systemd/extras/mtd_probe/probe_smartmedia.c

/*
 * Copyright (C) 2010 - Maxim Levitsky
 *
 * mtd_probe is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * mtd_probe is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with mtd_probe; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, 
 * Boston, MA  02110-1301  USA
 */

#include <stdio.h>
#include <stdlib.h>
#include <mtd/mtd-user.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdint.h>
#include <stdlib.h>
#include "mtd_probe.h"

static const uint8_t cis_signature[] = {
	0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20
};


void probe_smart_media(int mtd_fd, mtd_info_t* info)
{
	char* cis_buffer = malloc(SM_SECTOR_SIZE);

	if (!cis_buffer)
		return;

	if (info->type != MTD_NANDFLASH)
		goto exit;

	int sector_size = info->writesize;
	int block_size = info->erasesize;
	int size_in_megs = info->size / (1024 * 1024);
	int spare_count;


	if (sector_size != SM_SECTOR_SIZE && sector_size != SM_SMALL_PAGE)
		goto exit;

	switch(size_in_megs) {
	case 1:
	case 2:
		spare_count = 6;
		break;
	case 4:
		spare_count = 12;
		break;
	default:
		spare_count = 24;
		break;
	}


	int offset;
	int cis_found = 0;

	for (offset = 0 ; offset < block_size * spare_count ;
						offset += sector_size) {

		lseek(mtd_fd, SEEK_SET, offset);
		if (read(mtd_fd, cis_buffer, SM_SECTOR_SIZE) == SM_SECTOR_SIZE){
			cis_found = 1;
			break;
		}
	}

	if (!cis_found)
		goto exit;

	if (memcmp(cis_buffer, cis_signature, sizeof(cis_signature)) != 0 &&
		(memcmp(cis_buffer + SM_SMALL_PAGE, cis_signature,
			sizeof(cis_signature)) != 0))
		goto exit;

	printf("MTD_FTL=smartmedia\n");
	free(cis_buffer);
	exit(0);
exit:
	free(cis_buffer);
	return;
}