fmap.c

/* Copyright 2010, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *    * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *    * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *    * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * This is ported from the flashmap utility: http://flashmap.googlecode.com
 */

#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "flash.h"
#include "fmap.h"
#include "search.h"

static int fmap_find_signature(struct flashchip *flash,
		int (*handler)(struct search_info *search, off_t *offset),
		off_t *offsetp)
{
	struct search_info search;
	uint64_t sig, tmp64;
	int sig_len;
	int ret = 0;	/* Assume not found */

	sig_len = strlen(FMAP_SIGNATURE);
	memcpy(&sig, FMAP_SIGNATURE, sig_len);
	search_init(&search, flash, sig_len);
	search.handler = handler;

	while (!search_find_next(&search, offsetp)) {
		if (search.image)
			memcpy(&tmp64, search.image + *offsetp, sizeof(tmp64));
		else if (read_flash(flash, (uint8_t *)&tmp64,
		                *offsetp, sizeof(tmp64))) {
			msg_gdbg("[L%d] failed to read flash at "
			         "offset 0x%lx\n", __LINE__, *offsetp);
			ret = -1;
			break;
		}
		if (!memcmp(&tmp64, &sig, sizeof(sig))) {
			ret = 1;	/* Found */
			break;
		}
	}

	search_free(&search);
	return ret;
}


int fmap_find(struct flashchip *flash,
	      int (*handler)(struct search_info *search, off_t *offset),
	      uint8_t **buf)
{
	struct fmap fmap;
	off_t offset;
	int fmap_size;
	int ret;

	ret = fmap_find_signature(flash, handler, &offset);
	if (ret <= 0)
		return ret;
	if (read_flash(flash, (uint8_t *)&fmap, offset, sizeof(fmap))) {
		msg_gdbg("[L%d] failed to read flash at offset 0x%lx\n",
		         __LINE__, offset);
		return -1;
	}

	fmap_size = sizeof(fmap) + (fmap.nareas * sizeof(struct fmap_area));
	*buf = malloc(fmap_size);

	if (read_flash(flash, *buf, offset, fmap_size)) {
		msg_gdbg("[L%d] failed to read %d bytes at offset 0x%lx\n",
		         __LINE__, fmap_size, offset);
		return -1;
	}
	return fmap_size;
}


/* Like fmap_find, but give a memory location to search FMAP. */
struct fmap *fmap_find_in_memory(uint8_t *image, int size)
{
	long int offset = 0;
	uint64_t sig;

	memcpy(&sig, FMAP_SIGNATURE, strlen(FMAP_SIGNATURE));

	for (offset = 0; offset < size; offset++) {
		if (!memcmp(&image[offset], &sig, sizeof(sig))) {
			return (struct fmap *)&image[offset];
		}
	}
	return NULL;
}