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support filesystem with only 1 fat

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This commit is contained in:
hathach 2022-10-05 18:11:00 +07:00
parent 628effa1c2
commit 84abec80a8
2 changed files with 11 additions and 5 deletions
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5
src/FatLib/FatPartition.cpp
View file

@ -431,10 +431,11 @@ bool FatPartition::init(FsBlockDevice* dev, uint8_t part, uint32_t volStart) {
goto fail;
}
bpb = reinterpret_cast<BpbFat32_t*>(pbs->bpb);
if (bpb->fatCount != 2 || getLe16(bpb->bytesPerSector) != m_bytesPerSector) {
if ( !(bpb->fatCount == 1 || bpb->fatCount == 2) || getLe16(bpb->bytesPerSector) != m_bytesPerSector) {
DBG_FAIL_MACRO;
goto fail;
}
m_fatCount = bpb->fatCount;
m_sectorsPerCluster = bpb->sectorsPerCluster;
m_clusterSectorMask = m_sectorsPerCluster - 1;
// determine shift that is same as multiply by m_sectorsPerCluster
@ -456,7 +457,7 @@ bool FatPartition::init(FsBlockDevice* dev, uint8_t part, uint32_t volStart) {
m_rootDirEntryCount = getLe16(bpb->rootDirEntryCount);
// directory start for FAT16 dataStart for FAT32
m_rootDirStart = m_fatStartSector + 2 * m_sectorsPerFat;
m_rootDirStart = m_fatStartSector + m_fatCount * m_sectorsPerFat;
// data start for FAT16 and FAT32
m_dataStartSector = m_rootDirStart +
((FS_DIR_SIZE*m_rootDirEntryCount + m_bytesPerSector - 1)/m_bytesPerSector);

11
src/FatLib/FatPartition.h
View file

@ -184,11 +184,12 @@ class FatPartition {
static const uint16_t m_bytesPerSector = 1 << m_bytesPerSectorShift;
static const uint16_t m_sectorMask = m_bytesPerSector - 1;
//----------------------------------------------------------------------------
FsBlockDevice* m_blockDev; // sector device
FsBlockDevice* m_blockDev; // sector device
uint8_t m_sectorsPerCluster; // Cluster size in sectors.
uint8_t m_clusterSectorMask; // Mask to extract sector of cluster.
uint8_t m_sectorsPerClusterShift; // Cluster count to sector count shift.
uint8_t m_fatType = 0; // Volume type (12, 16, OR 32).
uint8_t m_fatCount; // Number of FAT (1 or 2)
uint16_t m_rootDirEntryCount; // Number of entries in FAT16 root dir.
uint32_t m_allocSearchStart; // Start cluster for alloc search.
uint32_t m_sectorsPerFat; // FAT size in sectors
@ -240,7 +241,9 @@ class FatPartition {
#if USE_SEPARATE_FAT_CACHE
FsCache m_fatCache;
uint8_t* fatCachePrepare(uint32_t sector, uint8_t options) {
options |= FsCache::CACHE_STATUS_MIRROR_FAT;
if ( m_fatCount == 2) {
options |= FsCache::CACHE_STATUS_MIRROR_FAT;
}
return m_fatCache.prepare(sector, options);
}
bool cacheSync() {
@ -248,7 +251,9 @@ class FatPartition {
}
#else // USE_SEPARATE_FAT_CACHE
uint8_t* fatCachePrepare(uint32_t sector, uint8_t options) {
options |= FsCache::CACHE_STATUS_MIRROR_FAT;
if ( m_fatCount == 2) {
options |= FsCache::CACHE_STATUS_MIRROR_FAT;
}
return dataCachePrepare(sector, options);
}
bool cacheSync() {