34.3. Android init
For Linux in general, see: Section 7, “init”.
The /init executable interprets the /init.rc files, which is in a custom Android init system language: https://android.googlesource.com/platform/system/core/+/ee0e63f71d90537bb0570e77aa8a699cc222cfaf/init/README.md
The top of that file then sources other .rc files present on the root directory:
import /init.environ.rc
import /init.usb.rc
import /init.${ro.hardware}.rc
import /vendor/etc/init/hw/init.${ro.hardware}.rc
import /init.usb.configfs.rc
import /init.${ro.zygote}.rc
TODO: how is ro.hardware determined? https://stackoverflow.com/questions/20572781/android-boot-where-is-the-init-hardware-rc-read-in-init-c-where-are-servic It is a system property and can be obtained with:
getprop ro.hardware
This gives:
ranchu
which is the codename for the QEMU virtual platform we are running on: https://www.oreilly.com/library/view/android-system-programming/9781787125360/9736a97c-cd09-40c3-b14d-955717648302.xhtml
TODO: is it possible to add a custom .rc file without modifying the initrd that gets mounted on root? https://stackoverflow.com/questions/9768103/make-persistent-changes-to-init-rc
Tested on: 8.1.0_r60.