-/*
- LUFA Library
- Copyright (C) Dean Camera, 2013.
-
- dean [at] fourwalledcubicle [dot] com
- www.lufa-lib.org
-*/
-
-/*
- Copyright 2013 Dean Camera (dean [at] fourwalledcubicle [dot] com)
-
- Permission to use, copy, modify, distribute, and sell this
- software and its documentation for any purpose is hereby granted
- without fee, provided that the above copyright notice appear in
- all copies and that both that the copyright notice and this
- permission notice and warranty disclaimer appear in supporting
- documentation, and that the name of the author not be used in
- advertising or publicity pertaining to distribution of the
- software without specific, written prior permission.
-
- The author disclaims all warranties with regard to this
- software, including all implied warranties of merchantability
- and fitness. In no event shall the author be liable for any
- special, indirect or consequential damages or any damages
- whatsoever resulting from loss of use, data or profits, whether
- in an action of contract, negligence or other tortious action,
- arising out of or in connection with the use or performance of
- 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},
- .Description = "mkdosfs",
- .SectorSize = SECTOR_SIZE_BYTES,
- .SectorsPerCluster = SECTOR_PER_CLUSTER,
- .ReservedSectors = 1,
- .FATCopies = 2,
- .RootDirectoryEntries = (SECTOR_SIZE_BYTES / sizeof(FATDirectoryEntry_t)),
- .TotalSectors16 = LUN_MEDIA_BLOCKS,
- .MediaDescriptor = 0xF8,
- .SectorsPerFAT = 1,
- .SectorsPerTrack = (LUN_MEDIA_BLOCKS % 64),
- .Heads = (LUN_MEDIA_BLOCKS / 64),
- .HiddenSectors = 0,
- .TotalSectors32 = 0,
- .PhysicalDriveNum = 0,
- .ExtendedBootRecordSig = 0x29,
- .VolumeSerialNumber = 0x12345678,
- .VolumeLabel = "LUFA BOOT ",
- .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 = FIRMWARE_FILE_SIZE_BYTES,
- };
-
-
-/** 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)
-{
- /* 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);
- }
-}
-
-/** 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();
-
- 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();
- }
- }
- }
-}
-
-/** 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[SECTOR_SIZE_BYTES];
- memset(BlockBuffer, 0x00, sizeof(BlockBuffer));
-
- switch (BlockNumber)
- {
- case 0: /* Block 0: Boot block sector */
- memcpy(BlockBuffer, &BootBlock, sizeof(FATBootBlock_t));
-
- /* 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 */
- UpdateFAT12ClusterEntry(BlockBuffer, 0, 0xF00 | BootBlock.MediaDescriptor);
-
- /* Cluster 1: Reserved */
- UpdateFAT12ClusterEntry(BlockBuffer, 1, 0xFFF);
-
- /* Cluster 2 onwards: Cluster chain of FIRMWARE.BIN */
- 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 */
- UpdateFAT12ClusterEntry(BlockBuffer, FILE_CLUSTERS(FIRMWARE_FILE_SIZE_BYTES) + 1, 0xFFF);
- break;
-
- case 3: /* Block 3: Root file entries */
- memcpy(BlockBuffer, &FirmwareFileEntry, sizeof(FATDirectoryEntry_t));
- break;
-
- default: /* Blocks 4 onwards: Data allocation section */
- if ((BlockNumber >= 4) && (BlockNumber < (4 + FILE_SECTORS(FIRMWARE_FILE_SIZE_BYTES))))
- {
- uint32_t ReadFlashAddress = (uint32_t)(BlockNumber - 4) * SECTOR_SIZE_BYTES;
-
- for (uint16_t i = 0; i < SECTOR_SIZE_BYTES; i++)
- BlockBuffer[i] = pgm_read_byte_far(ReadFlashAddress++);
- }
-
- break;
- }
-
- /* 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)
-{
- uint16_t CurrentBlock = (uint16_t)BlockAddress;
-
- /* Emulated FAT is performed per-block, pass each requested block index
- * to the emulated FAT block write function */
- while (TotalBlocks--)
- 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)
-{
- uint16_t CurrentBlock = (uint16_t)BlockAddress;
-
- /* Emulated FAT is performed per-block, pass each requested block index
- * to the emulated FAT block read function */
- while (TotalBlocks--)
- ReadVirtualBlock(CurrentBlock++);
-}
-
projects / pub / lufa.git / blobdiff