The crc32 used by pblimgae is NOT the same as zlib crc32. The pbl_crc32 is useful for other purposes in mkimage so split it out. While we are about it, clean up redundant and confusing code. Signed-off-by: Charles Manning <cdhmanning@gmail.com>master
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/*
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* Copyright 2012 Freescale Semiconductor, Inc. |
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* |
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* Cleaned up and refactored by Charles Manning. |
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* |
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* SPDX-License-Identifier: GPL-2.0+ |
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*/ |
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#include "pblimage.h" |
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static uint32_t crc_table[256]; |
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static int crc_table_valid; |
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static void make_crc_table(void) |
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{ |
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uint32_t mask; |
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int i, j; |
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uint32_t poly; /* polynomial exclusive-or pattern */ |
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if (crc_table_valid) |
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return; |
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/*
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* the polynomial used by PBL is 1 + x1 + x2 + x4 + x5 + x7 + x8 + x10 |
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* + x11 + x12 + x16 + x22 + x23 + x26 + x32. |
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*/ |
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poly = 0x04c11db7; |
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for (i = 0; i < 256; i++) { |
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mask = i << 24; |
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for (j = 0; j < 8; j++) { |
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if (mask & 0x80000000) |
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mask = (mask << 1) ^ poly; |
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else |
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mask <<= 1; |
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} |
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crc_table[i] = mask; |
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} |
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crc_table_valid = 1; |
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} |
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uint32_t pbl_crc32(uint32_t in_crc, const char *buf, uint32_t len) |
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{ |
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uint32_t crc32_val; |
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int i; |
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make_crc_table(); |
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crc32_val = ~in_crc; |
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for (i = 0; i < len; i++) |
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crc32_val = (crc32_val << 8) ^ |
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crc_table[(crc32_val >> 24) ^ (*buf++ & 0xff)]; |
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return crc32_val; |
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} |
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/*
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* Copyright 2012 Freescale Semiconductor, Inc. |
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* |
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* SPDX-License-Identifier: GPL-2.0+ |
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*/ |
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#ifndef PBLCRC32_H |
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#define PBLCRC32_H |
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#include <stdint.h> |
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uint32_t pbl_crc32(uint32_t in_crc, const char *buf, uint32_t len); |
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#endif |
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