### Setup

* Download the lastest alpine-minirootfs for armv7 from [alpinelinux](https://www.alpinelinux.org/downloads/)
* Once you have root access use adb to push these files to `/data/` (e.g. `adb push setup.sh /data/`):
    * `alpine-minirootfs-3.22.1-armv7.tar.gz`
    * `setup.sh`
    * `busybox-armv7l`
* Navigate to `/data` and then run `sh setup.sh` which should setup the chroot (mounting the `/dev` etc)
* This will then drop you into a `localhost` shell, to get out 

### Start Up Scripts

 * To start up a binary we need to insert a script somewhere in the start up procedure, I noted that the binary `debuggerd` is started and didn't think we needed this so instead replaced the binary with a shell script that would start my own programs.
 * Android mounts its `/system/bin` as read only so it is necessary to temporarily remount this to make the changes:
   * `mount -o remount,rw /system`
   * `chmod o+w /system/bin`
   * Backup debuggerd binary and then replace it with the shell script
   * `chmod o-w /system/bin`
   * `mount -o remount,ro /system`

### Links

* [alpine-minirootfs](https://dl-cdn.alpinelinux.org/alpine/v3.22/releases/armv7/alpine-minirootfs-3.22.1-armv7.tar.gz)
* [Setting up chroot](https://wiki.alpinelinux.org/wiki/Alpine_Linux_in_a_chroot)
* [android - changing system permissions](https://iamcmotc.blogspot.com/2015/04/android-how-to-run-script-or-system.html)