view loadtools/hexdecode.c @ 718:098fea21ba13

doc/Host-tools-overview: tiffs-mkfs description updated The first version of tiffs-mkfs did not include a journal file in the created FFS, expecting the firmware to create it on first boot. All historical firmwares prior to a recent FC fix (2020-05) contain a bug in that code path, thus images made with the first version of tiffs-mkfs were only acceptable to very recent FC firmwares. tiffs-mkfs has now been extended to include an empty journal in the created FFS, thus the restriction of working with recent fw only has been lifted.
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 23 Aug 2020 04:55:02 +0000
parents e7502631a0f9
children
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/*
 * This module contains the decode_hex_byte() function,
 * which is used by the SREC file reader and will likely be used
 * by other code as well, such as the dump-to-file function
 * of loadtool.
 */

#include <ctype.h>

decode_hex_byte(s)
	char *s;
{
	register int u, l;

	if (!isxdigit(s[0]) || !isxdigit(s[1]))
		return(-1);
	if (isdigit(s[0]))
		u = s[0] - '0';
	else if (isupper(s[0]))
		u = s[0] - 'A' + 10;
	else
		u = s[0] - 'a' + 10;
	if (isdigit(s[1]))
		l = s[1] - '0';
	else if (isupper(s[1]))
		l = s[1] - 'A' + 10;
	else
		l = s[1] - 'a' + 10;
	return((u << 4) | l);
}