/* mbed Microcontroller Library
* Copyright (c) 2017 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_BLOCK_DEVICE_H
#define MBED_BLOCK_DEVICE_H
#include <stdint.h>
namespace mbed {
/** \defgroup storage Storage
* \ingroup mbed-os-public
* @{
* \defgroup storage-blockdevice BlockDevice
* \ingroup storage */
/** @{ */
/** Enum of standard error codes
*
* @enum bd_error
*/
enum bd_error {
BD_ERROR_OK = 0, /*!< no error */
BD_ERROR_DEVICE_ERROR = -4001, /*!< device specific error */
};
/** Type representing the address of a specific block
*/
typedef uint64_t bd_addr_t;
/** Type representing a quantity of 8-bit bytes
*/
typedef uint64_t bd_size_t;
/** A hardware device capable of writing and reading blocks
*/
class BlockDevice {
public:
/** Return the default block device
*
* Returns the default block device based on the configuration JSON.
* Use the components in target.json or application config to change
* the default block device.
*
* An application can override all target settings by implementing
* BlockDevice::get_default_instance() - the default
* definition is weak, and calls get_target_default_instance().
*/
static BlockDevice *get_default_instance();
/** Lifetime of a block device
*/
virtual ~BlockDevice() {};
/** Initialize a block device
*
* @return 0 on success or a negative error code on failure
*/
virtual int init() = 0;
/** Deinitialize a block device
*
* @return 0 on success or a negative error code on failure
*/
virtual int deinit() = 0;
/** Ensure data on storage is in sync with the driver
*
* @return 0 on success or a negative error code on failure
*/
virtual int sync()
{
return 0;
}
/** Read blocks from a block device
*
* If a failure occurs, it is not possible to determine how many bytes succeeded
*
* @param buffer Buffer to write blocks to
* @param addr Address of block to begin reading from
* @param size Size to read in bytes, must be a multiple of the 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) = 0;
/** Program blocks to a block device
*
* The blocks must have been erased prior to being programmed
*
* If a failure occurs, it is not possible to determine how many bytes succeeded
*
* @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 the 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) = 0;
/** 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 the 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)
{
return 0;
}
/** Mark blocks as no longer in use
*
* This function provides a hint to the underlying block device that a region of blocks
* is no longer in use and may be erased without side effects. Erase must still be called
* before programming, but trimming allows flash-translation-layers to schedule erases when
* the device is not busy.
*
* @param addr Address of block to mark as unused
* @param size Size to mark as unused in bytes, must be a multiple of the erase block size
* @return 0 on success or a negative error code on failure
*/
virtual int trim(bd_addr_t addr, bd_size_t size)
{
return 0;
}
/** Get the size of a readable block
*
* @return Size of a readable block in bytes
*/
virtual bd_size_t get_read_size() const = 0;
/** 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 = 0;
/** 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
{
return get_program_size();
}
/** 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
{
return get_erase_size();
}
/** 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 the erased storage
*/
virtual int get_erase_value() const
{
return -1;
}
/** Get the total size of the underlying device
*
* @return Size of the underlying device in bytes
*/
virtual bd_size_t size() const = 0;
/** 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
{
return (
addr % get_read_size() == 0 &&
size % get_read_size() == 0 &&
addr + size <= this->size());
}
/** 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
{
return (
addr % get_program_size() == 0 &&
size % get_program_size() == 0 &&
addr + size <= this->size());
}
/** 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
{
return (
addr % get_erase_size(addr) == 0 &&
(addr + size) % get_erase_size(addr + size - 1) == 0 &&
addr + size <= this->size());
}
/** Get the BlockDevice class type.
*
* @return A string represent the BlockDevice class type.
*/
virtual const char *get_type() const = 0;
};
/** @}
* @}
*/
} // namespace mbed
// Added "using" for backwards compatibility
#ifndef MBED_NO_GLOBAL_USING_DIRECTIVE
using mbed::BlockDevice;
using mbed::bd_addr_t;
using mbed::bd_size_t;
using mbed::BD_ERROR_OK;
using mbed::BD_ERROR_DEVICE_ERROR;
#endif
#endif
