Lazily allocated heap-backed block device. More...

#include <HeapBlockDevice.h>

Inheritance diagram for HeapBlockDevice:

Public Member Functions
	HeapBlockDevice (bd_size_t size, bd_size_t block=512)
	Lifetime of the memory block device. More...

	HeapBlockDevice (bd_size_t size, bd_size_t read, bd_size_t program, bd_size_t erase)
	Lifetime of the memory block device. More...

virtual int	init ()
	Initialize a block device. More...

virtual int	deinit ()
	Deinitialize a block device. More...

virtual int	read (void *buffer, bd_addr_t addr, bd_size_t size)
	Read blocks from a block device. More...

virtual int	program (const void *buffer, bd_addr_t addr, bd_size_t size)
	Program blocks to a block device. More...

virtual int	erase (bd_addr_t addr, bd_size_t size)
	Erase blocks on a block device. More...

virtual bd_size_t	get_read_size () const
	Get the size of a readable block. More...

virtual bd_size_t	get_program_size () const
	Get the size of a programmable block. More...

virtual bd_size_t	get_erase_size () const
	Get the size of an erasable block. More...

virtual bd_size_t	get_erase_size (bd_addr_t addr) const
	Get the size of an erasable block given address. More...

virtual bd_size_t	size () const
	Get the total size of the underlying device. More...

virtual const char *	get_type () const
	Get the BlockDevice class type. More...

virtual int	sync ()
	Ensure data on storage is in sync with the driver. More...

virtual int	trim (bd_addr_t addr, bd_size_t size)
	Mark blocks as no longer in use. More...

virtual int	get_erase_value () const
	Get the value of storage when erased. More...

virtual bool	is_valid_read (bd_addr_t addr, bd_size_t size) const
	Convenience function for checking block read validity. More...

virtual bool	is_valid_program (bd_addr_t addr, bd_size_t size) const
	Convenience function for checking block program validity. More...

virtual bool	is_valid_erase (bd_addr_t addr, bd_size_t size) const
	Convenience function for checking block erase validity. More...

Static Public Member Functions
static BlockDevice *	get_default_instance ()
	Return the default block device. More...

Detailed Description

Lazily allocated heap-backed block device.

Useful for simulating a block device and tests.

Note: Each block is allocated when used, and freed when erased.

#include "mbed.h"
#include "HeapBlockDevice.h"
#define BLOCK_SIZE 512
HeapBlockDevice bd(2048, BLOCK_SIZE); // 2048 bytes with a block size of 512 bytes
uint8_t block[BLOCK_SIZE] = "Hello World!\n";
int main() {
    bd.init();
    bd.erase(0, BLOCK_SIZE);
    bd.program(block, 0, BLOCK_SIZE);
    bd.read(block, 0, BLOCK_SIZE);
    printf("%s", block);
    bd.deinit();
}

Definition at line 56 of file HeapBlockDevice.h.

Constructor & Destructor Documentation

HeapBlockDevice	(	bd_size_t	size,
		bd_size_t	block = `512`
	)

Lifetime of the memory block device.

Parameters

size	Size of the Block Device in bytes
block	Block size in bytes. Minimum read, program, and erase sizes are configured to this value

HeapBlockDevice	(	bd_size_t	size,
		bd_size_t	read,
		bd_size_t	program,
		bd_size_t	erase
	)

Lifetime of the memory block device.

Parameters

size	Size of the Block Device in bytes
read	Minimum read size required in bytes
program	Minimum program size required in bytes
erase	Minimum erase size required in bytes

Member Function Documentation

virtual int deinit ( )

virtual

Deinitialize a block device.

Returns: 0 on success or a negative error code on failure

Implements BlockDevice.

virtual int erase	(	bd_addr_t	addr,
		bd_size_t	size
	)

virtual

Erase blocks on a block device.

The state of an erased block is undefined until it has been programmed

Parameters

addr	Address of block to begin erasing
size	Size to erase in bytes, must be a multiple of erase block size

Returns: 0 on success, negative error code on failure

Reimplemented from BlockDevice.

static BlockDevice* get_default_instance ( )

staticinherited

Return the default block device.

Returns the default block device based on the configuration JSON. Use the components in target.json or application config to change the default block device.

An application can override all target settings by implementing BlockDevice::get_default_instance() - the default definition is weak, and calls get_target_default_instance().

virtual bd_size_t get_erase_size ( ) const

virtual

Get the size of an erasable block.

Returns: Size of an erasable block in bytes

Reimplemented from BlockDevice.

virtual bd_size_t get_erase_size ( bd_addr_t addr ) const

virtual

Get the size of an erasable block given address.

Parameters

addr	Address within the erasable block

Returns: Size of an erasable block in bytes

Note: Must be a multiple of the program size

Reimplemented from BlockDevice.

virtual int get_erase_value ( ) const

virtualinherited

Get the value of storage when erased.

If get_erase_value returns a non-negative byte value, the underlying storage is set to that value when erased, and storage containing that value can be programmed without another erase.

Returns: The value of storage when erased, or -1 if you can't rely on the value of the erased storage

Reimplemented in OSPIFBlockDevice, QSPIFBlockDevice, SPINANDBlockDevice, SPIFBlockDevice, MBRBlockDevice, ChainingBlockDevice, ExhaustibleBlockDevice, BufferedBlockDevice, SlicingBlockDevice, ProfilingBlockDevice, ObservingBlockDevice, FlashSimBlockDevice, ReadOnlyBlockDevice, and FlashIAPBlockDevice.

Definition at line 185 of file BlockDevice.h.

virtual bd_size_t get_program_size ( ) const

virtual

Get the size of a programmable block.

Returns: Size of a programmable block in bytes

Implements BlockDevice.

virtual bd_size_t get_read_size ( ) const

virtual

Get the size of a readable block.

Returns: Size of a readable block in bytes

Implements BlockDevice.

virtual const char* get_type ( ) const

virtual

Get the BlockDevice class type.

Returns: A string represent the BlockDevice class type.

Implements BlockDevice.

virtual int init ( )

virtual

Initialize a block device.

Returns: 0 on success or a negative error code on failure

Implements BlockDevice.

virtual bool is_valid_erase	(	bd_addr_t	addr,
		bd_size_t	size
	)		const

virtualinherited

Convenience function for checking block erase validity.

Parameters

addr	Address of block to begin erasing
size	Size to erase in bytes

Returns: True if erase is valid for underlying block device

Reimplemented in SlicingBlockDevice, and FlashIAPBlockDevice.

Definition at line 230 of file BlockDevice.h.

virtual bool is_valid_program	(	bd_addr_t	addr,
		bd_size_t	size
	)		const

virtualinherited

Convenience function for checking block program validity.

Parameters

addr	Address of block to begin writing to
size	Size to write in bytes

Returns: True if program is valid for underlying block device

Reimplemented in SlicingBlockDevice.

Definition at line 216 of file BlockDevice.h.

virtual bool is_valid_read	(	bd_addr_t	addr,
		bd_size_t	size
	)		const

virtualinherited

Convenience function for checking block read validity.

Parameters

addr	Address of block to begin reading from
size	Size to read in bytes

Returns: True if read is valid for underlying block device

Reimplemented in SlicingBlockDevice.

Definition at line 202 of file BlockDevice.h.

virtual int program	(	const void *	buffer,
		bd_addr_t	addr,
		bd_size_t	size
	)

virtual

Program blocks to a block device.

The blocks must have been erased prior to being programmed

Parameters

buffer	Buffer of data to write to blocks
addr	Address of block to begin writing to
size	Size to write in bytes, must be a multiple of program block size

Returns: 0 on success, negative error code on failure

Implements BlockDevice.

virtual int read	(	void *	buffer,
		bd_addr_t	addr,
		bd_size_t	size
	)

virtual

Read blocks from a block device.

Parameters

buffer	Buffer to read blocks into
addr	Address of block to begin reading from
size	Size to read in bytes, must be a multiple of read block size

Returns: 0 on success, negative error code on failure

Implements BlockDevice.

virtual bd_size_t size ( ) const

virtual

Get the total size of the underlying device.

Returns: Size of the underlying device in bytes

Implements BlockDevice.

virtual int sync ( )

virtualinherited

Ensure data on storage is in sync with the driver.

Returns: 0 on success or a negative error code on failure

Reimplemented in MBRBlockDevice, ChainingBlockDevice, ExhaustibleBlockDevice, SlicingBlockDevice, FlashSimBlockDevice, ObservingBlockDevice, ProfilingBlockDevice, BufferedBlockDevice, and ReadOnlyBlockDevice.

Definition at line 83 of file BlockDevice.h.

virtual int trim	(	bd_addr_t	addr,
		bd_size_t	size
	)

virtualinherited

Mark blocks as no longer in use.

This function provides a hint to the underlying block device that a region of blocks is no longer in use and may be erased without side effects. Erase must still be called before programming, but trimming allows flash-translation-layers to schedule erases when the device is not busy.

Parameters

addr	Address of block to mark as unused
size	Size to mark as unused in bytes, must be a multiple of the erase block size

Returns: 0 on success or a negative error code on failure

Reimplemented in SDBlockDevice, and BufferedBlockDevice.

Definition at line 137 of file BlockDevice.h.

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Important Information for this Arm website