view stashaway/mkcrc32tab.c @ 992:a7b0b426f9ca

target-utils: boot ROM UART autodetection revamped The new implementation should work with both the familiar Calypso C035 boot ROM version found in our regular targets as well as the older Calypso F741979B version found on the vintage D-Sample board.
author Mychaela Falconia <falcon@ivan.Harhan.ORG>
date Wed, 30 Dec 2015 21:28:41 +0000
parents 8fbd52a639a5
children
line wrap: on
line source

/*
 * This program generates the CRC-32 table for the LSB-first direction.
 * Derived from the MSB-first version written years earlier by the
 * same author (Michael Spacefalcon) for SDSL/ATM AAL5.
 */

#include <sys/types.h>
#include <stdio.h>

u_long table[256];

main(argc, argv)
	char **argv;
{
	build_table();
	emit_table();
	exit(0);
}

u_long
crc_byte(crc, inb)
	u_long crc;
	int inb;
{
	register int bit;

	crc ^= inb & 0xFF;
	for (bit = 0; bit < 8; bit++) {
		if (crc & 1)
			crc = (crc >> 1) ^ 0xEDB88320;
		else
			crc >>= 1;
	}
	return(crc);
}

build_table()
{
	int i;

	for (i = 0; i < 256; i++)
		table[i] = crc_byte(0, i);
}

emit_table()
{
	int i, j, idx;

	printf("unsigned long crc32_table[256] = {\n");
	for (i = 0, idx = 0; i < 64; i++) {
		putchar('\t');
		for (j = 0; j < 4; j++, idx++)
			printf("0x%08X,%c", table[idx], j==3 ? '\n' : ' ');
	}
	printf("};\n");
}