view stashaway/mkcrc32tab.c @ 923:10b4bed10192

gsm-fw/L1: fix for the DSP patch corruption bug The L1 code we got from the LoCosto fw contains a feature for DSP CPU load measurement. This feature is a LoCosto-ism, i.e., not applicable to earlier DBB chips (Calypso) with their respective earlier DSP ROMs. Most of the code dealing with that feature is conditionalized as #if (DSP >= 38), but one spot was missed, and the MCU code was writing into an API word dealing with this feature. In TCS211 this DSP API word happens to be used by the DSP code patch, hence that write was corrupting the patched DSP code.
author Mychaela Falconia <falcon@ivan.Harhan.ORG>
date Mon, 19 Oct 2015 17:13:56 +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");
}