HeapBlockDevice.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2017 ARM Limited
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy
00005  * of this software and associated documentation files (the "Software"), to deal
00006  * in the Software without restriction, including without limitation the rights
00007  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008  * copies of the Software, and to permit persons to whom the Software is
00009  * furnished to do so, subject to the following conditions:
00010  *
00011  * The above copyright notice and this permission notice shall be included in
00012  * all copies or substantial portions of the Software.
00013  *
00014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
00020  * SOFTWARE.
00021  */
00022 #ifndef MBED_MEM_BLOCK_DEVICE_H
00023 #define MBED_MEM_BLOCK_DEVICE_H
00024 
00025 #include "BlockDevice.h"
00026 #include "platform/mbed_assert.h"
00027 #include <string.h>
00028 #include <stdlib.h>
00029 
00030 /** Lazily allocated heap-backed block device
00031  *
00032  * Useful for simulating a block device and tests
00033  *
00034  * @code
00035  * #include "mbed.h"
00036  * #include "HeapBlockDevice.h"
00037  *
00038  * #define BLOCK_SIZE 512
00039  *
00040  * HeapBlockDevice bd(2048, BLOCK_SIZE); // 2048 bytes with a block size of 512 bytes
00041  * uint8_t block[BLOCK_SIZE] = "Hello World!\n";
00042  *
00043  * int main() {
00044  *     bd.init();
00045  *     bd.erase(0, BLOCK_SIZE);
00046  *     bd.program(block, 0, BLOCK_SIZE);
00047  *     bd.read(block, 0, BLOCK_SIZE);
00048  *     printf("%s", block);
00049  *     bd.deinit();
00050  * }
00051  * @endcode
00052  */
00053 class HeapBlockDevice : public BlockDevice
00054 {
00055 public:
00056 
00057     /** Lifetime of the memory block device
00058      *
00059      * @param size      Size of the Block Device in bytes
00060      * @param block     Block size in bytes. Minimum read, program, and erase sizes are
00061      *                  configured to this value
00062      */
00063     HeapBlockDevice(bd_size_t size, bd_size_t block=512);
00064     /** Lifetime of the memory block device
00065      *
00066      * @param size      Size of the Block Device in bytes
00067      * @param read      Minimum read size required in bytes
00068      * @param program   Minimum program size required in bytes
00069      * @param erase     Minimum erase size required in bytes
00070      */
00071     HeapBlockDevice(bd_size_t size, bd_size_t read, bd_size_t program, bd_size_t erase);
00072     virtual ~HeapBlockDevice();
00073 
00074     /** Initialize a block device
00075      *
00076      *  @return         0 on success or a negative error code on failure
00077      */
00078     virtual int init();
00079 
00080     /** Deinitialize a block device
00081      *
00082      *  @return         0 on success or a negative error code on failure
00083      */
00084     virtual int deinit();
00085 
00086     /** Read blocks from a block device
00087      *
00088      *  @param buffer   Buffer to read blocks into
00089      *  @param addr     Address of block to begin reading from
00090      *  @param size     Size to read in bytes, must be a multiple of read block size
00091      *  @return         0 on success, negative error code on failure
00092      */
00093     virtual int read(void *buffer, bd_addr_t addr, bd_size_t size);
00094 
00095     /** Program blocks to a block device
00096      *
00097      *  The blocks must have been erased prior to being programmed
00098      *
00099      *  @param buffer   Buffer of data to write to blocks
00100      *  @param addr     Address of block to begin writing to
00101      *  @param size     Size to write in bytes, must be a multiple of program block size
00102      *  @return         0 on success, negative error code on failure
00103      */
00104     virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size);
00105 
00106     /** Erase blocks on a block device
00107      *
00108      *  The state of an erased block is undefined until it has been programmed
00109      *
00110      *  @param addr     Address of block to begin erasing
00111      *  @param size     Size to erase in bytes, must be a multiple of erase block size
00112      *  @return         0 on success, negative error code on failure
00113      */
00114     virtual int erase(bd_addr_t addr, bd_size_t size);
00115 
00116     /** Get the size of a readable block
00117      *
00118      *  @return         Size of a readable block in bytes
00119      */
00120     virtual bd_size_t get_read_size() const;
00121 
00122     /** Get the size of a programmable block
00123      *
00124      *  @return         Size of a programmable block in bytes
00125      */
00126     virtual bd_size_t get_program_size() const;
00127 
00128     /** Get the size of an erasable block
00129      *
00130      *  @return         Size of an erasable block in bytes
00131      */
00132     virtual bd_size_t get_erase_size() const;
00133 
00134     /** Get the size of an erasable block given address
00135      *
00136      *  @param addr     Address within the erasable block
00137      *  @return         Size of an erasable block in bytes
00138      *  @note Must be a multiple of the program size
00139      */
00140     virtual bd_size_t get_erase_size(bd_addr_t addr) const;
00141 
00142     /** Get the total size of the underlying device
00143      *
00144      *  @return         Size of the underlying device in bytes
00145      */
00146     virtual bd_size_t size() const;
00147 
00148 private:
00149     bd_size_t _read_size;
00150     bd_size_t _program_size;
00151     bd_size_t _erase_size;
00152     bd_size_t _count;
00153     uint8_t **_blocks;
00154     uint32_t _init_ref_count;
00155     bool _is_initialized;
00156 };
00157 
00158 
00159 #endif