// Copyright 2015-2017 Espressif Systems (Shanghai) PTE LTD // // 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. #include <stdint.h> #include "esp32/rom/crc.h" #include "sdspi_crc.h" static const uint8_t crc7_table[256] = { 0x00, 0x09, 0x12, 0x1b, 0x24, 0x2d, 0x36, 0x3f, 0x48, 0x41, 0x5a, 0x53, 0x6c, 0x65, 0x7e, 0x77, 0x19, 0x10, 0x0b, 0x02, 0x3d, 0x34, 0x2f, 0x26, 0x51, 0x58, 0x43, 0x4a, 0x75, 0x7c, 0x67, 0x6e, 0x32, 0x3b, 0x20, 0x29, 0x16, 0x1f, 0x04, 0x0d, 0x7a, 0x73, 0x68, 0x61, 0x5e, 0x57, 0x4c, 0x45, 0x2b, 0x22, 0x39, 0x30, 0x0f, 0x06, 0x1d, 0x14, 0x63, 0x6a, 0x71, 0x78, 0x47, 0x4e, 0x55, 0x5c, 0x64, 0x6d, 0x76, 0x7f, 0x40, 0x49, 0x52, 0x5b, 0x2c, 0x25, 0x3e, 0x37, 0x08, 0x01, 0x1a, 0x13, 0x7d, 0x74, 0x6f, 0x66, 0x59, 0x50, 0x4b, 0x42, 0x35, 0x3c, 0x27, 0x2e, 0x11, 0x18, 0x03, 0x0a, 0x56, 0x5f, 0x44, 0x4d, 0x72, 0x7b, 0x60, 0x69, 0x1e, 0x17, 0x0c, 0x05, 0x3a, 0x33, 0x28, 0x21, 0x4f, 0x46, 0x5d, 0x54, 0x6b, 0x62, 0x79, 0x70, 0x07, 0x0e, 0x15, 0x1c, 0x23, 0x2a, 0x31, 0x38, 0x41, 0x48, 0x53, 0x5a, 0x65, 0x6c, 0x77, 0x7e, 0x09, 0x00, 0x1b, 0x12, 0x2d, 0x24, 0x3f, 0x36, 0x58, 0x51, 0x4a, 0x43, 0x7c, 0x75, 0x6e, 0x67, 0x10, 0x19, 0x02, 0x0b, 0x34, 0x3d, 0x26, 0x2f, 0x73, 0x7a, 0x61, 0x68, 0x57, 0x5e, 0x45, 0x4c, 0x3b, 0x32, 0x29, 0x20, 0x1f, 0x16, 0x0d, 0x04, 0x6a, 0x63, 0x78, 0x71, 0x4e, 0x47, 0x5c, 0x55, 0x22, 0x2b, 0x30, 0x39, 0x06, 0x0f, 0x14, 0x1d, 0x25, 0x2c, 0x37, 0x3e, 0x01, 0x08, 0x13, 0x1a, 0x6d, 0x64, 0x7f, 0x76, 0x49, 0x40, 0x5b, 0x52, 0x3c, 0x35, 0x2e, 0x27, 0x18, 0x11, 0x0a, 0x03, 0x74, 0x7d, 0x66, 0x6f, 0x50, 0x59, 0x42, 0x4b, 0x17, 0x1e, 0x05, 0x0c, 0x33, 0x3a, 0x21, 0x28, 0x5f, 0x56, 0x4d, 0x44, 0x7b, 0x72, 0x69, 0x60, 0x0e, 0x07, 0x1c, 0x15, 0x2a, 0x23, 0x38, 0x31, 0x46, 0x4f, 0x54, 0x5d, 0x62, 0x6b, 0x70, 0x79, }; // returns the CRC-7 for a message of "length" bytes uint8_t sdspi_crc7(const uint8_t *data, size_t size) { uint8_t result = 0; for (size_t i = 0; i < size; ++i) { result = crc7_table[(result << 1) ^ data[i]]; } return result; } /// Return CRC16 of data, in the on-the-wire format used by SD protocol uint16_t sdspi_crc16(const uint8_t* data, size_t size) { return __builtin_bswap16(crc16_be(UINT16_MAX, data, size) ^ UINT16_MAX); }