bootloader_message_twrp/bootloader_message.cpp - android_bootable_recovery - Gitiles

 /*
  * Copyright (C) 2016 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_message_twrp/bootloader_message.h>

 #include <errno.h>
 #include <fcntl.h>
 #include <string.h>
 #include <stdlib.h>
 #include <sys/stat.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/system_properties.h>

 #include <string>
 #include <vector>

 static std::string misc_blkdev;

 void set_misc_device(const char* name) {
     misc_blkdev = name;
 }

 static std::string get_misc_blk_device(std::string* err) {
   *err = "";
   return misc_blkdev;
 }

 // In recovery mode, recovery can get started and try to access the misc
 // device before the kernel has actually created it.
 static bool wait_for_device(const std::string& blk_device, std::string* err) {
   int tries = 0;
   int ret;
   err->clear();
   do {
     ++tries;
     struct stat buf;
     ret = stat(blk_device.c_str(), &buf);
     if (ret == -1) {
       char buffer[2048];
       sprintf(buffer, "failed to stat %s try %d: %s\n",
                                           blk_device.c_str(), tries, strerror(errno));
       *err += buffer;
       /*
       *err += android::base::StringPrintf("failed to stat %s try %d: %s\n",
                                           blk_device.c_str(), tries, strerror(errno));
       */
       sleep(1);
     }
   } while (ret && tries < 10);

   if (ret) {
     *err += "failed to stat " + blk_device + "\n";
     /*
     *err += android::base::StringPrintf("failed to stat %s\n", blk_device.c_str());
     */
   }
   return ret == 0;
 }

 static bool read_misc_partition(void* p, size_t size, const std::string& misc_blk_device,
                                 size_t offset, std::string* err) {
   if (!wait_for_device(misc_blk_device, err)) {
     return false;
   }

   int fd(open(misc_blk_device.c_str(), O_RDONLY));
   if (fd < 0) {
     *err = "failed to open " + misc_blk_device + ": ";
     *err += strerror(errno);
     /*
   android::base::unique_fd fd(open(misc_blk_device.c_str(), O_RDONLY));
   if (fd == -1) {
     *err = android::base::StringPrintf("failed to open %s: %s", misc_blk_device.c_str(),
                                        strerror(errno));
     */
     return false;
   }
   if (lseek(fd, static_cast<off_t>(offset), SEEK_SET) != static_cast<off_t>(offset)) {
     *err = "failed to lseek " + misc_blk_device + ": ";
     *err += strerror(errno);
     close(fd);
     /*

     *err = android::base::StringPrintf("failed to lseek %s: %s", misc_blk_device.c_str(),
                                        strerror(errno));
     */
     return false;
   }

   if ((size_t)read(fd, p, size) != size) {
     *err = "failed to read " + misc_blk_device + ": ";
     *err += strerror(errno);
     close(fd);
     /*
   if (!android::base::ReadFully(fd, p, size)) {
     *err = android::base::StringPrintf("failed to read %s: %s", misc_blk_device.c_str(),
                                        strerror(errno));
     */
     return false;
   }
   close(fd);
   return true;
 }

 static bool write_misc_partition(const void* p, size_t size, size_t offset, std::string* err) {
   std::string misc_blk_device = get_misc_blk_device(err);
   if (misc_blk_device.empty()) {
     *err = "no misc device set";
     return false;
   }
   int fd = (open(misc_blk_device.c_str(), O_WRONLY | O_SYNC));
   if (fd == -1) {
     *err = "failed to open " + misc_blk_device + ": ";
     *err += strerror(errno);
     /*
 static bool write_misc_partition(const void* p, size_t size, const std::string& misc_blk_device,
                                  size_t offset, std::string* err) {
   android::base::unique_fd fd(open(misc_blk_device.c_str(), O_WRONLY));
   if (fd == -1) {
     *err = android::base::StringPrintf("failed to open %s: %s", misc_blk_device.c_str(),
                                        strerror(errno));
     */
     return false;
   }
   if (lseek(fd, static_cast<off_t>(offset), SEEK_SET) != static_cast<off_t>(offset)) {
     *err = "failed to lseek " + misc_blk_device + ": ";
     *err += strerror(errno);
     close(fd);
     /*
     *err = android::base::StringPrintf("failed to lseek %s: %s", misc_blk_device.c_str(),
                                        strerror(errno));
     */
     return false;
   }
   if ((size_t)write(fd, p, size) != size) {
     *err = "failed to write " + misc_blk_device + ": ";
     *err += strerror(errno);
     close(fd);
     /*
   if (!android::base::WriteFully(fd, p, size)) {
     *err = android::base::StringPrintf("failed to write %s: %s", misc_blk_device.c_str(),
                                        strerror(errno));
     */
     return false;
   }

   // TODO: O_SYNC and fsync duplicates each other?
   if (fsync(fd) == -1) {
     *err = "failed to fsync " + misc_blk_device + ": ";
     *err += strerror(errno);
     close(fd);
     /*
   if (fsync(fd) == -1) {
     *err = android::base::StringPrintf("failed to fsync %s: %s", misc_blk_device.c_str(),
                                        strerror(errno));
     */
     return false;
   }
   close(fd);
   return true;
 }

 bool read_bootloader_message_from(bootloader_message* boot, const std::string& misc_blk_device,
                                   std::string* err) {
   return read_misc_partition(boot, sizeof(*boot), misc_blk_device,
                              BOOTLOADER_MESSAGE_OFFSET_IN_MISC, err);
 }

 bool read_bootloader_message(bootloader_message* boot, std::string* err) {
   std::string misc_blk_device = get_misc_blk_device(err);
   if (misc_blk_device.empty()) {
     return false;
   }
   return read_bootloader_message_from(boot, misc_blk_device, err);
 }

 bool write_bootloader_message_to(const bootloader_message& boot, __unused const std::string& misc_blk_device,
                                  std::string* err) {
   return write_misc_partition(&boot, sizeof(boot),
                               BOOTLOADER_MESSAGE_OFFSET_IN_MISC, err);
 }

 bool write_bootloader_message(const bootloader_message& boot, std::string* err) {
   std::string misc_blk_device = get_misc_blk_device(err);
   if (misc_blk_device.empty()) {
     return false;
   }
   return write_bootloader_message_to(boot, misc_blk_device, err);
 }

 // libc++ in 5.1 does not know how to handle a std::string* so this craziness is needed
 bool clear_bootloader_message(void* err) {
   std::string &s = *(static_cast<std::string*>(err));
   return clear_bootloader_message(&s);
 }

 bool clear_bootloader_message(std::string* err) {
   bootloader_message boot = {};
   return write_bootloader_message(boot, err);
 }

 bool write_bootloader_message(const std::vector<std::string>& options, std::string* err) {
   bootloader_message boot = {};
   strlcpy(boot.command, "boot-recovery", sizeof(boot.command));
   strlcpy(boot.recovery, "recovery\n", sizeof(boot.recovery));
   for (const auto& s : options) {
     strlcat(boot.recovery, s.c_str(), sizeof(boot.recovery));
     if (s.substr(s.size() - 1) != "\n") {
       strlcat(boot.recovery, "\n", sizeof(boot.recovery));
     }
   }
   return write_bootloader_message(boot, err);
 }

 bool update_bootloader_message(const std::vector<std::string>& options, std::string* err) {
   bootloader_message boot;
   if (!read_bootloader_message(&boot, err)) {
     return false;
   }

   // Zero out the entire fields.
   memset(boot.command, 0, sizeof(boot.command));
   memset(boot.recovery, 0, sizeof(boot.recovery));

   strlcpy(boot.command, "boot-recovery", sizeof(boot.command));
   strlcpy(boot.recovery, "recovery\n", sizeof(boot.recovery));
   for (const auto& s : options) {
     strlcat(boot.recovery, s.c_str(), sizeof(boot.recovery));
     if (s.back() != '\n') {
       strlcat(boot.recovery, "\n", sizeof(boot.recovery));
     }
   }
   return write_bootloader_message(boot, err);
 }

 bool write_reboot_bootloader(std::string* err) {
   bootloader_message boot;
   if (!read_bootloader_message(&boot, err)) {
     return false;
   }
   if (boot.command[0] != '\0') {
     *err = "Bootloader command pending.";
     return false;
   }
   strlcpy(boot.command, "bootonce-bootloader", sizeof(boot.command));
   return write_bootloader_message(boot, err);
 }

 bool read_wipe_package(std::string* package_data, size_t size, std::string* err) {
   std::string misc_blk_device = get_misc_blk_device(err);
   if (misc_blk_device.empty()) {
     return false;
   }
   package_data->resize(size);
   return read_misc_partition(&(*package_data)[0], size, misc_blk_device,
                              WIPE_PACKAGE_OFFSET_IN_MISC, err);
 }

 bool write_wipe_package(const std::string& package_data, std::string* err) {
   std::string misc_blk_device = get_misc_blk_device(err);
   if (misc_blk_device.empty()) {
     return false;
   }
   return write_misc_partition(package_data.data(), package_data.size(),
                               WIPE_PACKAGE_OFFSET_IN_MISC, err);
 }

 extern "C" bool write_reboot_bootloader(void) {
   std::string err;
   return write_reboot_bootloader(&err);
 }

 extern "C" bool write_bootloader_message(const char* options) {
   std::string err;
   bootloader_message boot = {};
   memcpy(&boot, options, sizeof(boot));
   return write_bootloader_message(boot, &err);
 }

 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) {
     bootloader_message boot = {};
     std::string err;
     if (!read_bootloader_message(&boot, &err)) {
         printf("%s\n", err.c_str());
         // If fails, leave a zeroed bootloader_message.
         memset(&boot, 0, sizeof(boot));
     }
     //stage = strndup(boot.stage, sizeof(boot.stage));

     if (boot.command[0] != 0 && boot.command[0] != (char)255) {
         printf("Boot command: %.*s\n", (int)sizeof(boot.command), boot.command);
     }

     if (boot.status[0] != 0 && boot.status[0] != (char)255) {
         printf("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;

 // if the device does not have an own recovery key combo we just want to open TWRP after
 // walking through the factory reset screen - without actually doing a factory reset
 #ifdef IGNORE_MISC_WIPE_DATA
                 if (!strcmp(arg, "--wipe_data")) {
                     (*argv)[*argc] = NULL;
                     *argc = *argc -1;
                     printf("Bootloader arg \"%s\" ignored because TWRP was compiled with TW_IGNORE_MISC_WIPE_DATA\n", arg);
                     continue;
                 }
 #endif
                 (*argv)[*argc] = strdup(arg);
             }
             printf("Got arguments from boot message\n");
         } else if (boot.recovery[0] != 0 && boot.recovery[0] != (char)255) {
             printf("Bad boot message\n\"%.20s\"\n", boot.recovery);
         }
     }

     // --- if that doesn't work, try the command file (if we have /cache).
     if (*argc <= 1/* && has_cache*/) {
         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;
                 }
             }

             fclose(fp);
             printf("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));
     }
     if (!write_bootloader_message(boot, &err)) {
         printf("%s\n", err.c_str());
     }
 }
	/*
	* Copyright (C) 2016 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_message_twrp/bootloader_message.h>

	#include <errno.h>
	#include <fcntl.h>
	#include <string.h>
	#include <stdlib.h>
	#include <sys/stat.h>
	#include <unistd.h>
	#include <sys/types.h>
	#include <sys/system_properties.h>

	#include <string>
	#include <vector>

	static std::string misc_blkdev;

	void set_misc_device(const char* name) {
	misc_blkdev = name;
	}

	static std::string get_misc_blk_device(std::string* err) {
	*err = "";
	return misc_blkdev;
	}

	// In recovery mode, recovery can get started and try to access the misc
	// device before the kernel has actually created it.
	static bool wait_for_device(const std::string& blk_device, std::string* err) {
	int tries = 0;
	int ret;
	err->clear();
	do {
	++tries;
	struct stat buf;
	ret = stat(blk_device.c_str(), &buf);
	if (ret == -1) {
	char buffer[2048];
	sprintf(buffer, "failed to stat %s try %d: %s\n",
	blk_device.c_str(), tries, strerror(errno));
	*err += buffer;
	/*
	*err += android::base::StringPrintf("failed to stat %s try %d: %s\n",
	blk_device.c_str(), tries, strerror(errno));
	*/
	sleep(1);
	}
	} while (ret && tries < 10);

	if (ret) {
	*err += "failed to stat " + blk_device + "\n";
	/*
	*err += android::base::StringPrintf("failed to stat %s\n", blk_device.c_str());
	*/
	}
	return ret == 0;
	}

	static bool read_misc_partition(void* p, size_t size, const std::string& misc_blk_device,
	size_t offset, std::string* err) {
	if (!wait_for_device(misc_blk_device, err)) {
	return false;
	}

	int fd(open(misc_blk_device.c_str(), O_RDONLY));
	if (fd < 0) {
	*err = "failed to open " + misc_blk_device + ": ";
	*err += strerror(errno);
	/*
	android::base::unique_fd fd(open(misc_blk_device.c_str(), O_RDONLY));
	if (fd == -1) {
	*err = android::base::StringPrintf("failed to open %s: %s", misc_blk_device.c_str(),
	strerror(errno));
	*/
	return false;
	}
	if (lseek(fd, static_cast<off_t>(offset), SEEK_SET) != static_cast<off_t>(offset)) {
	*err = "failed to lseek " + misc_blk_device + ": ";
	*err += strerror(errno);
	close(fd);
	/*

	*err = android::base::StringPrintf("failed to lseek %s: %s", misc_blk_device.c_str(),
	strerror(errno));
	*/
	return false;
	}

	if ((size_t)read(fd, p, size) != size) {
	*err = "failed to read " + misc_blk_device + ": ";
	*err += strerror(errno);
	close(fd);
	/*
	if (!android::base::ReadFully(fd, p, size)) {
	*err = android::base::StringPrintf("failed to read %s: %s", misc_blk_device.c_str(),
	strerror(errno));
	*/
	return false;
	}
	close(fd);
	return true;
	}

	static bool write_misc_partition(const void* p, size_t size, size_t offset, std::string* err) {
	std::string misc_blk_device = get_misc_blk_device(err);
	if (misc_blk_device.empty()) {
	*err = "no misc device set";
	return false;
	}
	int fd = (open(misc_blk_device.c_str(), O_WRONLY \| O_SYNC));
	if (fd == -1) {
	*err = "failed to open " + misc_blk_device + ": ";
	*err += strerror(errno);
	/*
	static bool write_misc_partition(const void* p, size_t size, const std::string& misc_blk_device,
	size_t offset, std::string* err) {
	android::base::unique_fd fd(open(misc_blk_device.c_str(), O_WRONLY));
	if (fd == -1) {
	*err = android::base::StringPrintf("failed to open %s: %s", misc_blk_device.c_str(),
	strerror(errno));
	*/
	return false;
	}
	if (lseek(fd, static_cast<off_t>(offset), SEEK_SET) != static_cast<off_t>(offset)) {
	*err = "failed to lseek " + misc_blk_device + ": ";
	*err += strerror(errno);
	close(fd);
	/*
	*err = android::base::StringPrintf("failed to lseek %s: %s", misc_blk_device.c_str(),
	strerror(errno));
	*/
	return false;
	}
	if ((size_t)write(fd, p, size) != size) {
	*err = "failed to write " + misc_blk_device + ": ";
	*err += strerror(errno);
	close(fd);
	/*
	if (!android::base::WriteFully(fd, p, size)) {
	*err = android::base::StringPrintf("failed to write %s: %s", misc_blk_device.c_str(),
	strerror(errno));
	*/
	return false;
	}

	// TODO: O_SYNC and fsync duplicates each other?
	if (fsync(fd) == -1) {
	*err = "failed to fsync " + misc_blk_device + ": ";
	*err += strerror(errno);
	close(fd);
	/*
	if (fsync(fd) == -1) {
	*err = android::base::StringPrintf("failed to fsync %s: %s", misc_blk_device.c_str(),
	strerror(errno));
	*/
	return false;
	}
	close(fd);
	return true;
	}

	bool read_bootloader_message_from(bootloader_message* boot, const std::string& misc_blk_device,
	std::string* err) {
	return read_misc_partition(boot, sizeof(*boot), misc_blk_device,
	BOOTLOADER_MESSAGE_OFFSET_IN_MISC, err);
	}

	bool read_bootloader_message(bootloader_message* boot, std::string* err) {
	std::string misc_blk_device = get_misc_blk_device(err);
	if (misc_blk_device.empty()) {
	return false;
	}
	return read_bootloader_message_from(boot, misc_blk_device, err);
	}

	bool write_bootloader_message_to(const bootloader_message& boot, __unused const std::string& misc_blk_device,
	std::string* err) {
	return write_misc_partition(&boot, sizeof(boot),
	BOOTLOADER_MESSAGE_OFFSET_IN_MISC, err);
	}

	bool write_bootloader_message(const bootloader_message& boot, std::string* err) {
	std::string misc_blk_device = get_misc_blk_device(err);
	if (misc_blk_device.empty()) {
	return false;
	}
	return write_bootloader_message_to(boot, misc_blk_device, err);
	}

	// libc++ in 5.1 does not know how to handle a std::string* so this craziness is needed
	bool clear_bootloader_message(void* err) {
	std::string &s = (static_cast<std::string>(err));
	return clear_bootloader_message(&s);
	}

	bool clear_bootloader_message(std::string* err) {
	bootloader_message boot = {};
	return write_bootloader_message(boot, err);
	}

	bool write_bootloader_message(const std::vector<std::string>& options, std::string* err) {
	bootloader_message boot = {};
	strlcpy(boot.command, "boot-recovery", sizeof(boot.command));
	strlcpy(boot.recovery, "recovery\n", sizeof(boot.recovery));
	for (const auto& s : options) {
	strlcat(boot.recovery, s.c_str(), sizeof(boot.recovery));
	if (s.substr(s.size() - 1) != "\n") {
	strlcat(boot.recovery, "\n", sizeof(boot.recovery));
	}
	}
	return write_bootloader_message(boot, err);
	}

	bool update_bootloader_message(const std::vector<std::string>& options, std::string* err) {
	bootloader_message boot;
	if (!read_bootloader_message(&boot, err)) {
	return false;
	}

	// Zero out the entire fields.
	memset(boot.command, 0, sizeof(boot.command));
	memset(boot.recovery, 0, sizeof(boot.recovery));

	strlcpy(boot.command, "boot-recovery", sizeof(boot.command));
	strlcpy(boot.recovery, "recovery\n", sizeof(boot.recovery));
	for (const auto& s : options) {
	strlcat(boot.recovery, s.c_str(), sizeof(boot.recovery));
	if (s.back() != '\n') {
	strlcat(boot.recovery, "\n", sizeof(boot.recovery));
	}
	}
	return write_bootloader_message(boot, err);
	}

	bool write_reboot_bootloader(std::string* err) {
	bootloader_message boot;
	if (!read_bootloader_message(&boot, err)) {
	return false;
	}
	if (boot.command[0] != '\0') {
	*err = "Bootloader command pending.";
	return false;
	}
	strlcpy(boot.command, "bootonce-bootloader", sizeof(boot.command));
	return write_bootloader_message(boot, err);
	}

	bool read_wipe_package(std::string* package_data, size_t size, std::string* err) {
	std::string misc_blk_device = get_misc_blk_device(err);
	if (misc_blk_device.empty()) {
	return false;
	}
	package_data->resize(size);
	return read_misc_partition(&(*package_data)[0], size, misc_blk_device,
	WIPE_PACKAGE_OFFSET_IN_MISC, err);
	}

	bool write_wipe_package(const std::string& package_data, std::string* err) {
	std::string misc_blk_device = get_misc_blk_device(err);
	if (misc_blk_device.empty()) {
	return false;
	}
	return write_misc_partition(package_data.data(), package_data.size(),
	WIPE_PACKAGE_OFFSET_IN_MISC, err);
	}

	extern "C" bool write_reboot_bootloader(void) {
	std::string err;
	return write_reboot_bootloader(&err);
	}

	extern "C" bool write_bootloader_message(const char* options) {
	std::string err;
	bootloader_message boot = {};
	memcpy(&boot, options, sizeof(boot));
	return write_bootloader_message(boot, &err);
	}

	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) {
	bootloader_message boot = {};
	std::string err;
	if (!read_bootloader_message(&boot, &err)) {
	printf("%s\n", err.c_str());
	// If fails, leave a zeroed bootloader_message.
	memset(&boot, 0, sizeof(boot));
	}
	//stage = strndup(boot.stage, sizeof(boot.stage));

	if (boot.command[0] != 0 && boot.command[0] != (char)255) {
	printf("Boot command: %.*s\n", (int)sizeof(boot.command), boot.command);
	}

	if (boot.status[0] != 0 && boot.status[0] != (char)255) {
	printf("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;

	// if the device does not have an own recovery key combo we just want to open TWRP after
	// walking through the factory reset screen - without actually doing a factory reset
	#ifdef IGNORE_MISC_WIPE_DATA
	if (!strcmp(arg, "--wipe_data")) {
	(argv)[argc] = NULL;
	argc = argc -1;
	printf("Bootloader arg \"%s\" ignored because TWRP was compiled with TW_IGNORE_MISC_WIPE_DATA\n", arg);
	continue;
	}
	#endif
	(argv)[argc] = strdup(arg);
	}
	printf("Got arguments from boot message\n");
	} else if (boot.recovery[0] != 0 && boot.recovery[0] != (char)255) {
	printf("Bad boot message\n\"%.20s\"\n", boot.recovery);
	}
	}

	// --- if that doesn't work, try the command file (if we have /cache).
	if (argc <= 1/ && has_cache*/) {
	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;
	}
	}

	fclose(fp);
	printf("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));
	}
	if (!write_bootloader_message(boot, &err)) {
	printf("%s\n", err.c_str());
	}
	}