Android启动脚本init.rc(1)
Android启动脚本init.rc
文章分类:移动开发
Actions take the form of:
on <trigger>
?? <command>
?? <command>
?? <command>
Services
--------
Services are programs which init launches and (optionally) restarts
when they exit. Services take the form of:
service <name> <pathname> [ <argument> ]*
?? <option>
?? <option>
?? ...
Options
-------
Options are modifiers to services. They affect how and when init
runs the service.
critical
?? This is a device-critical service. If it exits more than four times in
?? four minutes, the device will reboot into recovery mode.
disabled
?? This service will not automatically start with its class.
?? It must be explicitly started by name.
setenv <name> <value>
?? Set the environment variable <name> to <value> in the launched process.
socket <name> <type> <perm> [ <user> [ <group> ] ]
?? Create a unix domain socket named /dev/socket/<name> and pass
?? its fd to the launched process. <type> must be "dgram" or "stream".
?? User and group default to 0.
user <username>
?? Change to username before exec'ing this service.
?? Currently defaults to root. (??? probably should default to nobody)
?? Currently, if your process requires linux capabilities then you cannot use
?? this command. You must instead request the capabilities in-process while
?? still root, and then drop to your desired uid.
group <groupname> [ <groupname> ]*
?? Change to groupname before exec'ing this service. Additional
?? groupnames beyond the (required) first one are used to set the
?? supplemental groups of the process (via setgroups()).
?? Currently defaults to root. (??? probably should default to nobody)
oneshot
?? Do not restart the service when it exits.
class <name>
?? Specify a class name for the service. All services in a
?? named class may be started or stopped together. A service
?? is in the class "default" if one is not specified via the
?? class option.
onrestart
??? Execute a Command (see below) when service restarts.
Triggers
--------
?? Triggers are strings which can be used to match certain kinds
?? of events and used to cause an action to occur.
boot
?? This is the first trigger that will occur when init starts
?? (after /init.conf is loaded)
<name>=<value>
?? Triggers of this form occur when the property <name> is set
?? to the specific value <value>.
device-added-<path>
device-removed-<path>
?? Triggers of these forms occur when a device node is added
?? or removed.
service-exited-<name>
?? Triggers of this form occur when the specified service exits.
Commands
--------
exec <path> [ <argument> ]*
?? Fork and execute a program (<path>). This will block until
?? the program completes execution. It is best to avoid exec
?? as unlike the builtin commands, it runs the risk of getting
?? init "stuck". (??? maybe there should be a timeout?)
export <name> <value>
?? Set the environment variable <name> equal to <value> in the
?? global environment (which will be inherited by all processes
?? started after this command is executed)
ifup <interface>
?? Bring the network interface <interface> online.
import <filename>
?? Parse an init config file, extending the current configuration.
hostname <name>
?? Set the host name.
chdir <directory>
?? Change working directory.
chmod <octal-mode> <path>
?? Change file access permissions.
chown <owner> <group> <path>
?? Change file owner and group.
chroot <directory>
Change process root directory.
class_start <serviceclass>
?? Start all services of the specified class if they are
?? not already running.
class_stop <serviceclass>
?? Stop all services of the specified class if they are
?? currently running.
domainname <name>
?? Set the domain name.
insmod <path>
?? Install the module at <path>
mkdir <path> [mode] [owner] [group]
?? Create a directory at <path>, optionally with the given mode, owner, and
?? group. If not provided, the directory is created with permissions 755 and
?? owned by the root user and root group.
mount <type> <device> <dir> [ <mountoption> ]*
?? Attempt to mount the named device at the directory <dir>
?? <device> may be of the form mtd@name to specify a mtd block
?? device by name.
?? <mountoption>s include "ro", "rw", "remount", "noatime", ...
setkey
?? TBD
setprop <name> <value>
?? Set system property <name> to <value>.
setrlimit <resource> <cur> <max>
?? Set the rlimit for a resource.
start <service>
?? Start a service running if it is not already running.
stop <service>
?? Stop a service from running if it is currently running.
symlink <target> <path>
?? Create a symbolic link at <path> with the value <target>
sysclktz <mins_west_of_gmt>
?? Set the system clock base (0 if system clock ticks in GMT)
trigger <event>
?? Trigger an event. Used to queue an action from another
?? action.
write <path> <string> [ <string> ]*
?? Open the file at <path> and write one or more strings
?? to it with write(2)
Properties
----------
Init updates some system properties to provide some insight into
what it's doing:
init.action
?? Equal to the name of the action currently being executed or "" if none
init.command
?? Equal to the command being executed or "" if none.
init.svc.<name>
?? State of a named service ("stopped", "running", "restarting")
Example init.conf
-----------------
# 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
Debugging notes
---------------
By default, programs executed by init will drop stdout and stderr into
/dev/null. To help with debugging, you can execute your program via the
Andoird program logwrapper. This will redirect stdout/stderr into the
Android logging system (accessed via logcat).
For example
service akmd /system/bin/logwrapper /sbin/akmd
?
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http://yueguc.iteye.com/blog/788748
