Alpine Linux - User contributions [en]

User:Jlyo/WIP:s6/android

2015-04-30T18:12:33Z

Jlyo: Mark as a draft

{{Draft}}

Notes about my Alpine Linux installation on a [https://oneplus.net/one 64GB OnePlus One] phone using [http://skarnet.org/software s6] to boot Alpine's userspace.

[http://whiteboard.ping.se/Android/Debian Similar Debian instructions]

There are two boot configurations I went through:
# Boot stock Android <tt>init</tt>, chrooting into Alpine. Hooks into <tt>/data/local/userinit.d/*</tt>
# Boot a custom <tt>init</tt>, where the Android root filesystem is a chroot under Alpine, but keeping Android's <tt>init</tt> as PID 1.

==Unlock the bootloader and root your phone==
{{Warning|Unlocking your bootloader will revert your phone to it's stock image, causing you to lose all your personal data on your phone!}}

Unlocking the bootloader is necessary, however rooting your phone ("ROM") is not if you hack on the boot image initrd.

fastboot oem unlock

Flash TWRP to the recovery partition.
Install SuperSU.

==Install Alpine in a chroot==
[[Installing Alpine Linux in a chroot]]

==Hack on Android's boot.img to boot Alpine==
* Download stock boot.img, unpack, hack, repack, flash.
* Change kernel command line so SELinux is set to permissive (TODO: figure out how to return it to enforcing)

fastboot boot boot.img
fastboot flash boot boot.img

==Further investigations==
* Employ PID namespaces, so <tt>s6-svscan</tt> can be the real PID 1, and not a <tt>fork()</tt>. This requires you to change your kernel configuration and recompile the kernel.
* Mount namespaces (?). Mount namespaces are already enabled in the OnePlus kernel.
* Employ <tt>s6-sudod</tt> so Android proceses can enter the Alpine environment (without SSH)
** Figure out how to open a new PTY and/or set terminal line disciplines so we can have process control in our shell.

User:Jlyo/WIP:s6/android

2015-04-30T18:09:09Z

Jlyo: Off to a start

Notes about my Alpine Linux installation on a [https://oneplus.net/one 64GB OnePlus One] phone using [http://skarnet.org/software s6] to boot Alpine's userspace.

[http://whiteboard.ping.se/Android/Debian Similar Debian instructions]

There are two boot configurations I went through:
# Boot stock Android <tt>init</tt>, chrooting into Alpine. Hooks into <tt>/data/local/userinit.d/*</tt>
# Boot a custom <tt>init</tt>, where the Android root filesystem is a chroot under Alpine, but keeping Android's <tt>init</tt> as PID 1.

==Unlock the bootloader and root your phone==
{{Warning|Unlocking your bootloader will revert your phone to it's stock image, causing you to lose all your personal data on your phone!}}

Unlocking the bootloader is necessary, however rooting your phone ("ROM") is not if you hack on the boot image initrd.

fastboot oem unlock

Flash TWRP to the recovery partition.
Install SuperSU.

==Install Alpine in a chroot==
[[Installing Alpine Linux in a chroot]]

==Hack on Android's boot.img to boot Alpine==
* Download stock boot.img, unpack, hack, repack, flash.
* Change kernel command line so SELinux is set to permissive (TODO: figure out how to return it to enforcing)

fastboot boot boot.img
fastboot flash boot boot.img

==Further investigations==
* Employ PID namespaces, so <tt>s6-svscan</tt> can be the real PID 1, and not a <tt>fork()</tt>. This requires you to change your kernel configuration and recompile the kernel.
* Mount namespaces (?). Mount namespaces are already enabled in the OnePlus kernel.
* Employ <tt>s6-sudod</tt> so Android proceses can enter the Alpine environment (without SSH)
** Figure out how to open a new PTY and/or set terminal line disciplines so we can have process control in our shell.