boot/freeldr/freeldr/disk/partition.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 along
  16  *  with this program; if not, write to the Free Software Foundation, Inc.,
  17  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #ifndef _M_ARM
  21 #include <freeldr.h>
  22 #include <debug.h>
  23
  24 DBG_DEFAULT_CHANNEL(DISK);
  25
  26 BOOLEAN DiskGetActivePartitionEntry(UCHAR DriveNumber,
  27                                  PPARTITION_TABLE_ENTRY PartitionTableEntry,
  28                                  ULONG *ActivePartition)
  29 {
  30     ULONG            BootablePartitionCount = 0;
  31     MASTER_BOOT_RECORD    MasterBootRecord;
  32
  33     *ActivePartition = 0;
  34     // Read master boot record
  35     if (!DiskReadBootRecord(DriveNumber, 0, &MasterBootRecord))
  36     {
  37         return FALSE;
  38     }
  39
  40     // Count the bootable partitions
  41     if (MasterBootRecord.PartitionTable[0].BootIndicator == 0x80)
  42     {
  43         BootablePartitionCount++;
  44         *ActivePartition = 1;
  45     }
  46     if (MasterBootRecord.PartitionTable[1].BootIndicator == 0x80)
  47     {
  48         BootablePartitionCount++;
  49         *ActivePartition = 2;
  50     }
  51     if (MasterBootRecord.PartitionTable[2].BootIndicator == 0x80)
  52     {
  53         BootablePartitionCount++;
  54         *ActivePartition = 3;
  55     }
  56     if (MasterBootRecord.PartitionTable[3].BootIndicator == 0x80)
  57     {
  58         BootablePartitionCount++;
  59         *ActivePartition = 4;
  60     }
  61
  62     // Make sure there was only one bootable partition
  63     if (BootablePartitionCount == 0)
  64     {
  65         ERR("No bootable (active) partitions found.\n");
  66         return FALSE;
  67     }
  68     else if (BootablePartitionCount != 1)
  69     {
  70         ERR("Too many bootable (active) partitions found.\n");
  71         return FALSE;
  72     }
  73
  74     // Copy the partition table entry
  75     RtlCopyMemory(PartitionTableEntry,
  76                   &MasterBootRecord.PartitionTable[*ActivePartition - 1],
  77                   sizeof(PARTITION_TABLE_ENTRY));
  78
  79     return TRUE;
  80 }
  81
  82 BOOLEAN DiskGetPartitionEntry(UCHAR DriveNumber, ULONG PartitionNumber, PPARTITION_TABLE_ENTRY PartitionTableEntry)
  83 {
  84     MASTER_BOOT_RECORD        MasterBootRecord;
  85     PARTITION_TABLE_ENTRY    ExtendedPartitionTableEntry;
  86     ULONG                        ExtendedPartitionNumber;
  87     ULONG                        ExtendedPartitionOffset;
  88     ULONG                        Index;
  89
  90     // Read master boot record
  91     if (!DiskReadBootRecord(DriveNumber, 0, &MasterBootRecord))
  92     {
  93         return FALSE;
  94     }
  95
  96     // If they are asking for a primary
  97     // partition then things are easy
  98     if (PartitionNumber < 5)
  99     {
 100         // PartitionNumber is one-based and we need it zero-based
 101         PartitionNumber--;
 102
 103         // Copy the partition table entry
 104         RtlCopyMemory(PartitionTableEntry, &MasterBootRecord.PartitionTable[PartitionNumber], sizeof(PARTITION_TABLE_ENTRY));
 105
 106         return TRUE;
 107     }
 108     else
 109     {
 110         // They want an extended partition entry so we will need
 111         // to loop through all the extended partitions on the disk
 112         // and return the one they want.
 113
 114         ExtendedPartitionNumber = PartitionNumber - 5;
 115
 116         // Set the initial relative starting sector to 0
 117         // This is because extended partition starting
 118         // sectors a numbered relative to their parent
 119         ExtendedPartitionOffset = 0;
 120
 121         for (Index=0; Index<=ExtendedPartitionNumber; Index++)
 122         {
 123             // Get the extended partition table entry
 124             if (!DiskGetFirstExtendedPartitionEntry(&MasterBootRecord, &ExtendedPartitionTableEntry))
 125             {
 126                 return FALSE;
 127             }
 128
 129             // Adjust the relative starting sector of the partition
 130             ExtendedPartitionTableEntry.SectorCountBeforePartition += ExtendedPartitionOffset;
 131             if (ExtendedPartitionOffset == 0)
 132             {
 133                 // Set the start of the parrent extended partition
 134                 ExtendedPartitionOffset = ExtendedPartitionTableEntry.SectorCountBeforePartition;
 135             }
 136             // Read the partition boot record
 137                 if (!DiskReadBootRecord(DriveNumber, ExtendedPartitionTableEntry.SectorCountBeforePartition, &MasterBootRecord))
 138             {
 139                 return FALSE;
 140             }
 141
 142             // Get the first real partition table entry
 143             if (!DiskGetFirstPartitionEntry(&MasterBootRecord, PartitionTableEntry))
 144             {
 145                 return FALSE;
 146             }
 147
 148             // Now correct the start sector of the partition
 149             PartitionTableEntry->SectorCountBeforePartition += ExtendedPartitionTableEntry.SectorCountBeforePartition;
 150         }
 151
 152         // When we get here we should have the correct entry
 153         // already stored in PartitionTableEntry
 154         // so just return TRUE
 155         return TRUE;
 156     }
 157
 158 }
 159
 160 BOOLEAN DiskGetFirstPartitionEntry(PMASTER_BOOT_RECORD MasterBootRecord, PPARTITION_TABLE_ENTRY PartitionTableEntry)
 161 {
 162     ULONG        Index;
 163
 164     for (Index=0; Index<4; Index++)
 165     {
 166         // Check the system indicator
 167         // If it's not an extended or unused partition
 168         // then we're done
 169         if ((MasterBootRecord->PartitionTable[Index].SystemIndicator != PARTITION_ENTRY_UNUSED) &&
 170             (MasterBootRecord->PartitionTable[Index].SystemIndicator != PARTITION_EXTENDED) &&
 171             (MasterBootRecord->PartitionTable[Index].SystemIndicator != PARTITION_XINT13_EXTENDED))
 172         {
 173             RtlCopyMemory(PartitionTableEntry, &MasterBootRecord->PartitionTable[Index], sizeof(PARTITION_TABLE_ENTRY));
 174             return TRUE;
 175         }
 176     }
 177
 178     return FALSE;
 179 }
 180
 181 BOOLEAN DiskGetFirstExtendedPartitionEntry(PMASTER_BOOT_RECORD MasterBootRecord, PPARTITION_TABLE_ENTRY PartitionTableEntry)
 182 {
 183     ULONG        Index;
 184
 185     for (Index=0; Index<4; Index++)
 186     {
 187         // Check the system indicator
 188         // If it an extended partition then we're done
 189         if ((MasterBootRecord->PartitionTable[Index].SystemIndicator == PARTITION_EXTENDED) ||
 190             (MasterBootRecord->PartitionTable[Index].SystemIndicator == PARTITION_XINT13_EXTENDED))
 191         {
 192             RtlCopyMemory(PartitionTableEntry, &MasterBootRecord->PartitionTable[Index], sizeof(PARTITION_TABLE_ENTRY));
 193             return TRUE;
 194         }
 195     }
 196
 197     return FALSE;
 198 }
 199
 200 BOOLEAN DiskReadBootRecord(UCHAR DriveNumber, ULONGLONG LogicalSectorNumber, PMASTER_BOOT_RECORD BootRecord)
 201 {
 202     ULONG        Index;
 203
 204     // Read master boot record
 205     if (!MachDiskReadLogicalSectors(DriveNumber, LogicalSectorNumber, 1, (PVOID)DISKREADBUFFER))
 206     {
 207         return FALSE;
 208     }
 209     RtlCopyMemory(BootRecord, (PVOID)DISKREADBUFFER, sizeof(MASTER_BOOT_RECORD));
 210
 211
 212     TRACE("Dumping partition table for drive 0x%x:\n", DriveNumber);
 213     TRACE("Boot record logical start sector = %d\n", LogicalSectorNumber);
 214     TRACE("sizeof(MASTER_BOOT_RECORD) = 0x%x.\n", sizeof(MASTER_BOOT_RECORD));
 215
 216     for (Index=0; Index<4; Index++)
 217     {
 218         TRACE("-------------------------------------------\n");
 219         TRACE("Partition %d\n", (Index + 1));
 220         TRACE("BootIndicator: 0x%x\n", BootRecord->PartitionTable[Index].BootIndicator);
 221         TRACE("StartHead: 0x%x\n", BootRecord->PartitionTable[Index].StartHead);
 222         TRACE("StartSector (Plus 2 cylinder bits): 0x%x\n", BootRecord->PartitionTable[Index].StartSector);
 223         TRACE("StartCylinder: 0x%x\n", BootRecord->PartitionTable[Index].StartCylinder);
 224         TRACE("SystemIndicator: 0x%x\n", BootRecord->PartitionTable[Index].SystemIndicator);
 225         TRACE("EndHead: 0x%x\n", BootRecord->PartitionTable[Index].EndHead);
 226         TRACE("EndSector (Plus 2 cylinder bits): 0x%x\n", BootRecord->PartitionTable[Index].EndSector);
 227         TRACE("EndCylinder: 0x%x\n", BootRecord->PartitionTable[Index].EndCylinder);
 228         TRACE("SectorCountBeforePartition: 0x%x\n", BootRecord->PartitionTable[Index].SectorCountBeforePartition);
 229         TRACE("PartitionSectorCount: 0x%x\n", BootRecord->PartitionTable[Index].PartitionSectorCount);
 230     }
 231
 232     // Check the partition table magic value
 233     if (BootRecord->MasterBootRecordMagic != 0xaa55)
 234     {
 235         return FALSE;
 236     }
 237
 238     return TRUE;
 239 }
 240
 241 NTSTATUS
 242 NTAPI
 243 IopReadBootRecord(
 244     IN PDEVICE_OBJECT DeviceObject,
 245     IN ULONGLONG LogicalSectorNumber,
 246     IN ULONG SectorSize,
 247     OUT PMASTER_BOOT_RECORD BootRecord)
 248 {
 249     ULONG FileId = (ULONG)DeviceObject;
 250     LARGE_INTEGER Position;
 251     ULONG BytesRead;
 252     ULONG Status;
 253
 254     Position.QuadPart = LogicalSectorNumber * SectorSize;
 255     Status = ArcSeek(FileId, &Position, SeekAbsolute);
 256     if (Status != ESUCCESS)
 257         return STATUS_IO_DEVICE_ERROR;
 258
 259     Status = ArcRead(FileId, BootRecord, SectorSize, &BytesRead);
 260     if (Status != ESUCCESS || BytesRead != SectorSize)
 261         return STATUS_IO_DEVICE_ERROR;
 262
 263     return STATUS_SUCCESS;
 264 }
 265
 266 BOOLEAN
 267 NTAPI
 268 IopCopyPartitionRecord(
 269     IN BOOLEAN ReturnRecognizedPartitions,
 270     IN ULONG SectorSize,
 271     IN PPARTITION_TABLE_ENTRY PartitionTableEntry,
 272     OUT PARTITION_INFORMATION *PartitionEntry)
 273 {
 274     BOOLEAN IsRecognized;
 275
 276     IsRecognized = TRUE; /* FIXME */
 277     if (!IsRecognized && ReturnRecognizedPartitions)
 278         return FALSE;
 279
 280     PartitionEntry->StartingOffset.QuadPart = (ULONGLONG)PartitionTableEntry->SectorCountBeforePartition * SectorSize;
 281     PartitionEntry->PartitionLength.QuadPart = (ULONGLONG)PartitionTableEntry->PartitionSectorCount * SectorSize;
 282     PartitionEntry->HiddenSectors = 0;
 283     PartitionEntry->PartitionNumber = 0; /* Will be filled later */
 284     PartitionEntry->PartitionType = PartitionTableEntry->SystemIndicator;
 285     PartitionEntry->BootIndicator = (PartitionTableEntry->BootIndicator & 0x80) ? TRUE : FALSE;
 286     PartitionEntry->RecognizedPartition = IsRecognized;
 287     PartitionEntry->RewritePartition = FALSE;
 288
 289     return TRUE;
 290 }
 291
 292 NTSTATUS
 293 FASTCALL
 294 IoReadPartitionTable(
 295     IN PDEVICE_OBJECT DeviceObject,
 296     IN ULONG SectorSize,
 297     IN BOOLEAN ReturnRecognizedPartitions,
 298     OUT PDRIVE_LAYOUT_INFORMATION *PartitionBuffer)
 299 {
 300     PMASTER_BOOT_RECORD MasterBootRecord;
 301     PDRIVE_LAYOUT_INFORMATION Partitions;
 302     ULONG NbPartitions, i, Size;
 303     NTSTATUS ret;
 304
 305     *PartitionBuffer = NULL;
 306
 307     if (SectorSize < sizeof(MASTER_BOOT_RECORD))
 308         return STATUS_NOT_SUPPORTED;
 309
 310     MasterBootRecord = ExAllocatePool(NonPagedPool, SectorSize);
 311     if (!MasterBootRecord)
 312         return STATUS_NO_MEMORY;
 313
 314     /* Read disk MBR */
 315     ret = IopReadBootRecord(DeviceObject, 0, SectorSize, MasterBootRecord);
 316     if (!NT_SUCCESS(ret))
 317     {
 318         ExFreePool(MasterBootRecord);
 319         return ret;
 320     }
 321
 322     /* Check validity of boot record */
 323     if (MasterBootRecord->MasterBootRecordMagic != 0xaa55)
 324     {
 325         ExFreePool(MasterBootRecord);
 326         return STATUS_NOT_SUPPORTED;
 327     }
 328
 329     /* Count number of partitions */
 330     NbPartitions = 0;
 331     for (i = 0; i < 4; i++)
 332     {
 333         NbPartitions++;
 334
 335         if (MasterBootRecord->PartitionTable[i].SystemIndicator == PARTITION_EXTENDED ||
 336             MasterBootRecord->PartitionTable[i].SystemIndicator == PARTITION_XINT13_EXTENDED)
 337         {
 338             /* FIXME: unhandled case; count number of partitions */
 339             UNIMPLEMENTED;
 340         }
 341     }
 342
 343     if (NbPartitions == 0)
 344     {
 345         ExFreePool(MasterBootRecord);
 346         return STATUS_NOT_SUPPORTED;
 347     }
 348
 349     /* Allocation space to store partitions */
 350     Size = FIELD_OFFSET(DRIVE_LAYOUT_INFORMATION, PartitionEntry) +
 351            NbPartitions * sizeof(PARTITION_INFORMATION);
 352     Partitions = ExAllocatePool(NonPagedPool, Size);
 353     if (!Partitions)
 354     {
 355         ExFreePool(MasterBootRecord);
 356         return STATUS_NO_MEMORY;
 357     }
 358
 359     /* Count number of partitions */
 360     NbPartitions = 0;
 361     for (i = 0; i < 4; i++)
 362     {
 363         if (IopCopyPartitionRecord(ReturnRecognizedPartitions,
 364                                    SectorSize,
 365                                    &MasterBootRecord->PartitionTable[i],
 366                                    &Partitions->PartitionEntry[NbPartitions]))
 367         {
 368             Partitions->PartitionEntry[NbPartitions].PartitionNumber = NbPartitions + 1;
 369             NbPartitions++;
 370         }
 371
 372         if (MasterBootRecord->PartitionTable[i].SystemIndicator == PARTITION_EXTENDED ||
 373             MasterBootRecord->PartitionTable[i].SystemIndicator == PARTITION_XINT13_EXTENDED)
 374         {
 375             /* FIXME: unhandled case; copy partitions */
 376             UNIMPLEMENTED;
 377         }
 378     }
 379
 380     Partitions->PartitionCount = NbPartitions;
 381     Partitions->Signature = MasterBootRecord->Signature;
 382     ExFreePool(MasterBootRecord);
 383
 384     *PartitionBuffer = Partitions;
 385     return STATUS_SUCCESS;
 386 }
 387
 388 #endif