Installing the Debian X32 port on a VM or real machine

Debootstrap

Debootstrap will install the system for us, but unfortunately there is no convenient way to get the debian-ports GPG keys into the rescue environment, so we'll just run with disabled signature checks.

debootstrap --no-check-gpg --arch=x32 unstable /target http://ftp.ports.debian.org/debian-ports/

You might notice that isc-dhcp-client fails to install at this step, this is not critical and will be dealt with later.

Chrooting

The next step is to enter the target system in a chroot:

mount --bind /dev /target/dev
mount --bind /proc /target/proc
mount --bind /sys /target/sys
chroot /target

First we'll do some basic system configuration.

The fstab you write needs to match the configured partition layout, in this example the layout is a single root partition (no /boot, no swap space). Using UUID=... notation here is also advisable but not fun to type out by hand (and irrelevant for a single-disk VM).

Here you should also uninstall the package that failed to install earlier.

passwd root
echo "/dev/sda1 / ext4 rw 0 1" >/etc/fstab

Repository configuration

The X32 repository does not include a Linux kernel package. This requires us to add the amd64 repository so we can install a kernel, but we need to make sure only linux-image but nothing else is pulled from there (via APT pinning).

Configure APT as follows:

apt install -y debian-ports-archive-keyring
cat >/etc/apt/sources.list
deb [arch=x32] http://ftp.ports.debian.org/debian-ports unstable main
deb [arch=amd64] http://deb.debian.org/debian unstable main
^D
cat >/etc/apt/preferences.d/amd64
Package: linux-image*:amd64
Pin: release b=amd64
Pin-Priority: 500

Package: *
Pin: release b=amd64
Pin-Priority: -1
^D
dpkg --add-architecture amd64
apt update

Kernel & Bootloader

When asked by GRUB, select your primary hard drive (here: /dev/sda) as installation device.

GRUB will ask for the Linux command line, which needs to be syscall.x32=y.

Cleaning up

The installation failure during debootstrap has left some files misconfigured.

The purpose of policy-rc.d and the modification to start-stop-daemon is that services are not started up during package installation. Since we're finished installing, these need to be undone:

mv /usr/sbin/start-stop-daemon.REAL /usr/sbin/start-stop-daemon

Lastly exit the chroot, umount the partitions and reboot:

sync; reboot

Why does isc-dhcp-client fail to install?

pandoc itself is not available on x32 since one of its dependencies is also missing.

This is tracked as Debian bug #956041 and has been solved in February 2021.

Quick DHCP setup using systemd-networkd

Since isc-dhcp-client would provide the DHCP client we have a problem when we want to connect our freshly installed system to a network.

Fortunately, setting up DHCP with systemd-networkd is quite easy:

cat >/etc/systemd/network/eth.network
[Match]
Name=en*
[Network]
DHCP=ipv4
^D
systemctl enable --now systemd-networkd

Installing standard system software

tasksel can take care of installing software you'd usually find on a standard Debian installation (man pages, locale support, Perl, ...).

tasksel install standard

Same issue as before: isc-dhcp-client and bind9-related packages are uninstallable, so that requires some manual working around:

eval $(tasksel -t install standard | tr ' ' '\n' | egrep -v 'isc-dhcp-client|^bind9-' | tr '\n' ' ')