host/commands/assemble_cvd/boot_image_utils.cc - device/google/cuttlefish - Git at Google

 /*
  * Copyright (C) 2020 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 "host/commands/assemble_cvd/boot_image_utils.h"
 #include "host/libs/config/cuttlefish_config.h"

 #include <string.h>
 #include <unistd.h>

 #include <fstream>
 #include <sstream>

 #include <android-base/logging.h>
 #include <android-base/strings.h>

 #include "common/libs/utils/files.h"
 #include "common/libs/utils/subprocess.h"

 const char TMP_EXTENSION[] = ".tmp";
 const char CPIO_EXT[] = ".cpio";
 const char TMP_RD_DIR[] = "stripped_ramdisk_dir";
 const char STRIPPED_RD[] = "stripped_ramdisk";
 const char CONCATENATED_VENDOR_RAMDISK[] = "concatenated_vendor_ramdisk";
 namespace cuttlefish {
 namespace {
 std::string ExtractValue(const std::string& dictionary, const std::string& key) {
   std::size_t index = dictionary.find(key);
   if (index != std::string::npos) {
     std::size_t end_index = dictionary.find('\n', index + key.length());
     if (end_index != std::string::npos) {
       return dictionary.substr(index + key.length(),
           end_index - index - key.length());
     }
   }
   return "";
 }

 // Though it is just as fast to overwrite the existing boot images with the newly generated ones,
 // the cuttlefish composite disk generator checks the age of each of the components and
 // regenerates the disk outright IF any one of the components is younger/newer than the current
 // composite disk. If this file overwrite occurs, that condition is fulfilled. This action then
 // causes data in the userdata partition from previous boots to be lost (which is not expected by
 // the user if they've been booting the same kernel/ramdisk combination repeatedly).
 // Consequently, the file is checked for differences and ONLY overwritten if there is a diff.
 bool DeleteTmpFileIfNotChanged(const std::string& tmp_file, const std::string& current_file) {
   if (!FileExists(current_file) ||
       ReadFile(current_file) != ReadFile(tmp_file)) {
     if (!RenameFile(tmp_file, current_file)) {
       LOG(ERROR) << "Unable to delete " << current_file;
       return false;
     }
     LOG(DEBUG) << "Updated " << current_file;
   } else {
     LOG(DEBUG) << "Didn't update " << current_file;
     RemoveFile(tmp_file);
   }

   return true;
 }

 bool UnpackBootImage(const std::string& boot_image_path,
                      const std::string& unpack_dir) {
   auto unpack_path = HostBinaryPath("unpack_bootimg");
   Command unpack_cmd(unpack_path);
   unpack_cmd.AddParameter("--boot_img");
   unpack_cmd.AddParameter(boot_image_path);
   unpack_cmd.AddParameter("--out");
   unpack_cmd.AddParameter(unpack_dir);

   auto output_file = SharedFD::Creat(unpack_dir + "/boot_params", 0666);
   if (!output_file->IsOpen()) {
     LOG(ERROR) << "Unable to create intermediate boot params file: "
                << output_file->StrError();
     return false;
   }
   unpack_cmd.RedirectStdIO(Subprocess::StdIOChannel::kStdOut, output_file);

   int success = unpack_cmd.Start().Wait();
   if (success != 0) {
     LOG(ERROR) << "Unable to run unpack_bootimg. Exited with status "
                << success;
     return false;
   }
   return true;
 }

 void RepackVendorRamdisk(const std::string& kernel_modules_ramdisk_path,
                          const std::string& original_ramdisk_path,
                          const std::string& new_ramdisk_path,
                          const std::string& build_dir) {
   int success = execute({"/bin/bash", "-c", HostBinaryPath("lz4") + " -c -d -l " +
                         original_ramdisk_path + " > " + original_ramdisk_path + CPIO_EXT});
   CHECK(success == 0) << "Unable to run lz4. Exited with status " << success;

   const std::string ramdisk_stage_dir = build_dir + "/" + TMP_RD_DIR;
   success =
       mkdir(ramdisk_stage_dir.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
   CHECK(success == 0) << "Could not mkdir \"" << ramdisk_stage_dir
                       << "\", error was " << strerror(errno);

   success = execute(
       {"/bin/bash", "-c",
        "(cd " + ramdisk_stage_dir + " && while " + HostBinaryPath("toybox") +
            " cpio -idu; do :; done) < " + original_ramdisk_path + CPIO_EXT});
   CHECK(success == 0) << "Unable to run cd or cpio. Exited with status "
                       << success;

   success = execute({"rm", "-rf", ramdisk_stage_dir + "/lib/modules"});
   CHECK(success == 0) << "Could not rmdir \"lib/modules\" in TMP_RD_DIR. "
                       << "Exited with status " << success;

   const std::string stripped_ramdisk_path = build_dir + "/" + STRIPPED_RD;
   success = execute({"/bin/bash", "-c",
                      HostBinaryPath("mkbootfs") + " " + ramdisk_stage_dir +
                          " > " + stripped_ramdisk_path + CPIO_EXT});
   CHECK(success == 0) << "Unable to run cd or cpio. Exited with status "
                       << success;

   success = execute({"/bin/bash", "-c", HostBinaryPath("lz4") +
                      " -c -l -12 --favor-decSpeed " + stripped_ramdisk_path + CPIO_EXT + " > " +
                      stripped_ramdisk_path});
   CHECK(success == 0) << "Unable to run lz4. Exited with status " << success;

   // Concatenates the stripped ramdisk and input ramdisk and places the result at new_ramdisk_path
   std::ofstream final_rd(new_ramdisk_path, std::ios_base::binary | std::ios_base::trunc);
   std::ifstream ramdisk_a(stripped_ramdisk_path, std::ios_base::binary);
   std::ifstream ramdisk_b(kernel_modules_ramdisk_path, std::ios_base::binary);
   final_rd << ramdisk_a.rdbuf() << ramdisk_b.rdbuf();
 }

 bool UnpackVendorBootImageIfNotUnpacked(
     const std::string& vendor_boot_image_path, const std::string& unpack_dir) {
   // the vendor boot params file is created during the first unpack. If it's
   // already there, a unpack has occurred and there's no need to repeat the
   // process.
   if (FileExists(unpack_dir + "/vendor_boot_params")) {
     return true;
   }

   auto unpack_path = HostBinaryPath("unpack_bootimg");
   Command unpack_cmd(unpack_path);
   unpack_cmd.AddParameter("--boot_img");
   unpack_cmd.AddParameter(vendor_boot_image_path);
   unpack_cmd.AddParameter("--out");
   unpack_cmd.AddParameter(unpack_dir);
   auto output_file = SharedFD::Creat(unpack_dir + "/vendor_boot_params", 0666);
   if (!output_file->IsOpen()) {
     LOG(ERROR) << "Unable to create intermediate vendor boot params file: "
                << output_file->StrError();
     return false;
   }
   unpack_cmd.RedirectStdIO(Subprocess::StdIOChannel::kStdOut, output_file);
   int success = unpack_cmd.Start().Wait();
   if (success != 0) {
     LOG(ERROR) << "Unable to run unpack_bootimg. Exited with status " << success;
     return false;
   }

   // Concatenates all vendor ramdisk into one single ramdisk.
   Command concat_cmd("/bin/bash");
   concat_cmd.AddParameter("-c");
   concat_cmd.AddParameter("cat " + unpack_dir + "/vendor_ramdisk*");
   auto concat_file =
       SharedFD::Creat(unpack_dir + "/" + CONCATENATED_VENDOR_RAMDISK, 0666);
   if (!concat_file->IsOpen()) {
     LOG(ERROR) << "Unable to create concatenated vendor ramdisk file: "
                << concat_file->StrError();
     return false;
   }
   concat_cmd.RedirectStdIO(Subprocess::StdIOChannel::kStdOut, concat_file);
   success = concat_cmd.Start().Wait();
   if (success != 0) {
     LOG(ERROR) << "Unable to run cat. Exited with status " << success;
     return false;
   }
   return true;
 }

 }  // namespace

 bool RepackBootImage(const std::string& new_kernel_path,
                      const std::string& boot_image_path,
                      const std::string& new_boot_image_path,
                      const std::string& build_dir) {
   if (UnpackBootImage(boot_image_path, build_dir) == false) {
     return false;
   }

   std::string boot_params = ReadFile(build_dir + "/boot_params");
   auto kernel_cmdline = ExtractValue(boot_params, "command line args: ");
   LOG(DEBUG) << "Cmdline from boot image is " << kernel_cmdline;

   auto tmp_boot_image_path = new_boot_image_path + TMP_EXTENSION;
   auto repack_path = HostBinaryPath("mkbootimg");
   Command repack_cmd(repack_path);
   repack_cmd.AddParameter("--kernel");
   repack_cmd.AddParameter(new_kernel_path);
   repack_cmd.AddParameter("--ramdisk");
   repack_cmd.AddParameter(build_dir + "/ramdisk");
   repack_cmd.AddParameter("--header_version");
   repack_cmd.AddParameter("4");
   repack_cmd.AddParameter("--cmdline");
   repack_cmd.AddParameter(kernel_cmdline);
   repack_cmd.AddParameter("-o");
   repack_cmd.AddParameter(tmp_boot_image_path);
   int success = repack_cmd.Start().Wait();
   if (success != 0) {
     LOG(ERROR) << "Unable to run mkbootimg. Exited with status " << success;
     return false;
   }

   auto fd = SharedFD::Open(tmp_boot_image_path, O_RDWR);
   auto original_size = FileSize(boot_image_path);
   CHECK(fd->Truncate(original_size) == 0)
     << "`truncate --size=" << original_size << " " << tmp_boot_image_path << "` "
     << "failed: " << fd->StrError();

   return DeleteTmpFileIfNotChanged(tmp_boot_image_path, new_boot_image_path);
 }

 bool RepackVendorBootImage(const std::string& new_ramdisk,
                            const std::string& vendor_boot_image_path,
                            const std::string& new_vendor_boot_image_path,
                            const std::string& unpack_dir,
                            const std::string& repack_dir,
                            const std::vector<std::string>& bootconfig_args,
                            bool bootconfig_supported) {
   if (UnpackVendorBootImageIfNotUnpacked(vendor_boot_image_path, unpack_dir) ==
       false) {
     return false;
   }

   std::string ramdisk_path;
   if (new_ramdisk.size()) {
     ramdisk_path = unpack_dir + "/vendor_ramdisk_repacked";
     if (!FileExists(ramdisk_path)) {
       RepackVendorRamdisk(new_ramdisk,
                           unpack_dir + "/" + CONCATENATED_VENDOR_RAMDISK,
                           ramdisk_path, unpack_dir);
     }
   } else {
     ramdisk_path = unpack_dir + "/" + CONCATENATED_VENDOR_RAMDISK;
   }

   auto bootconfig_fd = SharedFD::Creat(repack_dir + "/bootconfig", 0666);
   if (!bootconfig_fd->IsOpen()) {
     LOG(ERROR) << "Unable to create intermediate bootconfig file: "
                << bootconfig_fd->StrError();
     return false;
   }
   std::string bootconfig = ReadFile(unpack_dir + "/bootconfig") +
                            android::base::Join(bootconfig_args, "\n") + "\n";
   bootconfig_fd->Write(bootconfig.c_str(), bootconfig.size());
   LOG(DEBUG) << "Bootconfig parameters from vendor boot image and config are "
              << ReadFile(repack_dir + "/bootconfig");
   std::string vendor_boot_params = ReadFile(unpack_dir + "/vendor_boot_params");
   auto kernel_cmdline =
       ExtractValue(vendor_boot_params, "vendor command line args: ") +
       (bootconfig_supported
            ? ""
            : " " + android::base::StringReplace(bootconfig, "\n", " ", true));
   if (!bootconfig_supported) {
     // "androidboot.hardware" kernel parameter has changed to "hardware" in
     // bootconfig and needs to be replaced before being used in the kernel
     // cmdline.
     kernel_cmdline = android::base::StringReplace(
         kernel_cmdline, " hardware=", " androidboot.hardware=", true);
     // TODO(b/182417593): Until we pass the module parameters through
     // modules.options, we pass them through bootconfig using
     // 'kernel.<key>=<value>' But if we don't support bootconfig, we need to
     // rename them back to the old cmdline version
     kernel_cmdline = android::base::StringReplace(
         kernel_cmdline, " kernel.", " ", true);
   }
   LOG(DEBUG) << "Cmdline from vendor boot image is " << kernel_cmdline;

   auto tmp_vendor_boot_image_path = new_vendor_boot_image_path + TMP_EXTENSION;
   auto repack_path = HostBinaryPath("mkbootimg");
   Command repack_cmd(repack_path);
   repack_cmd.AddParameter("--vendor_ramdisk");
   repack_cmd.AddParameter(ramdisk_path);
   repack_cmd.AddParameter("--header_version");
   repack_cmd.AddParameter("4");
   repack_cmd.AddParameter("--vendor_cmdline");
   repack_cmd.AddParameter(kernel_cmdline);
   repack_cmd.AddParameter("--vendor_boot");
   repack_cmd.AddParameter(tmp_vendor_boot_image_path);
   repack_cmd.AddParameter("--dtb");
   repack_cmd.AddParameter(unpack_dir + "/dtb");
   if (bootconfig_supported) {
     repack_cmd.AddParameter("--vendor_bootconfig");
     repack_cmd.AddParameter(repack_dir + "/bootconfig");
   }

   int success = repack_cmd.Start().Wait();
   if (success != 0) {
     LOG(ERROR) << "Unable to run mkbootimg. Exited with status " << success;
     return false;
   }

   auto fd = SharedFD::Open(tmp_vendor_boot_image_path, O_RDWR);
   auto original_size = FileSize(vendor_boot_image_path);
   CHECK(fd->Truncate(original_size) == 0)
     << "`truncate --size=" << original_size << " " << tmp_vendor_boot_image_path << "` "
     << "failed: " << fd->StrError();

   return DeleteTmpFileIfNotChanged(tmp_vendor_boot_image_path, new_vendor_boot_image_path);
 }

 bool RepackVendorBootImageWithEmptyRamdisk(
     const std::string& vendor_boot_image_path,
     const std::string& new_vendor_boot_image_path,
     const std::string& unpack_dir, const std::string& repack_dir,
     const std::vector<std::string>& bootconfig_args,
     bool bootconfig_supported) {
   auto empty_ramdisk_file =
       SharedFD::Creat(unpack_dir + "/empty_ramdisk", 0666);
   return RepackVendorBootImage(
       unpack_dir + "/empty_ramdisk", vendor_boot_image_path,
       new_vendor_boot_image_path, unpack_dir, repack_dir, bootconfig_args,
       bootconfig_supported);
 }
 } // namespace cuttlefish
	/*
	* Copyright (C) 2020 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 "host/commands/assemble_cvd/boot_image_utils.h"
	#include "host/libs/config/cuttlefish_config.h"

	#include <string.h>
	#include <unistd.h>

	#include <fstream>
	#include <sstream>

	#include <android-base/logging.h>
	#include <android-base/strings.h>

	#include "common/libs/utils/files.h"
	#include "common/libs/utils/subprocess.h"

	const char TMP_EXTENSION[] = ".tmp";
	const char CPIO_EXT[] = ".cpio";
	const char TMP_RD_DIR[] = "stripped_ramdisk_dir";
	const char STRIPPED_RD[] = "stripped_ramdisk";
	const char CONCATENATED_VENDOR_RAMDISK[] = "concatenated_vendor_ramdisk";
	namespace cuttlefish {
	namespace {
	std::string ExtractValue(const std::string& dictionary, const std::string& key) {
	std::size_t index = dictionary.find(key);
	if (index != std::string::npos) {
	std::size_t end_index = dictionary.find('\n', index + key.length());
	if (end_index != std::string::npos) {
	return dictionary.substr(index + key.length(),
	end_index - index - key.length());
	}
	}
	return "";
	}

	// Though it is just as fast to overwrite the existing boot images with the newly generated ones,
	// the cuttlefish composite disk generator checks the age of each of the components and
	// regenerates the disk outright IF any one of the components is younger/newer than the current
	// composite disk. If this file overwrite occurs, that condition is fulfilled. This action then
	// causes data in the userdata partition from previous boots to be lost (which is not expected by
	// the user if they've been booting the same kernel/ramdisk combination repeatedly).
	// Consequently, the file is checked for differences and ONLY overwritten if there is a diff.
	bool DeleteTmpFileIfNotChanged(const std::string& tmp_file, const std::string& current_file) {
	if (!FileExists(current_file) \|\|
	ReadFile(current_file) != ReadFile(tmp_file)) {
	if (!RenameFile(tmp_file, current_file)) {
	LOG(ERROR) << "Unable to delete " << current_file;
	return false;
	}
	LOG(DEBUG) << "Updated " << current_file;
	} else {
	LOG(DEBUG) << "Didn't update " << current_file;
	RemoveFile(tmp_file);
	}

	return true;
	}

	bool UnpackBootImage(const std::string& boot_image_path,
	const std::string& unpack_dir) {
	auto unpack_path = HostBinaryPath("unpack_bootimg");
	Command unpack_cmd(unpack_path);
	unpack_cmd.AddParameter("--boot_img");
	unpack_cmd.AddParameter(boot_image_path);
	unpack_cmd.AddParameter("--out");
	unpack_cmd.AddParameter(unpack_dir);

	auto output_file = SharedFD::Creat(unpack_dir + "/boot_params", 0666);
	if (!output_file->IsOpen()) {
	LOG(ERROR) << "Unable to create intermediate boot params file: "
	<< output_file->StrError();
	return false;
	}
	unpack_cmd.RedirectStdIO(Subprocess::StdIOChannel::kStdOut, output_file);

	int success = unpack_cmd.Start().Wait();
	if (success != 0) {
	LOG(ERROR) << "Unable to run unpack_bootimg. Exited with status "
	<< success;
	return false;
	}
	return true;
	}

	void RepackVendorRamdisk(const std::string& kernel_modules_ramdisk_path,
	const std::string& original_ramdisk_path,
	const std::string& new_ramdisk_path,
	const std::string& build_dir) {
	int success = execute({"/bin/bash", "-c", HostBinaryPath("lz4") + " -c -d -l " +
	original_ramdisk_path + " > " + original_ramdisk_path + CPIO_EXT});
	CHECK(success == 0) << "Unable to run lz4. Exited with status " << success;

	const std::string ramdisk_stage_dir = build_dir + "/" + TMP_RD_DIR;
	success =
	mkdir(ramdisk_stage_dir.c_str(), S_IRWXU \| S_IRWXG \| S_IROTH \| S_IXOTH);
	CHECK(success == 0) << "Could not mkdir \"" << ramdisk_stage_dir
	<< "\", error was " << strerror(errno);

	success = execute(
	{"/bin/bash", "-c",
	"(cd " + ramdisk_stage_dir + " && while " + HostBinaryPath("toybox") +
	" cpio -idu; do :; done) < " + original_ramdisk_path + CPIO_EXT});
	CHECK(success == 0) << "Unable to run cd or cpio. Exited with status "
	<< success;

	success = execute({"rm", "-rf", ramdisk_stage_dir + "/lib/modules"});
	CHECK(success == 0) << "Could not rmdir \"lib/modules\" in TMP_RD_DIR. "
	<< "Exited with status " << success;

	const std::string stripped_ramdisk_path = build_dir + "/" + STRIPPED_RD;
	success = execute({"/bin/bash", "-c",
	HostBinaryPath("mkbootfs") + " " + ramdisk_stage_dir +
	" > " + stripped_ramdisk_path + CPIO_EXT});
	CHECK(success == 0) << "Unable to run cd or cpio. Exited with status "
	<< success;

	success = execute({"/bin/bash", "-c", HostBinaryPath("lz4") +
	" -c -l -12 --favor-decSpeed " + stripped_ramdisk_path + CPIO_EXT + " > " +
	stripped_ramdisk_path});
	CHECK(success == 0) << "Unable to run lz4. Exited with status " << success;

	// Concatenates the stripped ramdisk and input ramdisk and places the result at new_ramdisk_path
	std::ofstream final_rd(new_ramdisk_path, std::ios_base::binary \| std::ios_base::trunc);
	std::ifstream ramdisk_a(stripped_ramdisk_path, std::ios_base::binary);
	std::ifstream ramdisk_b(kernel_modules_ramdisk_path, std::ios_base::binary);
	final_rd << ramdisk_a.rdbuf() << ramdisk_b.rdbuf();
	}

	bool UnpackVendorBootImageIfNotUnpacked(
	const std::string& vendor_boot_image_path, const std::string& unpack_dir) {
	// the vendor boot params file is created during the first unpack. If it's
	// already there, a unpack has occurred and there's no need to repeat the
	// process.
	if (FileExists(unpack_dir + "/vendor_boot_params")) {
	return true;
	}

	auto unpack_path = HostBinaryPath("unpack_bootimg");
	Command unpack_cmd(unpack_path);
	unpack_cmd.AddParameter("--boot_img");
	unpack_cmd.AddParameter(vendor_boot_image_path);
	unpack_cmd.AddParameter("--out");
	unpack_cmd.AddParameter(unpack_dir);
	auto output_file = SharedFD::Creat(unpack_dir + "/vendor_boot_params", 0666);
	if (!output_file->IsOpen()) {
	LOG(ERROR) << "Unable to create intermediate vendor boot params file: "
	<< output_file->StrError();
	return false;
	}
	unpack_cmd.RedirectStdIO(Subprocess::StdIOChannel::kStdOut, output_file);
	int success = unpack_cmd.Start().Wait();
	if (success != 0) {
	LOG(ERROR) << "Unable to run unpack_bootimg. Exited with status " << success;
	return false;
	}

	// Concatenates all vendor ramdisk into one single ramdisk.
	Command concat_cmd("/bin/bash");
	concat_cmd.AddParameter("-c");
	concat_cmd.AddParameter("cat " + unpack_dir + "/vendor_ramdisk*");
	auto concat_file =
	SharedFD::Creat(unpack_dir + "/" + CONCATENATED_VENDOR_RAMDISK, 0666);
	if (!concat_file->IsOpen()) {
	LOG(ERROR) << "Unable to create concatenated vendor ramdisk file: "
	<< concat_file->StrError();
	return false;
	}
	concat_cmd.RedirectStdIO(Subprocess::StdIOChannel::kStdOut, concat_file);
	success = concat_cmd.Start().Wait();
	if (success != 0) {
	LOG(ERROR) << "Unable to run cat. Exited with status " << success;
	return false;
	}
	return true;
	}

	} // namespace

	bool RepackBootImage(const std::string& new_kernel_path,
	const std::string& boot_image_path,
	const std::string& new_boot_image_path,
	const std::string& build_dir) {
	if (UnpackBootImage(boot_image_path, build_dir) == false) {
	return false;
	}

	std::string boot_params = ReadFile(build_dir + "/boot_params");
	auto kernel_cmdline = ExtractValue(boot_params, "command line args: ");
	LOG(DEBUG) << "Cmdline from boot image is " << kernel_cmdline;

	auto tmp_boot_image_path = new_boot_image_path + TMP_EXTENSION;
	auto repack_path = HostBinaryPath("mkbootimg");
	Command repack_cmd(repack_path);
	repack_cmd.AddParameter("--kernel");
	repack_cmd.AddParameter(new_kernel_path);
	repack_cmd.AddParameter("--ramdisk");
	repack_cmd.AddParameter(build_dir + "/ramdisk");
	repack_cmd.AddParameter("--header_version");
	repack_cmd.AddParameter("4");
	repack_cmd.AddParameter("--cmdline");
	repack_cmd.AddParameter(kernel_cmdline);
	repack_cmd.AddParameter("-o");
	repack_cmd.AddParameter(tmp_boot_image_path);
	int success = repack_cmd.Start().Wait();
	if (success != 0) {
	LOG(ERROR) << "Unable to run mkbootimg. Exited with status " << success;
	return false;
	}

	auto fd = SharedFD::Open(tmp_boot_image_path, O_RDWR);
	auto original_size = FileSize(boot_image_path);
	CHECK(fd->Truncate(original_size) == 0)
	<< "`truncate --size=" << original_size << " " << tmp_boot_image_path << "` "
	<< "failed: " << fd->StrError();

	return DeleteTmpFileIfNotChanged(tmp_boot_image_path, new_boot_image_path);
	}

	bool RepackVendorBootImage(const std::string& new_ramdisk,
	const std::string& vendor_boot_image_path,
	const std::string& new_vendor_boot_image_path,
	const std::string& unpack_dir,
	const std::string& repack_dir,
	const std::vector<std::string>& bootconfig_args,
	bool bootconfig_supported) {
	if (UnpackVendorBootImageIfNotUnpacked(vendor_boot_image_path, unpack_dir) ==
	false) {
	return false;
	}

	std::string ramdisk_path;
	if (new_ramdisk.size()) {
	ramdisk_path = unpack_dir + "/vendor_ramdisk_repacked";
	if (!FileExists(ramdisk_path)) {
	RepackVendorRamdisk(new_ramdisk,
	unpack_dir + "/" + CONCATENATED_VENDOR_RAMDISK,
	ramdisk_path, unpack_dir);
	}
	} else {
	ramdisk_path = unpack_dir + "/" + CONCATENATED_VENDOR_RAMDISK;
	}

	auto bootconfig_fd = SharedFD::Creat(repack_dir + "/bootconfig", 0666);
	if (!bootconfig_fd->IsOpen()) {
	LOG(ERROR) << "Unable to create intermediate bootconfig file: "
	<< bootconfig_fd->StrError();
	return false;
	}
	std::string bootconfig = ReadFile(unpack_dir + "/bootconfig") +
	android::base::Join(bootconfig_args, "\n") + "\n";
	bootconfig_fd->Write(bootconfig.c_str(), bootconfig.size());
	LOG(DEBUG) << "Bootconfig parameters from vendor boot image and config are "
	<< ReadFile(repack_dir + "/bootconfig");
	std::string vendor_boot_params = ReadFile(unpack_dir + "/vendor_boot_params");
	auto kernel_cmdline =
	ExtractValue(vendor_boot_params, "vendor command line args: ") +
	(bootconfig_supported
	? ""
	: " " + android::base::StringReplace(bootconfig, "\n", " ", true));
	if (!bootconfig_supported) {
	// "androidboot.hardware" kernel parameter has changed to "hardware" in
	// bootconfig and needs to be replaced before being used in the kernel
	// cmdline.
	kernel_cmdline = android::base::StringReplace(
	kernel_cmdline, " hardware=", " androidboot.hardware=", true);
	// TODO(b/182417593): Until we pass the module parameters through
	// modules.options, we pass them through bootconfig using
	// 'kernel.<key>=<value>' But if we don't support bootconfig, we need to
	// rename them back to the old cmdline version
	kernel_cmdline = android::base::StringReplace(
	kernel_cmdline, " kernel.", " ", true);
	}
	LOG(DEBUG) << "Cmdline from vendor boot image is " << kernel_cmdline;

	auto tmp_vendor_boot_image_path = new_vendor_boot_image_path + TMP_EXTENSION;
	auto repack_path = HostBinaryPath("mkbootimg");
	Command repack_cmd(repack_path);
	repack_cmd.AddParameter("--vendor_ramdisk");
	repack_cmd.AddParameter(ramdisk_path);
	repack_cmd.AddParameter("--header_version");
	repack_cmd.AddParameter("4");
	repack_cmd.AddParameter("--vendor_cmdline");
	repack_cmd.AddParameter(kernel_cmdline);
	repack_cmd.AddParameter("--vendor_boot");
	repack_cmd.AddParameter(tmp_vendor_boot_image_path);
	repack_cmd.AddParameter("--dtb");
	repack_cmd.AddParameter(unpack_dir + "/dtb");
	if (bootconfig_supported) {
	repack_cmd.AddParameter("--vendor_bootconfig");
	repack_cmd.AddParameter(repack_dir + "/bootconfig");
	}

	int success = repack_cmd.Start().Wait();
	if (success != 0) {
	LOG(ERROR) << "Unable to run mkbootimg. Exited with status " << success;
	return false;
	}

	auto fd = SharedFD::Open(tmp_vendor_boot_image_path, O_RDWR);
	auto original_size = FileSize(vendor_boot_image_path);
	CHECK(fd->Truncate(original_size) == 0)
	<< "`truncate --size=" << original_size << " " << tmp_vendor_boot_image_path << "` "
	<< "failed: " << fd->StrError();

	return DeleteTmpFileIfNotChanged(tmp_vendor_boot_image_path, new_vendor_boot_image_path);
	}

	bool RepackVendorBootImageWithEmptyRamdisk(
	const std::string& vendor_boot_image_path,
	const std::string& new_vendor_boot_image_path,
	const std::string& unpack_dir, const std::string& repack_dir,
	const std::vector<std::string>& bootconfig_args,
	bool bootconfig_supported) {
	auto empty_ramdisk_file =
	SharedFD::Creat(unpack_dir + "/empty_ramdisk", 0666);
	return RepackVendorBootImage(
	unpack_dir + "/empty_ramdisk", vendor_boot_image_path,
	new_vendor_boot_image_path, unpack_dir, repack_dir, bootconfig_args,
	bootconfig_supported);
	}
	} // namespace cuttlefish