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drivers/MbedCRC.h@2:7aab896b1a3b, 2019-03-13 (annotated)
- Committer:
- kevman
- Date:
- Wed Mar 13 11:03:24 2019 +0000
- Revision:
- 2:7aab896b1a3b
- Parent:
- 0:38ceb79fef03
2019-03-13
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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kevman | 0:38ceb79fef03 | 1 | /* mbed Microcontroller Library |
kevman | 0:38ceb79fef03 | 2 | * Copyright (c) 2018 ARM Limited |
kevman | 0:38ceb79fef03 | 3 | * |
kevman | 0:38ceb79fef03 | 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
kevman | 0:38ceb79fef03 | 5 | * you may not use this file except in compliance with the License. |
kevman | 0:38ceb79fef03 | 6 | * You may obtain a copy of the License at |
kevman | 0:38ceb79fef03 | 7 | * |
kevman | 0:38ceb79fef03 | 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
kevman | 0:38ceb79fef03 | 9 | * |
kevman | 0:38ceb79fef03 | 10 | * Unless required by applicable law or agreed to in writing, software |
kevman | 0:38ceb79fef03 | 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
kevman | 0:38ceb79fef03 | 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
kevman | 0:38ceb79fef03 | 13 | * See the License for the specific language governing permissions and |
kevman | 0:38ceb79fef03 | 14 | * limitations under the License. |
kevman | 0:38ceb79fef03 | 15 | */ |
kevman | 0:38ceb79fef03 | 16 | #ifndef MBED_CRC_API_H |
kevman | 0:38ceb79fef03 | 17 | #define MBED_CRC_API_H |
kevman | 0:38ceb79fef03 | 18 | |
kevman | 0:38ceb79fef03 | 19 | #include "drivers/TableCRC.h" |
kevman | 0:38ceb79fef03 | 20 | #include "hal/crc_api.h" |
kevman | 0:38ceb79fef03 | 21 | #include "platform/mbed_assert.h" |
kevman | 0:38ceb79fef03 | 22 | #include "platform/SingletonPtr.h" |
kevman | 0:38ceb79fef03 | 23 | #include "platform/PlatformMutex.h" |
kevman | 0:38ceb79fef03 | 24 | |
kevman | 0:38ceb79fef03 | 25 | /* This is invalid warning from the compiler for below section of code |
kevman | 0:38ceb79fef03 | 26 | if ((width < 8) && (NULL == _crc_table)) { |
kevman | 0:38ceb79fef03 | 27 | p_crc = (uint32_t)(p_crc << (8 - width)); |
kevman | 0:38ceb79fef03 | 28 | } |
kevman | 0:38ceb79fef03 | 29 | Compiler warns of the shift operation with width as it is width=(std::uint8_t), |
kevman | 0:38ceb79fef03 | 30 | but we check for ( width < 8) before performing shift, so it should not be an issue. |
kevman | 0:38ceb79fef03 | 31 | */ |
kevman | 0:38ceb79fef03 | 32 | #if defined ( __CC_ARM ) |
kevman | 0:38ceb79fef03 | 33 | #pragma diag_suppress 62 // Shift count is negative |
kevman | 0:38ceb79fef03 | 34 | #elif defined ( __GNUC__ ) |
kevman | 0:38ceb79fef03 | 35 | #pragma GCC diagnostic push |
kevman | 0:38ceb79fef03 | 36 | #pragma GCC diagnostic ignored "-Wshift-count-negative" |
kevman | 0:38ceb79fef03 | 37 | #elif defined (__ICCARM__) |
kevman | 0:38ceb79fef03 | 38 | #pragma diag_suppress=Pe062 // Shift count is negative |
kevman | 0:38ceb79fef03 | 39 | #endif |
kevman | 0:38ceb79fef03 | 40 | |
kevman | 0:38ceb79fef03 | 41 | namespace mbed { |
kevman | 0:38ceb79fef03 | 42 | /** \addtogroup drivers */ |
kevman | 0:38ceb79fef03 | 43 | /** @{*/ |
kevman | 0:38ceb79fef03 | 44 | |
kevman | 0:38ceb79fef03 | 45 | /** CRC object provides CRC generation through hardware/software |
kevman | 0:38ceb79fef03 | 46 | * |
kevman | 0:38ceb79fef03 | 47 | * ROM polynomial tables for supported polynomials (:: crc_polynomial_t) will be used for |
kevman | 0:38ceb79fef03 | 48 | * software CRC computation, if ROM tables are not available then CRC is computed runtime |
kevman | 0:38ceb79fef03 | 49 | * bit by bit for all data input. |
kevman | 0:38ceb79fef03 | 50 | * @note Synchronization level: Thread safe |
kevman | 0:38ceb79fef03 | 51 | * |
kevman | 0:38ceb79fef03 | 52 | * @tparam polynomial CRC polynomial value in hex |
kevman | 0:38ceb79fef03 | 53 | * @tparam width CRC polynomial width |
kevman | 0:38ceb79fef03 | 54 | * |
kevman | 0:38ceb79fef03 | 55 | * Example: Compute CRC data |
kevman | 0:38ceb79fef03 | 56 | * @code |
kevman | 0:38ceb79fef03 | 57 | * |
kevman | 0:38ceb79fef03 | 58 | * #include "mbed.h" |
kevman | 0:38ceb79fef03 | 59 | * |
kevman | 0:38ceb79fef03 | 60 | * int main() { |
kevman | 0:38ceb79fef03 | 61 | * MbedCRC<POLY_32BIT_ANSI, 32> ct; |
kevman | 0:38ceb79fef03 | 62 | * |
kevman | 0:38ceb79fef03 | 63 | * char test[] = "123456789"; |
kevman | 0:38ceb79fef03 | 64 | * uint32_t crc = 0; |
kevman | 0:38ceb79fef03 | 65 | * |
kevman | 0:38ceb79fef03 | 66 | * printf("\nPolynomial = 0x%lx Width = %d \n", ct.get_polynomial(), ct.get_width()); |
kevman | 0:38ceb79fef03 | 67 | * |
kevman | 0:38ceb79fef03 | 68 | * ct.compute((void *)test, strlen((const char*)test), &crc); |
kevman | 0:38ceb79fef03 | 69 | * |
kevman | 0:38ceb79fef03 | 70 | * printf("The CRC of data \"123456789\" is : 0x%lx\n", crc); |
kevman | 0:38ceb79fef03 | 71 | * return 0; |
kevman | 0:38ceb79fef03 | 72 | * } |
kevman | 0:38ceb79fef03 | 73 | * @endcode |
kevman | 0:38ceb79fef03 | 74 | * Example: Compute CRC with data available in parts |
kevman | 0:38ceb79fef03 | 75 | * @code |
kevman | 0:38ceb79fef03 | 76 | * |
kevman | 0:38ceb79fef03 | 77 | * #include "mbed.h" |
kevman | 0:38ceb79fef03 | 78 | * int main() { |
kevman | 0:38ceb79fef03 | 79 | * MbedCRC<POLY_32BIT_ANSI, 32> ct; |
kevman | 0:38ceb79fef03 | 80 | * |
kevman | 0:38ceb79fef03 | 81 | * char test[] = "123456789"; |
kevman | 0:38ceb79fef03 | 82 | * uint32_t crc = 0; |
kevman | 0:38ceb79fef03 | 83 | * |
kevman | 0:38ceb79fef03 | 84 | * printf("\nPolynomial = 0x%lx Width = %d \n", ct.get_polynomial(), ct.get_width()); |
kevman | 0:38ceb79fef03 | 85 | * ct.compute_partial_start(&crc); |
kevman | 0:38ceb79fef03 | 86 | * ct.compute_partial((void *)&test, 4, &crc); |
kevman | 0:38ceb79fef03 | 87 | * ct.compute_partial((void *)&test[4], 5, &crc); |
kevman | 0:38ceb79fef03 | 88 | * ct.compute_partial_stop(&crc); |
kevman | 0:38ceb79fef03 | 89 | * printf("The CRC of data \"123456789\" is : 0x%lx\n", crc); |
kevman | 0:38ceb79fef03 | 90 | * return 0; |
kevman | 0:38ceb79fef03 | 91 | * } |
kevman | 0:38ceb79fef03 | 92 | * @endcode |
kevman | 0:38ceb79fef03 | 93 | * @ingroup drivers |
kevman | 0:38ceb79fef03 | 94 | */ |
kevman | 0:38ceb79fef03 | 95 | |
kevman | 0:38ceb79fef03 | 96 | extern SingletonPtr<PlatformMutex> mbed_crc_mutex; |
kevman | 0:38ceb79fef03 | 97 | |
kevman | 0:38ceb79fef03 | 98 | template <uint32_t polynomial = POLY_32BIT_ANSI, uint8_t width = 32> |
kevman | 0:38ceb79fef03 | 99 | class MbedCRC { |
kevman | 0:38ceb79fef03 | 100 | |
kevman | 0:38ceb79fef03 | 101 | public: |
kevman | 0:38ceb79fef03 | 102 | enum CrcMode |
kevman | 0:38ceb79fef03 | 103 | { |
kevman | 0:38ceb79fef03 | 104 | #ifdef DEVICE_CRC |
kevman | 0:38ceb79fef03 | 105 | HARDWARE = 0, |
kevman | 0:38ceb79fef03 | 106 | #endif |
kevman | 0:38ceb79fef03 | 107 | TABLE = 1, |
kevman | 0:38ceb79fef03 | 108 | BITWISE |
kevman | 0:38ceb79fef03 | 109 | }; |
kevman | 0:38ceb79fef03 | 110 | |
kevman | 0:38ceb79fef03 | 111 | typedef uint64_t crc_data_size_t; |
kevman | 0:38ceb79fef03 | 112 | |
kevman | 0:38ceb79fef03 | 113 | /** Lifetime of CRC object |
kevman | 0:38ceb79fef03 | 114 | * |
kevman | 0:38ceb79fef03 | 115 | * @param initial_xor Inital value/seed to Xor |
kevman | 0:38ceb79fef03 | 116 | * @param final_xor Final Xor value |
kevman | 0:38ceb79fef03 | 117 | * @param reflect_data |
kevman | 0:38ceb79fef03 | 118 | * @param reflect_remainder |
kevman | 0:38ceb79fef03 | 119 | * @note Default constructor without any arguments is valid only for supported CRC polynomials. :: crc_polynomial_t |
kevman | 0:38ceb79fef03 | 120 | * MbedCRC <POLY_7BIT_SD, 7> ct; --- Valid POLY_7BIT_SD |
kevman | 0:38ceb79fef03 | 121 | * MbedCRC <0x1021, 16> ct; --- Valid POLY_16BIT_CCITT |
kevman | 0:38ceb79fef03 | 122 | * MbedCRC <POLY_16BIT_CCITT, 32> ct; --- Invalid, compilation error |
kevman | 0:38ceb79fef03 | 123 | * MbedCRC <POLY_16BIT_CCITT, 32> ct (i,f,rd,rr) Constructor can be used for not supported polynomials |
kevman | 0:38ceb79fef03 | 124 | * MbedCRC<POLY_16BIT_CCITT, 16> sd(0, 0, false, false); Constructor can also be used for supported |
kevman | 0:38ceb79fef03 | 125 | * polynomials with different intial/final/reflect values |
kevman | 0:38ceb79fef03 | 126 | * |
kevman | 0:38ceb79fef03 | 127 | */ |
kevman | 0:38ceb79fef03 | 128 | MbedCRC(uint32_t initial_xor, uint32_t final_xor, bool reflect_data, bool reflect_remainder) : |
kevman | 0:38ceb79fef03 | 129 | _initial_value(initial_xor), _final_xor(final_xor), _reflect_data(reflect_data), |
kevman | 0:38ceb79fef03 | 130 | _reflect_remainder(reflect_remainder) |
kevman | 0:38ceb79fef03 | 131 | { |
kevman | 0:38ceb79fef03 | 132 | mbed_crc_ctor(); |
kevman | 0:38ceb79fef03 | 133 | } |
kevman | 0:38ceb79fef03 | 134 | MbedCRC(); |
kevman | 0:38ceb79fef03 | 135 | virtual ~MbedCRC() |
kevman | 0:38ceb79fef03 | 136 | { |
kevman | 0:38ceb79fef03 | 137 | // Do nothing |
kevman | 0:38ceb79fef03 | 138 | } |
kevman | 0:38ceb79fef03 | 139 | |
kevman | 0:38ceb79fef03 | 140 | /** Compute CRC for the data input |
kevman | 0:38ceb79fef03 | 141 | * Compute CRC performs the initialization, computation and collection of |
kevman | 0:38ceb79fef03 | 142 | * final CRC. |
kevman | 0:38ceb79fef03 | 143 | * |
kevman | 0:38ceb79fef03 | 144 | * @param buffer Data bytes |
kevman | 0:38ceb79fef03 | 145 | * @param size Size of data |
kevman | 0:38ceb79fef03 | 146 | * @param crc CRC is the output value |
kevman | 0:38ceb79fef03 | 147 | * @return 0 on success, negative error code on failure |
kevman | 0:38ceb79fef03 | 148 | */ |
kevman | 0:38ceb79fef03 | 149 | int32_t compute(void *buffer, crc_data_size_t size, uint32_t *crc) |
kevman | 0:38ceb79fef03 | 150 | { |
kevman | 0:38ceb79fef03 | 151 | MBED_ASSERT(crc != NULL); |
kevman | 0:38ceb79fef03 | 152 | int32_t status = 0; |
kevman | 0:38ceb79fef03 | 153 | |
kevman | 0:38ceb79fef03 | 154 | status = compute_partial_start(crc); |
kevman | 0:38ceb79fef03 | 155 | if (0 != status) { |
kevman | 0:38ceb79fef03 | 156 | unlock(); |
kevman | 0:38ceb79fef03 | 157 | return status; |
kevman | 0:38ceb79fef03 | 158 | } |
kevman | 0:38ceb79fef03 | 159 | |
kevman | 0:38ceb79fef03 | 160 | status = compute_partial(buffer, size, crc); |
kevman | 0:38ceb79fef03 | 161 | if (0 != status) { |
kevman | 0:38ceb79fef03 | 162 | unlock(); |
kevman | 0:38ceb79fef03 | 163 | return status; |
kevman | 0:38ceb79fef03 | 164 | } |
kevman | 0:38ceb79fef03 | 165 | |
kevman | 0:38ceb79fef03 | 166 | status = compute_partial_stop(crc); |
kevman | 0:38ceb79fef03 | 167 | if (0 != status) { |
kevman | 0:38ceb79fef03 | 168 | *crc = 0; |
kevman | 0:38ceb79fef03 | 169 | } |
kevman | 0:38ceb79fef03 | 170 | |
kevman | 0:38ceb79fef03 | 171 | return status; |
kevman | 0:38ceb79fef03 | 172 | |
kevman | 0:38ceb79fef03 | 173 | } |
kevman | 0:38ceb79fef03 | 174 | |
kevman | 0:38ceb79fef03 | 175 | /** Compute partial CRC for the data input. |
kevman | 0:38ceb79fef03 | 176 | * |
kevman | 0:38ceb79fef03 | 177 | * CRC data if not available fully, CRC can be computed in parts with available data. |
kevman | 0:38ceb79fef03 | 178 | * |
kevman | 0:38ceb79fef03 | 179 | * In case of hardware, intermediate values and states are saved by hardware. Mutex |
kevman | 0:38ceb79fef03 | 180 | * locking is used to serialize access to hardware CRC. |
kevman | 0:38ceb79fef03 | 181 | * |
kevman | 0:38ceb79fef03 | 182 | * In case of software CRC, previous CRC output should be passed as argument to the |
kevman | 0:38ceb79fef03 | 183 | * current compute_partial call. Please note the intermediate CRC value is maintained by |
kevman | 0:38ceb79fef03 | 184 | * application and not the driver. |
kevman | 0:38ceb79fef03 | 185 | * |
kevman | 0:38ceb79fef03 | 186 | * @pre: Call `compute_partial_start` to start the partial CRC calculation. |
kevman | 0:38ceb79fef03 | 187 | * @post: Call `compute_partial_stop` to get the final CRC value. |
kevman | 0:38ceb79fef03 | 188 | * |
kevman | 0:38ceb79fef03 | 189 | * @param buffer Data bytes |
kevman | 0:38ceb79fef03 | 190 | * @param size Size of data |
kevman | 0:38ceb79fef03 | 191 | * @param crc CRC value is intermediate CRC value filled by API. |
kevman | 0:38ceb79fef03 | 192 | * @return 0 on success or a negative error code on failure |
kevman | 0:38ceb79fef03 | 193 | * @note: CRC as output in compute_partial is not final CRC value, call `compute_partial_stop` |
kevman | 0:38ceb79fef03 | 194 | * to get final correct CRC value. |
kevman | 0:38ceb79fef03 | 195 | */ |
kevman | 0:38ceb79fef03 | 196 | int32_t compute_partial(void *buffer, crc_data_size_t size, uint32_t *crc) |
kevman | 0:38ceb79fef03 | 197 | { |
kevman | 0:38ceb79fef03 | 198 | int32_t status = 0; |
kevman | 0:38ceb79fef03 | 199 | |
kevman | 0:38ceb79fef03 | 200 | switch (_mode) { |
kevman | 0:38ceb79fef03 | 201 | #ifdef DEVICE_CRC |
kevman | 0:38ceb79fef03 | 202 | case HARDWARE: |
kevman | 0:38ceb79fef03 | 203 | hal_crc_compute_partial((uint8_t *)buffer, size); |
kevman | 0:38ceb79fef03 | 204 | *crc = 0; |
kevman | 0:38ceb79fef03 | 205 | break; |
kevman | 0:38ceb79fef03 | 206 | #endif |
kevman | 0:38ceb79fef03 | 207 | case TABLE: |
kevman | 0:38ceb79fef03 | 208 | status = table_compute_partial(buffer, size, crc); |
kevman | 0:38ceb79fef03 | 209 | break; |
kevman | 0:38ceb79fef03 | 210 | case BITWISE: |
kevman | 0:38ceb79fef03 | 211 | status = bitwise_compute_partial(buffer, size, crc); |
kevman | 0:38ceb79fef03 | 212 | break; |
kevman | 0:38ceb79fef03 | 213 | default: |
kevman | 0:38ceb79fef03 | 214 | status = -1; |
kevman | 0:38ceb79fef03 | 215 | break; |
kevman | 0:38ceb79fef03 | 216 | } |
kevman | 0:38ceb79fef03 | 217 | |
kevman | 0:38ceb79fef03 | 218 | return status; |
kevman | 0:38ceb79fef03 | 219 | } |
kevman | 0:38ceb79fef03 | 220 | |
kevman | 0:38ceb79fef03 | 221 | /** Compute partial start, indicate start of partial computation. |
kevman | 0:38ceb79fef03 | 222 | * |
kevman | 0:38ceb79fef03 | 223 | * This API should be called before performing any partial computation |
kevman | 0:38ceb79fef03 | 224 | * with compute_partial API. |
kevman | 0:38ceb79fef03 | 225 | * |
kevman | 0:38ceb79fef03 | 226 | * @param crc Initial CRC value set by the API |
kevman | 0:38ceb79fef03 | 227 | * @return 0 on success or a negative in case of failure |
kevman | 0:38ceb79fef03 | 228 | * @note: CRC is an out parameter and must be reused with compute_partial |
kevman | 0:38ceb79fef03 | 229 | * and `compute_partial_stop` without any modifications in application. |
kevman | 0:38ceb79fef03 | 230 | */ |
kevman | 0:38ceb79fef03 | 231 | int32_t compute_partial_start(uint32_t *crc) |
kevman | 0:38ceb79fef03 | 232 | { |
kevman | 0:38ceb79fef03 | 233 | MBED_ASSERT(crc != NULL); |
kevman | 0:38ceb79fef03 | 234 | |
kevman | 0:38ceb79fef03 | 235 | #ifdef DEVICE_CRC |
kevman | 0:38ceb79fef03 | 236 | if (_mode == HARDWARE) { |
kevman | 0:38ceb79fef03 | 237 | lock(); |
kevman | 0:38ceb79fef03 | 238 | crc_mbed_config_t config; |
kevman | 0:38ceb79fef03 | 239 | config.polynomial = polynomial; |
kevman | 0:38ceb79fef03 | 240 | config.width = width; |
kevman | 0:38ceb79fef03 | 241 | config.initial_xor = _initial_value; |
kevman | 0:38ceb79fef03 | 242 | config.final_xor = _final_xor; |
kevman | 0:38ceb79fef03 | 243 | config.reflect_in = _reflect_data; |
kevman | 0:38ceb79fef03 | 244 | config.reflect_out = _reflect_remainder; |
kevman | 0:38ceb79fef03 | 245 | |
kevman | 0:38ceb79fef03 | 246 | hal_crc_compute_partial_start(&config); |
kevman | 0:38ceb79fef03 | 247 | } |
kevman | 0:38ceb79fef03 | 248 | #endif |
kevman | 0:38ceb79fef03 | 249 | |
kevman | 0:38ceb79fef03 | 250 | *crc = _initial_value; |
kevman | 0:38ceb79fef03 | 251 | return 0; |
kevman | 0:38ceb79fef03 | 252 | } |
kevman | 0:38ceb79fef03 | 253 | |
kevman | 0:38ceb79fef03 | 254 | /** Get the final CRC value of partial computation. |
kevman | 0:38ceb79fef03 | 255 | * |
kevman | 0:38ceb79fef03 | 256 | * CRC value available in partial computation is not correct CRC, as some |
kevman | 0:38ceb79fef03 | 257 | * algorithms require remainder to be reflected and final value to be XORed |
kevman | 0:38ceb79fef03 | 258 | * This API is used to perform final computation to get correct CRC value. |
kevman | 0:38ceb79fef03 | 259 | * |
kevman | 0:38ceb79fef03 | 260 | * @param crc CRC result |
kevman | 0:38ceb79fef03 | 261 | * @return 0 on success or a negative in case of failure. |
kevman | 0:38ceb79fef03 | 262 | */ |
kevman | 0:38ceb79fef03 | 263 | int32_t compute_partial_stop(uint32_t *crc) |
kevman | 0:38ceb79fef03 | 264 | { |
kevman | 0:38ceb79fef03 | 265 | MBED_ASSERT(crc != NULL); |
kevman | 0:38ceb79fef03 | 266 | |
kevman | 0:38ceb79fef03 | 267 | #ifdef DEVICE_CRC |
kevman | 0:38ceb79fef03 | 268 | if (_mode == HARDWARE) { |
kevman | 0:38ceb79fef03 | 269 | *crc = hal_crc_get_result(); |
kevman | 0:38ceb79fef03 | 270 | unlock(); |
kevman | 0:38ceb79fef03 | 271 | return 0; |
kevman | 0:38ceb79fef03 | 272 | } |
kevman | 0:38ceb79fef03 | 273 | #endif |
kevman | 0:38ceb79fef03 | 274 | uint32_t p_crc = *crc; |
kevman | 0:38ceb79fef03 | 275 | if ((width < 8) && (NULL == _crc_table)) { |
kevman | 0:38ceb79fef03 | 276 | p_crc = (uint32_t)(p_crc << (8 - width)); |
kevman | 0:38ceb79fef03 | 277 | } |
kevman | 0:38ceb79fef03 | 278 | // Optimized algorithm for 32BitANSI does not need additional reflect_remainder |
kevman | 0:38ceb79fef03 | 279 | if ((TABLE == _mode) && (POLY_32BIT_REV_ANSI == polynomial)) { |
kevman | 0:38ceb79fef03 | 280 | *crc = (p_crc ^ _final_xor) & get_crc_mask(); |
kevman | 0:38ceb79fef03 | 281 | } else { |
kevman | 0:38ceb79fef03 | 282 | *crc = (reflect_remainder(p_crc) ^ _final_xor) & get_crc_mask(); |
kevman | 0:38ceb79fef03 | 283 | } |
kevman | 0:38ceb79fef03 | 284 | unlock(); |
kevman | 0:38ceb79fef03 | 285 | return 0; |
kevman | 0:38ceb79fef03 | 286 | } |
kevman | 0:38ceb79fef03 | 287 | |
kevman | 0:38ceb79fef03 | 288 | /** Get the current CRC polynomial. |
kevman | 0:38ceb79fef03 | 289 | * |
kevman | 0:38ceb79fef03 | 290 | * @return Polynomial value |
kevman | 0:38ceb79fef03 | 291 | */ |
kevman | 0:38ceb79fef03 | 292 | uint32_t get_polynomial(void) const |
kevman | 0:38ceb79fef03 | 293 | { |
kevman | 0:38ceb79fef03 | 294 | return polynomial; |
kevman | 0:38ceb79fef03 | 295 | } |
kevman | 0:38ceb79fef03 | 296 | |
kevman | 0:38ceb79fef03 | 297 | /** Get the current CRC width |
kevman | 0:38ceb79fef03 | 298 | * |
kevman | 0:38ceb79fef03 | 299 | * @return CRC width |
kevman | 0:38ceb79fef03 | 300 | */ |
kevman | 0:38ceb79fef03 | 301 | uint8_t get_width(void) const |
kevman | 0:38ceb79fef03 | 302 | { |
kevman | 0:38ceb79fef03 | 303 | return width; |
kevman | 0:38ceb79fef03 | 304 | } |
kevman | 0:38ceb79fef03 | 305 | |
kevman | 0:38ceb79fef03 | 306 | private: |
kevman | 0:38ceb79fef03 | 307 | uint32_t _initial_value; |
kevman | 0:38ceb79fef03 | 308 | uint32_t _final_xor; |
kevman | 0:38ceb79fef03 | 309 | bool _reflect_data; |
kevman | 0:38ceb79fef03 | 310 | bool _reflect_remainder; |
kevman | 0:38ceb79fef03 | 311 | uint32_t *_crc_table; |
kevman | 0:38ceb79fef03 | 312 | CrcMode _mode; |
kevman | 0:38ceb79fef03 | 313 | |
kevman | 0:38ceb79fef03 | 314 | /** Acquire exclusive access to CRC hardware/software. |
kevman | 0:38ceb79fef03 | 315 | */ |
kevman | 0:38ceb79fef03 | 316 | void lock() |
kevman | 0:38ceb79fef03 | 317 | { |
kevman | 0:38ceb79fef03 | 318 | #ifdef DEVICE_CRC |
kevman | 0:38ceb79fef03 | 319 | if (_mode == HARDWARE) { |
kevman | 0:38ceb79fef03 | 320 | mbed_crc_mutex->lock(); |
kevman | 0:38ceb79fef03 | 321 | } |
kevman | 0:38ceb79fef03 | 322 | #endif |
kevman | 0:38ceb79fef03 | 323 | } |
kevman | 0:38ceb79fef03 | 324 | |
kevman | 0:38ceb79fef03 | 325 | /** Release exclusive access to CRC hardware/software. |
kevman | 0:38ceb79fef03 | 326 | */ |
kevman | 0:38ceb79fef03 | 327 | virtual void unlock() |
kevman | 0:38ceb79fef03 | 328 | { |
kevman | 0:38ceb79fef03 | 329 | #ifdef DEVICE_CRC |
kevman | 0:38ceb79fef03 | 330 | if (_mode == HARDWARE) { |
kevman | 0:38ceb79fef03 | 331 | mbed_crc_mutex->unlock(); |
kevman | 0:38ceb79fef03 | 332 | } |
kevman | 0:38ceb79fef03 | 333 | #endif |
kevman | 0:38ceb79fef03 | 334 | } |
kevman | 0:38ceb79fef03 | 335 | |
kevman | 0:38ceb79fef03 | 336 | /** Get the current CRC data size. |
kevman | 0:38ceb79fef03 | 337 | * |
kevman | 0:38ceb79fef03 | 338 | * @return CRC data size in bytes |
kevman | 0:38ceb79fef03 | 339 | */ |
kevman | 0:38ceb79fef03 | 340 | uint8_t get_data_size(void) const |
kevman | 0:38ceb79fef03 | 341 | { |
kevman | 0:38ceb79fef03 | 342 | return (width <= 8 ? 1 : (width <= 16 ? 2 : 4)); |
kevman | 0:38ceb79fef03 | 343 | } |
kevman | 0:38ceb79fef03 | 344 | |
kevman | 0:38ceb79fef03 | 345 | /** Get the top bit of current CRC. |
kevman | 0:38ceb79fef03 | 346 | * |
kevman | 0:38ceb79fef03 | 347 | * @return Top bit is set high for respective data width of current CRC |
kevman | 0:38ceb79fef03 | 348 | * Top bit for CRC width less then 8 bits will be set as 8th bit. |
kevman | 0:38ceb79fef03 | 349 | */ |
kevman | 0:38ceb79fef03 | 350 | uint32_t get_top_bit(void) const |
kevman | 0:38ceb79fef03 | 351 | { |
kevman | 0:38ceb79fef03 | 352 | return (width < 8 ? (1u << 7) : (uint32_t)(1ul << (width - 1))); |
kevman | 0:38ceb79fef03 | 353 | } |
kevman | 0:38ceb79fef03 | 354 | |
kevman | 0:38ceb79fef03 | 355 | /** Get the CRC data mask. |
kevman | 0:38ceb79fef03 | 356 | * |
kevman | 0:38ceb79fef03 | 357 | * @return CRC data mask is generated based on current CRC width |
kevman | 0:38ceb79fef03 | 358 | */ |
kevman | 0:38ceb79fef03 | 359 | uint32_t get_crc_mask(void) const |
kevman | 0:38ceb79fef03 | 360 | { |
kevman | 0:38ceb79fef03 | 361 | return (width < 8 ? ((1u << 8) - 1) : (uint32_t)((uint64_t)(1ull << width) - 1)); |
kevman | 0:38ceb79fef03 | 362 | } |
kevman | 0:38ceb79fef03 | 363 | |
kevman | 0:38ceb79fef03 | 364 | /** Final value of CRC is reflected. |
kevman | 0:38ceb79fef03 | 365 | * |
kevman | 0:38ceb79fef03 | 366 | * @param data final crc value, which should be reflected |
kevman | 0:38ceb79fef03 | 367 | * @return Reflected CRC value |
kevman | 0:38ceb79fef03 | 368 | */ |
kevman | 0:38ceb79fef03 | 369 | uint32_t reflect_remainder(uint32_t data) const |
kevman | 0:38ceb79fef03 | 370 | { |
kevman | 0:38ceb79fef03 | 371 | if (_reflect_remainder) { |
kevman | 0:38ceb79fef03 | 372 | uint32_t reflection = 0x0; |
kevman | 0:38ceb79fef03 | 373 | uint8_t const nBits = (width < 8 ? 8 : width); |
kevman | 0:38ceb79fef03 | 374 | |
kevman | 0:38ceb79fef03 | 375 | for (uint8_t bit = 0; bit < nBits; ++bit) { |
kevman | 0:38ceb79fef03 | 376 | if (data & 0x01) { |
kevman | 0:38ceb79fef03 | 377 | reflection |= (1 << ((nBits - 1) - bit)); |
kevman | 0:38ceb79fef03 | 378 | } |
kevman | 0:38ceb79fef03 | 379 | data = (data >> 1); |
kevman | 0:38ceb79fef03 | 380 | } |
kevman | 0:38ceb79fef03 | 381 | return (reflection); |
kevman | 0:38ceb79fef03 | 382 | } else { |
kevman | 0:38ceb79fef03 | 383 | return data; |
kevman | 0:38ceb79fef03 | 384 | } |
kevman | 0:38ceb79fef03 | 385 | } |
kevman | 0:38ceb79fef03 | 386 | |
kevman | 0:38ceb79fef03 | 387 | /** Data bytes are reflected. |
kevman | 0:38ceb79fef03 | 388 | * |
kevman | 0:38ceb79fef03 | 389 | * @param data value to be reflected |
kevman | 0:38ceb79fef03 | 390 | * @return Reflected data value |
kevman | 0:38ceb79fef03 | 391 | */ |
kevman | 0:38ceb79fef03 | 392 | uint32_t reflect_bytes(uint32_t data) const |
kevman | 0:38ceb79fef03 | 393 | { |
kevman | 0:38ceb79fef03 | 394 | if (_reflect_data) { |
kevman | 0:38ceb79fef03 | 395 | uint32_t reflection = 0x0; |
kevman | 0:38ceb79fef03 | 396 | |
kevman | 0:38ceb79fef03 | 397 | for (uint8_t bit = 0; bit < 8; ++bit) { |
kevman | 0:38ceb79fef03 | 398 | if (data & 0x01) { |
kevman | 0:38ceb79fef03 | 399 | reflection |= (1 << (7 - bit)); |
kevman | 0:38ceb79fef03 | 400 | } |
kevman | 0:38ceb79fef03 | 401 | data = (data >> 1); |
kevman | 0:38ceb79fef03 | 402 | } |
kevman | 0:38ceb79fef03 | 403 | return (reflection); |
kevman | 0:38ceb79fef03 | 404 | } else { |
kevman | 0:38ceb79fef03 | 405 | return data; |
kevman | 0:38ceb79fef03 | 406 | } |
kevman | 0:38ceb79fef03 | 407 | } |
kevman | 0:38ceb79fef03 | 408 | |
kevman | 0:38ceb79fef03 | 409 | /** Bitwise CRC computation. |
kevman | 0:38ceb79fef03 | 410 | * |
kevman | 0:38ceb79fef03 | 411 | * @param buffer data buffer |
kevman | 0:38ceb79fef03 | 412 | * @param size size of the data |
kevman | 0:38ceb79fef03 | 413 | * @param crc CRC value is filled in, but the value is not the final |
kevman | 0:38ceb79fef03 | 414 | * @return 0 on success or a negative error code on failure |
kevman | 0:38ceb79fef03 | 415 | */ |
kevman | 0:38ceb79fef03 | 416 | int32_t bitwise_compute_partial(const void *buffer, crc_data_size_t size, uint32_t *crc) const |
kevman | 0:38ceb79fef03 | 417 | { |
kevman | 0:38ceb79fef03 | 418 | MBED_ASSERT(crc != NULL); |
kevman | 0:38ceb79fef03 | 419 | |
kevman | 0:38ceb79fef03 | 420 | const uint8_t *data = static_cast<const uint8_t *>(buffer); |
kevman | 0:38ceb79fef03 | 421 | uint32_t p_crc = *crc; |
kevman | 0:38ceb79fef03 | 422 | |
kevman | 0:38ceb79fef03 | 423 | if (width < 8) { |
kevman | 0:38ceb79fef03 | 424 | uint8_t data_byte; |
kevman | 0:38ceb79fef03 | 425 | for (crc_data_size_t byte = 0; byte < size; byte++) { |
kevman | 0:38ceb79fef03 | 426 | data_byte = reflect_bytes(data[byte]); |
kevman | 0:38ceb79fef03 | 427 | for (uint8_t bit = 8; bit > 0; --bit) { |
kevman | 0:38ceb79fef03 | 428 | p_crc <<= 1; |
kevman | 0:38ceb79fef03 | 429 | if ((data_byte ^ p_crc) & get_top_bit()) { |
kevman | 0:38ceb79fef03 | 430 | p_crc ^= polynomial; |
kevman | 0:38ceb79fef03 | 431 | } |
kevman | 0:38ceb79fef03 | 432 | data_byte <<= 1; |
kevman | 0:38ceb79fef03 | 433 | } |
kevman | 0:38ceb79fef03 | 434 | } |
kevman | 0:38ceb79fef03 | 435 | } else { |
kevman | 0:38ceb79fef03 | 436 | for (crc_data_size_t byte = 0; byte < size; byte++) { |
kevman | 0:38ceb79fef03 | 437 | p_crc ^= (reflect_bytes(data[byte]) << (width - 8)); |
kevman | 0:38ceb79fef03 | 438 | |
kevman | 0:38ceb79fef03 | 439 | // Perform modulo-2 division, a bit at a time |
kevman | 0:38ceb79fef03 | 440 | for (uint8_t bit = 8; bit > 0; --bit) { |
kevman | 0:38ceb79fef03 | 441 | if (p_crc & get_top_bit()) { |
kevman | 0:38ceb79fef03 | 442 | p_crc = (p_crc << 1) ^ polynomial; |
kevman | 0:38ceb79fef03 | 443 | } else { |
kevman | 0:38ceb79fef03 | 444 | p_crc = (p_crc << 1); |
kevman | 0:38ceb79fef03 | 445 | } |
kevman | 0:38ceb79fef03 | 446 | } |
kevman | 0:38ceb79fef03 | 447 | } |
kevman | 0:38ceb79fef03 | 448 | } |
kevman | 0:38ceb79fef03 | 449 | *crc = p_crc & get_crc_mask(); |
kevman | 0:38ceb79fef03 | 450 | return 0; |
kevman | 0:38ceb79fef03 | 451 | } |
kevman | 0:38ceb79fef03 | 452 | |
kevman | 0:38ceb79fef03 | 453 | /** CRC computation using ROM tables. |
kevman | 0:38ceb79fef03 | 454 | * |
kevman | 0:38ceb79fef03 | 455 | * @param buffer data buffer |
kevman | 0:38ceb79fef03 | 456 | * @param size size of the data |
kevman | 0:38ceb79fef03 | 457 | * @param crc CRC value is filled in, but the value is not the final |
kevman | 0:38ceb79fef03 | 458 | * @return 0 on success or a negative error code on failure |
kevman | 0:38ceb79fef03 | 459 | */ |
kevman | 0:38ceb79fef03 | 460 | int32_t table_compute_partial(const void *buffer, crc_data_size_t size, uint32_t *crc) const |
kevman | 0:38ceb79fef03 | 461 | { |
kevman | 0:38ceb79fef03 | 462 | MBED_ASSERT(crc != NULL); |
kevman | 0:38ceb79fef03 | 463 | |
kevman | 0:38ceb79fef03 | 464 | const uint8_t *data = static_cast<const uint8_t *>(buffer); |
kevman | 0:38ceb79fef03 | 465 | uint32_t p_crc = *crc; |
kevman | 0:38ceb79fef03 | 466 | uint8_t data_byte = 0; |
kevman | 0:38ceb79fef03 | 467 | |
kevman | 0:38ceb79fef03 | 468 | if (width <= 8) { |
kevman | 0:38ceb79fef03 | 469 | uint8_t *crc_table = (uint8_t *)_crc_table; |
kevman | 0:38ceb79fef03 | 470 | for (crc_data_size_t byte = 0; byte < size; byte++) { |
kevman | 0:38ceb79fef03 | 471 | data_byte = reflect_bytes(data[byte]) ^ p_crc; |
kevman | 0:38ceb79fef03 | 472 | p_crc = crc_table[data_byte]; |
kevman | 0:38ceb79fef03 | 473 | } |
kevman | 0:38ceb79fef03 | 474 | } else if (width <= 16) { |
kevman | 0:38ceb79fef03 | 475 | uint16_t *crc_table = (uint16_t *)_crc_table; |
kevman | 0:38ceb79fef03 | 476 | for (crc_data_size_t byte = 0; byte < size; byte++) { |
kevman | 0:38ceb79fef03 | 477 | data_byte = reflect_bytes(data[byte]) ^ (p_crc >> (width - 8)); |
kevman | 0:38ceb79fef03 | 478 | p_crc = crc_table[data_byte] ^ (p_crc << 8); |
kevman | 0:38ceb79fef03 | 479 | } |
kevman | 0:38ceb79fef03 | 480 | } else { |
kevman | 0:38ceb79fef03 | 481 | uint32_t *crc_table = (uint32_t *)_crc_table; |
kevman | 0:38ceb79fef03 | 482 | if (POLY_32BIT_REV_ANSI == polynomial) { |
kevman | 0:38ceb79fef03 | 483 | for (crc_data_size_t i = 0; i < size; i++) { |
kevman | 0:38ceb79fef03 | 484 | p_crc = (p_crc >> 4) ^ crc_table[(p_crc ^ (data[i] >> 0)) & 0xf]; |
kevman | 0:38ceb79fef03 | 485 | p_crc = (p_crc >> 4) ^ crc_table[(p_crc ^ (data[i] >> 4)) & 0xf]; |
kevman | 0:38ceb79fef03 | 486 | } |
kevman | 0:38ceb79fef03 | 487 | } |
kevman | 0:38ceb79fef03 | 488 | else { |
kevman | 0:38ceb79fef03 | 489 | for (crc_data_size_t byte = 0; byte < size; byte++) { |
kevman | 0:38ceb79fef03 | 490 | data_byte = reflect_bytes(data[byte]) ^ (p_crc >> (width - 8)); |
kevman | 0:38ceb79fef03 | 491 | p_crc = crc_table[data_byte] ^ (p_crc << 8); |
kevman | 0:38ceb79fef03 | 492 | } |
kevman | 0:38ceb79fef03 | 493 | } |
kevman | 0:38ceb79fef03 | 494 | } |
kevman | 0:38ceb79fef03 | 495 | *crc = p_crc & get_crc_mask(); |
kevman | 0:38ceb79fef03 | 496 | return 0; |
kevman | 0:38ceb79fef03 | 497 | } |
kevman | 0:38ceb79fef03 | 498 | |
kevman | 0:38ceb79fef03 | 499 | /** Constructor init called from all specialized cases of constructor. |
kevman | 0:38ceb79fef03 | 500 | * Note: All construtor common code should be in this function. |
kevman | 0:38ceb79fef03 | 501 | */ |
kevman | 0:38ceb79fef03 | 502 | void mbed_crc_ctor(void) |
kevman | 0:38ceb79fef03 | 503 | { |
kevman | 0:38ceb79fef03 | 504 | MBED_STATIC_ASSERT(width <= 32, "Max 32-bit CRC supported"); |
kevman | 0:38ceb79fef03 | 505 | |
kevman | 0:38ceb79fef03 | 506 | #ifdef DEVICE_CRC |
kevman | 0:38ceb79fef03 | 507 | if (POLY_32BIT_REV_ANSI == polynomial) { |
kevman | 0:38ceb79fef03 | 508 | _crc_table = (uint32_t *)Table_CRC_32bit_Rev_ANSI; |
kevman | 0:38ceb79fef03 | 509 | _mode = TABLE; |
kevman | 0:38ceb79fef03 | 510 | return; |
kevman | 0:38ceb79fef03 | 511 | } |
kevman | 0:38ceb79fef03 | 512 | crc_mbed_config_t config; |
kevman | 0:38ceb79fef03 | 513 | config.polynomial = polynomial; |
kevman | 0:38ceb79fef03 | 514 | config.width = width; |
kevman | 0:38ceb79fef03 | 515 | config.initial_xor = _initial_value; |
kevman | 0:38ceb79fef03 | 516 | config.final_xor = _final_xor; |
kevman | 0:38ceb79fef03 | 517 | config.reflect_in = _reflect_data; |
kevman | 0:38ceb79fef03 | 518 | config.reflect_out = _reflect_remainder; |
kevman | 0:38ceb79fef03 | 519 | |
kevman | 0:38ceb79fef03 | 520 | if (hal_crc_is_supported(&config)) { |
kevman | 0:38ceb79fef03 | 521 | _mode = HARDWARE; |
kevman | 0:38ceb79fef03 | 522 | return; |
kevman | 0:38ceb79fef03 | 523 | } |
kevman | 0:38ceb79fef03 | 524 | #endif |
kevman | 0:38ceb79fef03 | 525 | |
kevman | 0:38ceb79fef03 | 526 | switch (polynomial) { |
kevman | 0:38ceb79fef03 | 527 | case POLY_32BIT_ANSI: |
kevman | 0:38ceb79fef03 | 528 | _crc_table = (uint32_t *)Table_CRC_32bit_ANSI; |
kevman | 0:38ceb79fef03 | 529 | break; |
kevman | 0:38ceb79fef03 | 530 | case POLY_32BIT_REV_ANSI: |
kevman | 0:38ceb79fef03 | 531 | _crc_table = (uint32_t *)Table_CRC_32bit_Rev_ANSI; |
kevman | 0:38ceb79fef03 | 532 | break; |
kevman | 0:38ceb79fef03 | 533 | case POLY_8BIT_CCITT: |
kevman | 0:38ceb79fef03 | 534 | _crc_table = (uint32_t *)Table_CRC_8bit_CCITT; |
kevman | 0:38ceb79fef03 | 535 | break; |
kevman | 0:38ceb79fef03 | 536 | case POLY_7BIT_SD: |
kevman | 0:38ceb79fef03 | 537 | _crc_table = (uint32_t *)Table_CRC_7Bit_SD; |
kevman | 0:38ceb79fef03 | 538 | break; |
kevman | 0:38ceb79fef03 | 539 | case POLY_16BIT_CCITT: |
kevman | 0:38ceb79fef03 | 540 | _crc_table = (uint32_t *)Table_CRC_16bit_CCITT; |
kevman | 0:38ceb79fef03 | 541 | break; |
kevman | 0:38ceb79fef03 | 542 | case POLY_16BIT_IBM: |
kevman | 0:38ceb79fef03 | 543 | _crc_table = (uint32_t *)Table_CRC_16bit_IBM; |
kevman | 0:38ceb79fef03 | 544 | break; |
kevman | 0:38ceb79fef03 | 545 | default: |
kevman | 0:38ceb79fef03 | 546 | _crc_table = NULL; |
kevman | 0:38ceb79fef03 | 547 | break; |
kevman | 0:38ceb79fef03 | 548 | } |
kevman | 0:38ceb79fef03 | 549 | _mode = (_crc_table != NULL) ? TABLE : BITWISE; |
kevman | 0:38ceb79fef03 | 550 | } |
kevman | 0:38ceb79fef03 | 551 | }; |
kevman | 0:38ceb79fef03 | 552 | |
kevman | 0:38ceb79fef03 | 553 | #if defined ( __CC_ARM ) |
kevman | 0:38ceb79fef03 | 554 | #elif defined ( __GNUC__ ) |
kevman | 0:38ceb79fef03 | 555 | #pragma GCC diagnostic pop |
kevman | 0:38ceb79fef03 | 556 | #elif defined (__ICCARM__) |
kevman | 0:38ceb79fef03 | 557 | #endif |
kevman | 0:38ceb79fef03 | 558 | |
kevman | 0:38ceb79fef03 | 559 | /** @}*/ |
kevman | 0:38ceb79fef03 | 560 | } // namespace mbed |
kevman | 0:38ceb79fef03 | 561 | |
kevman | 0:38ceb79fef03 | 562 | #endif |