diff options
| -rw-r--r-- | Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c | 72 |
1 files changed, 38 insertions, 34 deletions
diff --git a/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c b/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c index b111a5352..d43ac86cb 100644 --- a/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c +++ b/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c @@ -64,10 +64,33 @@ static FATDirectoryEntry_t FirmwareFileEntry = .CreationTime = FAT_TIME(1, 1, 0), .CreationDate = FAT_DATE(14, 2, 1989), .StartingCluster = 2, - .FileSizeBytes = 2049, + .FileSizeBytes = FIRMWARE_FILE_SIZE, }; -static void WriteBlock(uint16_t BlockNumber) + +static void UpdateFAT12ClusterEntry(uint8_t* FATTable, + const uint16_t Index, + const uint16_t ChainEntry) +{ + /* Calculate the starting offset of the cluster entry in the FAT12 table */ + uint8_t FATOffset = (Index * 3) / 2; + bool UpperNibble = (((Index * 3) % 2) != 0); + + /* Check if the start of the entry is at an upper nibble of the byte, fill + * out FAT12 entry as required */ + if (UpperNibble) + { + FATTable[FATOffset] = (FATTable[FATOffset] & 0x0F) | ((ChainEntry & 0x0F) << 4); + FATTable[FATOffset + 1] = (ChainEntry >> 4); + } + else + { + FATTable[FATOffset] = ChainEntry; + FATTable[FATOffset + 1] = (FATTable[FATOffset] & 0xF0) | (ChainEntry >> 8); + } +} + +static void WriteBlock(const uint16_t BlockNumber) { uint8_t BlockBuffer[512]; @@ -82,67 +105,48 @@ static void WriteBlock(uint16_t BlockNumber) // TODO: Write to FLASH } -void WriteFAT12ClusterEntry(uint8_t* FATTable, uint8_t Index, uint16_t NextEntry) -{ - uint8_t StartOffset = ((uint16_t)Index * 3) / 2; - - /* Check if the start of the entry is at an upper nibble of the byte */ - if (((uint16_t)Index * 3) % 2) - { - FATTable[StartOffset] |= ((NextEntry & 0x0F) << 4); - FATTable[StartOffset + 1] = (NextEntry >> 4); - } - else - { - FATTable[StartOffset] = NextEntry; - FATTable[StartOffset + 1] = (NextEntry >> 8); - } -} - -static void ReadBlock(uint16_t BlockNumber) +static void ReadBlock(const uint16_t BlockNumber) { uint8_t BlockBuffer[512]; memset(BlockBuffer, 0x00, sizeof(BlockBuffer)); - printf("READ %d", BlockNumber); - switch (BlockNumber) { case 0: memcpy(BlockBuffer, &BootBlock, sizeof(FATBootBlock_t)); - printf(" <B>\r\n"); break; case 1: case 2: - printf(" <F>\r\n"); - /* Cluster 0: Media type/Reserved */ - WriteFAT12ClusterEntry(BlockBuffer, 0, 0xF00 | BootBlock.MediaDescriptor); + UpdateFAT12ClusterEntry(BlockBuffer, 0, 0xF00 | BootBlock.MediaDescriptor); /* Cluster 1: Reserved */ - WriteFAT12ClusterEntry(BlockBuffer, 1, 0xFFF); + UpdateFAT12ClusterEntry(BlockBuffer, 1, 0xFFF); /* Cluster 2 onwards: Cluster chain of FIRMWARE.BIN */ - for (uint16_t i = 0; i < FILE_CLUSTERS(2049); i++) - WriteFAT12ClusterEntry(BlockBuffer, i+2, i+3); + for (uint16_t i = 0; i < FILE_CLUSTERS(FIRMWARE_FILE_SIZE); i++) + UpdateFAT12ClusterEntry(BlockBuffer, i+2, i+3); /* Mark last cluster as end of file */ - WriteFAT12ClusterEntry(BlockBuffer, FILE_CLUSTERS(2049) + 1, 0xFFF); + UpdateFAT12ClusterEntry(BlockBuffer, FILE_CLUSTERS(FIRMWARE_FILE_SIZE) + 1, 0xFFF); break; case 3: - printf("<R>\r\n"); memcpy(BlockBuffer, &FirmwareFileEntry, sizeof(FATDirectoryEntry_t)); break; default: - if ((BlockNumber >= 4) && (BlockNumber < (4 + FILE_CLUSTERS(FIRMWARE_FILE_SIZE)))) + if ((BlockNumber >= 4) && (BlockNumber < (4 + (FIRMWARE_FILE_SIZE / SECTOR_SIZE_BYTES)))) { - printf("<D>\r\n"); +// printf("<D>\r\n"); for (uint16_t i = 0; i < 512; i++) - BlockBuffer[i] = '0' + BlockNumber; //A' + (i % 26); + BlockBuffer[i] = 'A' + (i % 26); + } + else + { + printf("INVALID %d\r\n", BlockNumber); } break; |