Customizing ArchLinux Installation Media

A short plug for hzArchiso, and general thoughts on archiso

Background

I recently had to switch server boxes, due to a cascade of hardware errors stemming from a remodeling of my home. The new box, however, did not see fit to include a WiFi card, which meant I had to add one of my own, a Realtek 88XXau, the kernel module for which is on the AUR.

This meant the official ArchLinux ISO would not be able to connect to the internet, and short of copying over files from PC to PC manually with a USB stick, my only option was to build my own installation media.

This then snowballed a little into a customized live-USB project called hzArchiso with a bunch of bells and whistles I need ¹. This post is not meant to supplant the ArchWiki and does not provide an in-depth introduction to using archiso ².

Makepkg tweaks

When building system images, I tend to modify my /etc/makepkg.conf to use all cores and also use the faster mold linker (detailed on the ArchWiki):

1MAKEFLAGS="-j$(nproc)"
2GITFLAGS="--filter=tree:0"
3LDFLAGS="... -fuse-ld=mold"
4RUSTFLAGS="... -C link-arg=-fuse-ld=mold"

• Do not use march=native or other processor specific flags.
• $GITFLAGS support needs pacman-git as of July 2023, check the ArchWiki for details.

Managing AUR packages

repoctl (repo) is a fantastic tool for setting up local repositories of packages, which make it pretty trivial to add to an installation media as well. Since the repository is meant only for use with the installation media, it is sufficient to define it in only within the project, as discussed on the archiso ArchWiki entry.

Updating / adding packages can be done with:

 1## Once
 2repoctl conf new ~/pkgs/hzarchiso.db.tar.gz
 3repoctl reset
 4## Separate terminal
 5repoctl serve
 6## Everytime
 7mkdir tmpUpd && cd tmpUpd
 8for pkg in $(cat ../aurpkgs.txt); do
 9    (
10        repoctl down "$pkg"
11    )
12done
13for dir in *; do cd $dir; makepkg -cs && repoctl add *.pkg.tar.zst && cd ../  && rm -rf $dir || cd ../; done
14cd ../ && rm -rf tmpUpd

Kernel modifications

It turns out that my new machine required a wireless card patch. I haven’t compiled a kernel for several years now³. The process was gratifyingly simplistic, following some discussion threads on the Archlinux Forums.

Essentially:

• Grab the relevant patchset
• Add it to the PKGBUILD
• Build (optionally add to local repo)
• Profit

1..
2source = (
3    "v2-wifi-iwlwifi-pcie-add-device-id51F1-for-killer-1675.patch::https://lore.kernel.org/linux-wireless/20230608082725.353150-1-yi@yikuo.dev/raw"
4)
5..
6b2sums=(
7    'e9f30d94b84a019c38842fbb468c64522782d14a347a12442704e185b4d9b131dc25661e7e9b9640ac20e0c949f5fa0375739d0c1badd0a0c637408a56091118'
8)

For building the nitrous kernel (an unofficial one for newer hardware) then:

1repoctl down linux-nitrous
2# modify the PKGBUILD
3makepkg -si

Building kernels takes around as long as I remember, several hours at on an older laptop.

Using hzArchiso

The general idea is to follow along with the ArchWiki installation steps (perhaps augmented by the dual-booting instructions) For some users, the archinstaller script (repo) might be a better option. There’s also an offlineInst.sh script which can be used to replicate the environment on the live-USB.

Conclusions

Modifying ArchLinux installation media is fun. Even if the exact set of packages bundled with hzArchiso isn’t for most, it serves as a useful blueprint for branching out into their own ISOs. Pull requests and other issues / contributions are always welcome as well, and more detailed build information is on the repo and on the ArchWiki. Personally, I expect to update the iso every now and then with more of my configuration / defaults / every time I get a new machine. I’ve also been using btrfs for almost a decade without any trouble ⁴, which is anecdotal but nice.