bootloader.c

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "bootloader.h"
#include "common.h"
#include "roots.h"
#include "ui.h"

#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>

static int get_bootloader_message_block(struct bootloader_message *out, const Volume* v);
static int set_bootloader_message_block(const struct bootloader_message *in, const Volume* v);

int get_bootloader_message(struct bootloader_message *out) 
{
	Volume* v = volume_for_path("/misc");
	if (v == NULL) 
	{
		LOGE("Cannot load volume /misc!\n");
		return -1;
	}
	if (strcmp(v->fs_type, "emmc") == 0)
		return get_bootloader_message_block(out, v);

	LOGE("unknown misc partition fs_type \"%s\"\n", v->fs_type);
	return -1;
}

int set_bootloader_message(const struct bootloader_message *in) 
{
	Volume* v = volume_for_path("/misc");
	if (v == NULL)
	{
		LOGE("Cannot load volume /misc!\n");
		return -1;
	}
	if (strcmp(v->fs_type, "emmc") == 0)
		return set_bootloader_message_block(in, v);

	LOGE("unknown misc partition fs_type \"%s\"\n", v->fs_type);
	return -1;
}

// ------------------------------------
// for misc partitions on block devices
// ------------------------------------

static void wait_for_device(const char* fn)
{
	int tries = 0;
	int ret;
	struct stat buf;
	do
	{
    ++tries;
    ret = stat(fn, &buf);
    if (ret)
    {
			printf("stat %s try %d: %s\n", fn, tries, strerror(errno));
			sleep(1);
    }
	} while (ret && tries < 10);

	if (ret)
		printf("failed to stat %s\n", fn);
}

static int get_bootloader_message_block(struct bootloader_message *out, const Volume* v)
{
	wait_for_device(v->device);
	FILE* f = fopen(v->device, "rb");
	
	if (f == NULL)
	{
	  LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
	  return -1;
	}
	struct bootloader_message temp;
	
	int count = fread(&temp, sizeof(temp), 1, f);
	if (count != 1)
	{
	  LOGE("Failed reading %s\n(%s)\n", v->device, strerror(errno));
	  return -1;
	}
	
	if (fclose(f) != 0)
	{
	  LOGE("Failed closing %s\n(%s)\n", v->device, strerror(errno));
	  return -1;
	}
	memcpy(out, &temp, sizeof(temp));
	return 0;
}

static int set_bootloader_message_block(const struct bootloader_message *in, const Volume* v)
{
	wait_for_device(v->device);
	FILE* f = fopen(v->device, "wb");
	if (f == NULL)
	{
		LOGE("Can't open %s\n(%s)\n", v->device, strerror(errno));
		return -1;
	}
	
	int count = fwrite(in, sizeof(*in), 1, f);
	if (count != 1)
	{
		LOGE("Failed writing %s\n(%s)\n", v->device, strerror(errno));
		return -1;
	}
	
	if (fclose(f) != 0)
	{
		LOGE("Failed closing %s\n(%s)\n", v->device, strerror(errno));
		return -1;
	}
	return 0;
}