Block device for chaining multiple block devices with the similar block sizes at sequential addresses. More...

#include <ChainingBlockDevice.h>

Public Member Functions
	ChainingBlockDevice (BlockDevice **bds, size_t bd_count)
	Lifetime of the memory block device.
template<size_t Size>
	ChainingBlockDevice (BlockDevice *(&bds)[Size])
	Lifetime of the memory block device.
virtual	~ChainingBlockDevice ()
	Lifetime of the memory block device.
virtual int	init ()
	Initialize a block device.
virtual int	deinit ()
	Deinitialize a block device.
virtual int	sync ()
	Ensure data on storage is in sync with the driver.
virtual int	read (void *buffer, bd_addr_t addr, bd_size_t size)
	Read blocks from a block device.
virtual int	program (const void *buffer, bd_addr_t addr, bd_size_t size)
	Program blocks to a block device.
virtual int	erase (bd_addr_t addr, bd_size_t size)
	Erase blocks on a block device.
virtual bd_size_t	get_read_size () const
	Get the size of a readable block.
virtual bd_size_t	get_program_size () const
	Get the size of a programmable block.
virtual bd_size_t	get_erase_size () const
	Get the size of an eraseable block.
virtual bd_size_t	get_erase_size (bd_addr_t addr) const
	Get the size of an erasable block given address.
virtual int	get_erase_value () const
	Get the value of storage when erased.
virtual bd_size_t	size () const
	Get the total size of the underlying device.
virtual int	trim (bd_addr_t addr, bd_size_t size)
	Mark blocks as no longer in use.
bool	is_valid_read (bd_addr_t addr, bd_size_t size) const
	Convenience function for checking block read validity.
bool	is_valid_program (bd_addr_t addr, bd_size_t size) const
	Convenience function for checking block program validity.
bool	is_valid_erase (bd_addr_t addr, bd_size_t size) const
	Convenience function for checking block erase validity.
Static Public Member Functions
static BlockDevice *	get_default_instance ()
	Return the default block device.

Detailed Description

Block device for chaining multiple block devices with the similar block sizes at sequential addresses.

  #include "mbed.h"
  #include "HeapBlockDevice.h"
  #include "ChainingBlockDevice.h"

  // Create two smaller block devices with
  // 64 and 32 blocks of size 512 bytes
  HeapBlockDevice mem1(64*512, 512);
  HeapBlockDevice mem2(32*512, 512);

  // Create a block device backed by mem1 and mem2
  // contains 96 blocks of size 512 bytes
  BlockDevice *bds[] = {&mem1, &mem2};
  ChainingBlockDevice chainmem(bds);

Definition at line 48 of file ChainingBlockDevice.h.

Constructor & Destructor Documentation

ChainingBlockDevice	(	BlockDevice **	bds,
		size_t	bd_count
	)

Lifetime of the memory block device.

Parameters:

bds	Array of block devices to chain with sequential block addresses
bd_count	Number of block devices to chain

Note:: All block devices must have the same block size

Definition at line 21 of file ChainingBlockDevice.cpp.

ChainingBlockDevice ( BlockDevice *(&) bds[Size] )

Lifetime of the memory block device.

Parameters:

bds	Array of block devices to chain with sequential block addresses

Note:: All block devices must have the same block size

Definition at line 65 of file ChainingBlockDevice.h.

virtual ~ChainingBlockDevice ( ) [virtual]

Lifetime of the memory block device.

Definition at line 74 of file ChainingBlockDevice.h.

Member Function Documentation

int deinit ( ) [virtual]

Deinitialize a block device.

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

Implements BlockDevice.

Definition at line 98 of file ChainingBlockDevice.cpp.

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, unless get_erase_value returns a non-negative byte value

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.

Definition at line 207 of file ChainingBlockDevice.cpp.

MBED_WEAK BlockDevice * get_default_instance ( ) [static, inherited]

Return the default block device.

Returns the default BlockDevice base on 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() themselves - the default definition is weak, and calls get_target_default_instance().

Definition at line 35 of file SystemStorage.cpp.

bd_size_t get_erase_size ( ) const [virtual]

Get the size of an eraseable block.

Returns:: Size of an erasable block in bytes

Note:: Must be a multiple of the program size

Reimplemented from BlockDevice.

Definition at line 249 of file ChainingBlockDevice.cpp.

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.

Definition at line 254 of file ChainingBlockDevice.cpp.

int get_erase_value ( ) const [virtual]

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 erased storage

Reimplemented from BlockDevice.

Definition at line 274 of file ChainingBlockDevice.cpp.

bd_size_t get_program_size ( ) const [virtual]

Get the size of a programmable block.

Returns:: Size of a programmable block in bytes

Note:: Must be a multiple of the read size

Implements BlockDevice.

Definition at line 244 of file ChainingBlockDevice.cpp.

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.

Definition at line 239 of file ChainingBlockDevice.cpp.

int init ( ) [virtual]

Initialize a block device.

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

Implements BlockDevice.

Definition at line 33 of file ChainingBlockDevice.cpp.

bool is_valid_erase	(	bd_addr_t	addr,
		bd_size_t	size
	)		const `[inherited]`

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

Definition at line 226 of file BlockDevice.h.

bool is_valid_program	(	bd_addr_t	addr,
		bd_size_t	size
	)		const `[inherited]`

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

Definition at line 212 of file BlockDevice.h.

bool is_valid_read	(	bd_addr_t	addr,
		bd_size_t	size
	)		const `[inherited]`

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

Definition at line 198 of file BlockDevice.h.

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.

Definition at line 172 of file ChainingBlockDevice.cpp.

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

Read blocks from a block device.

Parameters:

buffer	Buffer to write blocks to
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.

Definition at line 137 of file ChainingBlockDevice.cpp.

bd_size_t size ( ) const [virtual]

Get the total size of the underlying device.

Returns:: Size of the underlying device in bytes

Implements BlockDevice.

Definition at line 279 of file ChainingBlockDevice.cpp.

int sync ( ) [virtual]

Ensure data on storage is in sync with the driver.

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

Reimplemented from BlockDevice.

Definition at line 121 of file ChainingBlockDevice.cpp.

virtual int trim	(	bd_addr_t	addr,
		bd_size_t	size
	)		`[virtual, inherited]`

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 erase block size

Returns:: 0 on success, negative error code on failure

Reimplemented in SDBlockDevice, and BufferedBlockDevice.

Definition at line 133 of file BlockDevice.h.

Type:	Program
Mbed OS support:	Mbed OS
Created:	11 Oct 2018
Imports:	23
Forks:	0
Commits:	4
Dependents:	0
Dependencies:	1
Followers:	1

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