FlashSimBlockDevice
FlashSimBlockDevice class hierarchy
The FlashSimBlockDevice class is a block device adapator, whose purpose is to simulate the behavior of a flash component if the underlying block device doesn't support such a behavior. This includes the following:
- Support the
eraseAPI (fills the erase unit with the predefined erase value). - Only allow programming of erased area or ones whose content is the same as the one given by the user.
- Support the
get\_erase\_valueAPI, returning the predefined erase value.
The constructor requires the following:
- bd - Block device to back the FlashSimBlockDevice.
- erase_value - Value given to each byte of the erase unit following an erase operation (defaults to 0xFF).
To configure this class, please see our BlockDevice configuration documentation.
FlashSimBlockDevice class reference
| Public Member Functions | |
| FlashSimBlockDevice (BlockDevice *bd, uint8_t erase_value=0xFF) | |
| Constructor. More... | |
| virtual int | init () |
| Initialize a block device. More... | |
| virtual int | deinit () |
| Deinitialize the block device. More... | |
| virtual int | sync () |
| Ensure data on storage is in sync with the driver. More... | |
| virtual int | read (void *buffer, bd_addr_t addr, bd_size_t size) |
| Read blocks from the block device. More... | |
| virtual int | program (const void *buffer, bd_addr_t addr, bd_size_t size) |
| Program blocks to the block device. More... | |
| virtual int | erase (bd_addr_t addr, bd_size_t size) |
| Erase blocks on the 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 int | get_erase_value () const |
| Get the value of storage when erased. 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 | trim (bd_addr_t addr, bd_size_t size) |
| Mark blocks as no longer in use. 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... | |
FlashSimBlockDevice example
This FlashSimBlockDevice example takes a HeapBlockDevice and turns it into a simulated flash BD.
/*
* Copyright (c) 2006-2020 Arm Limited and affiliates.
* SPDX-License-Identifier: Apache-2.0
*/
#include "mbed.h"
#include "HeapBlockDevice.h"
#include "FlashSimBlockDevice.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()
{
int erase_unit_size = 512;
HeapBlockDevice heap_bd(4 * erase_unit_size, 1, 4, erase_unit_size);
FlashSimBlockDevice flash_bd(&heap_bd);
// This initializes the flash simulator block device (as well as the underlying heap block device).
int err = flash_bd.init();
uint8_t buf[16];
for (int i = 0; i < sizeof(buf); i++) {
buf[i] = i;
}
// This will fail because the erase unit in address 0 has not been erased.
err = flash_bd.program(buf, 0, sizeof(buf));
// Erase the erase unit in address 0.
err = flash_bd.erase(0, erase_unit_size);
// This will succeed now that the erase unit is erased.
err = flash_bd.program(buf, 0, sizeof(buf));
}
Related content
- HeapBlockDevice API reference.
- BlockDevice configuration documentation.