[Miscellaneous Android Development] stevemp:
init.rc

Explanation of init.rc in boot.img and recovery.img

Android Init Language

The Android Init Language consists of four broad classes of statements:

Actionn

Commands

Services

Options

The language syntax includes the following conventions:

All classes are line-oriented and consist of tokens separated by whitespace. c-style backslash escapes may be used to insert whitespace into a token. Double quotes may also be used to prevent whitespace from breaking text into multiple tokens. A backslash

appearing as the last character on a line is used for line-folding.

Lines that start with a # (leading whitespace allowed) are comments.

Actions and Services implicitly declare new sections. All commands or options belong to the section most recently declared. Commands or options before the first section are ignored.

Actions and Services have unique names. If a second Action or Service is declared with the same name as an existing one, it is ignored as an error.

Actions

Actions are named sequences of commands. Actions have a trigger used to determine when the action should occur. When an event occurs which matches an action's trigger, that action is added to the tail of a to-be-executed queue (unless it is already on the queue).

Each action in the queue is dequeued in sequence. Each command in an action is executed in sequence. Init handles other activities (such as, device creation/destruction, property setting, process restarting) "between" the execution of the commands in activities.

Actions take the form of:

on <trigger>

<command>

<command>

<command>

Services

Services are programs that 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 that affect how and when init runs a service. Options are described in the table below:

Option	Description

disabled	This service will not automatically start with its class. It must be explicitly started by name.

socket <type> <name> <perm> [ <user> [ <group> ] ]	Create a unix domain socket named /dev/socket/<name> and pass its fd to the launched process. Valid <type> values include dgram and stream. user and group default to 0.

user <username>	Change to username before exec'ing this service. Currently defaults to root.

group <groupname> [ <groupname> ]*	Change to groupname before exec'ing this service. Additional groupnames beyond the first, which is required, are used to set additional groups of the process (with setgroups()). Currently defaults to root.

capability [ <capability> ]+	Set linux capability before exec'ing this service

oneshot	Do not restart the service when it exits.

class <name>	Specify a class name for the service. All services in a named class must start and stop together. A service is considered of class "default" if one is not specified via the class option.

Triggers

Triggers are strings used to match certain kinds of events that cause an action to occur.

Trigger	Description

boot	This is the first trigger that occurs 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

Command	Description

exec <path> [ <argument> ]*	Fork and execute a program (<path>). This will block until the program completes execution. Try to avoid exec. Unlike the builtin commands, it runs the risk of getting init "stuck".

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.

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>	Make a directory at <path>.

mount <type> <device> <dir> [ <mountoption> ]*	Attempt to mount the named device at the directory <dir> <device>. This may be of the form mtd@name to specify a mtd block device by name.

setkey	- currenlty undefined -

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>.

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:

Property	Description

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", or "restarting").

---------- Post added at 12:12 PM ---------- Previous post was at 12:08 PM ----------

JDfense_Moage_ext4_CWM boot.img init.rc

# Copyright (C) 2012 The Android Open Source Project
#
# IMPORTANT: Do not create world writable files or directories.
# This is a common source of Android security bugs.
#

import /init.${ro.hardware}.rc
import /init.trace.rc

on early-init
# Set init and its forked children's oom_adj.
write /proc/1/oom_adj -16

start ueventd

# create mountpoints
mkdir /mnt 0775 root system

on init

sysclktz 0

loglevel 3

# setup the global environment
export PATH /sbin:/vendor/bin:/system/sbin:/system/bin:/system/xbin
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 ASEC_MOUNTPOINT /mnt/asec
export LOOP_MOUNTPOINT /mnt/obb
export BOOTCLASSPATH /system/framework/core.jar:/system/framework/core-junit.jar:/system/framework/bouncycastle.jar:/system/framework/ext.jar:/system/framework/framework.jar:/system/framework/android.policy.jar:/system/framework/services.jar:/system/framework/apache-xml.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/sdcard 0000 system system

# Create cgroup mount point for cpu accounting
mkdir /acct
mount cgroup none /acct cpuacct
mkdir /acct/uid

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

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
write /proc/sys/kernel/randomize_va_space 2
write /proc/sys/kernel/kptr_restrict 2
write /proc/sys/kernel/dmesg_restrict 1
write /proc/sys/vm/mmap_min_addr 32768
write /proc/sys/kernel/sched_rt_runtime_us 950000
write /proc/sys/kernel/sched_rt_period_us 1000000

# 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 0660 /dev/cpuctl/tasks
write /dev/cpuctl/cpu.shares 1024
write /dev/cpuctl/cpu.rt_runtime_us 950000
write /dev/cpuctl/cpu.rt_period_us 1000000

mkdir /dev/cpuctl/apps
chown system system /dev/cpuctl/apps/tasks
chmod 0666 /dev/cpuctl/apps/tasks
write /dev/cpuctl/apps/cpu.shares 1024
write /dev/cpuctl/apps/cpu.rt_runtime_us 800000
write /dev/cpuctl/apps/cpu.rt_period_us 1000000

mkdir /dev/cpuctl/apps/bg_non_interactive
chown system system /dev/cpuctl/apps/bg_non_interactive/tasks
chmod 0666 /dev/cpuctl/apps/bg_non_interactive/tasks
# 5.0 %
write /dev/cpuctl/apps/bg_non_interactive/cpu.shares 52
write /dev/cpuctl/apps/bg_non_interactive/cpu.rt_runtime_us 700000
write /dev/cpuctl/apps/bg_non_interactive/cpu.rt_period_us 1000000

# Allow everybody to read the xt_qtaguid resource tracking misc dev.
# This is needed by any process that uses socket tagging.
chmod 0644 /dev/xt_qtaguid

on fs
insmod /rk29xxnand_ko.ko
# mount mtd partitions
mount ext4 mtd@system /system ro noatime nodiratime
mount ext4 mtd@userdata /data noatime nodiratime nosuid nodev
mount ext4 mtd@cache /cache noatime nodiratime nosuid nodev

on post-fs
# once everything is setup, no need to modify /
mount rootfs rootfs / ro remount

# We chown/chmod /cache again so because mount is run as root + defaults
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 the lost+found directories, so as to enforce our permissions
mkdir /cache/lost+found 0770 root root

on post-fs-data
# 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 0750 root log

# 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

# create basic filesystem structure
mkdir /data/misc 01771 system misc
mkdir /data/misc/bluetoothd 0770 bluetooth bluetooth
mkdir /data/misc/bluetooth 0770 system system
mkdir /data/misc/keystore 0700 keystore keystore
mkdir /data/misc/keychain 0771 system system
mkdir /data/misc/vpn 0770 system vpn
mkdir /data/misc/systemkeys 0700 system system
# give system access to wpa_supplicant.conf for backup and restore
mkdir /data/misc/wifi 0770 wifi wifi
chmod 0660 /data/misc/wifi/wpa_supplicant.conf
mkdir /data/local 0751 root root

# For security reasons, /data/local/tmp should always be empty.
# Do not place files or directories in /data/local/tmp
mkdir /data/local/tmp 0771 shell shell
mkdir /data/data 0771 system system
mkdir /data/app-private 0771 system system
mkdir /data/app-asec 0700 root root
mkdir /data/app 0771 system system
mkdir /data/property 0700 root root
mkdir /data/ssh 0750 root shell
mkdir /data/ssh/empty 0700 root root

# create dalvik-cache, so as to enforce our permissions
mkdir /data/dalvik-cache 0771 system system

# create resource-cache and double-check the perms
mkdir /data/resource-cache 0771 system system
chown system system /data/resource-cache
chmod 0771 /data/resource-cache

# create the lost+found directories, so as to enforce our permissions
mkdir /data/lost+found 0770 root root

# create directory for DRM plug-ins - give drm the read/write access to
# the following directory.
mkdir /data/drm 0770 drm drm

# If there is no fs-post-data action in the init.<device>.rc file, you
# must uncomment this line, otherwise encrypted filesystems
# won't work.
# Set indication (checked by vold) that we have finished this action
#setprop vold.post_fs_data_done 1

chown system system /sys/class/android_usb/android0/f_mass_storage/lun/file
chmod 0660 /sys/class/android_usb/android0/f_mass_storage/lun/file
chown system system /sys/class/android_usb/android0/f_rndis/ethaddr
chmod 0660 /sys/class/android_usb/android0/f_rndis/ethaddr
chmod 0777 /sys/module/gt801_ts/parameters/debug1
chmod 0777 /sys/module/ft5306_ts/parameters/debug1
chmod 0777 /sys/module/ct360_ts/parameters/debug1
chmod 0777 /sys/module/goodix_touch_82x/parameters/debug1

on boot
# basic network init
ifup lo
hostname localhost
domainname localdomain
setprop UserVolumeLabel "U9GT2"

# set RLIMIT_NICE to allow priorities from 19 to -20
setrlimit 13 40 40

# Memory management. Basic kernel parameters, and allow the high
# level system server to be able to adjust the kernel OOM driver
# parameters to match how it is managing things.
write /proc/sys/vm/overcommit_memory 1
write /proc/sys/vm/min_free_order_shift 4
chown root system /sys/module/lowmemorykiller/parameters/adj
chmod 0664 /sys/module/lowmemorykiller/parameters/adj
chown root system /sys/module/lowmemorykiller/parameters/minfree
chmod 0664 /sys/module/lowmemorykiller/parameters/minfree

# 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 system system /sys/power/state
chown system system /sys/power/wakeup_count
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

chown system system /sys/devices/system/cpu/cpufreq/interactive/timer_rate
chmod 0660 /sys/devices/system/cpu/cpufreq/interactive/timer_rate
chown system system /sys/devices/system/cpu/cpufreq/interactive/min_sample_time
chmod 0660 /sys/devices/system/cpu/cpufreq/interactive/min_sample_time
chown system system /sys/devices/system/cpu/cpufreq/interactive/hispeed_freq
chmod 0660 /sys/devices/system/cpu/cpufreq/interactive/hispeed_freq
chown system system /sys/devices/system/cpu/cpufreq/interactive/go_hispeed_load
chmod 0660 /sys/devices/system/cpu/cpufreq/interactive/go_hispeed_load
chown system system /sys/devices/system/cpu/cpufreq/interactive/above_hispeed_delay
chmod 0660 /sys/devices/system/cpu/cpufreq/interactive/above_hispeed_delay
chown system system /sys/devices/system/cpu/cpufreq/interactive/boost
chmod 0660 /sys/devices/system/cpu/cpufreq/interactive/boost
chown system system /sys/devices/system/cpu/cpufreq/interactive/boostpulse
chown system system /sys/devices/system/cpu/cpufreq/interactive/input_boost
chmod 0660 /sys/devices/system/cpu/cpufreq/interactive/input_boost

# Assume SMP uses shared cpufreq policy for all CPUs
chown system system /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
chmod 0660 /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq

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 524288,1048576,2097152,262144,524288,1048576
setprop net.tcp.buffersize.lte 524288,1048576,2097152,262144,524288,1048576
setprop net.tcp.buffersize.umts 4094,87380,110208,4096,16384,110208
setprop net.tcp.buffersize.hspa 4094,87380,262144,4096,16384,262144
setprop net.tcp.buffersize.edge 4093,26280,35040,4096,16384,35040
setprop net.tcp.buffersize.gprs 4092,8760,11680,4096,8760,11680

# Set this property so surfaceflinger is not started by system_init
setprop system_init.startsurfaceflinger 0

class_start core
class_start main

on nonencrypted
class_start late_start

on charger
class_start charger

on property:vold.decrypt=trigger_reset_main
class_reset main

on property:vold.decrypt=trigger_load_persist_props
load_persist_props

on property:vold.decrypt=trigger_post_fs_data
trigger post-fs-data

on property:vold.decrypt=trigger_restart_min_framework
class_start main

on property:vold.decrypt=trigger_restart_framework
class_start main
class_start late_start

on property:vold.decrypt=trigger_shutdown_framework
class_reset late_start
class_reset main

# Used to disable USB when switching states
on property:sys.usb.config=none
stop adbd
write /sys/class/android_usb/android0/enable 0
write /sys/class/android_usb/android0/bDeviceClass 0
setprop sys.usb.state ${sys.usb.config}

# adb only USB configuration
# This should only be used during device bringup
# and as a fallback if the USB manager fails to set a standard configuration
on property:sys.usb.config=adb
write /sys/class/android_usb/android0/enable 0
write /sys/class/android_usb/android0/idVendor 0bb4
write /sys/class/android_usb/android0/idProduct 0c01
write /sys/class/android_usb/android0/functions ${sys.usb.config}
write /sys/class/android_usb/android0/enable 1
start adbd
setprop sys.usb.state ${sys.usb.config}

# USB accessory configuration
on property:sys.usb.config=accessory
write /sys/class/android_usb/android0/enable 0
write /sys/class/android_usb/android0/idVendor 18d1
write /sys/class/android_usb/android0/idProduct 2d00
write /sys/class/android_usb/android0/functions ${sys.usb.config}
write /sys/class/android_usb/android0/enable 1
setprop sys.usb.state ${sys.usb.config}

# USB accessory configuration, with adb
on property:sys.usb.config=accessory,adb
write /sys/class/android_usb/android0/enable 0
write /sys/class/android_usb/android0/idVendor 18d1
write /sys/class/android_usb/android0/idProduct 2d01
write /sys/class/android_usb/android0/functions ${sys.usb.config}
write /sys/class/android_usb/android0/enable 1
start adbd
setprop sys.usb.state ${sys.usb.config}

# Used to set USB configuration at boot and to switch the configuration
# when changing the default configuration
on property:persist.sys.usb.config=*
setprop sys.usb.config ${persist.sys.usb.config}

## Daemon processes to be run by init.
##

#enable init.d
service sysinit /system/bin/sysinit
class core
oneshot

service ueventd /sbin/ueventd
class core
critical

service console /system/bin/sh
class core
console
disabled
user shell
group log

on property:ro.debuggable=1
start console

# adbd is controlled via property triggers in init.<platform>.usb.rc
service adbd /sbin/adbd
class core
disabled

# adbd on at boot in emulator
on property:ro.kernel.qemu=1
start adbd

# This property trigger has added to imitiate the previous behavior of "adb root".
# The adb gadget driver used to reset the USB bus when the adbd daemon exited,
# and the host side adb relied on this behavior to force it to reconnect with the
# new adbd instance after init relaunches it. So now we force the USB bus to reset
# here when adbd sets the service.adb.root property to 1. We also restart adbd here
# rather than waiting for init to notice its death and restarting it so the timing
# of USB resetting and adb restarting more closely matches the previous behavior.
on property:service.adb.root=1
write /sys/class/android_usb/android0/enable 0
restart adbd
write /sys/class/android_usb/android0/enable 1

service servicemanager /system/bin/servicemanager
class core
user system
group system
critical
onrestart restart zygote
onrestart restart media
onrestart restart surfaceflinger
onrestart restart drm

service vold /system/bin/vold
class core
socket vold stream 0660 root mount
ioprio be 2

service netd /system/bin/netd
class main
socket netd stream 0660 root system
socket dnsproxyd stream 0660 root inet
socket mdns stream 0660 root system

service debuggerd /system/bin/debuggerd
class main

service ril-daemon /system/bin/rild
class main
socket rild stream 660 root radio
socket rild-debug stream 660 radio system
user root
group radio cache inet misc audio sdcard_rw log

service surfaceflinger /system/bin/surfaceflinger
class main
user system
group graphics
onrestart restart zygote

service zygote /system/bin/app_process -Xzygote /system/bin --zygote --start-system-server
class main
socket zygote stream 660 root system
onrestart write /sys/android_power/request_state wake
onrestart write /sys/power/state on
onrestart restart media
onrestart restart netd

service drm /system/bin/drmserver
class main
user drm
group drm system inet drmrpc sdcard_r

service media /system/bin/mediaserver
class main
user media
group audio camera inet net_bt net_bt_admin net_bw_acct drmrpc
ioprio rt 4

service bootanim /system/bin/bootanimation
class main
user graphics
group graphics
disabled
oneshot

service dbus /system/bin/dbus-daemon --system --nofork
class main
socket dbus stream 660 bluetooth bluetooth
user bluetooth
group bluetooth net_bt_admin

service bluetoothd /system/bin/bluetoothd -n
class main
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 installd /system/bin/installd
class main
socket installd stream 600 system system

service flash_recovery /system/etc/install-recovery.sh
class main
oneshot

service racoon /system/bin/racoon
class main
socket racoon stream 600 system system
# IKE uses UDP port 500. Racoon will setuid to vpn after binding the port.
group vpn net_admin inet
disabled
oneshot

service mtpd /system/bin/mtpd
class main
socket mtpd stream 600 system system
user vpn
group vpn net_admin inet net_raw
disabled
oneshot

service keystore /system/bin/keystore /data/misc/keystore
class main
user keystore
group keystore drmrpc
socket keystore stream 666

service dumpstate /system/bin/dumpstate -s
class main
socket dumpstate stream 0660 shell log
disabled
oneshot

service sshd /system/bin/start-ssh
class main
disabled

service mdnsd /system/bin/mdnsd
class main
user mdnsr
group inet net_raw
socket mdnsd stream 0660 mdnsr inet
disabled
oneshot
service whtest /system/bin/whtest.sh
disabled
oneshot

Mount system.img to modify

mkdir tmp

mount -t ext4 system.img tmp

apps are in /system/app -> add or remove apps here

boot animation is /system/media bootanimation.zip can be changed to whatever you want.

After you finish unmount system.img and flash to your tablet.

umount tmp

Any questions about modding, feel free to ask!

stevemp