1*4882a593Smuzhiyun /* 2*4882a593Smuzhiyun * Copyright 2012 Freescale Semiconductor, Inc. 3*4882a593Smuzhiyun * 4*4882a593Smuzhiyun * Cleaned up and refactored by Charles Manning. 5*4882a593Smuzhiyun * 6*4882a593Smuzhiyun * SPDX-License-Identifier: GPL-2.0+ 7*4882a593Smuzhiyun */ 8*4882a593Smuzhiyun #include "pblimage.h" 9*4882a593Smuzhiyun 10*4882a593Smuzhiyun static uint32_t crc_table[256]; 11*4882a593Smuzhiyun static int crc_table_valid; 12*4882a593Smuzhiyun make_crc_table(void)13*4882a593Smuzhiyunstatic void make_crc_table(void) 14*4882a593Smuzhiyun { 15*4882a593Smuzhiyun uint32_t mask; 16*4882a593Smuzhiyun int i, j; 17*4882a593Smuzhiyun uint32_t poly; /* polynomial exclusive-or pattern */ 18*4882a593Smuzhiyun 19*4882a593Smuzhiyun if (crc_table_valid) 20*4882a593Smuzhiyun return; 21*4882a593Smuzhiyun 22*4882a593Smuzhiyun /* 23*4882a593Smuzhiyun * the polynomial used by PBL is 1 + x1 + x2 + x4 + x5 + x7 + x8 + x10 24*4882a593Smuzhiyun * + x11 + x12 + x16 + x22 + x23 + x26 + x32. 25*4882a593Smuzhiyun */ 26*4882a593Smuzhiyun poly = 0x04c11db7; 27*4882a593Smuzhiyun 28*4882a593Smuzhiyun for (i = 0; i < 256; i++) { 29*4882a593Smuzhiyun mask = i << 24; 30*4882a593Smuzhiyun for (j = 0; j < 8; j++) { 31*4882a593Smuzhiyun if (mask & 0x80000000) 32*4882a593Smuzhiyun mask = (mask << 1) ^ poly; 33*4882a593Smuzhiyun else 34*4882a593Smuzhiyun mask <<= 1; 35*4882a593Smuzhiyun } 36*4882a593Smuzhiyun crc_table[i] = mask; 37*4882a593Smuzhiyun } 38*4882a593Smuzhiyun 39*4882a593Smuzhiyun crc_table_valid = 1; 40*4882a593Smuzhiyun } 41*4882a593Smuzhiyun pbl_crc32(uint32_t in_crc,const char * buf,uint32_t len)42*4882a593Smuzhiyunuint32_t pbl_crc32(uint32_t in_crc, const char *buf, uint32_t len) 43*4882a593Smuzhiyun { 44*4882a593Smuzhiyun uint32_t crc32_val; 45*4882a593Smuzhiyun int i; 46*4882a593Smuzhiyun 47*4882a593Smuzhiyun make_crc_table(); 48*4882a593Smuzhiyun 49*4882a593Smuzhiyun crc32_val = ~in_crc; 50*4882a593Smuzhiyun 51*4882a593Smuzhiyun for (i = 0; i < len; i++) 52*4882a593Smuzhiyun crc32_val = (crc32_val << 8) ^ 53*4882a593Smuzhiyun crc_table[(crc32_val >> 24) ^ (*buf++ & 0xff)]; 54*4882a593Smuzhiyun 55*4882a593Smuzhiyun return crc32_val; 56*4882a593Smuzhiyun } 57