* refind/gpt.c
* Functions related to GPT data structures
*
- * Copyright (c) 2014 Roderick W. Smith
+ * Copyright (c) 2014-2015 Roderick W. Smith
* All rights reserved.
*
- * This program is distributed under the terms of the GNU General Public
- * License (GPL) version 3 (GPLv3), a copy of which must be distributed
- * with this source code or binaries made from it.
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
*
- */
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
#include "gpt.h"
#include "lib.h"
#include "screen.h"
+#include "crc32.h"
#include "../include/refit_call_wrapper.h"
#ifdef __MAKEWITH_TIANO
extern GPT_DATA *gPartitions;
+// Allocate data for the main GPT_DATA structure, as well as the ProtectiveMBR
+// and Header structures it contains. This function does *NOT*, however,
+// allocate memory for the Entries data structure, since its size is variable
+// and is determined by the contents of Header.
GPT_DATA * AllocateGptData(VOID) {
GPT_DATA *GptData;
return GptData;
} // GPT_DATA * AllocateGptData()
+// Unallocate a single GPT_DATA structure. This does NOT follow the
+// linked list, though.
VOID ClearGptData(GPT_DATA *Data) {
if (Data) {
if (Data->ProtectiveMBR)
} // if
} // VOID ClearGptData()
-// TODO: Add more tests, like a CRC check.
-// Returns TRUE if the GPT header data appear valid, FALSE otherwise.
-static BOOLEAN GptHeaderValid(GPT_HEADER *Header) {
- BOOLEAN IsValid = TRUE;
+// TODO: Make this work on big-endian systems; at the moment, it contains
+// little-endian assumptions!
+// Returns TRUE if the GPT protective MBR and header data appear valid,
+// FALSE otherwise.
+static BOOLEAN GptHeaderValid(GPT_DATA *GptData) {
+ BOOLEAN IsValid;
+ UINT32 CrcValue, StoredCrcValue;
+ UINTN HeaderSize = sizeof(GPT_HEADER);
+
+ if ((GptData == NULL) || (GptData->ProtectiveMBR == NULL) || (GptData->Header == NULL))
+ return FALSE;
+
+ IsValid = (GptData->ProtectiveMBR->MBRSignature == 0xAA55);
+ IsValid = IsValid && ((GptData->ProtectiveMBR->partitions[0].type == 0xEE) ||
+ (GptData->ProtectiveMBR->partitions[1].type == 0xEE) ||
+ (GptData->ProtectiveMBR->partitions[2].type == 0xEE) ||
+ (GptData->ProtectiveMBR->partitions[3].type == 0xEE));
- if ((Header->signature != 0x5452415020494645ULL) || (Header->entry_count > 2048))
- IsValid = FALSE;
+ IsValid = IsValid && ((GptData->Header->signature == 0x5452415020494645ULL) &&
+ (GptData->Header->spec_revision == 0x00010000) &&
+ (GptData->Header->entry_size == 128));
+
+ // Looks good so far; check CRC value....
+ if (IsValid) {
+ if (GptData->Header->header_size < HeaderSize)
+ HeaderSize = GptData->Header->header_size;
+ StoredCrcValue = GptData->Header->header_crc32;
+ GptData->Header->header_crc32 = 0;
+ CrcValue = crc32(0x0, GptData->Header, HeaderSize);
+ if (CrcValue != StoredCrcValue)
+ IsValid = FALSE;
+ GptData->Header->header_crc32 = StoredCrcValue;
+ } // if
return IsValid;
-} // BOOLEAN GptHeaderValid
+} // BOOLEAN GptHeaderValid()
-// Read GPT data from Volume and store it in Data. Note that this function
-// may be called on a Volume that is not in fact the protective MBR of a GPT
-// disk, in which case it will return EFI_LOAD_ERROR or some other error
-// condition. In this case, *Data will be left alone.
+// Read GPT data from Volume and store it in *Data. Note that this function
+// may be called on a Volume that is not in fact a GPT disk (an MBR disk,
+// a partition, etc.), in which case it will return EFI_LOAD_ERROR or some
+// other error condition. In this case, *Data will be left alone.
+// Note also that this function checks CRCs and does other sanity checks
+// on the input data, but does NOT resort to using the backup data if the
+// primary data structures are damaged. The intent is that the function
+// be very conservative about reading GPT data. Currently (version 0.7.10),
+// rEFInd uses the data only to provide access to partition names. This is
+// non-critical data, so it's OK to return nothing, but having the program
+// hang on reading garbage or return nonsense could be very bad.
EFI_STATUS ReadGptData(REFIT_VOLUME *Volume, GPT_DATA **Data) {
EFI_STATUS Status = EFI_SUCCESS;
UINT64 BufferSize;
- GPT_DATA *GptData; // Temporary holding storage; transferred to *Data later
+ UINTN i;
+ GPT_DATA *GptData = NULL; // Temporary holding storage; transferred to *Data later
if ((Volume == NULL) || (Data == NULL))
- Status = EFI_INVALID_PARAMETER;
+ return EFI_INVALID_PARAMETER;
// get block i/o
if ((Status == EFI_SUCCESS) && (Volume->BlockIO == NULL)) {
Status = refit_call3_wrapper(BS->HandleProtocol, Volume->DeviceHandle, &BlockIoProtocol, (VOID **) &(Volume->BlockIO));
if (EFI_ERROR(Status)) {
Volume->BlockIO = NULL;
- Print(L"Warning: Can't get BlockIO protocol.\n");
- Status = EFI_INVALID_PARAMETER;
+ Print(L"Warning: Can't get BlockIO protocol in ReadGptData().\n");
+ Status = EFI_NOT_READY;
}
} // if
Status = EFI_NO_MEDIA;
if (Status == EFI_SUCCESS) {
- GptData = AllocateGptData();
+ GptData = AllocateGptData(); // Note: All but GptData->Entries
if (GptData == NULL) {
Status = EFI_OUT_OF_RESOURCES;
} // if
// Read the MBR and store it in GptData->ProtectiveMBR.
if (Status == EFI_SUCCESS) {
Status = refit_call5_wrapper(Volume->BlockIO->ReadBlocks, Volume->BlockIO, Volume->BlockIO->Media->MediaId,
- 0, 512, (VOID*) GptData->ProtectiveMBR);
+ 0, sizeof(MBR_RECORD), (VOID*) GptData->ProtectiveMBR);
}
- // If it looks like a valid protective MBR, try to do more with it....
- if ((Status == EFI_SUCCESS) && (GptData->ProtectiveMBR->MBRSignature == 0xAA55) &&
- ((GptData->ProtectiveMBR->partitions[0].type == 0xEE) || (GptData->ProtectiveMBR->partitions[1].type == 0xEE) ||
- (GptData->ProtectiveMBR->partitions[2].type = 0xEE) || (GptData->ProtectiveMBR->partitions[3].type == 0xEE))) {
+ // Read the GPT header and store it in GptData->Header.
+ if (Status == EFI_SUCCESS) {
Status = refit_call5_wrapper(Volume->BlockIO->ReadBlocks, Volume->BlockIO, Volume->BlockIO->Media->MediaId,
1, sizeof(GPT_HEADER), GptData->Header);
+ }
- // Do basic sanity check on GPT header.
- if ((Status == EFI_SUCCESS) && !GptHeaderValid(GptData->Header)) {
- Status = EFI_UNSUPPORTED;
- }
-
- // Load actual GPT table....
- if (Status == EFI_SUCCESS) {
+ // If it looks like a valid protective MBR & GPT header, try to do more with it....
+ if (Status == EFI_SUCCESS) {
+ if (GptHeaderValid(GptData)) {
+ // Load actual GPT table....
BufferSize = GptData->Header->entry_count * 128;
- if (GptData->Entries != NULL)
- MyFreePool(GptData->Entries);
GptData->Entries = AllocatePool(BufferSize);
- if (GptData->Entries == NULL) {
+ if (GptData->Entries == NULL)
Status = EFI_OUT_OF_RESOURCES;
- } // if
- } // if
- if (Status == EFI_SUCCESS) {
- Status = refit_call5_wrapper(Volume->BlockIO->ReadBlocks, Volume->BlockIO, Volume->BlockIO->Media->MediaId,
- GptData->Header->header_lba, BufferSize, GptData->Entries);
- } // if
+ if (Status == EFI_SUCCESS)
+ Status = refit_call5_wrapper(Volume->BlockIO->ReadBlocks, Volume->BlockIO, Volume->BlockIO->Media->MediaId,
+ GptData->Header->entry_lba, BufferSize, GptData->Entries);
- } else {
- Status = EFI_LOAD_ERROR;
- } // if/else
+ // Check CRC status of table
+ if ((Status == EFI_SUCCESS) && (crc32(0x0, GptData->Entries, BufferSize) != GptData->Header->entry_crc32))
+ Status = EFI_CRC_ERROR;
+
+ // Now, ensure that every name is null-terminated....
+ if (Status == EFI_SUCCESS) {
+ for (i = 0; i < GptData->Header->entry_count; i++)
+ GptData->Entries[i].name[35] = '\0';
+ } // if
+ } else {
+ Status = EFI_UNSUPPORTED;
+ } // if/else valid header
+ } // if header read OK
if (Status == EFI_SUCCESS) {
// Everything looks OK, so copy it over
} // EFI_STATUS ReadGptData()
// Look in gPartitions for a partition with the specified Guid. If found, return
-// a pointer to that partition's name string. If not found, return a NULL pointer.
+// a pointer to that partition's data. If not found, return a NULL pointer.
// The calling function is responsible for freeing the returned memory.
-CHAR16 * PartNameFromGuid(EFI_GUID *Guid) {
+GPT_ENTRY * FindPartWithGuid(EFI_GUID *Guid) {
UINTN i;
- CHAR16 *Found = NULL;
+ GPT_ENTRY *Found = NULL;
GPT_DATA *GptData;
if ((Guid == NULL) || (gPartitions == NULL))
while ((GptData != NULL) && (!Found)) {
i = 0;
while ((i < GptData->Header->entry_count) && (!Found)) {
- if (GuidsAreEqual((EFI_GUID*) &(GptData->Entries[i].partition_guid), Guid))
- Found = StrDuplicate(GptData->Entries[i].name);
- else
+ if (GuidsAreEqual((EFI_GUID*) &(GptData->Entries[i].partition_guid), Guid)) {
+ Found = AllocateZeroPool(sizeof(GPT_ENTRY));
+ CopyMem(Found, &GptData->Entries[i], sizeof(GPT_ENTRY));
+ } else {
i++;
+ } // if/else
} // while(scanning entries)
GptData = GptData->NextEntry;
} // while(scanning GPTs)
return Found;
-} // CHAR16 * PartNameFromGuid()
+} // GPT_ENTRY * FindPartWithGuid()
// Erase the gPartitions linked-list data structure
VOID ForgetPartitionTables(VOID) {
VOID AddPartitionTable(REFIT_VOLUME *Volume) {
GPT_DATA *GptData = NULL, *GptList;
EFI_STATUS Status;
+ UINTN NumTables = 1;
Status = ReadGptData(Volume, &GptData);
if (Status == EFI_SUCCESS) {
GptList = gPartitions;
while (GptList->NextEntry != NULL) {
GptList = GptList->NextEntry;
+ NumTables++;
} // while
GptList->NextEntry = GptData;
+ NumTables++;
} // if/else
} else if (GptData != NULL) {
ClearGptData(GptData);
+ NumTables = 0;
} // if/else
} // VOID AddPartitionTable()