61                 if( mbr.Parts[0].SystemID == 0 )        continue;
  62                 if(     mbr.Parts[0].Boot == 0x0 || mbr.Parts[0].Boot == 0x80   // LBA 28
  63                 ||      mbr.Parts[0].Boot == 0x1 || mbr.Parts[0].Boot == 0x81   // LBA 48
  64                         )
  65                 {
  66                         if(mbr.Parts[0].SystemID == 0xF || mbr.Parts[0].SystemID == 0x7)
  67                                 extendedLBA = mbr.Parts[0].LBAStart;
  68                         else
  69                                 gATA_Disks[Disk].NumPartitions ++;
  70                 }
  71
  72                 if( mbr.Parts[1].SystemID == 0 )        continue;
  73                 if(     mbr.Parts[1].Boot == 0x0 || mbr.Parts[1].Boot == 0x80   // LBA 28
  74                 ||      mbr.Parts[1].Boot == 0x1 || mbr.Parts[1].Boot == 0x81   // LBA 48
  75                         )
  76                 {
  77                         if(mbr.Parts[1].SystemID == 0xF || mbr.Parts[1].SystemID == 0x7) {
  78                                 if(extendedLBA == 0) {
  79                                         Warning("Disk %i has twp forward link in the extended partition",
  80                                                 Disk);
  81                                         break;
  82                                 }
  83                                 extendedLBA = mbr.Parts[1].LBAStart;
  84                         }
  85                         else {
  86                                 if(extendedLBA != 0) {
  87                                         Warning("Disk %i lacks a forward link in the extended partition",
  88                                                 Disk);
  89                                         break;
  90                                 }
  91                                 gATA_Disks[Disk].NumPartitions ++;
  92                         }
  93                 }
  94         }
  95         LOG("gATA_Disks[Disk].NumPartitions = %i", gATA_Disks[Disk].NumPartitions);
  96
  97         // Create patition array
  98         gATA_Disks[Disk].Partitions = malloc( gATA_Disks[Disk].NumPartitions * sizeof(tATA_Partition) );
  99
 100         // --- Fill Partition Info ---
 101         extendedLBA = 0;
 102         for( i = 0; i < 4; i ++ )
 103         {
 104                 Log("mbr.Parts[%i].SystemID = 0x%02x", i, mbr.Parts[i].SystemID);
 105                 if( mbr.Parts[i].SystemID == 0 )        continue;
 106                 if(     mbr.Parts[i].Boot == 0x0 || mbr.Parts[i].Boot == 0x80 ) // LBA 28
 107                 {
 108                         if( mbr.Parts[1].SystemID == 0xF || mbr.Parts[1].SystemID == 5 ) {
 109                                 if(extendedLBA != 0) {
 110                                         Warning("Disk %i has multiple extended partitions, ignoring rest", Disk);
 111                                         continue;
 112                                 }
 113                                 extendedLBA = mbr.Parts[1].LBAStart;
 114                                 continue;
 115                         }
 116                         // Create Partition
 117                         ATA_int_MakePartition( &gATA_Disks[Disk].Partitions[j], Disk, i,
 118                                 mbr.Parts[i].LBAStart, mbr.Parts[i].LBALength
 119                                 );
 120                         j ++;
 121                         continue;
 122                 }
 123                 if(     mbr.Parts[i].Boot == 0x1 || mbr.Parts[i].Boot == 0x81 ) // LBA 48
 124                 {
 125                         if( mbr.Parts[i].SystemID == 0xF || mbr.Parts[i].SystemID == 5 ) {
 126                                 if(extendedLBA != 0) {
 127                                         Warning("Disk %i has multiple extended partitions, ignoring rest", Disk);
 128                                         continue;
 129                                 }
 130                                 extendedLBA = (mbr.Parts[i].StartHi << 16) | mbr.Parts[i].LBAStart;
 131                                 continue;
 132                         }
 133                         ATA_int_MakePartition( &gATA_Disks[Disk].Partitions[j], Disk, i,
 134                                 (mbr.Parts[i].StartHi << 16) | mbr.Parts[i].LBAStart,
 135                                 (mbr.Parts[i].LengthHi << 16) | mbr.Parts[i].LBALength
 136                                 );
 137                         j ++;
 138                 }
 139                 // Invalid Partition, so don't count it
 140         }
 141         // Scan extended partition
 142         while(extendedLBA != 0)
 143         {
 144                 if( ATA_ReadDMA( Disk, extendedLBA, 1, &mbr ) != 0 )
 145                         break;  // Stop on Errors
 146
 147                 extendedLBA = 0;
 148
 149                 // Check first entry (should be partition)
 150                 if( mbr.Parts[0].SystemID != 0)
 151                 {
 152                         if( mbr.Parts[0].Boot == 0x0 || mbr.Parts[0].Boot == 0x80 )     // LBA 28
 153                         {
 154                                 // Forward Link to next Extended partition entry
 155                                 if(mbr.Parts[0].SystemID == 0xF || mbr.Parts[0].SystemID == 0x7)
 156                                         extendedLBA = mbr.Parts[0].LBAStart;
 157                                 else {
 158                                         ATA_int_MakePartition( &gATA_Disks[Disk].Partitions[j], Disk, k,
 159                                                 mbr.Parts[0].LBAStart, mbr.Parts[0].LBALength
 160                                                 );
 161                                         j ++;   k ++;
 162                                 }
 163                         }
 164                         else if( mbr.Parts[0].Boot == 0x1 || mbr.Parts[0].Boot == 0x81 )        // LBA 48
 165                         {
 166                                 if(mbr.Parts[0].SystemID == 0xF || mbr.Parts[0].SystemID == 0x7)
 167                                         extendedLBA = (mbr.Parts[0].StartHi << 16) | mbr.Parts[0].LBAStart;
 168                                 else {
 169                                         ATA_int_MakePartition( &gATA_Disks[Disk].Partitions[j], Disk, k,
 170                                                 (mbr.Parts[0].StartHi << 16) | mbr.Parts[0].LBAStart,
 171                                                 (mbr.Parts[0].LengthHi << 16) | mbr.Parts[0].LBALength
 172                                                 );
 173                                         j ++;   k ++;
 174                                 }
 175                         }
 176                 }
 177
 178                 // Check second entry (should be forward link)
 179                 if( mbr.Parts[1].SystemID != 0)
 180                 {
 181                         if(mbr.Parts[1].Boot == 0x0 || mbr.Parts[1].Boot == 0x80 )      // LBA 28
 182                         {
 183                                 if(mbr.Parts[1].SystemID == 0xF || mbr.Parts[1].SystemID == 0x7) {
 184                                         if(extendedLBA == 0) {
 185                                                 Warning("Disk %i has twp forward link in the extended partition",
 186                                                         Disk);
 187                                                 break;
 188                                         }
 189                                         extendedLBA = mbr.Parts[1].LBAStart;
 190                                 }
 191                                 else
 192                                 {
 193                                         if(extendedLBA != 0) {
 194                                                 Warning("Disk %i lacks a forward link in the extended partition",
 195                                                         Disk);
 196                                                 break;
 197                                         }
 198                                         ATA_int_MakePartition( &gATA_Disks[Disk].Partitions[j], Disk, k,
 199                                                 mbr.Parts[1].LBAStart, mbr.Parts[1].LBALength
 200                                                 );
 201                                         j ++;   k ++;
 202                                 }
 203
 204                         }
 205                         else if( mbr.Parts[1].Boot == 0x1 || mbr.Parts[1].Boot == 0x81 )        // LBA 48
 206                         {
 207                                 if(mbr.Parts[1].SystemID == 0xF || mbr.Parts[1].SystemID == 0x7) {
 208                                         if(extendedLBA == 0) {
 209                                                 Warning("Disk %i has twp forward link in the extended partition",
 210                                                         Disk);
 211                                                 break;
 212                                         }
 213                                         extendedLBA = (mbr.Parts[1].StartHi << 16) | mbr.Parts[1].LBAStart;
 214                                 }
 215                                 else
 216                                 {
 217                                         if(extendedLBA != 0) {
 218                                                 Warning("Disk %i lacks a forward link in the extended partition",
 219                                                         Disk);
 220                                                 break;
 221                                         }
 222                                         ATA_int_MakePartition( &gATA_Disks[Disk].Partitions[j], Disk, k,
 223                                                 (mbr.Parts[1].StartHi << 16) | mbr.Parts[1].LBAStart,
 224                                                 (mbr.Parts[1].LengthHi << 16) | mbr.Parts[1].LBALength
 225                                                 );
 226                                         j ++;   k ++;
 227                                 }
 228                         }
 229                 }
 230         }
 231
 232         LEAVE('-');
 233 }