LineageOS/android_external_gptfdisk
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Initial commit of support for moving main partition table to arbitrary

Browse Source 
location on disk (within limits based on existing partitions).
This commit is contained in:
Rod Smith
2017-07-21 21:48:13 -04:00
parent e7452642ac
commit 503e9ada12
10 changed files with 123 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

56
gpt.cc
View File

@@ -276,6 +276,23 @@ int GPTData::Verify(void) {
<< "The 'e' option on the experts' menu may fix this problem.\n";
} // if
// Check the main and backup partition tables for overlap with things
if (mainHeader.partitionEntriesLBA + GetTableSizeInSectors() > mainHeader.firstUsableLBA) {
problems++;
cout << "\nProblem: Main partition table extends past the first usable LBA.\n"
<< "Using 'j' on the experts' menu may enable fixing this problem.\n";
} // if
if (mainHeader.partitionEntriesLBA < 2) {
problems++;
cout << "\nProblem: Main partition table appears impossibly early on the disk.\n"
<< "Using 'j' on the experts' menu may enable fixing this problem.\n";
} // if
if (secondHeader.partitionEntriesLBA + GetTableSizeInSectors() > secondHeader.currentLBA) {
problems++;
cout << "\nProblem: The backup partition table overlaps the backup header.\n"
<< "Using 'e' on the experts' menu may fix this problem.\n";
} // if
if ((mainHeader.lastUsableLBA >= diskSize) || (mainHeader.lastUsableLBA > mainHeader.backupLBA)) {
problems++;
cout << "\nProblem: GPT claims the disk is larger than it is! (Claimed last usable\n"
@@ -552,8 +569,8 @@ void GPTData::RebuildMainHeader(void) {
mainHeader.firstUsableLBA = secondHeader.firstUsableLBA;
mainHeader.lastUsableLBA = secondHeader.lastUsableLBA;
mainHeader.diskGUID = secondHeader.diskGUID;
mainHeader.partitionEntriesLBA = UINT64_C(2);
mainHeader.numParts = secondHeader.numParts;
mainHeader.partitionEntriesLBA = secondHeader.firstUsableLBA - GetTableSizeInSectors();
mainHeader.sizeOfPartitionEntries = secondHeader.sizeOfPartitionEntries;
mainHeader.partitionEntriesCRC = secondHeader.partitionEntriesCRC;
memcpy(mainHeader.reserved2, secondHeader.reserved2, sizeof(mainHeader.reserved2));
@@ -658,7 +675,7 @@ int GPTData::FindInsanePartitions(void) {
} // if
if (partitions[i].GetLastLBA() >= diskSize) {
problems++;
cout << "\nProblem: partition " << i + 1 << " is too big for the disk.\n";
cout << "\nProblem: partition " << i + 1 << " is too big for the disk.\n";
} // if
} // if
} // for
@@ -1441,6 +1458,8 @@ void GPTData::DisplayGPTData(void) {
cout << "Logical sector size: " << blockSize << " bytes\n";
cout << "Disk identifier (GUID): " << mainHeader.diskGUID << "\n";
cout << "Partition table holds up to " << numParts << " entries\n";
cout << "Main partition table begins at sector " << mainHeader.partitionEntriesLBA
<< " and ends at sector " << mainHeader.partitionEntriesLBA + GetTableSizeInSectors() - 1 << "\n";
cout << "First usable sector is " << mainHeader.firstUsableLBA
<< ", last usable sector is " << mainHeader.lastUsableLBA << "\n";
totalFree = FindFreeBlocks(&i, &temp);
@@ -1732,7 +1751,7 @@ int GPTData::SetGPTSize(uint32_t numEntries, int fillGPTSectors) {
partitions = newParts;
} // if/else existing partitions
numParts = numEntries;
mainHeader.firstUsableLBA = ((numEntries * GPT_SIZE) / blockSize) + (((numEntries * GPT_SIZE) % blockSize) != 0) + 2 ;
mainHeader.firstUsableLBA = GetTableSizeInSectors() + mainHeader.partitionEntriesLBA;
secondHeader.firstUsableLBA = mainHeader.firstUsableLBA;
MoveSecondHeaderToEnd();
if (diskSize > 0)
@@ -1747,6 +1766,23 @@ int GPTData::SetGPTSize(uint32_t numEntries, int fillGPTSectors) {
return (allOK);
} // GPTData::SetGPTSize()
// Change the start sector for the main partition table.
// Returns 1 on success, 0 on failure
int GPTData::MoveMainTable(uint64_t pteSector) {
uint64_t pteSize = GetTableSizeInSectors();
int retval = 1;
if ((pteSector >= 2) && ((pteSector + pteSize) <= FindFirstUsedLBA())) {
mainHeader.partitionEntriesLBA = pteSector;
mainHeader.firstUsableLBA = pteSector + pteSize;
RebuildSecondHeader();
} else {
cerr << "Unable to set the main partition table's location to " << pteSector << "!\n";
retval = 0;
} // if/else
return retval;
} // GPTData::MoveMainTable()
// Blank the partition array
void GPTData::BlankPartitions(void) {
uint32_t i;
@@ -2121,6 +2157,20 @@ uint64_t GPTData::FindFirstAvailable(uint64_t start) {
return (first);
} // GPTData::FindFirstAvailable()
// Returns the LBA of the start of the first partition on the disk (by
// sector number), or 0 if there are no partitions defined.
uint64_t GPTData::FindFirstUsedLBA(void) {
uint32_t i;
uint64_t firstFound = UINT64_MAX;
for (i = 0; i < numParts; i++) {
if ((partitions[i].IsUsed()) && (partitions[i].GetFirstLBA() < firstFound)) {
firstFound = partitions[i].GetFirstLBA();
} // if
} // for
return firstFound;
} // GPTData::FindFirstUsedLBA()
// Finds the first available sector in the largest block of unallocated
// space on the disk. Returns 0 if there are no available blocks left
uint64_t GPTData::FindFirstInLargest(void) {