Merge "init: fixes to README.mk"

The intention of these directories is:

   1. /system/etc/init/ is for core system items such as

      SurfaceFlinger, MediaService, and logcatd.

      SurfaceFlinger, MediaService, and logd.

   2. /vendor/etc/init/ is for SoC vendor items such as actions or

      daemons needed for core SoC functionality.

   3. /odm/etc/init/ is for device manufacturer items such as

init .rc file should additionally contain any actions associated with

its service.

An example is the logcatd.rc and Android.mk files located in the

An example is the userdebug logcatd.rc and Android.mk files located in the

system/core/logcat directory.  The LOCAL\_INIT\_RC macro in the

Android.mk file places logcatd.rc in /system/etc/init/ during the

build process.  Init loads logcatd.rc during the mount\_all command and

  See the below section on debugging for how this can be used.

`socket <name> <type> <perm> [ <user> [ <group> [ <seclabel> ] ] ]`

> Create a unix domain socket named /dev/socket/_name_ and pass its fd to the

> Create a UNIX domain socket named /dev/socket/_name_ and pass its fd to the

  launched process.  _type_ must be "dgram", "stream" or "seqpacket".  User and

  group default to 0.  'seclabel' is the SELinux security context for the

  socket.  It defaults to the service security context, as specified by

> Attempt to mount the named device at the directory _dir_

  _flag_s include "ro", "rw", "remount", "noatime", ...

  _options_ include "barrier=1", "noauto\_da\_alloc", "discard", ... as

  a comma separated string, eg: barrier=1,noauto\_da\_alloc

  a comma separated string, e.g. barrier=1,noauto\_da\_alloc

`parse_apex_configs`

> Parses config file(s) from the mounted APEXes. Intented to be used only once

> Parses config file(s) from the mounted APEXes. Intended to be used only once

  when apexd notifies the mount event by setting apexd.status to ready.

`restart <service>`

`symlink <target> <path>`

> Create a symbolic link at _path_ with the value _target_

`sysclktz <mins_west_of_gmt>`

`sysclktz <minutes_west_of_gmt>`

> Set the system clock base (0 if system clock ticks in GMT)

`trigger <event>`

A handy script named compare-bootcharts.py can be used to compare the

start/end time of selected processes. The aforementioned grab-bootchart.sh

will leave a bootchart tarball named bootchart.tgz at /tmp/android-bootchart.

If two such barballs are preserved on the host machine under different

If two such tarballs are preserved on the host machine under different

directories, the script can list the timestamps differences. For example:

Usage: system/core/init/compare-bootcharts.py _base-bootchart-dir_ _exp-bootchart-dir_

This option will send SIGSTOP to a service immediately before calling exec. This gives a window

where developers can attach a debugger, strace, etc before continuing the service with SIGCONT.

This flag can also be dynamically controled via the ctl.sigstop_on and ctl.sigstop_off properties.

This flag can also be dynamically controlled via the ctl.sigstop_on and ctl.sigstop_off properties.

Below is an example of dynamically debugging logd via the above: