lib_generic/chromeos/boot_device.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.
 */

#include <config.h>
#include <common.h>
#include <part.h>
#include <boot_device.h>

static struct {
	block_dev_desc_t *dev_desc;
	ulong offset, limit;
} bootdev_config = {
	.dev_desc = NULL,
	.offset = 0u,
	.limit = 0u
};

block_dev_desc_t *get_bootdev(void)
{
	return bootdev_config.dev_desc;
}

int set_bootdev(char *ifname, int dev, int part)
{
	disk_partition_t part_info;

	if ((bootdev_config.dev_desc = get_dev(ifname, dev)) == NULL)
		goto cleanup; /* block device not supported */

	/* largest address not available in block_dev_desc_t */
	if (part == 0) {
		bootdev_config.limit = ~0;
		return 0;
	}

	if (get_partition_info(bootdev_config.dev_desc, part, &part_info))
		goto cleanup; /* cannot find partition */

	bootdev_config.offset = part_info.start;
	bootdev_config.limit = part_info.size;

	return 0;

cleanup:
	bootdev_config.dev_desc = NULL;
	bootdev_config.offset = 0;
	bootdev_config.limit = 0;

	return 1;
}

int BootDeviceReadLBA(uint64_t lba_start, uint64_t lba_count, void *buffer)
{
	block_dev_desc_t *dev_desc;

	if ((dev_desc = bootdev_config.dev_desc) == NULL)
		return 1; /* No boot device configured */

	if (lba_start + lba_count > bootdev_config.limit)
		return 1; /* read out of range */

	if (dev_desc->block_read(dev_desc->dev,
				bootdev_config.offset + lba_start, lba_count,
				buffer) < 0)
		return 1; /* error reading blocks */

	return 0;
}

int BootDeviceWriteLBA(uint64_t lba_start, uint64_t lba_count,
		const void *buffer)
{
	block_dev_desc_t *dev_desc;

	if ((dev_desc = bootdev_config.dev_desc) == NULL)
		return 1; /* No boot device configured */

	if (lba_start + lba_count > bootdev_config.limit)
		return 1; /* read out of range */

	if (dev_desc->block_write(dev_desc->dev,
				bootdev_config.offset + lba_start, lba_count,
				buffer) < 0)
		return 1; /* error reading blocks */

	return 0;
}