483 lines
16 KiB
C
483 lines
16 KiB
C
/*
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LUFA Library
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Copyright (C) Dean Camera, 2019.
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dean [at] fourwalledcubicle [dot] com
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www.lufa-lib.org
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*/
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/*
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Copyright 2019 Dean Camera (dean [at] fourwalledcubicle [dot] com)
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Permission to use, copy, modify, distribute, and sell this
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software and its documentation for any purpose is hereby granted
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without fee, provided that the above copyright notice appear in
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all copies and that both that the copyright notice and this
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permission notice and warranty disclaimer appear in supporting
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documentation, and that the name of the author not be used in
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advertising or publicity pertaining to distribution of the
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software without specific, written prior permission.
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The author disclaims all warranties with regard to this
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software, including all implied warranties of merchantability
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and fitness. In no event shall the author be liable for any
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special, indirect or consequential damages or any damages
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whatsoever resulting from loss of use, data or profits, whether
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in an action of contract, negligence or other tortious action,
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arising out of or in connection with the use or performance of
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this software.
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*/
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/** \file
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*
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* Virtualized FAT12 filesystem implementation, to perform self-programming
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* in response to read and write requests to the virtual filesystem by the
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* host PC.
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*/
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#define INCLUDE_FROM_VIRTUAL_FAT_C
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#include "VirtualFAT.h"
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/** FAT filesystem boot sector block, must be the first sector on the physical
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* disk so that the host can identify the presence of a FAT filesystem. This
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* block is truncated; normally a large bootstrap section is located near the
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* end of the block for booting purposes however as this is not meant to be a
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* bootable disk it is omitted for space reasons.
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*
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* \note When returning the boot block to the host, the magic signature 0xAA55
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* must be added to the very end of the block to identify it as a boot
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* block.
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*/
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static const FATBootBlock_t BootBlock =
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{
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.Bootstrap = {0xEB, 0x3C, 0x90},
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.Description = "mkdosfs",
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.SectorSize = SECTOR_SIZE_BYTES,
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.SectorsPerCluster = SECTOR_PER_CLUSTER,
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.ReservedSectors = 1,
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.FATCopies = 2,
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.RootDirectoryEntries = (SECTOR_SIZE_BYTES / sizeof(FATDirectoryEntry_t)),
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.TotalSectors16 = LUN_MEDIA_BLOCKS,
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.MediaDescriptor = 0xF8,
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.SectorsPerFAT = 1,
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.SectorsPerTrack = (LUN_MEDIA_BLOCKS % 64),
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.Heads = (LUN_MEDIA_BLOCKS / 64),
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.HiddenSectors = 0,
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.TotalSectors32 = 0,
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.PhysicalDriveNum = 0,
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.ExtendedBootRecordSig = 0x29,
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.VolumeSerialNumber = 0x12345678,
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.VolumeLabel = "LUFA BOOT ",
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.FilesystemIdentifier = "FAT12 ",
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};
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/** FAT 8.3 style directory entry, for the virtual FLASH contents file. */
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static FATDirectoryEntry_t FirmwareFileEntries[] =
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{
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/* Root volume label entry; disk label is contained in the Filename and
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* Extension fields (concatenated) with a special attribute flag - other
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* fields are ignored. Should be the same as the label in the boot block.
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*/
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[DISK_FILE_ENTRY_VolumeID] =
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{
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.MSDOS_Directory =
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{
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.Name = "LUFA BOOT ",
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.Attributes = FAT_FLAG_VOLUME_NAME,
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.Reserved = {0},
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.CreationTime = 0,
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.CreationDate = 0,
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.StartingCluster = 0,
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.Reserved2 = 0,
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}
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},
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/* VFAT Long File Name entry for the virtual firmware file; required to
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* prevent corruption from systems that are unable to detect the device
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* as being a legacy MSDOS style FAT12 volume. */
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[DISK_FILE_ENTRY_FLASH_LFN] =
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{
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.VFAT_LongFileName =
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{
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.Ordinal = 1 | FAT_ORDINAL_LAST_ENTRY,
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.Attribute = FAT_FLAG_LONG_FILE_NAME,
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.Reserved1 = 0,
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.Reserved2 = 0,
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.Checksum = FAT_CHECKSUM('F','L','A','S','H',' ',' ',' ','B','I','N'),
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.Unicode1 = 'F',
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.Unicode2 = 'L',
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.Unicode3 = 'A',
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.Unicode4 = 'S',
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.Unicode5 = 'H',
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.Unicode6 = '.',
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.Unicode7 = 'B',
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.Unicode8 = 'I',
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.Unicode9 = 'N',
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.Unicode10 = 0,
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.Unicode11 = 0,
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.Unicode12 = 0,
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.Unicode13 = 0,
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}
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},
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/* MSDOS file entry for the virtual Firmware image. */
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[DISK_FILE_ENTRY_FLASH_MSDOS] =
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{
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.MSDOS_File =
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{
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.Filename = "FLASH ",
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.Extension = "BIN",
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.Attributes = 0,
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.Reserved = {0},
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.CreationTime = FAT_TIME(1, 1, 0),
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.CreationDate = FAT_DATE(14, 2, 1989),
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.StartingCluster = 2,
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.FileSizeBytes = FLASH_FILE_SIZE_BYTES,
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}
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},
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[DISK_FILE_ENTRY_EEPROM_LFN] =
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{
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.VFAT_LongFileName =
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{
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.Ordinal = 1 | FAT_ORDINAL_LAST_ENTRY,
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.Attribute = FAT_FLAG_LONG_FILE_NAME,
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.Reserved1 = 0,
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.Reserved2 = 0,
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.Checksum = FAT_CHECKSUM('E','E','P','R','O','M',' ',' ','B','I','N'),
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.Unicode1 = 'E',
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.Unicode2 = 'E',
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.Unicode3 = 'P',
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.Unicode4 = 'R',
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.Unicode5 = 'O',
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.Unicode6 = 'M',
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.Unicode7 = '.',
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.Unicode8 = 'B',
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.Unicode9 = 'I',
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.Unicode10 = 'N',
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.Unicode11 = 0,
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.Unicode12 = 0,
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.Unicode13 = 0,
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}
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},
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[DISK_FILE_ENTRY_EEPROM_MSDOS] =
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{
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.MSDOS_File =
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{
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.Filename = "EEPROM ",
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.Extension = "BIN",
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.Attributes = 0,
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.Reserved = {0},
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.CreationTime = FAT_TIME(1, 1, 0),
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.CreationDate = FAT_DATE(14, 2, 1989),
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.StartingCluster = 2 + FILE_CLUSTERS(FLASH_FILE_SIZE_BYTES),
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.FileSizeBytes = EEPROM_FILE_SIZE_BYTES,
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}
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},
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};
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/** Starting cluster of the virtual FLASH.BIN file on disk, tracked so that the
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* offset from the start of the data sector can be determined. On Windows
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* systems files are usually replaced using the original file's disk clusters,
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* while Linux appears to overwrite with an offset which must be compensated for.
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*/
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static const uint16_t* FLASHFileStartCluster = &FirmwareFileEntries[DISK_FILE_ENTRY_FLASH_MSDOS].MSDOS_File.StartingCluster;
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/** Starting cluster of the virtual EEPROM.BIN file on disk, tracked so that the
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* offset from the start of the data sector can be determined. On Windows
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* systems files are usually replaced using the original file's disk clusters,
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* while Linux appears to overwrite with an offset which must be compensated for.
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*/
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static const uint16_t* EEPROMFileStartCluster = &FirmwareFileEntries[DISK_FILE_ENTRY_EEPROM_MSDOS].MSDOS_File.StartingCluster;
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/** Reads a byte of EEPROM out from the EEPROM memory space.
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*
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* \note This function is required as the avr-libc EEPROM functions do not cope
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* with linker relaxations, and a jump longer than 4K of FLASH on the
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* larger USB AVRs will break the linker. This function is marked as
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* never inlinable and placed into the normal text segment so that the
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* call to the EEPROM function will be short even if the AUX boot section
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* is used.
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*
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* \param[in] Address Address of the EEPROM location to read from
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*
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* \return Read byte of EEPROM data.
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*/
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static uint8_t ReadEEPROMByte(const uint8_t* const Address)
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{
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return eeprom_read_byte(Address);
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}
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/** Writes a byte of EEPROM out to the EEPROM memory space.
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*
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* \note This function is required as the avr-libc EEPROM functions do not cope
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* with linker relaxations, and a jump longer than 4K of FLASH on the
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* larger USB AVRs will break the linker. This function is marked as
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* never inlinable and placed into the normal text segment so that the
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* call to the EEPROM function will be short even if the AUX boot section
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* is used.
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*
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* \param[in] Address Address of the EEPROM location to write to
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* \param[in] Data New data to write to the EEPROM location
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*/
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static void WriteEEPROMByte(uint8_t* const Address,
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const uint8_t Data)
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{
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eeprom_update_byte(Address, Data);
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}
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/** Updates a FAT12 cluster entry in the FAT file table with the specified next
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* chain index. If the cluster is the last in the file chain, the magic value
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* \c 0xFFF should be used.
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*
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* \note FAT data cluster indexes are offset by 2, so that cluster 2 is the
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* first file data cluster on the disk. See the FAT specification.
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*
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* \param[out] FATTable Pointer to the FAT12 allocation table
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* \param[in] Index Index of the cluster entry to update
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* \param[in] ChainEntry Next cluster index in the file chain
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*/
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static void UpdateFAT12ClusterEntry(uint8_t* const FATTable,
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const uint16_t Index,
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const uint16_t ChainEntry)
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{
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/* Calculate the starting offset of the cluster entry in the FAT12 table */
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uint8_t FATOffset = (Index + (Index >> 1));
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bool UpperNibble = ((Index & 1) != 0);
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/* Check if the start of the entry is at an upper nibble of the byte, fill
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* out FAT12 entry as required */
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if (UpperNibble)
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{
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FATTable[FATOffset] = (FATTable[FATOffset] & 0x0F) | ((ChainEntry & 0x0F) << 4);
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FATTable[FATOffset + 1] = (ChainEntry >> 4);
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}
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else
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{
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FATTable[FATOffset] = ChainEntry;
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FATTable[FATOffset + 1] = (FATTable[FATOffset] & 0xF0) | (ChainEntry >> 8);
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}
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}
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/** Updates a FAT12 cluster chain in the FAT file table with a linear chain of
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* the specified length.
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*
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* \note FAT data cluster indexes are offset by 2, so that cluster 2 is the
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* first file data cluster on the disk. See the FAT specification.
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*
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* \param[out] FATTable Pointer to the FAT12 allocation table
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* \param[in] Index Index of the start of the cluster chain to update
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* \param[in] ChainLength Length of the chain to write, in clusters
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*/
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static void UpdateFAT12ClusterChain(uint8_t* const FATTable,
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const uint16_t Index,
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const uint8_t ChainLength)
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{
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for (uint8_t i = 0; i < ChainLength; i++)
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{
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uint16_t CurrentCluster = Index + i;
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uint16_t NextCluster = CurrentCluster + 1;
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/* Mark last cluster as end of file */
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if (i == (ChainLength - 1))
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NextCluster = 0xFFF;
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UpdateFAT12ClusterEntry(FATTable, CurrentCluster, NextCluster);
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}
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}
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/** Reads or writes a block of data from/to the physical device FLASH using a
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* block buffer stored in RAM, if the requested block is within the virtual
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* firmware file's sector ranges in the emulated FAT file system.
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*
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* \param[in] BlockNumber Physical disk block to read from/write to
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* \param[in,out] BlockBuffer Pointer to the start of the block buffer in RAM
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* \param[in] Read If \c true, the requested block is read, if
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* \c false, the requested block is written
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*/
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static void ReadWriteFLASHFileBlock(const uint16_t BlockNumber,
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uint8_t* BlockBuffer,
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const bool Read)
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{
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uint16_t FileStartBlock = DISK_BLOCK_DataStartBlock + (*FLASHFileStartCluster - 2) * SECTOR_PER_CLUSTER;
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uint16_t FileEndBlock = FileStartBlock + (FILE_SECTORS(FLASH_FILE_SIZE_BYTES) - 1);
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/* Range check the write request - abort if requested block is not within the
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* virtual firmware file sector range */
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if (!((BlockNumber >= FileStartBlock) && (BlockNumber <= FileEndBlock)))
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return;
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#if (FLASHEND > 0xFFFF)
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uint32_t FlashAddress = (uint32_t)(BlockNumber - FileStartBlock) * SECTOR_SIZE_BYTES;
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#else
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uint16_t FlashAddress = (uint16_t)(BlockNumber - FileStartBlock) * SECTOR_SIZE_BYTES;
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#endif
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if (Read)
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{
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/* Read out the mapped block of data from the device's FLASH */
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for (uint16_t i = 0; i < SECTOR_SIZE_BYTES; i++)
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{
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#if (FLASHEND > 0xFFFF)
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BlockBuffer[i] = pgm_read_byte_far(FlashAddress++);
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#else
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BlockBuffer[i] = pgm_read_byte(FlashAddress++);
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#endif
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}
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}
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else
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{
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/* Write out the mapped block of data to the device's FLASH */
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for (uint16_t i = 0; i < SECTOR_SIZE_BYTES; i += 2)
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{
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if ((FlashAddress % SPM_PAGESIZE) == 0)
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{
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/* Erase the given FLASH page, ready to be programmed */
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BootloaderAPI_ErasePage(FlashAddress);
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}
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/* Write the next data word to the FLASH page */
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BootloaderAPI_FillWord(FlashAddress, (BlockBuffer[i + 1] << 8) | BlockBuffer[i]);
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FlashAddress += 2;
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if ((FlashAddress % SPM_PAGESIZE) == 0)
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{
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/* Write the filled FLASH page to memory */
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BootloaderAPI_WritePage(FlashAddress - SPM_PAGESIZE);
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}
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}
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}
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}
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/** Reads or writes a block of data from/to the physical device EEPROM using a
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* block buffer stored in RAM, if the requested block is within the virtual
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* firmware file's sector ranges in the emulated FAT file system.
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*
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* \param[in] BlockNumber Physical disk block to read from/write to
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* \param[in,out] BlockBuffer Pointer to the start of the block buffer in RAM
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* \param[in] Read If \c true, the requested block is read, if
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* \c false, the requested block is written
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*/
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static void ReadWriteEEPROMFileBlock(const uint16_t BlockNumber,
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uint8_t* BlockBuffer,
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const bool Read)
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{
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uint16_t FileStartBlock = DISK_BLOCK_DataStartBlock + (*EEPROMFileStartCluster - 2) * SECTOR_PER_CLUSTER;
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uint16_t FileEndBlock = FileStartBlock + (FILE_SECTORS(EEPROM_FILE_SIZE_BYTES) - 1);
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/* Range check the write request - abort if requested block is not within the
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* virtual firmware file sector range */
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if (!((BlockNumber >= FileStartBlock) && (BlockNumber <= FileEndBlock)))
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return;
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uint16_t EEPROMAddress = (uint16_t)(BlockNumber - FileStartBlock) * SECTOR_SIZE_BYTES;
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if (Read)
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{
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/* Read out the mapped block of data from the device's EEPROM */
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for (uint16_t i = 0; i < SECTOR_SIZE_BYTES; i++)
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BlockBuffer[i] = ReadEEPROMByte((uint8_t*)EEPROMAddress++);
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}
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else
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{
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/* Write out the mapped block of data to the device's EEPROM */
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for (uint16_t i = 0; i < SECTOR_SIZE_BYTES; i++)
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WriteEEPROMByte((uint8_t*)EEPROMAddress++, BlockBuffer[i]);
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}
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}
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/** Writes a block of data to the virtual FAT filesystem, from the USB Mass
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* Storage interface.
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*
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* \param[in] BlockNumber Index of the block to write.
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*/
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void VirtualFAT_WriteBlock(const uint16_t BlockNumber)
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{
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uint8_t BlockBuffer[SECTOR_SIZE_BYTES];
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/* Buffer the entire block to be written from the host */
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Endpoint_Read_Stream_LE(BlockBuffer, sizeof(BlockBuffer), NULL);
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Endpoint_ClearOUT();
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switch (BlockNumber)
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{
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case DISK_BLOCK_BootBlock:
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case DISK_BLOCK_FATBlock1:
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case DISK_BLOCK_FATBlock2:
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/* Ignore writes to the boot and FAT blocks */
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break;
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case DISK_BLOCK_RootFilesBlock:
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/* Copy over the updated directory entries */
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memcpy(FirmwareFileEntries, BlockBuffer, sizeof(FirmwareFileEntries));
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break;
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default:
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ReadWriteFLASHFileBlock(BlockNumber, BlockBuffer, false);
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ReadWriteEEPROMFileBlock(BlockNumber, BlockBuffer, false);
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break;
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}
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}
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/** Reads a block of data from the virtual FAT filesystem, and sends it to the
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* host via the USB Mass Storage interface.
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*
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* \param[in] BlockNumber Index of the block to read.
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*/
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void VirtualFAT_ReadBlock(const uint16_t BlockNumber)
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{
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uint8_t BlockBuffer[SECTOR_SIZE_BYTES];
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memset(BlockBuffer, 0x00, sizeof(BlockBuffer));
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switch (BlockNumber)
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{
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case DISK_BLOCK_BootBlock:
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memcpy(BlockBuffer, &BootBlock, sizeof(FATBootBlock_t));
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/* Add the magic signature to the end of the block */
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BlockBuffer[SECTOR_SIZE_BYTES - 2] = 0x55;
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BlockBuffer[SECTOR_SIZE_BYTES - 1] = 0xAA;
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break;
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case DISK_BLOCK_FATBlock1:
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case DISK_BLOCK_FATBlock2:
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/* Cluster 0: Media type/Reserved */
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UpdateFAT12ClusterEntry(BlockBuffer, 0, 0xF00 | BootBlock.MediaDescriptor);
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/* Cluster 1: Reserved */
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UpdateFAT12ClusterEntry(BlockBuffer, 1, 0xFFF);
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/* Cluster 2 onwards: Cluster chain of FLASH.BIN */
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UpdateFAT12ClusterChain(BlockBuffer, *FLASHFileStartCluster, FILE_CLUSTERS(FLASH_FILE_SIZE_BYTES));
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/* Cluster 2+n onwards: Cluster chain of EEPROM.BIN */
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UpdateFAT12ClusterChain(BlockBuffer, *EEPROMFileStartCluster, FILE_CLUSTERS(EEPROM_FILE_SIZE_BYTES));
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break;
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case DISK_BLOCK_RootFilesBlock:
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memcpy(BlockBuffer, FirmwareFileEntries, sizeof(FirmwareFileEntries));
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break;
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default:
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ReadWriteFLASHFileBlock(BlockNumber, BlockBuffer, true);
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ReadWriteEEPROMFileBlock(BlockNumber, BlockBuffer, true);
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break;
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}
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/* Write the entire read block Buffer to the host */
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Endpoint_Write_Stream_LE(BlockBuffer, sizeof(BlockBuffer), NULL);
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Endpoint_ClearIN();
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}
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