Installing Gentoo on Android

I am tired of re-installing gentoo (from an chroot approach) on my phone by connecting parts from different resources and so here is the guide to do it all in a go.

This guide assumes the prerequisite of a rooted phone. Just fire up an adb shell / termux and follow this :

First we proceed with downloading the correct stage3 tarballs. Copy it in your phone's storage.

Then we make a folder for the Gentoo root. Since we are following SharkBait, we will use data/gnu as root. Copy the stage3 into it.

mkdir -p /data/gnu
cp /sdcard/stage3-arm64-* /data/gnu/
cd /data/gnu

Then we extract the stage3

tar xpvf stage3-* `--xattrs-include='*.*'` --numeric-owner
# no those backticks are not just a content generation error

After this we will copy the DNS information in /etc/resolve.conf so that networking works after entering the new environment.

cp --dereference /etc/resolv.conf /data/gnu/etc/

Mount the required filesystems:

cd /
mount -t proc proc /data/gnu/proc
busybox mount --rbind /dev /data/gnu/dev
busybox mount --rbind /sys /data/gnu/sys

Finally we enter the new environment:

chroot /data/gnu /bin/bash
source /etc/profile
export PS1="(chroot) ${PS1}"

Add Portage to gid 3003(inet):

groupadd -g 3003 inet && gpasswd -a portage inet

Configuring Portage and Emerging Packages:

These for preventing mount errors while emerging:

mkdir -p /dev/shm
mount -t tmpfs -o nodev,nosuid,noexec,mode=1777,size=6144m tmpfs /dev/shm
mount /dev/pts -o remount,gid=5,mode=620

Unless you want to stare at your phone for more than 4 hours, or just have a lot of time, I would recommend you to perform these steps while before going to bed, because this takes time. The best approach would be to do all this in a wake-lock(ed) termux session.

emerge-webrsync
emerge --ask --verbose --update --deep --newuse @world

Configuring Timezone and Locales

Set your timezone with the correct one from /usr/share/zoneinfo :

echo "Asia/Calcutta" > /etc/timezone
emerge --config sys-libs/timezone-data

Configure locales by uncommenting the correct one from /etc/locale.gen.

locale-gen
eselect locale list
# proceed to chose the desired locale
env-update && source /etc/profile && export PS1="(chroot) ${PS1}"

I believe I have covered the information required until device specific steps. Now the part left is to add your device specific unofficial overlay, or continue with the official one, if your device is enlisted in it. An upcoming guide will guide you to make your kernel for SharkBait and finally, deploy SharkBait. Deploying SharkBait currently is a breeze for devices shipping with Android version lower than 9. Since mine did not, I would have to hack around the current script. If the results turn out to be positive, expect another blog coming up. Till then, Happy Hacking !