Rootfs configurator/generator for Arch Linux ARM

This collection of scripts can prepare an Arch Linux ARM (ALARM) rootfs, then optionally also apply some board-specific tweaks and flash to an SD card.

The following boards are currently supported:

• Odroid HC4
• Pine H64

However, the rootfs preparation part is completely hardware-agnostic and uses the official generic AArch64 ALARM rootfs as a base.

Usage

Download ArchLinuxARM-aarch64-latest.tar.gz from https://archlinuxarm.org/platforms/armv8/generic. Then:

sudo su
./do.sh

What does do.sh do?

• delete any existing previously-generated rootfs for this board (the board can be specified as 'none' to generate a generic rootfs)
• run extract.sh: extracts ArchLinuxARM-aarch64-latest.tar.gz to rootfs-$BOARD
• bind mount the rootfs folder onto itself, to prepare for arch-chroot
• run configure.sh and, if it exists, $BOARD/configure.sh: copy into the extracted rootfs the rootfs configuration scripts, also copy SSH key into the rootfs
• arch-chroot into the rootfs and run the configuration script
  • This is the only point where manual intervention is required, you will need to run one command inside the chroot and then enter a password for the generated system
• unmount the rootfs folder

At this point, if you've been running the individual steps manually, you can tar up the rootfs folder to save a copy of your generated rootfs. However, the do.sh script will continue with the following steps:

• run flash.sh: partition the SD card and flash the filesystem onto it
• run, if it exists, $BOARD/flash.sh: do things like install the bootloader onto the SD card and generate files for U-Boot
• sync and unmount the SD card

At this point you can put the SD card into your board and start using your system.

How is the generic ALARM rootfs modified?

The aim of this project is to generate a minimal, unbloated, but usable ALARM system for various single board computers.

The configuration script does the following things:

• set up locale, timezone, fstab, hostname
• initialize pacman and do a system update
• install basic packages such as base-devel man vim ncdu git rsync python cronie zip
• configure sudo (set up sudoers, allow passwordlesssudo ), ssh (install public keys), ufw (default deny, allow all from LAN, limit SSH)
• install log2ram to reduce SD card wear
• systemctl enable services like sshd, cronie, ufw, log2ram
• delete the default alarm user and set up a new user with the username/password that you want
• install a bashrc
• create an (empty by default) /startup.sh which runs on boot

You will want to change the locale, timezone, and bashrc parts of _configure.sh to suit your preferences, and also have it install any other packages you want to have in the base system. The provided _configuration.sh is not supposed to be a 'one thing fits all' solution.

The board-specific configuration scripts do things like set up files that U-Boot needs, and add board-specific configuration to startup.sh. These should not need to be modified.