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