Mbed OS Reference | HeapBlockDevice.h Source File

 /* mbed Microcontroller Library
  * Copyright (c) 2017-2020 ARM Limited
  * SPDX-License-Identifier: Apache-2.0
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 
 /** \addtogroup storage */
 /** @{*/
 
 #ifndef MBED_MEM_BLOCK_DEVICE_H
 #define MBED_MEM_BLOCK_DEVICE_H
 
 #include "BlockDevice.h"
 #include "platform/mbed_assert.h"
 #include <string.h>
 #include <stdlib.h>
 
 namespace mbed {
 
 /** 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.
  *
  * @code
  * #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();
  * }
  * @endcode
  */
 class HeapBlockDevice : public BlockDevice {
 public:
 
     /** Lifetime of the memory block device
      *
      * @param size      Size of the Block Device in bytes
      * @param block     Block size in bytes. Minimum read, program, and erase sizes are
      *                  configured to this value
      */
     HeapBlockDevice(bd_size_t size, bd_size_t block = 512);
     /** Lifetime of the memory block device
      *
      * @param size      Size of the Block Device in bytes
      * @param read      Minimum read size required in bytes
      * @param program   Minimum program size required in bytes
      * @param erase     Minimum erase size required in bytes
      */
     HeapBlockDevice(bd_size_t size, bd_size_t read, bd_size_t program, bd_size_t erase);
     virtual ~HeapBlockDevice();
 
     /** Initialize a block device
      *
      *  @return         0 on success or a negative error code on failure
      */
     virtual int init();
 
     /** Deinitialize a block device
      *
      *  @return         0 on success or a negative error code on failure
      */
     virtual int deinit();
 
     /** Read blocks from a block device
      *
      *  @param buffer   Buffer to read blocks into
      *  @param addr     Address of block to begin reading from
      *  @param size     Size to read in bytes, must be a multiple of read block size
      *  @return         0 on success, negative error code on failure
      */
     virtual int read(void *buffer, bd_addr_t addr, bd_size_t size);
 
     /** Program blocks to a block device
      *
      *  The blocks must have been erased prior to being programmed
      *
      *  @param buffer   Buffer of data to write to blocks
      *  @param addr     Address of block to begin writing to
      *  @param size     Size to write in bytes, must be a multiple of program block size
      *  @return         0 on success, negative error code on failure
      */
     virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size);
 
     /** Erase blocks on a block device
      *
      *  The state of an erased block is undefined until it has been programmed
      *
      *  @param addr     Address of block to begin erasing
      *  @param size     Size to erase in bytes, must be a multiple of erase block size
      *  @return         0 on success, negative error code on failure
      */
     virtual int erase(bd_addr_t addr, bd_size_t size);
 
     /** Get the size of a readable block
      *
      *  @return         Size of a readable block in bytes
      */
     virtual bd_size_t get_read_size() const;
 
     /** Get the size of a programmable block
      *
      *  @return         Size of a programmable block in bytes
      */
     virtual bd_size_t get_program_size() const;
 
     /** Get the size of an erasable block
      *
      *  @return         Size of an erasable block in bytes
      */
     virtual bd_size_t get_erase_size() const;
 
     /** Get the size of an erasable block given address
      *
      *  @param addr     Address within the erasable block
      *  @return         Size of an erasable block in bytes
      *  @note Must be a multiple of the program size
      */
     virtual bd_size_t get_erase_size(bd_addr_t addr) const;
 
     /** Get the total size of the underlying device
      *
      *  @return         Size of the underlying device in bytes
      */
     virtual bd_size_t size() const;
 
     /** Get the BlockDevice class type.
      *
      *  @return         A string represent the BlockDevice class type.
      */
     virtual const char *get_type() const;
 
 private:
     bd_size_t _read_size;
     bd_size_t _program_size;
     bd_size_t _erase_size;
     bd_size_t _count;
     uint8_t **_blocks;
     uint32_t _init_ref_count;
     bool _is_initialized;
 };
 
 } // namespace mbed
 
 // Added "using" for backwards compatibility
 #ifndef MBED_NO_GLOBAL_USING_DIRECTIVE
 using mbed::HeapBlockDevice;
 #endif
 
 #endif
 
 /** @}*/
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