lib/crc8.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2013 Google, Inc
   4  */
   5
   6 #ifdef USE_HOSTCC
   7 #include <arpa/inet.h>
   8 #else
   9 #include <common.h>
  10 #endif
  11 #include <u-boot/crc.h>
  12
  13 #define POLY    (0x1070U << 3)
  14
  15 static unsigned char _crc8(unsigned short data)
  16 {
  17         int i;
  18
  19         for (i = 0; i < 8; i++) {
  20                 if (data & 0x8000)
  21                         data = data ^ POLY;
  22                 data = data << 1;
  23         }
  24
  25         return (unsigned char)(data >> 8);
  26 }
  27
  28 unsigned int crc8(unsigned int crc, const unsigned char *vptr, int len)
  29 {
  30         int i;
  31
  32         for (i = 0; i < len; i++)
  33                 crc = _crc8((crc ^ vptr[i]) << 8);
  34
  35         return crc;
  36 }