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