（二）android升级--完整包updater-script脚本语法简介及执行流程

一、update-script脚本源码

assert(!less_than_int(1377158385, getprop("ro.build.date.utc")));

assert(getprop("ro.product.device") == "g18ref" ||
       getprop("ro.build.product") == "g18ref");
show_progress(0.500000, 0);
format("ext4", "EMMC", "/dev/block/system", "0", "/system");
mount("ext4", "EMMC", "/dev/block/system", "/system");
package_extract_dir("recovery", "/system");
package_extract_dir("system", "/system");
symlink("Roboto-Bold.ttf", "/system/fonts/DroidSans-Bold.ttf");
symlink("Roboto-Regular.ttf", "/system/fonts/DroidSans.ttf");
symlink("busybox", "/system/xbin/[", "/system/xbin/[[",
        "/system/xbin/adjtimex", "/system/xbin/arp", "/system/xbin/ash",
        "/system/xbin/awk", "/system/xbin/base64", "/system/xbin/basename",
        "/system/xbin/bbconfig", "/system/xbin/blkid", "/system/xbin/blockdev",
        "/system/xbin/brctl", "/system/xbin/bunzip2", "/system/xbin/bzcat",
        "/system/xbin/bzip2", "/system/xbin/cal", "/system/xbin/cat",
        "/system/xbin/catv", "/system/xbin/chattr", "/system/xbin/chgrp",
        "/system/xbin/chmod", "/system/xbin/chown", "/system/xbin/chroot",
        "/system/xbin/clear", "/system/xbin/cmp", "/system/xbin/comm",
        "/system/xbin/cp", "/system/xbin/cpio", "/system/xbin/crond",
        "/system/xbin/crontab", "/system/xbin/cut", "/system/xbin/date",
        "/system/xbin/dc", "/system/xbin/dd", "/system/xbin/depmod",
        "/system/xbin/devmem", "/system/xbin/df", "/system/xbin/diff",
        "/system/xbin/dirname", "/system/xbin/dmesg", "/system/xbin/dnsd",
        "/system/xbin/dos2unix", "/system/xbin/du", "/system/xbin/echo",
        "/system/xbin/ed", "/system/xbin/egrep", "/system/xbin/env",
        "/system/xbin/expand", "/system/xbin/expr", "/system/xbin/false",
        "/system/xbin/fbset", "/system/xbin/fbsplash", "/system/xbin/fdisk",
        "/system/xbin/fgrep", "/system/xbin/find", "/system/xbin/flash_lock",
        "/system/xbin/flash_unlock", "/system/xbin/flashcp",
        "/system/xbin/flock", "/system/xbin/fold", "/system/xbin/free",
        "/system/xbin/freeramdisk", "/system/xbin/fstrim", "/system/xbin/fsync",
        "/system/xbin/ftpget", "/system/xbin/ftpput", "/system/xbin/fuser",
        "/system/xbin/getopt", "/system/xbin/grep", "/system/xbin/groups",
        "/system/xbin/gunzip", "/system/xbin/gzip", "/system/xbin/halt",
        "/system/xbin/head", "/system/xbin/hexdump", "/system/xbin/id",
        "/system/xbin/ifconfig", "/system/xbin/inetd", "/system/xbin/insmod",
        "/system/xbin/install", "/system/xbin/ionice", "/system/xbin/iostat",
        "/system/xbin/ip", "/system/xbin/kill", "/system/xbin/killall",
        "/system/xbin/killall5", "/system/xbin/less", "/system/xbin/ln",
        "/system/xbin/losetup", "/system/xbin/ls", "/system/xbin/lsattr",
        "/system/xbin/lsmod", "/system/xbin/lsof", "/system/xbin/lsusb",
        "/system/xbin/lzcat", "/system/xbin/lzma", "/system/xbin/lzop",
        "/system/xbin/lzopcat", "/system/xbin/man", "/system/xbin/md5sum",
        "/system/xbin/mesg", "/system/xbin/mkdir", "/system/xbin/mkdosfs",
        "/system/xbin/mke2fs", "/system/xbin/mkfifo", "/system/xbin/mkfs.ext2",
        "/system/xbin/mkfs.vfat", "/system/xbin/mknod", "/system/xbin/mkswap",
        "/system/xbin/mktemp", "/system/xbin/modinfo", "/system/xbin/modprobe",
        "/system/xbin/more", "/system/xbin/mount", "/system/xbin/mountpoint",
        "/system/xbin/mpstat", "/system/xbin/mv", "/system/xbin/nanddump",
        "/system/xbin/nandwrite", "/system/xbin/nbd-client",
        "/system/xbin/netstat", "/system/xbin/nice", "/system/xbin/nohup",
        "/system/xbin/nslookup", "/system/xbin/ntpd", "/system/xbin/od",
        "/system/xbin/patch", "/system/xbin/pgrep", "/system/xbin/pidof",
        "/system/xbin/ping", "/system/xbin/pipe_progress", "/system/xbin/pkill",
        "/system/xbin/pmap", "/system/xbin/poweroff", "/system/xbin/printenv",
        "/system/xbin/printf", "/system/xbin/ps", "/system/xbin/pstree",
        "/system/xbin/pwd", "/system/xbin/pwdx", "/system/xbin/rdev",
        "/system/xbin/readlink", "/system/xbin/realpath", "/system/xbin/reboot",
        "/system/xbin/renice", "/system/xbin/reset", "/system/xbin/resize",
        "/system/xbin/rev", "/system/xbin/rm", "/system/xbin/rmdir",
        "/system/xbin/rmmod", "/system/xbin/route", "/system/xbin/run-parts",
        "/system/xbin/rx", "/system/xbin/sed", "/system/xbin/seq",
        "/system/xbin/setconsole", "/system/xbin/setserial",
        "/system/xbin/setsid", "/system/xbin/sh", "/system/xbin/sha1sum",
        "/system/xbin/sha256sum", "/system/xbin/sha3sum",
        "/system/xbin/sha512sum", "/system/xbin/sleep", "/system/xbin/sort",
        "/system/xbin/split", "/system/xbin/stat", "/system/xbin/strings",
        "/system/xbin/stty", "/system/xbin/sum", "/system/xbin/swapoff",
        "/system/xbin/swapon", "/system/xbin/sync", "/system/xbin/sysctl",
        "/system/xbin/tac", "/system/xbin/tail", "/system/xbin/tar",
        "/system/xbin/taskset", "/system/xbin/tee", "/system/xbin/telnet",
        "/system/xbin/telnetd", "/system/xbin/test", "/system/xbin/tftp",
        "/system/xbin/tftpd", "/system/xbin/time", "/system/xbin/timeout",
        "/system/xbin/top", "/system/xbin/touch", "/system/xbin/tr",
        "/system/xbin/traceroute", "/system/xbin/true", "/system/xbin/ttysize",
        "/system/xbin/tune2fs", "/system/xbin/umount", "/system/xbin/uname",
        "/system/xbin/uncompress", "/system/xbin/unexpand", "/system/xbin/uniq",
        "/system/xbin/unix2dos", "/system/xbin/unlzma", "/system/xbin/unlzop",
        "/system/xbin/unxz", "/system/xbin/unzip", "/system/xbin/uptime",
        "/system/xbin/usleep", "/system/xbin/uudecode", "/system/xbin/uuencode",
        "/system/xbin/vi", "/system/xbin/watch", "/system/xbin/wc",
        "/system/xbin/wget", "/system/xbin/whoami", "/system/xbin/xargs",
        "/system/xbin/xz", "/system/xbin/xzcat", "/system/xbin/yes",
        "/system/xbin/zcat");
symlink("mksh", "/system/bin/sh");
symlink("toolbox", "/system/bin/cat", "/system/bin/chmod",
        "/system/bin/chown", "/system/bin/cmp", "/system/bin/cp",
        "/system/bin/date", "/system/bin/dd", "/system/bin/df",
        "/system/bin/dmesg", "/system/bin/du", "/system/bin/getevent",
        "/system/bin/getprop", "/system/bin/grep", "/system/bin/hd",
        "/system/bin/id", "/system/bin/ifconfig", "/system/bin/iftop",
        "/system/bin/insmod", "/system/bin/ioctl", "/system/bin/ionice",
        "/system/bin/kill", "/system/bin/ln", "/system/bin/log",
        "/system/bin/ls", "/system/bin/lsmod", "/system/bin/lsof",
        "/system/bin/md5", "/system/bin/mkdir", "/system/bin/mount",
        "/system/bin/mv", "/system/bin/nandread", "/system/bin/netstat",
        "/system/bin/newfs_msdos", "/system/bin/notify", "/system/bin/printenv",
        "/system/bin/ps", "/system/bin/r", "/system/bin/reboot",
        "/system/bin/renice", "/system/bin/rm", "/system/bin/rmdir",
        "/system/bin/rmmod", "/system/bin/route", "/system/bin/schedtop",
        "/system/bin/sendevent", "/system/bin/setconsole",
        "/system/bin/setprop", "/system/bin/sleep", "/system/bin/smd",
        "/system/bin/start", "/system/bin/stop", "/system/bin/sync",
        "/system/bin/top", "/system/bin/touch", "/system/bin/umount",
        "/system/bin/uptime", "/system/bin/vmstat", "/system/bin/watchprops",
        "/system/bin/wipe");
write_raw_image(package_extract_file("logo.img"), "logo");
set_perm_recursive(0, 0, 0755, 0644, "/system");
set_perm_recursive(0, 2000, 0755, 0755, "/system/bin");
set_perm(0, 3003, 02750, "/system/bin/netcfg");
set_perm(0, 3004, 02755, "/system/bin/ping");
set_perm(0, 2000, 06750, "/system/bin/run-as");
set_perm(1002, 1002, 0440, "/system/etc/dbus.conf");
set_perm(1014, 2000, 0550, "/system/etc/dhcpcd/dhcpcd-run-hooks");
set_perm(0, 2000, 0550, "/system/etc/init.goldfish.sh");
set_perm(0, 0, 0544, "/system/etc/install-recovery.sh");
set_perm_recursive(0, 0, 0755, 0555, "/system/etc/ppp");
set_perm_recursive(0, 2000, 0755, 0644, "/system/vendor");
set_perm(0, 0, 0644, "/system/vendor/pittpatt/models/detection/multi_pose_face_landmark_detectors.7/left_eye-y0-yi45-p0-pi45-r0-ri20.lg_32/full_model.bin");
set_perm(0, 0, 0644, "/system/vendor/pittpatt/models/detection/multi_pose_face_landmark_detectors.7/nose_base-y0-yi45-p0-pi45-r0-ri20.lg_32/full_model.bin");
set_perm(0, 0, 0644, "/system/vendor/pittpatt/models/detection/multi_pose_face_landmark_detectors.7/right_eye-y0-yi45-p0-pi45-r0-ri20.lg_32-2/full_model.bin");
set_perm(0, 0, 0644, "/system/vendor/pittpatt/models/detection/yaw_roll_face_detectors.6/head-y0-yi45-p0-pi45-r0-ri30.4a-v24/full_model.bin");
set_perm(0, 0, 0644, "/system/vendor/pittpatt/models/detection/yaw_roll_face_detectors.6/head-y0-yi45-p0-pi45-rn30-ri30.5-v24/full_model.bin");
set_perm(0, 0, 0644, "/system/vendor/pittpatt/models/detection/yaw_roll_face_detectors.6/head-y0-yi45-p0-pi45-rp30-ri30.5-v24/full_model.bin");
set_perm(0, 0, 0644, "/system/vendor/pittpatt/models/recognition/face.face.y0-y0-22-b-N/full_model.bin");
set_perm_recursive(0, 2000, 0755, 0755, "/system/xbin");
set_perm(0, 0, 06755, "/system/xbin/librank");
set_perm(0, 0, 06755, "/system/xbin/procmem");
set_perm(0, 0, 06755, "/system/xbin/procrank");
set_perm(0, 0, 06755, "/system/xbin/su");
set_perm(0, 0, 06755, "/system/xbin/tcpdump");
unmount("/system");
show_progress(0.200000, 0);
show_progress(0.200000, 10);
write_raw_image(package_extract_file("boot.img"), "boot");
write_raw_image(package_extract_file("bootloader.img"), "bootloader");
set_bootloader_env("upgrade_step", "1");
set_bootloader_env("boot_zero", "true");

show_progress(0.100000, 0);

二、update-script脚本语法简介

1、assert(condition)：如果condition参数的计算结果为False，则停止脚本执行，否则继续执行脚本。

2、show_progress(frac,sec)：frac表示进度完成的数值，sec表示整个过程的总秒数。主要用与显示UI上的进度条。

3、format(fs_type,partition_type,location)：fs_type，文件系统类型，取值一般为“yaffs2”或“ext4”。Partition_type，分区类型，一般取值为“ext4”

4、mount(fs_type,partition_type,location,mount_point)：前两个参数同上，location要挂载的设备，mount_point挂载点。作用：挂载一个文件系统到指定的挂载点。

5、package_extract_dir(src_path,destination_path)：src_path，要提取的目录，destination_path目标目录。作用：从升级包内，提取目录到指定的位置。示例：package_extract_dir(“system”,”/system”)。

6、symlink(target,src1,src2,……,srcN)：target，字符串类型，是符号连接的目标。srcX代表要创建的符号连接的目标点。示例：symlink(“toolbox”,”/system/bin/ps”),建立指向toolbox符号连接/system/bin/ps，值得注意的是，在建立新的符号连接之前，要断开已经存在的符号连接。

7、set_perm(uid,gid,mode,file1,file2,……,fileN)：作用是设置单个文件或则一系列文件的权限，最少要指定一个文件。

8、set_perm_recursive(uid,gid,mode,dir1,dir2,……,dirN)：作用同上，但是这里同时改变的是一个或多个目录及其文件的权限。

9、package_extract_file(srcfile_path,desfile_path)：srcfile_path，要提取的文件，desfile_path，提取文件的目标位置。示例：package_extract_file(“boot.img”,”/tmp/boot.img”)将升级包中的boot.img文件拷贝到内存文件系统的/tmp下；也可以是单个参数的，比如：package_extract_file("boot.img")，提取升级包的boot.img。

10、write_raw_image(src-image,partition)：src-image源镜像文件，partition，目标分区。作用：将镜像写入目标分区。示例：write_raw_image(package_extract_file("boot.img"), "boot");将boot.img镜像写入到系统的boot分区。

11、getprop(key)：通过指定key的值来获取对应的属性信息。示例：getprop(“ro.product.device”)获取ro.product.device的属性值。

三、update-script脚本执行过程

   根据以上的源码以及语法的介绍可以看出脚本的执行过程如下：

1、比较时间戳，如果升级包较旧则终止脚本的执行。

2、比较版本信息，如果升级包版本信息和板子不一样则终止脚本的执行。

3、显示进度条，如果以上两步匹配成功则开始显示升级进度条。

4、格式化系统分区并挂载。

5、提取包中的recovery以及system目录下的内容到系统所创建的/system下。

6、为/system/bin/和/system/xbin/下的命令文件建立符号连接。

7、设置/system/目录下各文件夹中的文件权限。

8、卸载根目录下的/system

9、两次显示升级进度条。

9、将包中的boot.img提取到boot分区，即更新内核信息。

10、将包中的bootloader.img提取到bootloader分区，即更新启动代码信息。

11、设置成功停止位和改变下次要启动的分区标志位。

12、完成最后进度条显示。