LCOV - code coverage report
Current view: top level - AP_Math - crc.cpp (source / functions) Hit Total Coverage
Test: lcov.info Lines: 132 193 68.4 %
Date: 2026-09-09 11:02:08 Functions: 20 28 71.4 %

          Line data    Source code
       1             : /*
       2             :   This program is free software: you can redistribute it and/or modify
       3             :   it under the terms of the GNU General Public License as published by
       4             :   the Free Software Foundation, either version 3 of the License, or
       5             :   (at your option) any later version.
       6             : 
       7             :   This program is distributed in the hope that it will be useful,
       8             :   but WITHOUT ANY WARRANTY; without even the implied warranty of
       9             :   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      10             :   GNU General Public License for more details.
      11             : 
      12             :   You should have received a copy of the GNU General Public License
      13             :   along with this program.  If not, see <http://www.gnu.org/licenses/>.
      14             : */
      15             : /*
      16             :   collection of CRCs. 
      17             :  */
      18             : 
      19             : #include <stdint.h>
      20             : #include "crc.h"
      21             : 
      22             : #include <AP_HAL/AP_HAL_Boards.h>
      23             : 
      24             : /**
      25             :  * crc4 method from datasheet for 16 bytes (8 short values)
      26             :  * 
      27             :  * @param [in] data
      28             :  * @return crc4 
      29             :  */
      30          86 : uint16_t crc_crc4(uint16_t *data)
      31             : {
      32          86 :     uint16_t n_rem = 0;
      33             :     uint8_t n_bit;
      34             : 
      35        1462 :     for (uint8_t cnt = 0; cnt < 16; cnt++) {
      36             :         /* uneven bytes */
      37        1376 :         if (cnt & 1) {
      38         688 :             n_rem ^= (uint8_t)((data[cnt >> 1]) & 0x00FF);
      39             :         } else {
      40         688 :             n_rem ^= (uint8_t)(data[cnt >> 1] >> 8);
      41             :         }
      42             : 
      43       12384 :         for (n_bit = 8; n_bit > 0; n_bit--) {
      44       11008 :             if (n_rem & 0x8000) {
      45        4813 :                 n_rem = (n_rem << 1) ^ 0x3000;
      46             :             } else {
      47        6195 :                 n_rem = (n_rem << 1);
      48             :             }
      49             :         }
      50             :     }
      51             : 
      52          86 :     return (n_rem >> 12) & 0xF;
      53             : }
      54             : 
      55             : static const uint8_t crc8_table[] = {
      56             :     0x00, 0x07, 0x0e, 0x09, 0x1c, 0x1b, 0x12, 0x15, 0x38, 0x3f, 0x36, 0x31,
      57             :     0x24, 0x23, 0x2a, 0x2d, 0x70, 0x77, 0x7e, 0x79, 0x6c, 0x6b, 0x62, 0x65,
      58             :     0x48, 0x4f, 0x46, 0x41, 0x54, 0x53, 0x5a, 0x5d, 0xe0, 0xe7, 0xee, 0xe9,
      59             :     0xfc, 0xfb, 0xf2, 0xf5, 0xd8, 0xdf, 0xd6, 0xd1, 0xc4, 0xc3, 0xca, 0xcd,
      60             :     0x90, 0x97, 0x9e, 0x99, 0x8c, 0x8b, 0x82, 0x85, 0xa8, 0xaf, 0xa6, 0xa1,
      61             :     0xb4, 0xb3, 0xba, 0xbd, 0xc7, 0xc0, 0xc9, 0xce, 0xdb, 0xdc, 0xd5, 0xd2,
      62             :     0xff, 0xf8, 0xf1, 0xf6, 0xe3, 0xe4, 0xed, 0xea, 0xb7, 0xb0, 0xb9, 0xbe,
      63             :     0xab, 0xac, 0xa5, 0xa2, 0x8f, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9d, 0x9a,
      64             :     0x27, 0x20, 0x29, 0x2e, 0x3b, 0x3c, 0x35, 0x32, 0x1f, 0x18, 0x11, 0x16,
      65             :     0x03, 0x04, 0x0d, 0x0a, 0x57, 0x50, 0x59, 0x5e, 0x4b, 0x4c, 0x45, 0x42,
      66             :     0x6f, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7d, 0x7a, 0x89, 0x8e, 0x87, 0x80,
      67             :     0x95, 0x92, 0x9b, 0x9c, 0xb1, 0xb6, 0xbf, 0xb8, 0xad, 0xaa, 0xa3, 0xa4,
      68             :     0xf9, 0xfe, 0xf7, 0xf0, 0xe5, 0xe2, 0xeb, 0xec, 0xc1, 0xc6, 0xcf, 0xc8,
      69             :     0xdd, 0xda, 0xd3, 0xd4, 0x69, 0x6e, 0x67, 0x60, 0x75, 0x72, 0x7b, 0x7c,
      70             :     0x51, 0x56, 0x5f, 0x58, 0x4d, 0x4a, 0x43, 0x44, 0x19, 0x1e, 0x17, 0x10,
      71             :     0x05, 0x02, 0x0b, 0x0c, 0x21, 0x26, 0x2f, 0x28, 0x3d, 0x3a, 0x33, 0x34,
      72             :     0x4e, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5c, 0x5b, 0x76, 0x71, 0x78, 0x7f,
      73             :     0x6a, 0x6d, 0x64, 0x63, 0x3e, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2c, 0x2b,
      74             :     0x06, 0x01, 0x08, 0x0f, 0x1a, 0x1d, 0x14, 0x13, 0xae, 0xa9, 0xa0, 0xa7,
      75             :     0xb2, 0xb5, 0xbc, 0xbb, 0x96, 0x91, 0x98, 0x9f, 0x8a, 0x8d, 0x84, 0x83,
      76             :     0xde, 0xd9, 0xd0, 0xd7, 0xc2, 0xc5, 0xcc, 0xcb, 0xe6, 0xe1, 0xe8, 0xef,
      77             :     0xfa, 0xfd, 0xf4, 0xf3
      78             : };
      79             : 
      80             : /*
      81             :   crc8 from trone driver by Luis Rodrigues
      82             :  */
      83       16058 : uint8_t crc_crc8(const uint8_t *p, uint8_t len)
      84             : {
      85       16058 :         uint16_t crc = 0x0;
      86             : 
      87       59084 :         while (len--) {
      88       43026 :                 const uint16_t i = (crc ^ *p++) & 0xFF;
      89       43026 :                 crc = (crc8_table[i] ^ (crc << 8)) & 0xFF;
      90             :         }
      91             : 
      92       16058 :         return crc & 0xFF;
      93             : }
      94             : 
      95             : // CRC8 that does not use a lookup table: for generic polynomials
      96       46070 : uint8_t crc8_generic(const uint8_t *buf, const uint16_t buf_len, const uint8_t polynomial, uint8_t initial_value)
      97             : {
      98       46070 :     uint8_t crc = initial_value;
      99     2016130 :     for (uint16_t i = 0; i < buf_len; i++) {
     100     1970060 :         crc = crc8_dvb(buf[i], crc, polynomial);
     101             :     }
     102       46070 :     return crc;
     103             : }
     104             : 
     105             : // crc8 from betaflight
     106        9120 : uint8_t crc8_dvb_s2(uint8_t crc, uint8_t a)
     107             : {
     108        9120 :     return crc8_dvb(crc, a, 0xD5);
     109             : }
     110             : 
     111             : // crc8 from betaflight
     112    10397915 : uint8_t crc8_dvb(uint8_t crc, uint8_t a, uint8_t seed)
     113             : {
     114    10397915 :     crc ^= a;
     115    93581235 :     for (uint8_t i = 0; i < 8; ++i) {
     116    83183320 :         if (crc & 0x80) {
     117    39095573 :             crc = (crc << 1) ^ seed;
     118             :         } else {
     119    44087747 :             crc = crc << 1;
     120             :         }
     121             :     }
     122    10397915 :     return crc;
     123             : }
     124             : 
     125             : // crc8 from betaflight
     126          84 : uint8_t crc8_dvb_s2_update(uint8_t crc, const void *data, uint32_t length)
     127             : {
     128          84 :     const uint8_t *p = (const uint8_t *)data;
     129          84 :     const uint8_t *pend = p + length;
     130             : 
     131        4872 :     for (; p != pend; p++) {
     132        4788 :         crc = crc8_dvb_s2(crc, *p);
     133             :     }
     134          84 :     return crc;
     135             : }
     136             : 
     137             : // copied from AP_FETtecOneWire.cpp
     138      757468 : uint8_t crc8_dvb_update(uint8_t crc, const uint8_t* buf, const uint16_t buf_len)
     139             : {
     140     9176203 :     for (uint16_t i = 0; i < buf_len; i++) {
     141     8418735 :         crc = crc8_dvb(buf[i], crc, 0x7);
     142             :     }
     143      757468 :     return crc;
     144             : }
     145             : 
     146             : /*
     147             :  CRC8-Maxim implementation based on FastCRC library
     148             :  see https://github.com/FrankBoesing/FastCRC
     149             :  */
     150             : static const uint8_t crc8_table_maxim[] = {
     151             :     0x00, 0x5e, 0xbc, 0xe2, 0x61, 0x3f, 0xdd, 0x83,
     152             :     0xc2, 0x9c, 0x7e, 0x20, 0xa3, 0xfd, 0x1f, 0x41,
     153             :     0x9d, 0xc3, 0x21, 0x7f, 0xfc, 0xa2, 0x40, 0x1e,
     154             :     0x5f, 0x01, 0xe3, 0xbd, 0x3e, 0x60, 0x82, 0xdc,
     155             :     0x23, 0x7d, 0x9f, 0xc1, 0x42, 0x1c, 0xfe, 0xa0,
     156             :     0xe1, 0xbf, 0x5d, 0x03, 0x80, 0xde, 0x3c, 0x62,
     157             :     0xbe, 0xe0, 0x02, 0x5c, 0xdf, 0x81, 0x63, 0x3d,
     158             :     0x7c, 0x22, 0xc0, 0x9e, 0x1d, 0x43, 0xa1, 0xff,
     159             :     0x46, 0x18, 0xfa, 0xa4, 0x27, 0x79, 0x9b, 0xc5,
     160             :     0x84, 0xda, 0x38, 0x66, 0xe5, 0xbb, 0x59, 0x07,
     161             :     0xdb, 0x85, 0x67, 0x39, 0xba, 0xe4, 0x06, 0x58,
     162             :     0x19, 0x47, 0xa5, 0xfb, 0x78, 0x26, 0xc4, 0x9a,
     163             :     0x65, 0x3b, 0xd9, 0x87, 0x04, 0x5a, 0xb8, 0xe6,
     164             :     0xa7, 0xf9, 0x1b, 0x45, 0xc6, 0x98, 0x7a, 0x24,
     165             :     0xf8, 0xa6, 0x44, 0x1a, 0x99, 0xc7, 0x25, 0x7b,
     166             :     0x3a, 0x64, 0x86, 0xd8, 0x5b, 0x05, 0xe7, 0xb9,
     167             :     0x8c, 0xd2, 0x30, 0x6e, 0xed, 0xb3, 0x51, 0x0f,
     168             :     0x4e, 0x10, 0xf2, 0xac, 0x2f, 0x71, 0x93, 0xcd,
     169             :     0x11, 0x4f, 0xad, 0xf3, 0x70, 0x2e, 0xcc, 0x92,
     170             :     0xd3, 0x8d, 0x6f, 0x31, 0xb2, 0xec, 0x0e, 0x50,
     171             :     0xaf, 0xf1, 0x13, 0x4d, 0xce, 0x90, 0x72, 0x2c,
     172             :     0x6d, 0x33, 0xd1, 0x8f, 0x0c, 0x52, 0xb0, 0xee,
     173             :     0x32, 0x6c, 0x8e, 0xd0, 0x53, 0x0d, 0xef, 0xb1,
     174             :     0xf0, 0xae, 0x4c, 0x12, 0x91, 0xcf, 0x2d, 0x73,
     175             :     0xca, 0x94, 0x76, 0x28, 0xab, 0xf5, 0x17, 0x49,
     176             :     0x08, 0x56, 0xb4, 0xea, 0x69, 0x37, 0xd5, 0x8b,
     177             :     0x57, 0x09, 0xeb, 0xb5, 0x36, 0x68, 0x8a, 0xd4,
     178             :     0x95, 0xcb, 0x29, 0x77, 0xf4, 0xaa, 0x48, 0x16,
     179             :     0xe9, 0xb7, 0x55, 0x0b, 0x88, 0xd6, 0x34, 0x6a,
     180             :     0x2b, 0x75, 0x97, 0xc9, 0x4a, 0x14, 0xf6, 0xa8,
     181             :     0x74, 0x2a, 0xc8, 0x96, 0x15, 0x4b, 0xa9, 0xf7,
     182             :     0xb6, 0xe8, 0x0a, 0x54, 0xd7, 0x89, 0x6b, 0x35
     183             : };
     184             : 
     185           0 : uint8_t crc8_maxim(const uint8_t *data, uint16_t length)
     186             : {
     187           0 :     uint16_t crc = 0x0;
     188             : 
     189           0 :     while (length--) {
     190           0 :         crc = crc8_table_maxim[crc ^ *data];
     191           0 :         data++;
     192             :     }
     193             : 
     194           0 :     return crc;
     195             : }
     196             : 
     197             : // CRC8-SAE J1850 (X8+X4+X3+X2+1) left move table
     198             : static const uint8_t crc8_table_sae[256] = {
     199             :     0x00, 0x1D, 0x3A, 0x27, 0x74, 0x69, 0x4E, 0x53, 0xE8, 0xF5, 0xD2, 0xCF, 0x9C, 0x81, 0xA6, 0xBB,
     200             :     0xCD, 0xD0, 0xF7, 0xEA, 0xB9, 0xA4, 0x83, 0x9E, 0x25, 0x38, 0x1F, 0x02, 0x51, 0x4C, 0x6B, 0x76,
     201             :     0x87, 0x9A, 0xBD, 0xA0, 0xF3, 0xEE, 0xC9, 0xD4, 0x6F, 0x72, 0x55, 0x48, 0x1B, 0x06, 0x21, 0x3C,
     202             :     0x4A, 0x57, 0x70, 0x6D, 0x3E, 0x23, 0x04, 0x19, 0xA2, 0xBF, 0x98, 0x85, 0xD6, 0xCB, 0xEC, 0xF1,
     203             :     0x13, 0x0E, 0x29, 0x34, 0x67, 0x7A, 0x5D, 0x40, 0xFB, 0xE6, 0xC1, 0xDC, 0x8F, 0x92, 0xB5, 0xA8,
     204             :     0xDE, 0xC3, 0xE4, 0xF9, 0xAA, 0xB7, 0x90, 0x8D, 0x36, 0x2B, 0x0C, 0x11, 0x42, 0x5F, 0x78, 0x65,
     205             :     0x94, 0x89, 0xAE, 0xB3, 0xE0, 0xFD, 0xDA, 0xC7, 0x7C, 0x61, 0x46, 0x5B, 0x08, 0x15, 0x32, 0x2F,
     206             :     0x59, 0x44, 0x63, 0x7E, 0x2D, 0x30, 0x17, 0x0A, 0xB1, 0xAC, 0x8B, 0x96, 0xC5, 0xD8, 0xFF, 0xE2,
     207             :     0x26, 0x3B, 0x1C, 0x01, 0x52, 0x4F, 0x68, 0x75, 0xCE, 0xD3, 0xF4, 0xE9, 0xBA, 0xA7, 0x80, 0x9D,
     208             :     0xEB, 0xF6, 0xD1, 0xCC, 0x9F, 0x82, 0xA5, 0xB8, 0x03, 0x1E, 0x39, 0x24, 0x77, 0x6A, 0x4D, 0x50,
     209             :     0xA1, 0xBC, 0x9B, 0x86, 0xD5, 0xC8, 0xEF, 0xF2, 0x49, 0x54, 0x73, 0x6E, 0x3D, 0x20, 0x07, 0x1A,
     210             :     0x6C, 0x71, 0x56, 0x4B, 0x18, 0x05, 0x22, 0x3F, 0x84, 0x99, 0xBE, 0xA3, 0xF0, 0xED, 0xCA, 0xD7,
     211             :     0x35, 0x28, 0x0F, 0x12, 0x41, 0x5C, 0x7B, 0x66, 0xDD, 0xC0, 0xE7, 0xFA, 0xA9, 0xB4, 0x93, 0x8E,
     212             :     0xF8, 0xE5, 0xC2, 0xDF, 0x8C, 0x91, 0xB6, 0xAB, 0x10, 0x0D, 0x2A, 0x37, 0x64, 0x79, 0x5E, 0x43,
     213             :     0xB2, 0xAF, 0x88, 0x95, 0xC6, 0xDB, 0xFC, 0xE1, 0x5A, 0x47, 0x60, 0x7D, 0x2E, 0x33, 0x14, 0x09,
     214             :     0x7F, 0x62, 0x45, 0x58, 0x0B, 0x16, 0x31, 0x2C, 0x97, 0x8A, 0xAD, 0xB0, 0xE3, 0xFE, 0xD9, 0xC4,
     215             : };
     216             : 
     217           0 : uint8_t crc8_sae(const uint8_t *data, uint16_t length)
     218             : {
     219           0 :     uint8_t crc = 0xFF;
     220             : 
     221           0 :     while (length--) {
     222           0 :         crc = crc8_table_sae[crc ^ (*data & 0xFF)];
     223           0 :         data++;
     224             :     }
     225           0 :     crc ^= 0xFF;
     226             : 
     227           0 :     return      crc;
     228             : }
     229             : 
     230             : // crc table for rangefinder rds02uf
     231             : static const uint8_t crc8_table_rds02uf[256] = {
     232             :     0x93,0x98,0xE4,0x46,0xEB,0xBA,0x04,0x4C,
     233             :     0xFA,0x40,0xB8,0x96,0x0E,0xB2,0xB7,0xC0,
     234             :     0x0C,0x32,0x9B,0x80,0xFF,0x30,0x7F,0x9D,
     235             :     0xB3,0x81,0x58,0xE7,0xF1,0x19,0x7E,0xB6,
     236             :     0xCD,0xF7,0xB4,0xCB,0xBC,0x5C,0xD6,0x09,
     237             :     0x20,0x0A,0xE0,0x37,0x51,0x67,0x24,0x95,
     238             :     0xE1,0x62,0xF8,0x5E,0x38,0x15,0x54,0x77,
     239             :     0x63,0x57,0x6D,0xE9,0x89,0x76,0xBE,0x41,
     240             :     0x5D,0xF9,0xB1,0x4D,0x6C,0x53,0x9C,0xA2,
     241             :     0x23,0xC4,0x8E,0xC8,0x05,0x42,0x61,0x71,
     242             :     0xC5,0x00,0x18,0x6F,0x5F,0xFB,0x7B,0x11,
     243             :     0x65,0x2D,0x8C,0xED,0x14,0xAB,0x88,0xD5,
     244             :     0xD9,0xC2,0x36,0x34,0x7C,0x5B,0x3C,0xF6,
     245             :     0x48,0x0B,0xEE,0x02,0x83,0x79,0x17,0xE6,
     246             :     0xA8,0x78,0xF5,0xD3,0x4E,0x50,0x52,0x91,
     247             :     0xD8,0xC6,0x22,0xEC,0x3B,0xE5,0x3F,0x86,
     248             :     0x06,0xCF,0x2B,0x2F,0x3D,0x59,0x1C,0x87,
     249             :     0xEF,0x4F,0x10,0xD2,0x7D,0xDA,0x72,0xA0,
     250             :     0x9F,0xDE,0x6B,0x75,0x56,0xBD,0xC7,0xC1,
     251             :     0x70,0x1D,0x25,0x92,0xA5,0x31,0xE2,0xD7,
     252             :     0xD0,0x9A,0xAF,0xA9,0xC9,0x97,0x08,0x33,
     253             :     0x5A,0x99,0xC3,0x16,0x84,0x82,0x8A,0xF3,
     254             :     0x4A,0xCE,0xDB,0x29,0x0F,0xAE,0x6E,0xE3,
     255             :     0x8B,0x07,0x3A,0x74,0x47,0xB0,0xBB,0xB5,
     256             :     0x7A,0xAA,0x2C,0xD4,0x03,0x3E,0x1A,0xA7,
     257             :     0x27,0x64,0x06,0xBF,0x55,0x73,0x1E,0xFE,
     258             :     0x49,0x01,0x39,0x28,0xF4,0x26,0xDF,0xDD,
     259             :     0x44,0x0D,0x21,0xF2,0x85,0xB9,0xEA,0x4B,
     260             :     0xDC,0x6A,0xCA,0xAC,0x12,0xFC,0x2E,0x2A,
     261             :     0xA3,0xF0,0x66,0xE8,0x60,0x45,0xA1,0x8D,
     262             :     0x68,0x35,0xFD,0x8F,0x9E,0x1F,0x13,0xD1,
     263             :     0xAD,0x69,0xCC,0xA4,0x94,0x90,0x1B,0x43,
     264             : };
     265             : 
     266         695 : uint8_t crc8_rds02uf(const uint8_t *data, uint16_t length)
     267             : {
     268         695 :     uint8_t crc = 0;
     269       11815 :     while (length--) {
     270       11120 :         crc = crc8_table_rds02uf[crc^*(data++)];
     271             :     }
     272         695 :     return crc;
     273             : }
     274             : 
     275      224258 : uint8_t crc_xor_of_bytes(const uint8_t* data, uint16_t length)
     276             : {
     277      224258 :     uint8_t checksum = 0;
     278    14140426 :     for (uint16_t i = 0; i < length; i++) {
     279    13916168 :         checksum ^= data[i];
     280             :     }
     281      224258 :     return checksum;
     282             : }
     283             : 
     284             : /*
     285             :   xmodem CRC thanks to avr-liberty
     286             :   https://github.com/dreamiurg/avr-liberty
     287             :  */
     288      180424 : uint16_t crc_xmodem_update(uint16_t crc, uint8_t data)
     289             : {
     290      180424 :         crc = crc ^ ((uint16_t)data << 8);
     291     1623816 :         for (uint16_t i=0; i<8; i++)
     292             :         {
     293     1443392 :                 if(crc & 0x8000) {
     294      691312 :                         crc = (crc << 1) ^ 0x1021;
     295             :                 } else {
     296      752080 :                         crc <<= 1;
     297             :         }
     298             :         }
     299             : 
     300      180424 :         return crc;
     301             : }
     302             : 
     303           0 : uint16_t crc_xmodem(const uint8_t *data, uint16_t len)
     304             : {
     305           0 :     uint16_t crc = 0;
     306           0 :     for (uint16_t i=0; i<len; i++) {
     307           0 :         crc = crc_xmodem_update(crc, data[i]);
     308             :     }
     309           0 :     return crc;
     310             : }
     311             : 
     312             : /*
     313             :   crc32 from Gary S Brown
     314             :  */
     315             : static const uint32_t crc32_tab[] = {
     316             :     0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
     317             :     0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
     318             :     0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
     319             :     0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
     320             :     0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
     321             :     0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
     322             :     0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
     323             :     0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
     324             :     0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
     325             :     0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
     326             :     0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
     327             :     0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
     328             :     0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
     329             :     0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
     330             :     0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
     331             :     0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
     332             :     0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
     333             :     0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
     334             :     0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
     335             :     0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
     336             :     0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
     337             :     0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
     338             :     0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
     339             :     0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
     340             :     0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
     341             :     0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
     342             :     0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
     343             :     0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
     344             :     0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
     345             :     0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
     346             :     0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
     347             :     0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
     348             :     0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
     349             :     0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
     350             :     0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
     351             :     0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
     352             :     0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
     353             :     0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
     354             :     0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
     355             :     0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
     356             :     0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
     357             :     0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
     358             :     0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
     359             : };
     360             : 
     361             : 
     362       88924 : uint32_t crc_crc32(uint32_t crc, const uint8_t *buf, uint32_t size)
     363             : {
     364     1814372 :         for (uint32_t i=0; i<size; i++) {
     365     1725448 :                 crc = crc32_tab[(crc ^ buf[i]) & 0xff] ^ (crc >> 8);
     366             :         }
     367             : 
     368       88924 :         return crc;
     369             : }
     370             : 
     371             : // smaller (and slower) crc32 for bootloader
     372       14360 : uint32_t crc32_small(uint32_t crc, const uint8_t *buf, uint32_t size)
     373             : {
     374    72999345 :     while (size--) {
     375    72984985 :         const uint8_t byte = *buf++;
     376    72984985 :         crc ^= byte;
     377   656864865 :         for (uint8_t i=0; i<8; i++) {
     378   583879880 :             const uint32_t mask = -(crc & 1);
     379   583879880 :             crc >>= 1;
     380   583879880 :             crc ^= (0xEDB88320 & mask);
     381             :         }
     382             :     }
     383       14360 :     return crc;
     384             : }
     385             : 
     386             : /*
     387             :  * Copyright (C) 2010 Swift Navigation Inc.
     388             :  * Contact: Fergus Noble <[email protected]>
     389             :  *
     390             :  * This source is subject to the license found in the file 'LICENSE' which must
     391             :  * be be distributed together with this source. All other rights reserved.
     392             :  *
     393             :  * THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
     394             :  * EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
     395             :  * WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
     396             :  */
     397             : /* CRC16 implementation according to CCITT standards */
     398             : static const uint16_t crc16tab[256] = {
     399             :   0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7,
     400             :   0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF,
     401             :   0x1231, 0x0210, 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6,
     402             :   0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE,
     403             :   0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7, 0x44A4, 0x5485,
     404             :   0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE, 0xF5CF, 0xC5AC, 0xD58D,
     405             :   0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4,
     406             :   0xB75B, 0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE, 0xD79D, 0xC7BC,
     407             :   0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823,
     408             :   0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969, 0xA90A, 0xB92B,
     409             :   0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12,
     410             :   0xDBFD, 0xCBDC, 0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B, 0xAB1A,
     411             :   0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41,
     412             :   0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, 0xAD2A, 0xBD0B, 0x8D68, 0x9D49,
     413             :   0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70,
     414             :   0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A, 0x9F59, 0x8F78,
     415             :   0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E, 0xE16F,
     416             :   0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067,
     417             :   0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E,
     418             :   0x02B1, 0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214, 0x6277, 0x7256,
     419             :   0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D,
     420             :   0x34E2, 0x24C3, 0x14A0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
     421             :   0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C,
     422             :   0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657, 0x7676, 0x4615, 0x5634,
     423             :   0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB,
     424             :   0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1, 0x3882, 0x28A3,
     425             :   0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A,
     426             :   0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, 0x2AB3, 0x3A92,
     427             :   0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9,
     428             :   0x7C26, 0x6C07, 0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1,
     429             :   0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8,
     430             :   0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0
     431             : };
     432             : 
     433     2149109 : uint16_t crc16_ccitt(const uint8_t *buf, uint32_t len, uint16_t crc)
     434             : {
     435    26995729 :     for (uint32_t i = 0; i < len; i++) {
     436    24846620 :         crc = (crc << 8) ^ crc16tab[((crc >> 8) ^ *buf++) & 0x00FF];
     437             :     }
     438     2149109 :     return crc;
     439             : }
     440             : 
     441             : // CRC16_CCITT algorithm using right shift
     442           0 : uint16_t crc16_ccitt_r(const uint8_t *buf, uint32_t len, uint16_t crc, uint16_t out)
     443             : {
     444           0 :         for (uint32_t i = 0; i < len; i++) {
     445           0 :                 crc ^= *buf++;                      // XOR byte into least sig. byte of crc
     446           0 :                 for (uint8_t j = 0; j < 8; j++) {   // loop over each bit
     447           0 :             if ((crc & 0x0001) != 0) {      // if the LSB is set
     448           0 :                 crc >>= 1;                  // shift right and XOR 0x8408
     449           0 :                 crc ^= 0x8408;
     450             :             } else {
     451           0 :                 crc >>= 1;                  // just shift right
     452             :             }
     453             :                 }
     454             :         }
     455             : 
     456             :     // output xor
     457           0 :     crc = crc ^ out;
     458           0 :         return crc;
     459             : }
     460             : 
     461           0 : uint16_t crc16_ccitt_GDL90(const uint8_t *buf, uint32_t len, uint16_t crc)
     462             : {
     463           0 :     for (uint32_t i = 0; i < len; i++) {
     464           0 :         crc = crc16tab[crc >> 8] ^ (crc << 8) ^ (uint16_t) *buf++;
     465             :     }
     466           0 :     return crc;
     467             : }
     468             : 
     469             : /**
     470             :  * Calculate Modbus CRC16 for array of bytes
     471             :  * 
     472             :  * @param [in] buf input buffer
     473             :  * @param [in] len size of buffer
     474             :  * @return CRC value
     475             :  */
     476        2789 : uint16_t calc_crc_modbus(const uint8_t *buf, uint16_t len)
     477             : {
     478        2789 :     uint16_t crc = 0xFFFF;
     479       50875 :     for (uint16_t pos = 0; pos < len; pos++) {
     480       48086 :         crc ^= (uint16_t) buf[pos]; // XOR byte into least sig. byte of crc
     481      432774 :         for (uint8_t i = 8; i != 0; i--) { // Loop over each bit
     482      384688 :             if ((crc & 0x0001) != 0) { // If the LSB is set
     483      202332 :                 crc >>= 1; // Shift right and XOR 0xA001
     484      202332 :                 crc ^= 0xA001;
     485             :             } else {
     486             :                 // Else LSB is not set
     487      182356 :                 crc >>= 1; // Just shift right
     488             :             }
     489             :         }
     490             :     }
     491        2789 :     return crc;
     492             : }
     493             : 
     494             : // fletcher 16 implementation
     495           0 : uint16_t crc_fletcher16(const uint8_t *buffer, uint32_t len) {
     496           0 :     uint16_t c0 = 0;
     497           0 :     uint16_t c1 = 0;
     498           0 :     for (uint32_t i = 0; i < len; i++) {
     499           0 :         c0 = (c0 + buffer[i]) % 255;
     500           0 :         c1 = (c1 + c0) % 255;
     501             :     }
     502             : 
     503           0 :     return (c1 << 8) | c0;
     504             : }
     505             : 
     506             : // FNV-1a implementation
     507             : #define FNV_1_PRIME_64 1099511628211UL
     508          24 : void hash_fnv_1a(uint32_t len, const uint8_t* buf, uint64_t* hash)
     509             : {
     510             :     uint32_t i;
     511         395 :     for (i=0; i<len; i++) {
     512         371 :         *hash ^= (uint64_t)buf[i];
     513         371 :         *hash *= FNV_1_PRIME_64;
     514             :     }
     515          24 : }
     516             : 
     517             : // calculate 24 bit crc. We take an approach that saves memory and flash at the cost of higher CPU load.
     518          28 : uint32_t crc_crc24(const uint8_t *bytes, uint16_t len)
     519             : {
     520             :     static constexpr uint32_t POLYCRC24 = 0x1864CFB;
     521          28 :     uint32_t crc = 0;
     522         514 :     while (len--) {
     523         486 :         uint8_t b = *bytes++;
     524         486 :         const uint8_t idx = (crc>>16) ^ b;
     525         486 :         uint32_t crct = idx<<16;
     526        4374 :         for (uint8_t j=0; j<8; j++) {
     527        3888 :             crct <<= 1;
     528        3888 :             if (crct & 0x1000000) {
     529        2057 :                 crct ^= POLYCRC24;
     530             :             }
     531             :         }
     532         486 :         crc = ((crc<<8)&0xFFFFFF) ^ crct;
     533             :     }
     534          28 :     return crc;
     535             : }
     536             : 
     537             : // simple 8 bit checksum used by FPort
     538           0 : uint8_t crc_sum8_with_carry(const uint8_t *p, uint8_t len)
     539             : {
     540           0 :     uint16_t sum = 0;
     541           0 :     for (uint8_t i=0; i<len; i++) {
     542           0 :         sum += p[i];
     543           0 :         sum += sum >> 8;
     544           0 :         sum &= 0xFF;              
     545             :     }
     546           0 :     sum = 0xff - ((sum & 0xff) + (sum >> 8));
     547           0 :     return sum;
     548             : }
     549             : 
     550             : // CRC-16 (IBM/ANSI)
     551             : // Polynomial : x16 + x15 + x2 + 1 (polynomial representation : 0x8005)
     552             : // Initial Value : 0
     553       91350 : uint16_t crc_crc16_ibm(uint16_t crc_accum, uint8_t *data_blk_ptr, uint16_t data_blk_size)
     554             : {
     555             :     uint16_t i;
     556             :     static const uint16_t crc_table[256] = {0x0000,
     557             :                                             0x8005, 0x800F, 0x000A, 0x801B, 0x001E, 0x0014, 0x8011,
     558             :                                             0x8033, 0x0036, 0x003C, 0x8039, 0x0028, 0x802D, 0x8027,
     559             :                                             0x0022, 0x8063, 0x0066, 0x006C, 0x8069, 0x0078, 0x807D,
     560             :                                             0x8077, 0x0072, 0x0050, 0x8055, 0x805F, 0x005A, 0x804B,
     561             :                                             0x004E, 0x0044, 0x8041, 0x80C3, 0x00C6, 0x00CC, 0x80C9,
     562             :                                             0x00D8, 0x80DD, 0x80D7, 0x00D2, 0x00F0, 0x80F5, 0x80FF,
     563             :                                             0x00FA, 0x80EB, 0x00EE, 0x00E4, 0x80E1, 0x00A0, 0x80A5,
     564             :                                             0x80AF, 0x00AA, 0x80BB, 0x00BE, 0x00B4, 0x80B1, 0x8093,
     565             :                                             0x0096, 0x009C, 0x8099, 0x0088, 0x808D, 0x8087, 0x0082,
     566             :                                             0x8183, 0x0186, 0x018C, 0x8189, 0x0198, 0x819D, 0x8197,
     567             :                                             0x0192, 0x01B0, 0x81B5, 0x81BF, 0x01BA, 0x81AB, 0x01AE,
     568             :                                             0x01A4, 0x81A1, 0x01E0, 0x81E5, 0x81EF, 0x01EA, 0x81FB,
     569             :                                             0x01FE, 0x01F4, 0x81F1, 0x81D3, 0x01D6, 0x01DC, 0x81D9,
     570             :                                             0x01C8, 0x81CD, 0x81C7, 0x01C2, 0x0140, 0x8145, 0x814F,
     571             :                                             0x014A, 0x815B, 0x015E, 0x0154, 0x8151, 0x8173, 0x0176,
     572             :                                             0x017C, 0x8179, 0x0168, 0x816D, 0x8167, 0x0162, 0x8123,
     573             :                                             0x0126, 0x012C, 0x8129, 0x0138, 0x813D, 0x8137, 0x0132,
     574             :                                             0x0110, 0x8115, 0x811F, 0x011A, 0x810B, 0x010E, 0x0104,
     575             :                                             0x8101, 0x8303, 0x0306, 0x030C, 0x8309, 0x0318, 0x831D,
     576             :                                             0x8317, 0x0312, 0x0330, 0x8335, 0x833F, 0x033A, 0x832B,
     577             :                                             0x032E, 0x0324, 0x8321, 0x0360, 0x8365, 0x836F, 0x036A,
     578             :                                             0x837B, 0x037E, 0x0374, 0x8371, 0x8353, 0x0356, 0x035C,
     579             :                                             0x8359, 0x0348, 0x834D, 0x8347, 0x0342, 0x03C0, 0x83C5,
     580             :                                             0x83CF, 0x03CA, 0x83DB, 0x03DE, 0x03D4, 0x83D1, 0x83F3,
     581             :                                             0x03F6, 0x03FC, 0x83F9, 0x03E8, 0x83ED, 0x83E7, 0x03E2,
     582             :                                             0x83A3, 0x03A6, 0x03AC, 0x83A9, 0x03B8, 0x83BD, 0x83B7,
     583             :                                             0x03B2, 0x0390, 0x8395, 0x839F, 0x039A, 0x838B, 0x038E,
     584             :                                             0x0384, 0x8381, 0x0280, 0x8285, 0x828F, 0x028A, 0x829B,
     585             :                                             0x029E, 0x0294, 0x8291, 0x82B3, 0x02B6, 0x02BC, 0x82B9,
     586             :                                             0x02A8, 0x82AD, 0x82A7, 0x02A2, 0x82E3, 0x02E6, 0x02EC,
     587             :                                             0x82E9, 0x02F8, 0x82FD, 0x82F7, 0x02F2, 0x02D0, 0x82D5,
     588             :                                             0x82DF, 0x02DA, 0x82CB, 0x02CE, 0x02C4, 0x82C1, 0x8243,
     589             :                                             0x0246, 0x024C, 0x8249, 0x0258, 0x825D, 0x8257, 0x0252,
     590             :                                             0x0270, 0x8275, 0x827F, 0x027A, 0x826B, 0x026E, 0x0264,
     591             :                                             0x8261, 0x0220, 0x8225, 0x822F, 0x022A, 0x823B, 0x023E,
     592             :                                             0x0234, 0x8231, 0x8213, 0x0216, 0x021C, 0x8219, 0x0208,
     593             :                                             0x820D, 0x8207, 0x0202 };
     594             : 
     595      456750 :     for (uint16_t j = 0; j < data_blk_size; j++) {
     596      365400 :         i = ((uint16_t)(crc_accum >> 8) ^ *data_blk_ptr++) & 0xFF;
     597      365400 :         crc_accum = (crc_accum << 8) ^ crc_table[i];
     598             :     }
     599             : 
     600       91350 :     return crc_accum;
     601             : }
     602             : 
     603             : /*
     604             :   64 bit crc matching px4 bootloader
     605             : */
     606           0 : uint64_t crc_crc64(const uint32_t *data, uint16_t num_words)
     607             : {
     608           0 :     const uint64_t poly = 0x42F0E1EBA9EA3693ULL;
     609           0 :     uint64_t crc = ~(0ULL);
     610           0 :     while (num_words--) {
     611           0 :         uint32_t value = *data++;
     612           0 :         for (uint8_t j = 0; j < 4; j++) {
     613           0 :             uint8_t byte = ((uint8_t *)&value)[j];
     614           0 :             crc ^= (uint64_t)byte << 56u;
     615           0 :             for (uint8_t i = 0; i < 8; i++) {
     616           0 :                 if (crc & (1ull << 63u)) {
     617           0 :                     crc = (uint64_t)(crc << 1u) ^ poly;
     618             :                 } else {
     619           0 :                     crc = (uint64_t)(crc << 1u);
     620             :                 }
     621             :             }
     622             :         }
     623             :     }
     624           0 :     crc ^= ~(0ULL);
     625             : 
     626           0 :     return crc;
     627             : }
     628             : 
     629             : // return the parity of byte - "1" if there is an odd number of bits
     630             : // set, "0" if there is an even number of bits set note that
     631             : // __builtin_parity causes hardfaults on Pixracer-periph - and is
     632             : // slower on 1 byte than this:
     633          14 : uint8_t parity(uint8_t byte)
     634             : {
     635          14 :     uint8_t p = 0;
     636             : 
     637          14 :     p ^= byte & 0x1;
     638          14 :     byte >>= 1;
     639          14 :     p ^= byte & 0x1;
     640          14 :     byte >>= 1;
     641          14 :     p ^= byte & 0x1;
     642          14 :     byte >>= 1;
     643          14 :     p ^= byte & 0x1;
     644          14 :     byte >>= 1;
     645          14 :     p ^= byte & 0x1;
     646          14 :     byte >>= 1;
     647          14 :     p ^= byte & 0x1;
     648          14 :     byte >>= 1;
     649          14 :     p ^= byte & 0x1;
     650          14 :     byte >>= 1;
     651          14 :     p ^= byte & 0x1;
     652             : 
     653          14 :     return p;
     654             : }
     655             : 
     656             : // sums the bytes in the supplied buffer, returns that sum mod 0xFFFF
     657      116318 : uint16_t crc_sum_of_bytes_16(const uint8_t *data, uint16_t count)
     658             : {
     659      116318 :     uint16_t ret = 0;
     660    15241850 :     for (uint32_t i=0; i<count; i++) {
     661    15125532 :         ret += data[i];
     662             :     }
     663      116318 :     return ret;
     664             : }
     665             : 
     666             : // sums the bytes in the supplied buffer, returns that sum mod 256
     667             : // (i.e. shoved into a uint8_t)
     668       41409 : uint8_t crc_sum_of_bytes(const uint8_t *data, uint16_t count)
     669             : {
     670       41409 :     return crc_sum_of_bytes_16(data, count) & 0xFF;
     671             : }

Generated by: LCOV version 1.14