Diff: features/filesystem/bd/SlicingBlockDevice.h

Revision:

0:f782d9c66c49

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/features/filesystem/bd/SlicingBlockDevice.h	Fri Feb 02 05:42:23 2018 +0000
@@ -0,0 +1,152 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2017 ARM Limited
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef MBED_SLICING_BLOCK_DEVICE_H
+#define MBED_SLICING_BLOCK_DEVICE_H
+
+#include "BlockDevice.h"
+#include "mbed.h"
+
+
+/** Block device for mapping to a slice of another block device
+ *
+ *  @code
+ *  #include "mbed.h"
+ *  #include "HeapBlockDevice.h"
+ *  #include "SlicingBlockDevice.h"
+ *
+ *  // Create a block device with 64 blocks of size 512
+ *  HeapBlockDevice mem(64*512, 512);
+ *
+ *  // Create a block device that maps to the first 32 blocks
+ *  SlicingBlockDevice slice1(&mem, 0*512, 32*512);
+ *
+ *  // Create a block device that maps to the last 32 blocks
+ *  SlicingBlockDevice slice2(&mem, 32*512);
+ *
+ *  // Create a block device that maps to the middle 32 blocks
+ *  SlicingBlockDevice slice3(&mem, 16*512, -16*512);
+ */
+class SlicingBlockDevice : public BlockDevice
+{
+public:
+    /** Lifetime of the memory block device
+     *
+     *  @param bd       Block device to back the SlicingBlockDevice
+     *  @param start    Start block address to map to block 0, negative addresses
+     *                  are calculated from the end of the underlying block device
+     *  @note This is the same as SlicingBlockDevice(bd, start, bd->size())
+     */
+    SlicingBlockDevice(BlockDevice *bd, bd_addr_t start);
+
+    /** Lifetime of the memory block device
+     *
+     *  @param bd       Block device to back the SlicingBlockDevice
+     *  @param start    Start block address to map to block 0, negative addresses
+     *                  are calculated from the end of the underlying block device
+     *  @param stop     End block address to mark the end of the block device,
+     *                  this block is not mapped, negative addresses are
+     *                  calculated from the end of the underlying block device
+     */
+    SlicingBlockDevice(BlockDevice *bd, bd_addr_t start, bd_addr_t end);
+
+    /** Lifetime of a block device
+     */
+    virtual ~SlicingBlockDevice() {};
+
+    /** 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 programable block
+     *
+     *  @return         Size of a programable block in bytes
+     *  @note Must be a multiple of the read size
+     */
+    virtual bd_size_t get_program_size() const;
+
+    /** Get the size of a eraseable block
+     *
+     *  @return         Size of a eraseable block in bytes
+     *  @note Must be a multiple of the program size
+     */
+    virtual bd_size_t get_erase_size() const;
+
+    /** Get the total size of the underlying device
+     *
+     *  @return         Size of the underlying device in bytes
+     */
+    virtual bd_size_t size() const;
+
+protected:
+    BlockDevice *_bd;
+    bool _start_from_end;
+    bd_size_t _start;
+    bool _stop_from_end;
+    bd_size_t _stop;
+};
+
+
+#endif