#include <avr/io.h>
#include <avr/pgmspace.h>
#include <LUFA/Drivers/USB/USB.h>
#include "../BootloaderAPI.h"

Data Structures
struct	FATBootBlock_t

union	FATDirectoryEntry_t

Macros
#define	FLASH_FILE_SIZE_BYTES (FLASHEND - (FLASHEND - BOOT_START_ADDR) - AUX_BOOT_SECTION_SIZE)

#define	EEPROM_FILE_SIZE_BYTES E2END

#define	SECTOR_PER_CLUSTER 4

#define	SECTOR_SIZE_BYTES 512

#define	CLUSTER_SIZE_BYTES (SECTOR_PER_CLUSTER * SECTOR_SIZE_BYTES)

#define	FILE_SECTORS(size) ((size / SECTOR_SIZE_BYTES) + ((size % SECTOR_SIZE_BYTES) ? 1 : 0))

#define	FILE_CLUSTERS(size) ((size / CLUSTER_SIZE_BYTES) + ((size % CLUSTER_SIZE_BYTES) ? 1 : 0))

#define	LUN_MEDIA_BLOCKS (FILE_SECTORS(FLASH_FILE_SIZE_BYTES) + FILE_SECTORS(EEPROM_FILE_SIZE_BYTES) + 32)

#define	FAT_TIME(hh, mm, ss) ((hh << 11) \| (mm << 5) \| (ss >> 1))

#define	FAT_DATE(dd, mm, yyyy) (((yyyy - 1980) << 9) \| (mm << 5) \| (dd << 0))

#define	_ROT8(x) ((((x) & 0xFE) >> 1) \| (((x) & 1) ? 0x80 : 0x00))

#define	FAT_CHECKSUM(n0, n1, n2, n3, n4, n5, n6, n7, e0, e1, e2) (uint8_t)(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(n0)+n1)+n2)+n3)+n4)+n5)+n6)+n7)+e0)+e1)+e2)

FAT Filesystem Flags
#define	FAT_FLAG_READONLY (1 << 0)

#define	FAT_FLAG_HIDDEN (1 << 1)

#define	FAT_FLAG_SYSTEM (1 << 2)

#define	FAT_FLAG_VOLUME_NAME (1 << 3)

#define	FAT_FLAG_DIRECTORY (1 << 4)

#define	FAT_FLAG_ARCHIVE (1 << 5)

#define	FAT_FLAG_LONG_FILE_NAME 0x0F

#define	FAT_ORDINAL_LAST_ENTRY (1 << 6)

Enumerations
enum	{ DISK_FILE_ENTRY_VolumeID = 0, DISK_FILE_ENTRY_FLASH_LFN = 1, DISK_FILE_ENTRY_FLASH_MSDOS = 2, DISK_FILE_ENTRY_EEPROM_LFN = 3, DISK_FILE_ENTRY_EEPROM_MSDOS = 4 }

enum	{ DISK_BLOCK_BootBlock = 0, DISK_BLOCK_FATBlock1 = 1, DISK_BLOCK_FATBlock2 = 2, DISK_BLOCK_RootFilesBlock = 3, DISK_BLOCK_DataStartBlock = 4 }

Functions
void	VirtualFAT_WriteBlock (const uint16_t BlockNumber) AUX_BOOT_SECTION

void	VirtualFAT_ReadBlock (const uint16_t BlockNumber) AUX_BOOT_SECTION

Macro Definition Documentation

#define _ROT8 ( x) ((((x) & 0xFE) >> 1) | (((x) & 1) ? 0x80 : 0x00))

Bit-rotates a given 8-bit value once to the right.

Parameters

x	Value to rotate right once

Returns: Bit-rotated input value, rotated once to the right.

#define CLUSTER_SIZE_BYTES (SECTOR_PER_CLUSTER * SECTOR_SIZE_BYTES)

Size of a logical cluster on the disk, in bytes

#define EEPROM_FILE_SIZE_BYTES E2END

Size of the virtual EEPROM.BIN file in bytes.

#define FAT_CHECKSUM	(	n0,
		n1,
		n2,
		n3,
		n4,
		n5,
		n6,
		n7,
		e0,
		e1,
		e2
	)	(uint8_t)(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(n0)+n1)+n2)+n3)+n4)+n5)+n6)+n7)+e0)+e1)+e2)

Computes the LFN entry checksum of a MSDOS 8.3 format file entry, to associate a LFN entry with its short file entry.

Parameters

n0	MSDOS Filename character 1
n1	MSDOS Filename character 2
n2	MSDOS Filename character 3
n3	MSDOS Filename character 4
n4	MSDOS Filename character 5
n5	MSDOS Filename character 6
n6	MSDOS Filename character 7
n7	MSDOS Filename character 8
e0	MSDOS Extension character 1
e1	MSDOS Extension character 2
e2	MSDOS Extension character 3

Returns: LFN checksum of the given MSDOS 8.3 filename.

#define FAT_DATE	(	dd,
		mm,
		yyyy
	)	(((yyyy - 1980) << 9) \| (mm << 5) \| (dd << 0))

Converts a given date in DD/MM/YYYY format to a FAT filesystem date.

Parameters

[in]	dd	Days in the month (1-31)
[in]	mm	Months in the year (1-12)
[in]	yyyy	Year (1980 - 2107)

Returns: Given date encoded as a FAT filesystem datestamp

#define FAT_FLAG_ARCHIVE (1 << 5)

FAT attribute flag to indicate a file ready for archiving.

#define FAT_FLAG_DIRECTORY (1 << 4)

FAT attribute flag to indicate a directory entry.

#define FAT_FLAG_HIDDEN (1 << 1)

FAT attribute flag to indicate a hidden file.

#define FAT_FLAG_LONG_FILE_NAME 0x0F

FAT pseudo-attribute flag to indicate a Long File Name entry.

#define FAT_FLAG_READONLY (1 << 0)

FAT attribute flag to indicate a read-only file.

#define FAT_FLAG_SYSTEM (1 << 2)

FAT attribute flag to indicate a system file.

#define FAT_FLAG_VOLUME_NAME (1 << 3)

FAT attribute flag to indicate a Volume name entry.

#define FAT_ORDINAL_LAST_ENTRY (1 << 6)

Ordinal flag marker for FAT Long File Name entries to mark the last entry.

#define FAT_TIME	(	hh,
		mm,
		ss
	)	((hh << 11) \| (mm << 5) \| (ss >> 1))

Converts a given time in HH:MM:SS format to a FAT filesystem time.

Note: The minimum seconds resolution of FAT is 2, thus odd seconds will be truncated to the previous integer multiple of 2 seconds.

Parameters

[in]	hh	Hours (0-23)
[in]	mm	Minutes (0-59)
[in]	ss	Seconds (0-59)

Returns: Given time encoded as a FAT filesystem timestamp

#define FILE_CLUSTERS ( size) ((size / CLUSTER_SIZE_BYTES) + ((size % CLUSTER_SIZE_BYTES) ? 1 : 0))

Number of clusters required to store a given size in bytes.

Parameters

[in] size Size of the data that needs to be stored

Returns: Number of clusters required to store the given data on the disk.

#define FILE_SECTORS ( size) ((size / SECTOR_SIZE_BYTES) + ((size % SECTOR_SIZE_BYTES) ? 1 : 0))

Number of sectors required to store a given size in bytes.

Parameters

[in] size Size of the data that needs to be stored

Returns: Number of sectors required to store the given data on the disk.

#define FLASH_FILE_SIZE_BYTES (FLASHEND - (FLASHEND - BOOT_START_ADDR) - AUX_BOOT_SECTION_SIZE)

Size of the virtual FLASH.BIN file in bytes.

#define LUN_MEDIA_BLOCKS (FILE_SECTORS(FLASH_FILE_SIZE_BYTES) + FILE_SECTORS(EEPROM_FILE_SIZE_BYTES) + 32)

Total number of logical sectors/blocks on the disk.

#define SECTOR_PER_CLUSTER 4

Number of sectors that comprise a single logical disk cluster.

#define SECTOR_SIZE_BYTES 512

Size of a single logical sector on the disk.

Enumeration Type Documentation

anonymous enum

Enum for the Root FAT file entry indexes on the disk. This can be used to retrieve the current contents of a known directory entry.

Enumerator
DISK_FILE_ENTRY_VolumeID	Volume ID directory entry, giving the name of the virtual disk.
DISK_FILE_ENTRY_FLASH_LFN	Long File Name FAT file entry of the virtual FLASH.BIN image file.
DISK_FILE_ENTRY_FLASH_MSDOS	Legacy MSDOS FAT file entry of the virtual FLASH.BIN image file.
DISK_FILE_ENTRY_EEPROM_LFN	Long File Name FAT file entry of the virtual EEPROM.BIN image file.
DISK_FILE_ENTRY_EEPROM_MSDOS	Legacy MSDOS FAT file entry of the virtual EEPROM.BIN image file.

anonymous enum

Enum for the physical disk blocks of the virtual disk.

Enumerator
DISK_BLOCK_BootBlock	Boot sector disk block.
DISK_BLOCK_FATBlock1	First copy of the FAT table block.
DISK_BLOCK_FATBlock2	Second copy of the FAT table block.
DISK_BLOCK_RootFilesBlock	Root file and directory entries block.
DISK_BLOCK_DataStartBlock	Start block of the disk data section.

Function Documentation

void VirtualFAT_ReadBlock ( const 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.

Parameters

[in] BlockNumber Index of the block to read.

void VirtualFAT_WriteBlock ( const uint16_t BlockNumber)

Writes a block of data to the virtual FAT filesystem, from the USB Mass Storage interface.

Parameters

[in] BlockNumber Index of the block to write.

Data Structures

Macros

Enumerations

Functions

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation