SlicingBlockDevice.h

/* 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.
 */
 
 
#ifndef MBED_SLICING_BLOCK_DEVICE_H
#define MBED_SLICING_BLOCK_DEVICE_H
 
#include "BlockDevice.h"
#include "platform/mbed_assert.h"
 
namespace mbed {
 
/** \addtogroup storage-blockdevice */
/** @{*/
 
/** Block device for mapping to a slice of another block device
 */
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
     *  @param end      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.
     *                  The default stops at end of the underlying block device.
     */
    SlicingBlockDevice(BlockDevice *bd, bd_addr_t start, bd_addr_t end = 0);
 
    /** 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();
 
    /** Ensure data on storage is in sync with the driver
     *
     *  @return         0 on success or a negative error code on failure
     */
    virtual int sync();
 
    /** 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 or a 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 or a 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,
     *  unless get_erase_value returns a non-negative byte value
     *
     *  @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 or a 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
     *  @note Must be a multiple of the read size
     */
    virtual bd_size_t get_program_size() const;
 
    /** Get the size of an 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() 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 value of storage when erased
     *
     *  If get_erase_value returns a non-negative byte value, the underlying
     *  storage is set to that value when erased, and storage containing
     *  that value can be programmed without another erase.
     *
     *  @return         The value of storage when erased, or -1 if you can't
     *                  rely on the value of erased storage
     */
    virtual int get_erase_value() 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;
 
    /** Convenience function for checking block program validity
     *
     *  @param addr     Address of block to begin writing to
     *  @param size     Size to write in bytes
     *  @return         True if program is valid for underlying block device
     */
    virtual bool is_valid_program(bd_addr_t addr, bd_size_t size) const;
 
    /** Convenience function for checking block read validity
     *
     *  @param addr     Address of block to begin reading from
     *  @param size     Size to read in bytes
     *  @return         True if read is valid for underlying block device
     */
    virtual bool is_valid_read(bd_addr_t addr, bd_size_t size) const;
 
    /** Convenience function for checking block erase validity
     *
     *  @param addr     Address of block to begin erasing
     *  @param size     Size to erase in bytes
     *  @return         True if erase is valid for underlying block device
     */
    virtual bool is_valid_erase(bd_addr_t addr, bd_size_t size) const;
 
 
protected:
    BlockDevice *_bd;
    bool _start_from_end;
    bd_size_t _start;
    bool _stop_from_end;
    bd_size_t _stop;
};
 
/** @}*/
 
} // namespace mbed
 
// Added "using" for backwards compatibility
#ifndef MBED_NO_GLOBAL_USING_DIRECTIVE
using mbed::SlicingBlockDevice;
#endif
 
#endif