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bootloader.cpp
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bootloader.cpp
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/*
* 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 <fs_mgr.h>
*/
#include "bootloader.h"
#include "common.h"
extern "C" {
#include "mtdutils/mtdutils.h"
}
/*
#include "roots.h"
*/
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdlib.h>
// fake Volume struct that allows us to use the AOSP code easily
struct Volume
{
char fs_type[8];
char blk_device[256];
};
static Volume misc;
void set_misc_device(const char* type, const char* name) {
strlcpy(misc.fs_type, type, sizeof(misc.fs_type));
if (strlen(name) >= sizeof(misc.blk_device)) {
LOGE("New device name of '%s' is too large for bootloader.cpp\n", name);
} else {
strcpy(misc.blk_device, name);
}
}
static int get_bootloader_message_mtd(struct bootloader_message *out, const Volume* v);
static int set_bootloader_message_mtd(const struct bootloader_message *in, const Volume* v);
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) {
#if 0
Volume* v = volume_for_path("/misc");
if (v == NULL) {
LOGE("Cannot load volume /misc!\n");
return -1;
}
#else
Volume* v = &misc;
if (v->fs_type[0] == 0) {
LOGI("Not using /misc, not defined in fstab.\n");
return -1;
}
#endif
if (strcmp(v->fs_type, "mtd") == 0) {
return get_bootloader_message_mtd(out, v);
} else 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) {
#if 0
Volume* v = volume_for_path("/misc");
if (v == NULL) {
LOGE("Cannot load volume /misc!\n");
return -1;
}
#else
Volume* v = &misc;
if (v->fs_type[0] == 0) {
LOGI("Not using /misc, not defined in fstab.\n");
return -1;
}
#endif
if (strcmp(v->fs_type, "mtd") == 0) {
return set_bootloader_message_mtd(in, v);
} else 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 MTD
// ------------------------------
static const int MISC_PAGES = 3; // number of pages to save
static const int MISC_COMMAND_PAGE = 1; // bootloader command is this page
static int get_bootloader_message_mtd(struct bootloader_message *out,
const Volume* v) {
size_t write_size;
mtd_scan_partitions();
const MtdPartition *part = mtd_find_partition_by_name(v->blk_device);
if (part == NULL || mtd_partition_info(part, NULL, NULL, &write_size)) {
LOGE("Can't find %s\n", v->blk_device);
return -1;
}
MtdReadContext *read = mtd_read_partition(part);
if (read == NULL) {
LOGE("Can't open %s\n(%s)\n", v->blk_device, strerror(errno));
return -1;
}
const ssize_t size = write_size * MISC_PAGES;
char data[size];
ssize_t r = mtd_read_data(read, data, size);
if (r != size) LOGE("Can't read %s\n(%s)\n", v->blk_device, strerror(errno));
mtd_read_close(read);
if (r != size) return -1;
memcpy(out, &data[write_size * MISC_COMMAND_PAGE], sizeof(*out));
return 0;
}
static int set_bootloader_message_mtd(const struct bootloader_message *in,
const Volume* v) {
size_t write_size;
mtd_scan_partitions();
const MtdPartition *part = mtd_find_partition_by_name(v->blk_device);
if (part == NULL || mtd_partition_info(part, NULL, NULL, &write_size)) {
LOGE("Can't find %s\n", v->blk_device);
return -1;
}
MtdReadContext *read = mtd_read_partition(part);
if (read == NULL) {
LOGE("Can't open %s\n(%s)\n", v->blk_device, strerror(errno));
return -1;
}
ssize_t size = write_size * MISC_PAGES;
char data[size];
ssize_t r = mtd_read_data(read, data, size);
if (r != size) LOGE("Can't read %s\n(%s)\n", v->blk_device, strerror(errno));
mtd_read_close(read);
if (r != size) return -1;
memcpy(&data[write_size * MISC_COMMAND_PAGE], in, sizeof(*in));
MtdWriteContext *write = mtd_write_partition(part);
if (write == NULL) {
LOGE("Can't open %s\n(%s)\n", v->blk_device, strerror(errno));
return -1;
}
if (mtd_write_data(write, data, size) != size) {
LOGE("Can't write %s\n(%s)\n", v->blk_device, strerror(errno));
mtd_write_close(write);
return -1;
}
if (mtd_write_close(write)) {
LOGE("Can't finish %s\n(%s)\n", v->blk_device, strerror(errno));
return -1;
}
LOGI("Set boot command \"%s\"\n", in->command[0] != 255 ? in->command : "");
return 0;
}
// ------------------------------------
// 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->blk_device);
FILE* f = fopen(v->blk_device, "rb");
if (f == NULL) {
LOGE("Can't open %s\n(%s)\n", v->blk_device, strerror(errno));
return -1;
}
#ifdef BOARD_RECOVERY_BLDRMSG_OFFSET
fseek(f, BOARD_RECOVERY_BLDRMSG_OFFSET, SEEK_SET);
#endif
struct bootloader_message temp;
int count = fread(&temp, sizeof(temp), 1, f);
if (count != 1) {
LOGE("Failed reading %s\n(%s)\n", v->blk_device, strerror(errno));
return -1;
}
if (fclose(f) != 0) {
LOGE("Failed closing %s\n(%s)\n", v->blk_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->blk_device);
FILE* f = fopen(v->blk_device, "rb+");
if (f == NULL) {
LOGE("Can't open %s\n(%s)\n", v->blk_device, strerror(errno));
return -1;
}
#ifdef BOARD_RECOVERY_BLDRMSG_OFFSET
fseek(f, BOARD_RECOVERY_BLDRMSG_OFFSET, SEEK_SET);
#endif
int count = fwrite(in, sizeof(*in), 1, f);
if (count != 1) {
LOGE("Failed writing %s\n(%s)\n", v->blk_device, strerror(errno));
return -1;
}
if (fclose(f) != 0) {
LOGE("Failed closing %s\n(%s)\n", v->blk_device, strerror(errno));
return -1;
}
return 0;
}
static const char *COMMAND_FILE = "/cache/recovery/command";
static const int MAX_ARG_LENGTH = 4096;
static const int MAX_ARGS = 100;
// command line args come from, in decreasing precedence:
// - the actual command line
// - the bootloader control block (one per line, after "recovery")
// - the contents of COMMAND_FILE (one per line)
void
get_args(int *argc, char ***argv) {
struct bootloader_message boot;
memset(&boot, 0, sizeof(boot));
get_bootloader_message(&boot); // this may fail, leaving a zeroed structure
if (boot.command[0] != 0 && boot.command[0] != 255) {
LOGI("Boot command: %.*s\n", (int)sizeof(boot.command), boot.command);
}
if (boot.status[0] != 0 && boot.status[0] != 255) {
LOGI("Boot status: %.*s\n", (int)sizeof(boot.status), boot.status);
}
// --- if arguments weren't supplied, look in the bootloader control block
if (*argc <= 1) {
boot.recovery[sizeof(boot.recovery) - 1] = '\0'; // Ensure termination
const char *arg = strtok(boot.recovery, "\n");
if (arg != NULL && !strcmp(arg, "recovery")) {
*argv = (char **) malloc(sizeof(char *) * MAX_ARGS);
(*argv)[0] = strdup(arg);
for (*argc = 1; *argc < MAX_ARGS; ++*argc) {
if ((arg = strtok(NULL, "\n")) == NULL) break;
(*argv)[*argc] = strdup(arg);
}
LOGI("Got arguments from boot message\n");
} else if (boot.recovery[0] != 0 && boot.recovery[0] != 255) {
LOGE("Bad boot message\n\"%.20s\"\n", boot.recovery);
}
}
// --- if that doesn't work, try the command file
if (*argc <= 1) {
FILE *fp = fopen(COMMAND_FILE, "r");
if (fp != NULL) {
char *token;
char *argv0 = (*argv)[0];
*argv = (char **) malloc(sizeof(char *) * MAX_ARGS);
(*argv)[0] = argv0; // use the same program name
char buf[MAX_ARG_LENGTH];
for (*argc = 1; *argc < MAX_ARGS; ++*argc) {
if (!fgets(buf, sizeof(buf), fp)) break;
token = strtok(buf, "\r\n");
if (token != NULL) {
(*argv)[*argc] = strdup(token); // Strip newline.
} else {
--*argc;
}
}
fflush(fp);
if (ferror(fp)) LOGE("Error in %s\n(%s)\n", COMMAND_FILE, strerror(errno));
fclose(fp);
LOGI("Got arguments from %s\n", COMMAND_FILE);
}
}
// --> write the arguments we have back into the bootloader control block
// always boot into recovery after this (until finish_recovery() is called)
strlcpy(boot.command, "boot-recovery", sizeof(boot.command));
strlcpy(boot.recovery, "recovery\n", sizeof(boot.recovery));
int i;
for (i = 1; i < *argc; ++i) {
strlcat(boot.recovery, (*argv)[i], sizeof(boot.recovery));
strlcat(boot.recovery, "\n", sizeof(boot.recovery));
}
set_bootloader_message(&boot);
}