SlicingBlockDevice.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_SLICING_BLOCK_DEVICE_H
00023 #define MBED_SLICING_BLOCK_DEVICE_H
00024 
00025 #include "BlockDevice.h"
00026 #include "mbed.h"
00027 
00028 
00029 /** Block device for mapping to a slice of another block device
00030  *
00031  *  @code
00032  *  #include "mbed.h"
00033  *  #include "HeapBlockDevice.h"
00034  *  #include "SlicingBlockDevice.h"
00035  *
00036  *  // Create a block device with 64 blocks of size 512
00037  *  HeapBlockDevice mem(64*512, 512);
00038  *
00039  *  // Create a block device that maps to the first 32 blocks
00040  *  SlicingBlockDevice slice1(&mem, 0*512, 32*512);
00041  *
00042  *  // Create a block device that maps to the last 32 blocks
00043  *  SlicingBlockDevice slice2(&mem, 32*512);
00044  *
00045  *  // Create a block device that maps to the middle 32 blocks
00046  *  SlicingBlockDevice slice3(&mem, 16*512, -16*512);
00047  */
00048 class SlicingBlockDevice : public BlockDevice
00049 {
00050 public:
00051     /** Lifetime of the memory block device
00052      *
00053      *  @param bd       Block device to back the SlicingBlockDevice
00054      *  @param start    Start block address to map to block 0, negative addresses
00055      *                  are calculated from the end of the underlying block device
00056      *  @note This is the same as SlicingBlockDevice(bd, start, bd->size())
00057      */
00058     SlicingBlockDevice(BlockDevice *bd, bd_addr_t start);
00059 
00060     /** Lifetime of the memory block device
00061      *
00062      *  @param bd       Block device to back the SlicingBlockDevice
00063      *  @param start    Start block address to map to block 0, negative addresses
00064      *                  are calculated from the end of the underlying block device
00065      *  @param stop     End block address to mark the end of the block device,
00066      *                  this block is not mapped, negative addresses are
00067      *                  calculated from the end of the underlying block device
00068      */
00069     SlicingBlockDevice(BlockDevice *bd, bd_addr_t start, bd_addr_t end);
00070 
00071     /** Lifetime of a block device
00072      */
00073     virtual ~SlicingBlockDevice() {};
00074 
00075     /** Initialize a block device
00076      *
00077      *  @return         0 on success or a negative error code on failure
00078      */
00079     virtual int init();
00080 
00081     /** Deinitialize a block device
00082      *
00083      *  @return         0 on success or a negative error code on failure
00084      */
00085     virtual int deinit();
00086 
00087     /** Read blocks from a block device
00088      *
00089      *  @param buffer   Buffer to read blocks into
00090      *  @param addr     Address of block to begin reading from
00091      *  @param size     Size to read in bytes, must be a multiple of read block size
00092      *  @return         0 on success, negative error code on failure
00093      */
00094     virtual int read(void *buffer, bd_addr_t addr, bd_size_t size);
00095 
00096     /** Program blocks to a block device
00097      *
00098      *  The blocks must have been erased prior to being programmed
00099      *
00100      *  @param buffer   Buffer of data to write to blocks
00101      *  @param addr     Address of block to begin writing to
00102      *  @param size     Size to write in bytes, must be a multiple of program block size
00103      *  @return         0 on success, negative error code on failure
00104      */
00105     virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size);
00106 
00107     /** Erase blocks on a block device
00108      *
00109      *  The state of an erased block is undefined until it has been programmed
00110      *
00111      *  @param addr     Address of block to begin erasing
00112      *  @param size     Size to erase in bytes, must be a multiple of erase block size
00113      *  @return         0 on success, negative error code on failure
00114      */
00115     virtual int erase(bd_addr_t addr, bd_size_t size);
00116 
00117     /** Get the size of a readable block
00118      *
00119      *  @return         Size of a readable block in bytes
00120      */
00121     virtual bd_size_t get_read_size() const;
00122 
00123     /** Get the size of a programable block
00124      *
00125      *  @return         Size of a programable block in bytes
00126      *  @note Must be a multiple of the read size
00127      */
00128     virtual bd_size_t get_program_size() const;
00129 
00130     /** Get the size of a eraseable block
00131      *
00132      *  @return         Size of a eraseable block in bytes
00133      *  @note Must be a multiple of the program size
00134      */
00135     virtual bd_size_t get_erase_size() const;
00136 
00137     /** Get the total size of the underlying device
00138      *
00139      *  @return         Size of the underlying device in bytes
00140      */
00141     virtual bd_size_t size() const;
00142 
00143 protected:
00144     BlockDevice *_bd;
00145     bool _start_from_end;
00146     bd_size_t _start;
00147     bool _stop_from_end;
00148     bd_size_t _stop;
00149 };
00150 
00151 
00152 #endif
00153