Android OTA - 李晓刚的博客

OTA更新过程

设备会与 OTA 服务器进行定期确认，获知是否有更新可用，包括更新软件包的 URL 和向用户显示的描述字符串。

将更新下载到 cache 或 userdata 分区，并根据 /system/etc/security/otacerts.zip 中的证书验证加密签名。系统提示用户安装更新。

设备重新启动进入恢复模式，引导 recovery 分区中的内核和系统（而非 boot 分区中的内核）启动。

recovery 分区的二进制文件由 init 启动。它会在 /cache/recovery/command 中寻找将其指向下载软件包的命令行参数。

恢复操作会根据 /res/keys（包含在 recovery 分区中的 RAM 磁盘的一部分）中的公钥来验证软件包的加密签名

从软件包中提取数据，并根据需要使用该数据更新 boot、system 和/或 vendor 分区。system 分区上的某个新文件包含新的 recovery 分区的内容。

设备正常重启。 a. 加载最新更新的 boot 分区，在最新更新的 system 分区中装载并开始执行二进制文件。 b. 作为正常启动的一部分，系统会根据所需内容（预先存储为 /system 中的一个文件）检查 recovery 分区的内容。二者内容不同，所以 recovery 分区会被所需内容重新刷写（在后续引导中，recovery 分区已经包含新内容，因此无需重新刷写）。系统更新完成！更新日志可以在 /cache/recovery/last_log.# 中找到。

* RecoverySystem contains methods for interacting with the Android * recovery system (the separate partition that can be used to install * system updates, wipe user data, etc.) public class RecoverySystem { * Reboots the device in order to install the given update * package. * Requires the {@link android.Manifest.permission#REBOOT} permission. * @param context the Context to use * @param packageFile the update package to install. Must be on * a partition mountable by recovery. (The set of partitions * known to recovery may vary from device to device. Generally, * /cache and /data are safe.) * @throws IOException if writing the recovery command file * fails, or if the reboot itself fails. public static void installPackage ( Context context , File packageFile ) throws IOException { String filename = packageFile . getCanonicalPath (); Log . w ( TAG , "!!! REBOOTING TO INSTALL " + filename + " !!!" ); String arg = "--update_package=" + filename + "\n--locale=" + Locale . getDefault (). toString (); bootCommand ( context , arg ); * Reboot into the recovery system with the supplied argument. * @param arg to pass to the recovery utility. * @throws IOException if something goes wrong. private static void bootCommand ( Context context , String arg ) throws IOException { RECOVERY_DIR . mkdirs (); // In case we need it COMMAND_FILE . delete (); // In case it's not writable LOG_FILE . delete (); FileWriter command = new FileWriter ( COMMAND_FILE ); try { command . write ( arg ); command . write ( "\n" ); } finally { command . close (); // Having written the command file, go ahead and reboot PowerManager pm = ( PowerManager ) context . getSystemService ( Context . POWER_SERVICE ); pm . reboot ( "recovery" ); throw new IOException ( "Reboot failed (no permissions?)" );

Recovery模式

adb reboot recovery

POWER + (VOL+)

fastboot 与 recovery 区别， fastboot俗称线刷，需要电脑和数据线刷机，recovery俗称卡刷，通过内部存储刷机

RK3288固件升级

Firefly-RK3288升级固件

差分资源包

make otapackage

用于制作差分升级包: out/target/product/rk3288/obj/PACKAGING/target_files_intermediates/rk3288-target_files-20210603.114202.zip

rk3288-target_files-20210603.114202$ tree -L 2 ├── BOOT │ ├── cmdline │ ├── kernel │ ├── RAMDISK │ └── resource.img ├── DATA │ ├── benchmarktest │ ├── DATA │ └── nativetest ├── IMAGES │ ├── boot.img │ ├── recovery.img │ ├── recovery-two-step.img │ ├── system.img │ └── system.map ├── META │ ├── apkcerts.txt │ ├── boot_filesystem_config.txt │ ├── file_contexts.bin │ ├── filesystem_config.txt │ ├── misc_info.txt │ ├── otakeys.txt │ ├── recovery_filesystem_config.txt │ ├── releasetools.py │ └── vendor_filesystem_config.txt ├── OTA │ ├── android-info.txt │ └── bin ├── RECOVERY │ ├── cmdline │ ├── kernel │ ├── RAMDISK │ └── resource.img ├── SYSTEM │ ├── app │ ├── bin │ ├── build.prop │ ├── etc │ ├── fake-libs │ ├── fonts │ ├── framework │ ├── lib │ ├── lib64 │ ├── manifest.xml │ ├── media │ ├── priv-app │ ├── recovery-from-boot.p │ ├── tts │ ├── usr │ ├── vendor -> /vendor │ └── xbin ├── trust.img ├── uboot.img ├── vendor0.img └── vendor1.img 26 directories, 29 files

OTA全量升级包

./mkimage.sh ota

out/target/product/rk3288/rk3288-ota-20210603.114202.zip

rk3288-ota-20210603.114202$ tree ├── boot.img ├── file_contexts.bin ├── META-INF │ ├── CERT.RSA │ ├── CERT.SF │ ├── com │ │ ├── android │ │ │ ├── metadata │ │ │ └── otacert │ │ └── google │ │ └── android │ │ ├── update-binary │ │ └── updater-script │ └── MANIFEST.MF ├── system.new.dat ├── system.patch.dat ├── system.transfer.list ├── trust.img ├── uboot.img ├── vendor0.img └── vendor1.img 5 directories, 16 files

差分升级包

./build/tools/releasetools/ota_from_target_files -v -i rk3188-target_files-v1.zip -p out/host/linux-x86 -k build/target/product/security/testkey rk3188-target_files-v2.zip out/target/product/rk3188/rk3188-v1-v2.zip

./build/tools/releasetools/ota_from_target_files -h Given a target-files zipfile, produces an OTA package that installs that build. An incremental OTA is produced if -i is given, otherwise a full OTA is produced. Usage: ota_from_target_files [flags] input_target_files output_ota_package -k (--package_key) <key> Key to use to sign the package (default is the value of default_system_dev_certificate from the input target-files's META/misc_info.txt, or "build/target/product/security/testkey" if that value is not specified). For incremental OTAs, the default value is based on the source target-file, not the target build. -i (--incremental_from) <file> Generate an incremental OTA using the given target-files zip as the starting build. -v (--verify) Remount and verify the checksums of the files written to the system and vendor (if used) partitions. Incremental builds only. -w (--wipe_user_data) Generate an OTA package that will wipe the user data partition when installed. -p (--path) <dir> Prepend <dir>/bin to the list of places to search for binaries run by this script, and expect to find jars in <dir>/framework. -v (--verbose) Show command lines being executed. -h (--help) Display this usage message and exit.