bootloader.cpp - android_bootable_recovery - Gitiles

 /*
  * 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>

 static char device_type = 'e'; // e for emmc or m for mtd, default is emmc
 static char device_name[256];

 /*
 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) {
     //volume_for_path("/misc");
     if (device_name[0] == 0) {
       LOGE("Cannot load volume /misc!\n");
       return -1;
     }
     if (device_type == 'm') {
         return get_bootloader_message_mtd_name(out);
     } else if (device_type == 'e') {
         return get_bootloader_message_block_name(out);
     }
     LOGE("unknown misc partition fs_type \"%c\"\n", device_type);
     return -1;
 }

 int set_bootloader_message(const struct bootloader_message *in) {
     //volume_for_path("/misc");
     if (device_name[0] == 0) {
       LOGE("Cannot load volume /misc!\n");
       return -1;
     }
     if (device_type == 'm') {
         return set_bootloader_message_mtd_name(in, device_name);
     } else if (device_type == 'e') {
         return set_bootloader_message_block_name(in, device_name);
     }
     LOGE("unknown misc partition type \"%c\"\n", device_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;
 }
 */

 void set_device_type(char new_type) {
 	device_type = new_type;
 }

 void set_device_name(const char* new_name) {
 	if (strlen(new_name) >= sizeof(device_name)) {
 		LOGE("New device name of '%s' is too large for bootloader.cpp\n", new_name);
 	} else {
 		strcpy(device_name, new_name);
 	}
 }

 int get_bootloader_message_mtd_name(struct bootloader_message *out) {
     size_t write_size;
     mtd_scan_partitions();
     const MtdPartition *part = mtd_find_partition_by_name(device_name);
     if (part == NULL || mtd_partition_info(part, NULL, NULL, &write_size)) {
         LOGE("Can't find %s\n", device_name);
         return -1;
     }

     MtdReadContext *read = mtd_read_partition(part);
     if (read == NULL) {
         LOGE("Can't open %s\n(%s)\n", device_name, 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", device_name, strerror(errno));
     mtd_read_close(read);
     if (r != size) return -1;

     memcpy(out, &data[write_size * MISC_COMMAND_PAGE], sizeof(*out));
     return 0;
 }

 int set_bootloader_message_mtd_name(const struct bootloader_message *in,
                                       const char* mtd_name) {
     size_t write_size;
     mtd_scan_partitions();
     const MtdPartition *part = mtd_find_partition_by_name(mtd_name);
     if (part == NULL || mtd_partition_info(part, NULL, NULL, &write_size)) {
         printf("Can't find %s\n", mtd_name);
         return -1;
     }

     MtdReadContext *read = mtd_read_partition(part);
     if (read == NULL) {
         printf("Can't open %s\n(%s)\n", mtd_name, 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) printf("Can't read %s\n(%s)\n", mtd_name, 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) {
         printf("Can't open %s\n(%s)\n", mtd_name, strerror(errno));
         return -1;
     }
     if (mtd_write_data(write, data, size) != size) {
         printf("Can't write %s\n(%s)\n", mtd_name, strerror(errno));
         mtd_write_close(write);
         return -1;
     }
     if (mtd_write_close(write)) {
         printf("Can't finish %s\n(%s)\n", mtd_name, strerror(errno));
         return -1;
     }

     printf("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;
 }
 */

 int get_bootloader_message_block_name(struct bootloader_message *out) {
     wait_for_device(device_name);
     FILE* f = fopen(device_name, "rb");
     if (f == NULL) {
         LOGE("Can't open %s\n(%s)\n", device_name, 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", device_name, strerror(errno));
         return -1;
     }
     if (fclose(f) != 0) {
         LOGE("Failed closing %s\n(%s)\n", device_name, strerror(errno));
         return -1;
     }
     memcpy(out, &temp, sizeof(temp));
     return 0;
 }

 int set_bootloader_message_block_name(const struct bootloader_message *in,
                                         const char* block_name) {
     wait_for_device(block_name);
     FILE* f = fopen(block_name, "rb+");
     if (f == NULL) {
         printf("Can't open %s\n(%s)\n", block_name, 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) {
         printf("Failed writing %s\n(%s)\n", block_name, strerror(errno));
         return -1;
     }
     if (fclose(f) != 0) {
         printf("Failed closing %s\n(%s)\n", block_name, 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", sizeof(boot.command), boot.command);
     }

     if (boot.status[0] != 0 && boot.status[0] != 255) {
         LOGI("Boot status: %.*s\n", 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 *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;
                 (*argv)[*argc] = strdup(strtok(buf, "\r\n"));  // Strip newline.
             }

             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);
 }
	/*
	* 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>

	static char device_type = 'e'; // e for emmc or m for mtd, default is emmc
	static char device_name[256];

	/*
	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) {
	//volume_for_path("/misc");
	if (device_name[0] == 0) {
	LOGE("Cannot load volume /misc!\n");
	return -1;
	}
	if (device_type == 'm') {
	return get_bootloader_message_mtd_name(out);
	} else if (device_type == 'e') {
	return get_bootloader_message_block_name(out);
	}
	LOGE("unknown misc partition fs_type \"%c\"\n", device_type);
	return -1;
	}

	int set_bootloader_message(const struct bootloader_message *in) {
	//volume_for_path("/misc");
	if (device_name[0] == 0) {
	LOGE("Cannot load volume /misc!\n");
	return -1;
	}
	if (device_type == 'm') {
	return set_bootloader_message_mtd_name(in, device_name);
	} else if (device_type == 'e') {
	return set_bootloader_message_block_name(in, device_name);
	}
	LOGE("unknown misc partition type \"%c\"\n", device_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;
	}
	*/

	void set_device_type(char new_type) {
	device_type = new_type;
	}

	void set_device_name(const char* new_name) {
	if (strlen(new_name) >= sizeof(device_name)) {
	LOGE("New device name of '%s' is too large for bootloader.cpp\n", new_name);
	} else {
	strcpy(device_name, new_name);
	}
	}

	int get_bootloader_message_mtd_name(struct bootloader_message *out) {
	size_t write_size;
	mtd_scan_partitions();
	const MtdPartition *part = mtd_find_partition_by_name(device_name);
	if (part == NULL \|\| mtd_partition_info(part, NULL, NULL, &write_size)) {
	LOGE("Can't find %s\n", device_name);
	return -1;
	}

	MtdReadContext *read = mtd_read_partition(part);
	if (read == NULL) {
	LOGE("Can't open %s\n(%s)\n", device_name, 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", device_name, strerror(errno));
	mtd_read_close(read);
	if (r != size) return -1;

	memcpy(out, &data[write_size * MISC_COMMAND_PAGE], sizeof(*out));
	return 0;
	}

	int set_bootloader_message_mtd_name(const struct bootloader_message *in,
	const char* mtd_name) {
	size_t write_size;
	mtd_scan_partitions();
	const MtdPartition *part = mtd_find_partition_by_name(mtd_name);
	if (part == NULL \|\| mtd_partition_info(part, NULL, NULL, &write_size)) {
	printf("Can't find %s\n", mtd_name);
	return -1;
	}

	MtdReadContext *read = mtd_read_partition(part);
	if (read == NULL) {
	printf("Can't open %s\n(%s)\n", mtd_name, 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) printf("Can't read %s\n(%s)\n", mtd_name, 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) {
	printf("Can't open %s\n(%s)\n", mtd_name, strerror(errno));
	return -1;
	}
	if (mtd_write_data(write, data, size) != size) {
	printf("Can't write %s\n(%s)\n", mtd_name, strerror(errno));
	mtd_write_close(write);
	return -1;
	}
	if (mtd_write_close(write)) {
	printf("Can't finish %s\n(%s)\n", mtd_name, strerror(errno));
	return -1;
	}

	printf("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;
	}
	*/

	int get_bootloader_message_block_name(struct bootloader_message *out) {
	wait_for_device(device_name);
	FILE* f = fopen(device_name, "rb");
	if (f == NULL) {
	LOGE("Can't open %s\n(%s)\n", device_name, 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", device_name, strerror(errno));
	return -1;
	}
	if (fclose(f) != 0) {
	LOGE("Failed closing %s\n(%s)\n", device_name, strerror(errno));
	return -1;
	}
	memcpy(out, &temp, sizeof(temp));
	return 0;
	}

	int set_bootloader_message_block_name(const struct bootloader_message *in,
	const char* block_name) {
	wait_for_device(block_name);
	FILE* f = fopen(block_name, "rb+");
	if (f == NULL) {
	printf("Can't open %s\n(%s)\n", block_name, 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) {
	printf("Failed writing %s\n(%s)\n", block_name, strerror(errno));
	return -1;
	}
	if (fclose(f) != 0) {
	printf("Failed closing %s\n(%s)\n", block_name, 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", sizeof(boot.command), boot.command);
	}

	if (boot.status[0] != 0 && boot.status[0] != 255) {
	LOGI("Boot status: %.*s\n", 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 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;
	(argv)[argc] = strdup(strtok(buf, "\r\n")); // Strip newline.
	}

	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);
	}