Android初始化语言由四大类声明组成:行为类(Actions),命令类(Commands),服务类(Services),选项类(Options).
* 初始化语言以行为单位,由以空格间隔的语言符号组成。C风格的反斜杠转义符可以用来插入空白到语言符号。双引号也可以用来防止文本被空格分成多个语言符号。当反斜杠在行末时,作为折行符。
* 以#开始(前面允许有空格)的行为注释行。
* Actions和Services隐含声明一个新的段落。所有该段落下Commands或Options的声明属于该段落。第一段落前的Commands或Options被忽略。
* Actions和Services拥有独一无二的命名。在它们之后声明相同命名的类将被当作错误并忽略。
Actions
-------
Actions是一系列命令的命名。Actions拥有一个触发器(trigger)用来决定action何时执行。当一个action在符合触发条件被执行时,如果它还没被加入到待执行队列中的话,则加入到队列最后。
队列中的action依次执行,action中的命令也依次执行。Init在执行命令的中间处理其它活动(设备创建/销毁,property设置,进程重启)。
Actions表现形式为:
on <trigger>
<command>
<command>
<command>
Services
--------
Services是由init启动,在它们退出时重启(可选)。Service表现形式为:
service <name> <pathname> [ <argument> ]*
<option>
<option>
...
Options
-------
Options是Services的修饰,它们影响init何时、如何运行service.
critical
这是一个设备关键服务(device-critical service) .如果它在4分钟内退出超过4次,设备将重启并进入恢复模式。
disabled
这个服务的级别将不会自动启动,它必须被依照服务名指定启动才可以启动。
setenv <name> <value>
设置已启动的进程的环境变量<name>的值<value>
socket <name> <type> <perm> [ <user> [ <group> ] ]
创建一个名为/dev/socket/<name>的unix domin socket,并传送它的fd到已启动的进程。<type>必须为"dgram"或"stream".用户和组默认为0.
user <username>
在执行服务前改变用户名。当前默认为root.如果你的进程需要linux能力,你不能使用这个命令。你必须在还是root时请求能力,并下降到你需要的uid.
group <groupname> [ <groupname> ]*
在执行服务前改变组。在第一个组后的组将设为进程附加组(通过setgroups()).当前默认为root.
oneshot
在服务退出后不重启。
class <name>
为service指定一个类别名。同样类名的所有的服务可以一起启动或停止。如果没有指定类别的服务默认为"default"类。
onrestart
当服务重启时执行一个命令。
Triggers
--------
Triggers(触发器)是一个字符串,可以用来匹配某种类型的事件并执行一个action。
boot
这是当init开始后执行的第一个触发器(当/init.conf被加载)
<name>=<value>
当property <name>被设为指定的值<value>时触发。
device-added-<path>
device-removed-<path>
当设备节点被添加或移除时触发。
service-exited-<name>
当指定的服务存在时触发
Commands
--------
exec <path> [ <argument> ]*
Fork并执行一个程序(<path>).这将被block直到程序执行完毕。最好避免执行例如内建命令以外的程序,它可能会导致init被阻塞不动。
export <name> <value>
设定全局环境变量<name>的值<value>,当这个命令执行后所有的进程都可以取得。
ifup <interface>
使网络接口<interface>联机。
import <filename>
解析一个init配置文件,扩展当前配置文件。
hostname <name>
设置主机名
chmod <octal-mode> <path>
改变文件访问权限
chown <owner> <group> <path>
改变文件所属和组
class_start <serviceclass>
当指定类别的服务没有运行,启动该类别所有的服务。
class_stop <serviceclass>
当指定类别的服务正在运行,停止该类别所有的服务。
domainname <name>
设置域名。
insmod <path>
加载该路径<path>的模块
mkdir <path> [mode] [owner] [group]
在<path>创建一个目录,可选选项:mod,owner,group.如果没有指定,目录以755权限,owner为root,group为root创建.
mount <type> <device> <dir> [ <mountoption> ]*
尝试mount <device>到目录<dir>. <device>可以用mtd@name格式以命名指定一个mtd块设备。<mountoption>包含"ro","rw","remount","noatime".
setkey
暂时没有
setprop <name> <value>
设置系统property <name>的值<value>.
setrlimit <resource> <cur> <max>
设置resource的rlimit.
start <service>
启动一个没有运行的服务。
stop <service>
停止一个正在运行的服务。
symlink <target> <path>
创建一个<path>的符号链接到<target>
sysclktz <mins_west_of_gmt>
设置系统时区(GMT为0)
trigger <event>
触发一个事件。用于调用其它action。
write <path> <string> [ <string> ]*
打开<path>的文件并写入一个或多个字符串。
Properties
----------
Init会更新一些系统property以提供查看它正在干嘛。
init.action
当前正在执行的action,如果没有则为""
init.command
被执行的命令,如果没有则为""
init.svc.<name>
命名为<name>的服务的状态("stopped", "running", "restarting")
init.rc 示例:
-----------------
# not complete -- just providing some examples of usage
#
on boot
export PATH /sbin:/system/sbin:/system/bin
export LD_LIBRARY_PATH /system/lib
mkdir /dev
mkdir /proc
mkdir /sys
mount tmpfs tmpfs /dev
mkdir /dev/pts
mkdir /dev/socket
mount devpts devpts /dev/pts
mount proc proc /proc
mount sysfs sysfs /sys
write /proc/cpu/alignment 4
ifup lo
hostname localhost
domainname localhost
mount yaffs2 mtd@system /system
mount yaffs2 mtd@userdata /data
import /system/etc/init.conf
class_start default
service adbd /sbin/adbd
user adb
group adb
service usbd /system/bin/usbd -r
user usbd
group usbd
socket usbd 666
service zygote /system/bin/app_process -Xzygote /system/bin --zygote
socket zygote 666
service runtime /system/bin/runtime
user system
group system
on device-added-/dev/compass
start akmd
on device-removed-/dev/compass
stop akmd
service akmd /sbin/akmd
disabled
user akmd
group akmd
调试
---------------
默认情况下,init执行的程序输出的信息和错误到/dev/null.为了debug,你可以通过Android程序logwrapper执行你的程序。这将复位向输出/错误输出到Android logging系统(通过logcat访问)。
例如
service akmd /system/bin/logwrapper /sbin/akmd
- on early-init
- start ueventd
- on init
- sysclktz 0
- loglevel 3
- # setup the global environment
- export PATH /sbin:/vendor/bin:/system/sbin:/system/bin:/system/xbin:/system/busybox/bin:/system/busybox/sbin:/system/busybox/usr/bin:/system/busybox/usr/sbin
- export LD_LIBRARY_PATH /vendor/lib:/system/lib
- export ANDROID_BOOTLOGO 1
- export ANDROID_ROOT /system
- export ANDROID_ASSETS /system/app
- export ANDROID_DATA /data
- export EXTERNAL_STORAGE /mnt/sdcard
- export ASEC_MOUNTPOINT /mnt/asec
- export LOOP_MOUNTPOINT /mnt/obb
- export BOOTCLASSPATH /system/framework/core.jar:/system/framework/bouncycastle.jar:/system/framework/ext.jar:/system/framework/framework.jar:/system/framework/android.policy.jar:/system/framework/services.jar:/system/framework/core-junit.jar
- # Backward compatibility
- symlink /system/etc /etc
- symlink /sys/kernel/debug /d
- # Right now vendor lives on the same filesystem as system,
- # but someday that may change.
- symlink /system/vendor /vendor
- # create mountpoints
- mkdir /mnt 0775 root system
- mkdir /mnt/sdcard 0000 system system
- # Create cgroup mount point for cpu accounting
- mkdir /acct
- mount cgroup none /acct cpuacct
- mkdir /acct/uid
- # Backwards Compat - XXX: Going away in G*
- symlink /mnt/sdcard /sdcard
- mkdir /system
- mkdir /data 0771 system system
- mkdir /cache 0770 system cache
- mkdir /config 0500 root root
- # Directory for putting things only root should see.
- mkdir /mnt/secure 0700 root root
- # Directory for staging bindmounts
- mkdir /mnt/secure/staging 0700 root root
- # Directory-target for where the secure container
- # imagefile directory will be bind-mounted
- mkdir /mnt/secure/asec 0700 root root
- # Secure container public mount points.
- mkdir /mnt/asec 0700 root system
- mount tmpfs tmpfs /mnt/asec mode=0755,gid=1000
- # Filesystem image public mount points.
- mkdir /mnt/obb 0700 root system
- mount tmpfs tmpfs /mnt/obb mode=0755,gid=1000
- #for cmdline 3G dialup
- mkdir /var 0000 system system
- mount tmpfs tmpfs /var size=2m
- mkdir /var/lock
- mkdir /var/run
- mkdir /var/log
- mount usbfs none /proc/bus/usb -o devmode=0666
- write /proc/sys/kernel/panic_on_oops 1
- write /proc/sys/kernel/hung_task_timeout_secs 0
- write /proc/cpu/alignment 4
- write /proc/sys/kernel/sched_latency_ns 10000000
- write /proc/sys/kernel/sched_wakeup_granularity_ns 2000000
- write /proc/sys/kernel/sched_compat_yield 1
- write /proc/sys/kernel/sched_child_runs_first 0
- # Create cgroup mount points for process groups
- mkdir /dev/cpuctl
- mount cgroup none /dev/cpuctl cpu
- chown system system /dev/cpuctl
- chown system system /dev/cpuctl/tasks
- chmod 0777 /dev/cpuctl/tasks
- write /dev/cpuctl/cpu.shares 1024
- mkdir /dev/cpuctl/fg_boost
- chown system system /dev/cpuctl/fg_boost/tasks
- chmod 0777 /dev/cpuctl/fg_boost/tasks
- write /dev/cpuctl/fg_boost/cpu.shares 1024
- mkdir /dev/cpuctl/bg_non_interactive
- chown system system /dev/cpuctl/bg_non_interactive/tasks
- chmod 0777 /dev/cpuctl/bg_non_interactive/tasks
- # 5.0 %
- write /dev/cpuctl/bg_non_interactive/cpu.shares 52
- on fs
- # mount mtd partitions
- # Mount /system rw first to give the filesystem a chance to save a checkpoint
- mount yaffs2 mtd@system /system
- mount yaffs2 mtd@system /system rw remount
- mount yaffs2 mtd@userdata /data nosuid nodev
- mount yaffs2 mtd@cache /cache nosuid nodev
- on post-fs
- # once everything is setup, no need to modify /
- # mount rootfs rootfs / rw remount
- # We chown/chmod /data again so because mount is run as root + defaults
- chown system system /data
- chmod 0771 /data
- # Create dump dir and collect dumps.
- # Do this before we mount cache so eventually we can use cache for
- # storing dumps on platforms which do not have a dedicated dump partition.
- mkdir /data/dontpanic
- chown root log /data/dontpanic
- chmod 0750 /data/dontpanic
- # Collect apanic data, free resources and re-arm trigger
- copy /proc/apanic_console /data/dontpanic/apanic_console
- chown root log /data/dontpanic/apanic_console
- chmod 0640 /data/dontpanic/apanic_console
- copy /proc/apanic_threads /data/dontpanic/apanic_threads
- chown root log /data/dontpanic/apanic_threads
- chmod 0640 /data/dontpanic/apanic_threads
- write /proc/apanic_console 1
- # Same reason as /data above
- chown system cache /cache
- chmod 0770 /cache
- # This may have been created by the recovery system with odd permissions
- chown system cache /cache/recovery
- chmod 0770 /cache/recovery
- #change permissions on vmallocinfo so we can grab it from bugreports
- chown root log /proc/vmallocinfo
- chmod 0440 /proc/vmallocinfo
- #change permissions on kmsg & sysrq-trigger so bugreports can grab kthread stacks
- chown root system /proc/kmsg
- chmod 0440 /proc/kmsg
- chown root system /proc/sysrq-trigger
- chmod 0220 /proc/sysrq-trigger
- # create basic filesystem structure
- mkdir /data/misc 01771 system misc
- mkdir /data/misc/bluetoothd 0770 bluetooth bir /data/lost+found 0770
- mkdir /cache/lost+found 0770
- # double check the perms, in case lost+found already exists, and set owner
- chown root root /data/lost+found
- chmod 0770 /data/lost+found
- chown root root /cache/lost+found
- chmod 0770 /cache/lost+found
- #forlinx add for app to operate devices
- chmod 0666 /dev/leds
- chmod 0666 /dev/pwm
- chmod 0666 /dev/adc
- chmod 0666 /dev/s3c-cmm
- chmod 0666 /dev/s3c-g2d
- chmod 0666 /dev/s3c-g3d
- chmod 0666 /dev/s3c-jpg
- chmod 0666 /dev/s3c-mfc
- on boot
- # basic network init
- ifup lo
- hostname localhost
- domainname localdomain
- # set RLIMIT_NICE to allow priorities from 19 to -20
- setrlimit 13 40 40
- # Define the oom_adj values for the classes of processes that can be
- # killed by the kernel. These are used in ActivityManagerService.
- setprop ro.FOREGROUND_APP_ADJ 0
- setprop ro.VISIBLE_APP_ADJ 1
- setprop ro.PERCEPTIBLE_APP_ADJ 2
- setprop ro.HEAVY_WEIGHT_APP_ADJ 3
- setprop ro.SECONDARY_SERVER_ADJ 4
- setprop ro.BACKUP_APP_ADJ 5
- setprop ro.HOME_APP_ADJ 6
- setprop ro.HIDDEN_APP_MIN_ADJ 7
- setprop ro.EMPTY_APP_ADJ 15
- # Define the memory thresholds at which the above process classes will
- # be killed. These numbers are in pages (4k).
- setprop ro.FOREGROUND_APP_MEM 2048
- setprop ro.VISIBLE_APP_MEM 3072
- setprop ro.PERCEPTIBLE_APP_MEM 4096
- setprop ro.HEAVY_WEIGHT_APP_MEM 4096
- setprop ro.SECONDARY_SERVER_MEM 6144
- setprop ro.BACKUP_APP_MEM 6144
- setprop ro.HOME_APP_MEM 6144
- setprop ro.HIDDEN_APP_MEM 7168
- setprop ro.EMPTY_APP_MEM 8192
- # Define the Wi-Fi and other props
- setprop wifi.interface wlan0
- setprop wlan.interface wlan0
- setprop wlan.driver.status ok
- setprop wlan.modpath /system/lib/libwifi/
- # setprop ro.sf.hwrotation 270
- # Write value must be consistent with the above properties.
- # Note that the driver only supports 6 slots, so we have combined some of
- # the classes into the same memory level; the associated processes of higher
- # classes will still be killed first.
- write /sys/module/lowmemorykiller/parameters/adj 0,1,2,4,7,15
- write /proc/sys/vm/overcommit_memory 1
- write /proc/sys/vm/min_free_order_shift 4
- write /sys/module/lowmemorykiller/parameters/minfree 2048,3072,4096,6144,7168,8192
- # Set init its forked children's oom_adj.
- write /proc/1/oom_adj -16
- # Tweak background writeout
- write /proc/sys/vm/dirty_expire_centisecs 200
- write /proc/sys/vm/dirty_background_ratio 5
- # Permissions for System Server and daemons.
- chown radio system /sys/android_power/state
- chown radio system /sys/android_power/request_state
- chown radio system /sys/android_power/acquire_full_wake_lock
- chown radio system /sys/android_power/acquire_partial_wake_lock
- chown radio system /sys/android_power/release_wake_lock
- chown radio system /sys/power/state
- chown radio system /sys/power/wake_lock
- chown radio system /sys/power/wake_unlock
- chmod 0660 /sys/power/state
- chmod 0660 /sys/power/wake_lock
- chmod 0660 /sys/power/wake_unlock
- chmod 0777 /sys/class/rfkill/rfkill0/state
- chmod 0777 /dev/video0
- chmod 0777 /dev/video1
- chmod 0777 /dev/video2
- chown system system /sys/class/timed_output/vibrator/enable
- chown system system /sys/class/leds/keyboard-backlight/brightness
- chown system system /sys/class/leds/lcd-backlight/brightness
- chown system system /sys/class/leds/button-backlight/brightness
- chown system system /sys/class/leds/jogball-backlight/brightness
- chown system system /sys/class/leds/red/brightness
- chown system system /sys/class/leds/green/brightness
- chown system system /sys/class/leds/blue/brightness
- chown system system /sys/class/leds/red/device/grpfreq
- chown system system /sys/class/leds/red/device/grppwm
- chown system system /sys/class/leds/red/device/blink
- chown system system /sys/class/leds/red/brightness
- chown system system /sys/class/leds/green/brightness
- chown system system /sys/class/leds/blue/brightness
- chown system system /sys/class/leds/red/device/grpfreq
- chown system system /sys/class/leds/red/device/grppwm
- chown system system /sys/class/leds/red/device/blink
- chown system system /sys/class/timed_output/vibrator/enable
- chown system system /sys/module/sco/parameters/disable_esco
- chown system system /sys/kernel/ipv4/tcp_wmem_min
- chown system system /sys/kernel/ipv4/tcp_wmem_def
- chown system system /sys/kernel/ipv4/tcp_wmem_max
- chown system system /sys/kernel/ipv4/tcp_rmem_min
- chown system system /sys/kernel/ipv4/tcp_rmem_def
- chown system system /sys/kernel/ipv4/tcp_rmem_max
- chown root radio /proc/cmdline
- # Define TCP buffer sizes for various networks
- # ReadMin, ReadInitial, ReadMax, WriteMin, WriteInitial, WriteMax,
- setprop net.tcp.buffersize.default 4096,87380,110208,4096,16384,110208
- setprop net.tcp.buffersize.wifi 4095,87380,110208,4096,16384,110208
- setprop net.tcp.buffersize.umts 4094,87380,110208,4096,16384,110208
- setprop net.tcp.buffersize.edge 4093,26280,35040,4096,16384,35040
- setprop net.tcp.buffersize.gprs 4092,8760,11680,4096,8760,11680
- setprop net.dns1 8.8.8.8
- setprop net.dns2 8.8.4.4
- class_start default
- ## Daemon processes to be run by init.
- ##
- service ueventd /sbin/ueventd
- critical
- service console /system/bin/sh
- console
- disabled
- user root
- group log
- on property:ro.secure=0
- start console
- # adbd is controlled by the persist.service.adb.enable system property
- service adbd /sbin/adbd
- disabled
- # adbd on at boot in emulator
- on property:ro.kernel.qemu=1
- start adbd
- on property:persist.service.adb.enable=1
- start adbd
- on property:persist.service.adb.enable=0
- stop adbd
- #forlinx add
- service forlinx /forlinx.rc
- oneshot
- service servicemanager /system/bin/servicemanager
- user system
- critical
- onrestart restart zygote
- onrestart restart media
- service vold /system/bin/vold
- socket vold stream 0660 root mount
- ioprio be 2
- service netd /system/bin/netd
- socket netd stream 0660 root system
- service debuggerd /system/bin/debuggerd
- service ril-daemon /system/bin/rild
- socket rild stream 660 root radio
- socket rild-debug stream 660 radio system
- user root
- group radio cache inet misc audio sdcard_rw
- service zygote /system/bin/app_process -Xzygote /system/bin --zygote --start-system-server
- socket zygote stream 666
- onrestart write /sys/android_power/request_state wake
- onrestart write /sys/power/state on
- onrestart restart media
- onrestart restart netd
- service media /system/bin/mediaserver
- user media
- group system audio camera graphics inet net_bt net_bt_admin net_raw
- ioprio rt 4
- service bootanim /system/bin/bootanimation
- user graphics
- group graphics
- disabled
- oneshot
- service dbus /system/bin/dbus-daemon --system --nofork
- socket dbus stream 660 bluetooth bluetooth
- user bluetooth
- group bluetooth net_bt_admin
- service bluetoothd /system/bin/bluetoothd -n
- socket bluetooth stream 660 bluetooth bluetooth
- socket dbus_bluetooth stream 660 bluetooth bluetooth
- # init.rc does not yet support applying capabilities, so run as root and
- # let bluetoothd drop uid to bluetooth with the right linux capabilities
- group bluetooth net_bt_admin misc
- disabled
- service hfag /system/bin/sdptool add --channel=10 HFAG
- user bluetooth
- group bluetooth net_bt_admin
- disabled
- oneshot
- service hsag /system/bin/sdptool add --channel=11 HSAG
- user bluetooth
- group bluetooth net_bt_admin
- disabled
- oneshot
- service opush /system/bin/sdptool add --channel=12 OPUSH
- user bluetooth
- group bluetooth net_bt_admin
- disabled
- oneshot
- service pbap /system/bin/sdptool add --channel=19 PBAP
- user bluetooth
- group bluetooth net_bt_admin
- disabled
- oneshot
- service installd /system/bin/installd
- socket installd stream 600 system system
- #service flash_recovery /system/etc/install-recovery.sh
- # oneshot
- service racoon /system/bin/racoon
- socket racoon stream 600 system system
- # racoon will setuid to vpn after getting necessary resources.
- group net_admin
- disabled
- oneshot
- service mtpd /system/bin/mtpd
- socket mtpd stream 600 system system
- user vpn
- group vpn net_admin net_raw
- disabled
- oneshot
- service keystore /system/bin/keystore /data/misc/keystore
- user keystore
- group keystore
- socket keystore stream 666
- service dumpstate /system/bin/dumpstate -s
- socket dumpstate stream 0660 shell log
- disabled
- oneshot
- service OK6410-setup /system/etc/init.OK6410.sh
- oneshot
- # we will start as root and wpa_supplicant will switch to user wifi
- # after setting up the capabilities required for WEXT
- service wpa_supplicant /system/bin/wpa_supplicant \
- -Dwext -iwlan0 -c/data/misc/wifi/wpa_supplicant.conf -dd
- # user wifi
- # group wifi inet keystore system
- socket wpa_wlan0 dgram 777 wifi wifi
- disabled
- oneshot
- service dhcpcd_wlan0 /system/bin/dhcpcd -o domain_name_servers -t 120 -f /system/etc/dhcpcd/dhcpcd.conf -d wlan0
- group dhcp wifi system
- disabled
- oneshot
- on property:init.svc.wpa_supplicant=stopped
- stop dhcpcd_wlan0