Nicolas Borla
BBR 1 Ebene
Diff: mbed-os/features/filesystem/bd/BlockDevice.h
- Revision:
- 0:fbdae7e6d805
diff -r 000000000000 -r fbdae7e6d805 mbed-os/features/filesystem/bd/BlockDevice.h
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os/features/filesystem/bd/BlockDevice.h Mon May 14 11:29:06 2018 +0000
@@ -0,0 +1,223 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2017 ARM Limited
+ *
+ * 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>
+
+
+/** 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:
+ /** 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 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) = 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 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) = 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 erase block size
+ * @return 0 on success, 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 erase block size
+ * @return 0 on success, 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 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
+ */
+ 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
+ */
+ 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
+ */
+ bool is_valid_erase(bd_addr_t addr, bd_size_t size) const
+ {
+ return (
+ addr % get_erase_size() == 0 &&
+ size % get_erase_size() == 0 &&
+ addr + size <= this->size());
+ }
+};
+
+
+#endif