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MBRBlockDevice.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_MBR_BLOCK_DEVICE_H 00023 #define MBED_MBR_BLOCK_DEVICE_H 00024 00025 #include "BlockDevice.h" 00026 #include "mbed.h" 00027 00028 00029 /** Additional error codes used for MBR records 00030 */ 00031 enum { 00032 BD_ERROR_INVALID_MBR = -3101, 00033 BD_ERROR_INVALID_PARTITION = -3102, 00034 }; 00035 00036 00037 /** Block device for managing a Master Boot Record 00038 * https://en.wikipedia.org/wiki/Master_boot_record 00039 * 00040 * Here is an example of partitioning a heap backed block device 00041 * @code 00042 * #include "mbed.h" 00043 * #include "HeapBlockDevice.h" 00044 * #include "MBRBlockDevice.h" 00045 * 00046 * // Create a block device with 64 blocks of size 512 00047 * HeapBlockDevice mem(64*512, 512); 00048 * 00049 * // Partition into two partitions with ~half the blocks 00050 * MBRBlockDevice::partition(&mem, 1, 0x83, 0*512, 32*512); 00051 * MBRBlockDevice::partition(&mem, 2, 0x83, 32*512); 00052 * 00053 * // Create a block device that maps to the first 32 blocks (excluding MBR block) 00054 * MBRBlockDevice part1(&mem, 1); 00055 * 00056 * // Create a block device that maps to the last 32 blocks 00057 * MBRBlockDevice part2(&mem, 2); 00058 * @endcode 00059 * 00060 * Here is a more realistic example where the MBRBlockDevice is used 00061 * to partition a region of space on an SD card. When plugged into a computer, 00062 * the partitions will be recognized appropriately. 00063 * @code 00064 * #include "mbed.h" 00065 * #include "SDBlockDevice.h" 00066 * #include "MBRBlockDevice.h" 00067 * #include "FATFileSystem.h" 00068 * 00069 * // Create an SD card 00070 * SDBlockDevice sd(s0, s1, s2, s3); 00071 * 00072 * // Create a partition with 1 GB of space 00073 * MBRBlockDevice::partition(&sd, 1, 0x83, 0, 1024*1024); 00074 * 00075 * // Create the block device that represents the partition 00076 * MBRBlockDevice part1(&sd, 1); 00077 * 00078 * // Format the partition with a FAT filesystem 00079 * FATFileSystem::format(&part1); 00080 * 00081 * // Create the FAT filesystem instance, files can now be written to 00082 * // the FAT filesystem in partition 1 00083 * FATFileSystem fat("fat", &part1); 00084 * @endcode 00085 * 00086 * @note 00087 * The MBR partition table is relatively limited: 00088 * - At most 4 partitions are supported 00089 * - Extended partitions are currently not supported and will error during init 00090 */ 00091 class MBRBlockDevice : public BlockDevice 00092 { 00093 public: 00094 /** Format the MBR to contain the following partition 00095 * 00096 * @param bd Block device to partition 00097 * @param part Partition to use, 1-4 00098 * @param type 8-bit partition type to identitfy partition's contents 00099 * @param start Start block address to map to block 0 of partition, 00100 * negative addresses are calculated from the end of the 00101 * underlying block devices. Block 0 is implicitly ignored 00102 * from the range to store the MBR. 00103 * @return 0 on success or a negative error code on failure 00104 * @note This is the same as partition(bd, part, type, start, bd->size()) 00105 */ 00106 static int partition(BlockDevice *bd, int part, uint8_t type, bd_addr_t start); 00107 00108 /** Format the MBR to contain the following partition 00109 * 00110 * @param bd Block device to partition 00111 * @param part Partition to use, 1-4 00112 * @param type 8-bit partition type to identitfy partition's contents 00113 * @param start Start block address to map to block 0 of partition, 00114 * negative addresses are calculated from the end of the 00115 * underlying block devices. Block 0 is implicitly ignored 00116 * from the range to store the MBR. 00117 * @param stop End block address to mark the end of the partition, 00118 * this block is not mapped, negative addresses are calculated 00119 * from the end of the underlying block device. 00120 * @return 0 on success or a negative error code on failure 00121 */ 00122 static int partition(BlockDevice *bd, int part, uint8_t type, bd_addr_t start, bd_addr_t stop); 00123 00124 /** Lifetime of the block device 00125 * 00126 * @param bd Block device to back the MBRBlockDevice 00127 * @param part Partition to use, 1-4 00128 */ 00129 MBRBlockDevice(BlockDevice *bd, int part); 00130 00131 /** Lifetime of the block device 00132 */ 00133 virtual ~MBRBlockDevice() {}; 00134 00135 /** Initialize a block device 00136 * 00137 * @return 0 on success or a negative error code on failure 00138 */ 00139 virtual int init(); 00140 00141 /** Deinitialize a block device 00142 * 00143 * @return 0 on success or a negative error code on failure 00144 */ 00145 virtual int deinit(); 00146 00147 /** Ensure data on storage is in sync with the driver 00148 * 00149 * @return 0 on success or a negative error code on failure 00150 */ 00151 virtual int sync(); 00152 00153 /** Read blocks from a block device 00154 * 00155 * @param buffer Buffer to read blocks into 00156 * @param addr Address of block to begin reading from 00157 * @param size Size to read in bytes, must be a multiple of read block size 00158 * @return 0 on success, negative error code on failure 00159 */ 00160 virtual int read(void *buffer, bd_addr_t addr, bd_size_t size); 00161 00162 /** Program blocks to a block device 00163 * 00164 * The blocks must have been erased prior to being programmed 00165 * 00166 * @param buffer Buffer of data to write to blocks 00167 * @param addr Address of block to begin writing to 00168 * @param size Size to write in bytes, must be a multiple of program block size 00169 * @return 0 on success, negative error code on failure 00170 */ 00171 virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size); 00172 00173 /** Erase blocks on a block device 00174 * 00175 * The state of an erased block is undefined until it has been programmed, 00176 * unless get_erase_value returns a non-negative byte value 00177 * 00178 * @param addr Address of block to begin erasing 00179 * @param size Size to erase in bytes, must be a multiple of erase block size 00180 * @return 0 on success, negative error code on failure 00181 */ 00182 virtual int erase(bd_addr_t addr, bd_size_t size); 00183 00184 /** Get the size of a readable block 00185 * 00186 * @return Size of a readable block in bytes 00187 */ 00188 virtual bd_size_t get_read_size() const; 00189 00190 /** Get the size of a programmable block 00191 * 00192 * @return Size of a programmable block in bytes 00193 * @note Must be a multiple of the read size 00194 */ 00195 virtual bd_size_t get_program_size() const; 00196 00197 /** Get the size of an erasable block 00198 * 00199 * @return Size of an erasable block in bytes 00200 * @note Must be a multiple of the program size 00201 */ 00202 virtual bd_size_t get_erase_size() const; 00203 00204 /** Get the size of an erasable block given address 00205 * 00206 * @param addr Address within the erasable block 00207 * @return Size of an erasable block in bytes 00208 * @note Must be a multiple of the program size 00209 */ 00210 virtual bd_size_t get_erase_size(bd_addr_t addr) const; 00211 00212 /** Get the value of storage when erased 00213 * 00214 * If get_erase_value returns a non-negative byte value, the underlying 00215 * storage is set to that value when erased, and storage containing 00216 * that value can be programmed without another erase. 00217 * 00218 * @return The value of storage when erased, or -1 if you can't 00219 * rely on the value of erased storage 00220 */ 00221 virtual int get_erase_value() const; 00222 00223 /** Get the total size of the underlying device 00224 * 00225 * @return Size of the underlying device in bytes 00226 */ 00227 virtual bd_size_t size() const; 00228 00229 /** Get the offset of the partition on the underlying block device 00230 * @return Offset of the partition on the underlying device 00231 */ 00232 virtual bd_addr_t get_partition_start() const; 00233 00234 /** Get size of partition on underlying block device 00235 * @return Size of the partition on the underlying device 00236 */ 00237 virtual bd_addr_t get_partition_stop() const; 00238 00239 /** Get 8-bit type of the partition 00240 * @return 8-bit type of partition assigned during format 00241 */ 00242 virtual uint8_t get_partition_type() const; 00243 00244 /** Get the partition number 00245 * @return The partition number, 1-4 00246 */ 00247 virtual int get_partition_number() const; 00248 00249 protected: 00250 BlockDevice *_bd; 00251 bd_size_t _offset; 00252 bd_size_t _size; 00253 uint8_t _type; 00254 uint8_t _part; 00255 }; 00256 00257 00258 #endif
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