This is a direct import of bootable/recovery from the AOSP master. A minimal
patch adds a new option install shsu which installs the included standard
su as shsu (shsu stands for shell-only su which means it only works over adb
shell).
The new option install shsu is executed every time before reboot. The action
is implemented by setting a property shsu.install=1. This change is picked
up by init which executes the action specified in init.rc using builtins
only:
# copy su to /system/xbin/shsu using builtins only
on property:shsu.install=1
mount yaffs2 mtd@system /system
mount yaffs2 mtd@system /system rw remount
mkdir /system/xbin
copy /sbin/su /system/xbin/shsu
chown root shell /system/xbin/shsu
chmod 4750 /system/xbin/shsu
setprop shsu.installed 1
write /sbin/shsu.installed 1
# also, recovery overwrite precautions
copy /system/etc/install-recovery.sh /system/etc/install-recovery.sh.not
write /system/etc/install-recovery.sh "exit #"
One of the effects of this action is also disabling the automated patching of
the recovery partition. You can later apply the recovery patch manually by
executing (in su shell):
sh /etc/install-recovery.sh.not
...although you might have to edit the script to remove the exit if you called
install shsu more than once.
A simple script tools/fix-recovery.sh automates the process of retrieving the
current recovery image, replacing the recovery binary, installing the
shsu.install hook, and reflashing the image. It also installs busybox if
available in your out directory and "unsecures" properties to enable adb.
This script depends on unbootimg
Usage:
./fix-recovery.sh (all|pull|fix|flash) [recovery-image-name]
You will need to build the following from the Android repo beforehand:
make su flash_image recovery adbd unpack.sh repack.sh mkbootimg unbootimg