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 // === PROTOTYPES ===
  11 Uint64  ATA_MBR_int_ReadExt(int Disk, Uint64 Addr, Uint64 *Base, Uint64 *Length);
  12
  13 // === GLOBALS ===
  14
  15 // === CODE ===
  16 /**
  17  * \fn void ATA_ParseMBR(int Disk)
  18  */
  19 void ATA_ParseMBR(int Disk)
  20 {
  21          int    i, j = 0, k = 4;
  22         tMBR    mbr;
  23         Uint64  extendedLBA;
  24         Uint64  base, len;
  25
  26         ENTER("iDisk", Disk);
  27
  28         // Read Boot Sector
  29         ATA_ReadDMA( Disk, 0, 1, &mbr );
  30
  31         // Count Partitions
  32         gATA_Disks[Disk].NumPartitions = 0;
  33         extendedLBA = 0;
  34         for( i = 0; i < 4; i ++ )
  35         {
  36                 if( mbr.Parts[i].SystemID == 0 )        continue;
  37                 if(
  38                         mbr.Parts[i].Boot == 0x0 || mbr.Parts[i].Boot == 0x80   // LBA 28
  39                 ||      mbr.Parts[i].Boot == 0x1 || mbr.Parts[i].Boot == 0x81   // LBA 48
  40                         )
  41                 {
  42                         if( mbr.Parts[i].SystemID == 0xF || mbr.Parts[i].SystemID == 5 ) {
  43                                 LOG("Extended Partition");
  44                                 if(extendedLBA != 0) {
  45                                         Warning("Disk %i has multiple extended partitions, ignoring rest", Disk);
  46                                         continue;
  47                                 }
  48                                 extendedLBA = mbr.Parts[i].LBAStart;
  49                                 continue;
  50                         }
  51                         LOG("Primary Partition");
  52
  53                         gATA_Disks[Disk].NumPartitions ++;
  54                         continue;
  55                 }
  56                 // Invalid Partition, so don't count it
  57         }
  58         while(extendedLBA != 0)
  59         {
  60                 extendedLBA = ATA_MBR_int_ReadExt(Disk, extendedLBA, &base, &len);
  61                 if( extendedLBA == -1 ) return ;
  62                 gATA_Disks[Disk].NumPartitions ++;
  63         }
  64         LOG("gATA_Disks[Disk].NumPartitions = %i", gATA_Disks[Disk].NumPartitions);
  65
  66         // Create patition array
  67         gATA_Disks[Disk].Partitions = malloc( gATA_Disks[Disk].NumPartitions * sizeof(tATA_Partition) );
  68
  69         // --- Fill Partition Info ---
  70         extendedLBA = 0;
  71         for( j = 0, i = 0; i < 4; i ++ )
  72         {
  73                 Log("mbr.Parts[%i].SystemID = 0x%02x", i, mbr.Parts[i].SystemID);
  74                 if( mbr.Parts[i].SystemID == 0 )        continue;
  75                 if( mbr.Parts[i].Boot == 0x0 || mbr.Parts[i].Boot == 0x80 )     // LBA 28
  76                 {
  77                         base = mbr.Parts[i].LBAStart;
  78                         len = mbr.Parts[i].LBALength;
  79                 }
  80                 else if( mbr.Parts[i].Boot == 0x1 || mbr.Parts[i].Boot == 0x81 )        // LBA 58
  81                 {
  82                         base = (mbr.Parts[i].StartHi << 16) | mbr.Parts[i].LBAStart;
  83                         len = (mbr.Parts[i].LengthHi << 16) | mbr.Parts[i].LBALength;
  84                 }
  85                 else
  86                         continue;
  87
  88                 if( mbr.Parts[i].SystemID == 0xF || mbr.Parts[i].SystemID == 5 ) {
  89                         if(extendedLBA != 0) {
  90                                 Warning("Disk %i has multiple extended partitions, ignoring rest", Disk);
  91                                 continue;
  92                         }
  93                         extendedLBA = base;
  94                         continue;
  95                 }
  96                 // Create Partition
  97                 ATA_int_MakePartition(
  98                         &gATA_Disks[Disk].Partitions[j], Disk, j,
  99                         base, len
 100                         );
 101                 j ++;
 102
 103         }
 104         // Scan extended partitions
 105         while(extendedLBA != 0)
 106         {
 107                 extendedLBA = ATA_MBR_int_ReadExt(Disk, extendedLBA, &base, &len);
 108                 ATA_int_MakePartition(
 109                         &gATA_Disks[Disk].Partitions[j], Disk, k, base, len
 110                         );
 111         }
 112
 113         LEAVE('-');
 114 }
 115
 116 /**
 117  * \brief Reads an extended partition
 118  * \return LBA of next Extended, -1 on error, 0 for last
 119  */
 120 Uint64 ATA_MBR_int_ReadExt(int Disk, Uint64 Addr, Uint64 *Base, Uint64 *Length)
 121 {
 122         Uint64  link = 0;
 123          int    bFoundPart = 0;;
 124          int    i;
 125         tMBR    mbr;
 126         Uint64  base, len;
 127
 128         if( ATA_ReadDMA( Disk, Addr, 1, &mbr ) != 0 )
 129                 return -1;      // Stop on Errors
 130
 131
 132         for( i = 0; i < 4; i ++ )
 133         {
 134                 if( mbr.Parts[i].SystemID == 0 )        continue;
 135
 136                 // LBA 24
 137                 if( mbr.Parts[i].Boot == 0x0 || mbr.Parts[i].Boot == 0x80 ) {
 138                         base = mbr.Parts[i].LBAStart;
 139                         len = mbr.Parts[i].LBALength;
 140                 }
 141                 // LBA 48
 142                 else if( mbr.Parts[i].Boot == 0x1 || mbr.Parts[i].Boot == 0x81 ) {
 143                         base = (mbr.Parts[i].StartHi << 16) | mbr.Parts[i].LBAStart;
 144                         len = (mbr.Parts[i].LengthHi << 16) | mbr.Parts[i].LBALength;
 145                 }
 146                 else {
 147                         Warning("Unknown partition type, Disk %i 0x%llx Part %i",
 148                                 Disk, Addr, i);
 149                         return -1;
 150                 }
 151
 152                 switch(mbr.Parts[i].SystemID)
 153                 {
 154                 case 0xF:
 155                 case 0x5:
 156                         if(link != 0) {
 157                                 Warning("Disk %i has two forward links in the extended partition",
 158                                         Disk);
 159                                 return -1;
 160                         }
 161                         link = base;
 162                         break;
 163                 default:
 164                         if(bFoundPart) {
 165                                 Warning("Disk %i has more than one partition in the extended partition at 0x%llx",
 166                                         Disk, Addr);
 167                                 return -1;
 168                         }
 169                         bFoundPart = 1;
 170                         *Base = base;
 171                         *Length = len;
 172                         break;
 173                 }
 174         }
 175
 176         if(!bFoundPart) {
 177                 Warning("No partition in extended partiton, Disk %i 0x%llx",
 178                         Disk, Addr);
 179                 return -1;
 180         }
 181
 182         return link;
 183 }