Emulates EEPROM in SPI-FLASH for the CC32xx platform. More...

#include <CC32xxEEPROMEmulation.hxx>

Inheritance diagram for CC32xxEEPROMEmulation:

Public Member Functions
	CC32xxEEPROMEmulation (const char *name, size_t file_size_bytes)
	Constructor.

	~CC32xxEEPROMEmulation ()
	Destructor.

void	flush ()
	Instructs the driver to write all changed data to disk.

void	mount ()
	Must be called exactly once after creation, after the simplelink stack has been started.

Public Member Functions inherited from EEPROM
	EEPROM (const char *name, size_t file_size)
	Constructor.

size_t	file_size ()

Public Member Functions inherited from Device
	Device (const char *name)
	Constructor.

virtual	~Device ()
	Destructor.

Private Member Functions
void	write (unsigned int index, const void *buf, size_t len) override
	Write to the EEPROM.

void	read (unsigned int index, void *buf, size_t len) override
	Read from the EEPROM.

int	open_file (unsigned sector, uint32_t open_mode, bool ignore_error=false)
	Opens a SL file.

void	flush_buffers () OVERRIDE
	REQUIRED: lock_ is held.

Private Attributes
unsigned	fileVersion_ {0}
	This number is increased by one every time the contents are flushed to a file.

uint8_t	readSector_ {0xff}
	The sector number of the last sector we used for reading.

uint8_t	isDirty_ {0}
	non-zero if we have unflushed writes.

uint8_t *	data_
	Holds the file payload in memory.

Static Private Attributes
static const uint8_t	SECTOR_COUNT = 8
	The total number of files which we are round-robining.

Additional Inherited Members
Static Public Member Functions inherited from Device
static int	open (struct _reent reent, const char path, int flags, int mode)
	Open a file or device.

static int	close (struct _reent *reent, int fd)
	Close a file or device.

static int	stat (struct _reent reent, const char path, struct stat *stat)
	Get the status information of a file or device.

static int	select (int nfds, fd_set readfds, fd_set writefds, fd_set *exceptfds, long long timeout)
	POSIX select().

static void	select_clear ()
	Clears the current thread's select bits.

Static Public Member Functions inherited from FileIO
static ssize_t	read (struct _reent reent, int fd, void buf, size_t count)
	Read from a file or device.

static ssize_t	write (struct _reent reent, int fd, const void buf, size_t count)
	Write to a file or device.

static _off_t	lseek (struct _reent *reent, int fd, _off_t offset, int whence)
	Change the offset index of a file or device.

static int	fstat (struct _reent reent, int fd, struct stat stat)
	Get the status information of a file or device.

static int	ioctl (int fd, unsigned long int key, unsigned long data)
	Request and ioctl transaction.

static int	fcntl (int fd, int cmd, unsigned long data)
	Manipulate a file descriptor.

static bool	is_device (int fd)
	Test if the file descriptor belongs to a device.

Protected Member Functions inherited from EEPROM
	EEPROM (const char *name, size_t file_size)
	Constructor.

	~EEPROM ()
	Destructor.

size_t	file_size ()
	Get the maximum file size of the EEPROM file.

Protected Member Functions inherited from Node
	Node (const char *name)
	Constructor.

virtual	~Node ()
	Destructor.

int	open (File , const char , int, int) OVERRIDE
	Open method.

int	close (File *) OVERRIDE
	Close method.

virtual int	fstat (File file, struct stat stat) override
	Get the status information of a file or device.

Protected Member Functions inherited from FileIO
	FileIO (const char *name)
	Constructor.

virtual	~FileIO ()
	Destructor.

virtual int	ioctl (File *file, unsigned long int key, unsigned long data)
	Request an ioctl transaction.

virtual int	fcntl (File *file, int cmd, unsigned long data)
	Manipulate a file descriptor.

virtual bool	select (File *file, int mode)
	Device select method.

Static Protected Member Functions inherited from Device
static void	select_insert (SelectInfo *info)
	Add client to list of clients needing woken.

static void	select_wakeup (SelectInfo *info)
	Wakeup the list of clients needing woken.

static void	select_wakeup_from_isr (SelectInfo info, int woken)
	Wakeup the list of clients needing woken.

Static Protected Member Functions inherited from FileIO
static int	fd_alloc (void)
	Allocate a free file descriptor.

static void	fd_free (int fd)
	Free up a file descriptor.

static File *	file_lookup (int fd)
	Looks up a reference to a File corresponding to a given file descriptor.

static int	fd_lookup (File *file)
	Looks up a file descriptor corresponding to a given File reference.

Protected Attributes inherited from Node
OSMutex	lock_
	protects internal structures.

mode_t	mode_
	File open mode, such as O_NONBLOCK.

unsigned int	references_
	number of open references

Protected Attributes inherited from FileIO
const char *	name
	device name

Static Protected Attributes inherited from FileIO
static const unsigned int	numOpenFiles = 20

static File	files []
	File descriptor pool.

static OSMutex	mutex
	mutual exclusion for fileio

Detailed Description

Emulates EEPROM in SPI-FLASH for the CC32xx platform.

Theory of operation:

We use one device file per sector. A sector, when erased, will start the file fresh and empty, in a read-write mode. The file will be in read-write mode until the device reboots. Upon the next boot, the files are opened in a read-only mode, and the available() value is set to zero. This will force upon the first write a new sector to be erased and all data to be copied over to it.

When the EEPROM driver wants to read a block, we load the data from the file into an in-memory cache, and return a pointer into that cache. This is how we map the file into memory. Fortunately we receive a call before the driver needs a different block, so we get a chance to update the memory mapped region.

One major difference is that there is no way to write the "used" block to the past file when the data has been copied over to the new sector. In spite of this we are using a different scheme for the used magic, and fake the writing of the used magic when data is loaded into the cache. The USED magic is virtually set for every sector except the sector last erased that has INTACT data. When we erase a sector we write a "rotation number" to the USED magic offset. The rotation number is incremented every time we jump from sector N-1 to sector 0. This way we can determine upon boot which sector was last erased.

Definition at line 69 of file CC32xxEEPROMEmulation.hxx.

Constructor & Destructor Documentation

◆ CC32xxEEPROMEmulation()

CC32xxEEPROMEmulation::CC32xxEEPROMEmulation	(	const char *	name,
		size_t	file_size_bytes
	)

Constructor.

Parameters

name	device name
file_size_bytes	maximum file size that we can grow to.

Definition at line 50 of file CC32xxEEPROMEmulation.cxx.

◆ ~CC32xxEEPROMEmulation()

CC32xxEEPROMEmulation::~CC32xxEEPROMEmulation ( )

Destructor.

Definition at line 98 of file CC32xxEEPROMEmulation.cxx.

Member Function Documentation

◆ flush()

void CC32xxEEPROMEmulation::flush ( )

inline

Instructs the driver to write all changed data to disk.

Definition at line 83 of file CC32xxEEPROMEmulation.hxx.

◆ flush_buffers()

void CC32xxEEPROMEmulation::flush_buffers ( )

privatevirtual

REQUIRED: lock_ is held.

Implements Node.

Definition at line 104 of file CC32xxEEPROMEmulation.cxx.

◆ mount()

void CC32xxEEPROMEmulation::mount ( )

Must be called exactly once after creation, after the simplelink stack has been started.

Definition at line 59 of file CC32xxEEPROMEmulation.cxx.

◆ open_file()

int CC32xxEEPROMEmulation::open_file	(	unsigned	sector,
		uint32_t	open_mode,
		bool	ignore_error = `false`
	)

private

Opens a SL file.

Parameters

sector	number suffix of the filename
open_mode	one of the SimpleLink constants FS_MODE_*
ignore_error	when false, HASSERT fails upon error

Returns: file handle. checked that it is >= 0

Definition at line 126 of file CC32xxEEPROMEmulation.cxx.

◆ read()

void CC32xxEEPROMEmulation::read	(	unsigned int	index,
		void *	buf,
		size_t	len
	)

overrideprivatevirtual

Read from the EEPROM.

Parameters

index	index within EEPROM address space to start read
buf	location to post read data
len	length in bytes of data to read

Implements EEPROM.

Definition at line 152 of file CC32xxEEPROMEmulation.cxx.

◆ write()

void CC32xxEEPROMEmulation::write	(	unsigned int	index,
		const void *	buf,
		size_t	len
	)

overrideprivatevirtual

Write to the EEPROM.

NOTE!!! This is not necessarily atomic across byte boundaries in the case of power loss. The user should take this into account as it relates to data integrity of a whole block.

Parameters

index	index within EEPROM address space to start write
buf	data to write
len	length in bytes of data to write

Implements EEPROM.

Definition at line 140 of file CC32xxEEPROMEmulation.cxx.

Member Data Documentation

◆ data_

uint8_t* CC32xxEEPROMEmulation::data_

private

Holds the file payload in memory.

Definition at line 139 of file CC32xxEEPROMEmulation.hxx.

◆ fileVersion_

unsigned CC32xxEEPROMEmulation::fileVersion_ {0}

private

This number is increased by one every time the contents are flushed to a file.

The version gets written to the file so that we can recognize which is the latest file.

Definition at line 130 of file CC32xxEEPROMEmulation.hxx.

◆ isDirty_

uint8_t CC32xxEEPROMEmulation::isDirty_ {0}

private

non-zero if we have unflushed writes.

Definition at line 136 of file CC32xxEEPROMEmulation.hxx.

◆ readSector_

uint8_t CC32xxEEPROMEmulation::readSector_ {0xff}

private

The sector number of the last sector we used for reading.

Definition at line 133 of file CC32xxEEPROMEmulation.hxx.

◆ SECTOR_COUNT

const uint8_t CC32xxEEPROMEmulation::SECTOR_COUNT = 8

staticprivate

The total number of files which we are round-robining.

Definition at line 125 of file CC32xxEEPROMEmulation.hxx.

The documentation for this class was generated from the following files:

Public Member Functions

Private Member Functions

Private Attributes

Static Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ CC32xxEEPROMEmulation()

◆ ~CC32xxEEPROMEmulation()

Member Function Documentation

◆ flush()

◆ flush_buffers()

◆ mount()

◆ open_file()

◆ read()

◆ write()

Member Data Documentation

◆ data_

◆ fileVersion_

◆ isDirty_

◆ readSector_

◆ SECTOR_COUNT