X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/7f5dab4f261e08972d3f31512c970c29e54707d1..dddb709c433f688597f6b8d8130eb42bd8d1667e:/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c diff --git a/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c b/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c index 883586c3d..0bcda0620 100644 --- a/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c +++ b/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c @@ -28,8 +28,26 @@ this software. */ +/** \file + * + * Virtualized FAT12 filesystem implementation, to perform self-programming + * in response to read and write requests to the virtual filesystem by the + * host PC. + */ + +#define INCLUDE_FROM_VIRTUAL_FAT_C #include "VirtualFAT.h" +/** FAT filesystem boot sector block, must be the first sector on the physical + * disk so that the host can identify the presence of a FAT filesystem. This + * block is truncated; normally a large bootstrap section is located near the + * end of the block for booting purposes however as this is not meant to be a + * bootable disk it is omitted for space reasons. + * + * \note When returning the boot block to the host, the magic signature 0xAA55 + * must be added to the very end of the block to identify it as a boot + * block. + */ static const FATBootBlock_t BootBlock = { .Bootstrap = {0xEB, 0x3C, 0x90}, @@ -42,106 +60,168 @@ static const FATBootBlock_t BootBlock = .TotalSectors16 = LUN_MEDIA_BLOCKS, .MediaDescriptor = 0xF8, .SectorsPerFAT = 1, - .SectorsPerTrack = 32, - .Heads = 64, + .SectorsPerTrack = (LUN_MEDIA_BLOCKS % 64), + .Heads = (LUN_MEDIA_BLOCKS / 64), .HiddenSectors = 0, .TotalSectors32 = 0, .PhysicalDriveNum = 0, .ExtendedBootRecordSig = 0x29, .VolumeSerialNumber = 0x12345678, .VolumeLabel = "LUFA BOOT ", - .FilesystemIdentifier = "FAT16 ", - .BootstrapProgram = {0}, - .MagicSignature = 0xAA55, + .FilesystemIdentifier = "FAT12 ", }; +/** FAT 8.3 style directory entry, for the virtual FLASH contents file. */ static FATDirectoryEntry_t FirmwareFileEntry = { - .Filename = "FIRMWARE", - .Extension = "BIN", - .Attributes = 0, - .Reserved = {0}, - .CreationTime = FAT_TIME(1, 1, 0), - .CreationDate = FAT_DATE(14, 2, 1989), - .StartingCluster = 2, - .FileSizeBytes = 2049, + .Filename = "FIRMWARE", + .Extension = "BIN", + .Attributes = 0, + .Reserved = {0}, + .CreationTime = FAT_TIME(1, 1, 0), + .CreationDate = FAT_DATE(14, 2, 1989), + .StartingCluster = 2, + .FileSizeBytes = FIRMWARE_FILE_SIZE_BYTES, }; -static void WriteBlock(uint16_t BlockNumber) +/** Updates a FAT12 cluster entry in the FAT file table with the specified next + * chain index. If the cluster is the last in the file chain, the magic value + * 0xFFF is used. + * + * \note FAT data cluster indexes are offset by 2, so that cluster 2 is the + * first file data cluster on the disk. See the FAT specification. + * + * \param[out] FATTable Pointer to the FAT12 allocation table + * \param[in] Index Index of the cluster entry to update + * \param[in] ChainEntry Next cluster index in the file chain + */ +static void UpdateFAT12ClusterEntry(uint8_t* const FATTable, + const uint16_t Index, + const uint16_t ChainEntry) { - uint8_t BlockBuffer[512]; + /* Calculate the starting offset of the cluster entry in the FAT12 table */ + uint8_t FATOffset = (Index * 3) / 2; + bool UpperNibble = (((Index * 3) % 2) != 0); - /* Wait until endpoint is ready before continuing */ - if (Endpoint_WaitUntilReady()) - return; + /* 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); + } +} +/** Writes a block of data to the virtual FAT filesystem, from the USB Mass + * Storage interface. + * + * \param[in] BlockNumber Index of the block to write. + */ +static void WriteVirtualBlock(const uint16_t BlockNumber) +{ + uint8_t BlockBuffer[SECTOR_SIZE_BYTES]; + + /* Buffer the entire block to be written from the host */ Endpoint_Read_Stream_LE(BlockBuffer, sizeof(BlockBuffer), NULL); Endpoint_ClearOUT(); - printf("WRITE %d\r\n", BlockNumber); - // TODO: Write to FLASH + if ((BlockNumber >= 4) && (BlockNumber < (4 + FILE_SECTORS(FIRMWARE_FILE_SIZE_BYTES)))) + { + uint32_t WriteFlashAddress = (uint32_t)(BlockNumber - 4) * SECTOR_SIZE_BYTES; + + for (uint16_t i = 0; i < SECTOR_SIZE_BYTES; i += 2) + { + if ((WriteFlashAddress % SPM_PAGESIZE) == 0) + { + /* Erase the given FLASH page, ready to be programmed */ + boot_page_erase(WriteFlashAddress); + boot_spm_busy_wait(); + } + + /* Write the next data word to the FLASH page */ + boot_page_fill(WriteFlashAddress, (BlockBuffer[i + 1] << 8) | BlockBuffer[i]); + WriteFlashAddress += 2; + + if ((WriteFlashAddress % SPM_PAGESIZE) == 0) + { + /* Write the filled FLASH page to memory */ + boot_page_write(WriteFlashAddress - SPM_PAGESIZE); + boot_spm_busy_wait(); + } + } + } } -static void ReadBlock(uint16_t BlockNumber) +/** Reads a block of data from the virtual FAT filesystem, and sends it to the + * host via the USB Mass Storage interface. + * + * \param[in] BlockNumber Index of the block to read. + */ +static void ReadVirtualBlock(const uint16_t BlockNumber) { - uint8_t BlockBuffer[512]; + uint8_t BlockBuffer[SECTOR_SIZE_BYTES]; memset(BlockBuffer, 0x00, sizeof(BlockBuffer)); - printf("READ %d", BlockNumber); - switch (BlockNumber) { - case 0: + case 0: /* Block 0: Boot block sector */ memcpy(BlockBuffer, &BootBlock, sizeof(FATBootBlock_t)); - printf(" \r\n"); - break; - case 1: - case 2: - printf(" \r\n"); + /* Add the magic signature to the end of the block */ + BlockBuffer[SECTOR_SIZE_BYTES - 2] = 0x55; + BlockBuffer[SECTOR_SIZE_BYTES - 1] = 0xAA; + break; + case 1: /* Block 1: First FAT12 cluster chain copy */ + case 2: /* Block 2: Second FAT12 cluster chain copy */ /* Cluster 0: Media type/Reserved */ - ((uint16_t*)&BlockBuffer)[0] = 0xFF00 | BootBlock.MediaDescriptor; + UpdateFAT12ClusterEntry(BlockBuffer, 0, 0xF00 | BootBlock.MediaDescriptor); /* Cluster 1: Reserved */ - ((uint16_t*)&BlockBuffer)[1] = 0xFFFF; + UpdateFAT12ClusterEntry(BlockBuffer, 1, 0xFFF); /* Cluster 2 onwards: Cluster chain of FIRMWARE.BIN */ - for (uint16_t i = 0; i < FILE_CLUSTERS(2049); i++) - { - ((uint16_t*)&BlockBuffer)[i + 2] = i + 3; - } + for (uint16_t i = 0; i < FILE_CLUSTERS(FIRMWARE_FILE_SIZE_BYTES); i++) + UpdateFAT12ClusterEntry(BlockBuffer, i+2, i+3); /* Mark last cluster as end of file */ - ((uint16_t*)&BlockBuffer)[FILE_CLUSTERS(2049) + 3] = 0xFFFF; + UpdateFAT12ClusterEntry(BlockBuffer, FILE_CLUSTERS(FIRMWARE_FILE_SIZE_BYTES) + 1, 0xFFF); break; - case 3: - printf("\r\n"); + case 3: /* Block 3: Root file entries */ memcpy(BlockBuffer, &FirmwareFileEntry, sizeof(FATDirectoryEntry_t)); break; - default: - if ((BlockNumber >= 4) && (BlockNumber < (4 + FILE_CLUSTERS(FIRMWARE_FILE_SIZE)))) + default: /* Blocks 4 onwards: Data allocation section */ + if ((BlockNumber >= 4) && (BlockNumber < (4 + FILE_SECTORS(FIRMWARE_FILE_SIZE_BYTES)))) { - printf("\r\n"); + uint32_t ReadFlashAddress = (uint32_t)(BlockNumber - 4) * SECTOR_SIZE_BYTES; - for (uint16_t i = 0; i < 512; i++) - BlockBuffer[i] = '0' + BlockNumber; //A' + (i % 26); + for (uint16_t i = 0; i < SECTOR_SIZE_BYTES; i++) + BlockBuffer[i] = pgm_read_byte_far(ReadFlashAddress++); } break; } - /* Wait until endpoint is ready before continuing */ - if (Endpoint_WaitUntilReady()) - return; - + /* Write the entire read block Buffer to the host */ Endpoint_Write_Stream_LE(BlockBuffer, sizeof(BlockBuffer), NULL); Endpoint_ClearIN(); } +/** Writes a number of blocks to the virtual FAT file system, from the host + * PC via the USB Mass Storage interface. + * + * \param[in] MSInterfaceInfo Pointer to a structure containing a Mass Storage Class configuration and state + * \param[in] BlockAddress Data block starting address for the write sequence + * \param[in] TotalBlocks Number of blocks of data to write + */ void VirtualFAT_WriteBlocks(USB_ClassInfo_MS_Device_t* const MSInterfaceInfo, const uint32_t BlockAddress, uint16_t TotalBlocks) @@ -149,11 +229,18 @@ void VirtualFAT_WriteBlocks(USB_ClassInfo_MS_Device_t* const MSInterfaceInfo, uint16_t CurrentBlock = (uint16_t)BlockAddress; /* Emulated FAT is performed per-block, pass each requested block index - * to the emulation function */ + * to the emulated FAT block write function */ while (TotalBlocks--) - WriteBlock(CurrentBlock++); + WriteVirtualBlock(CurrentBlock++); } +/** Reads a number of blocks from the virtual FAT file system, and sends them + * to the host PC via the USB Mass Storage interface. + * + * \param[in] MSInterfaceInfo Pointer to a structure containing a Mass Storage Class configuration and state + * \param[in] BlockAddress Data block starting address for the read sequence + * \param[in] TotalBlocks Number of blocks of data to read + */ void VirtualFAT_ReadBlocks(USB_ClassInfo_MS_Device_t* const MSInterfaceInfo, const uint32_t BlockAddress, uint16_t TotalBlocks) @@ -161,8 +248,8 @@ void VirtualFAT_ReadBlocks(USB_ClassInfo_MS_Device_t* const MSInterfaceInfo, uint16_t CurrentBlock = (uint16_t)BlockAddress; /* Emulated FAT is performed per-block, pass each requested block index - * to the emulation function */ + * to the emulated FAT block read function */ while (TotalBlocks--) - ReadBlock(CurrentBlock++); + ReadVirtualBlock(CurrentBlock++); }