How to test ARM Ubuntu under Qemu the easiest way?

Question

I would like to play with ARM version of Ubuntu (with graphical support) under Qemu, but I have problems finding any tutorial on how to get it done most easily (I would prefer to just download some image and run one command to execute it). How to achieve that with least hassle?

Answer 1

In this answer: https://askubuntu.com/questions/281763/is-there-any-prebuilt-qemu-ubuntu-image32bit-online/1081171#1081171 I have described the following working setups for Ubuntu 18.04 guest / host:

• cloud image arm64: quickest setup to get started
• debootstrap arm64: reasonably quick, but allows for more image customization

Those setups provide prebuilt disk images, and don't go through the installer. They are the best choices that I've seen so far.

Next, I've also managed to run the arm64 server image on QEMU. However, this goes through the installer, which is borderline impractically slow to do, unless you are not on an ARM host with KVM. This is specially painful because dozens of interactions are required to finish installation.

Here is the server script, tested on an Ubuntu 18.10 host:

#!/usr/bin/env bash

set -eux

# Tested on Ubuntu 18.10.
# - https://superuser.com/questions/942657/how-to-test-arm-ubuntu-under-qemu-the-easiest-way
# - https://askubuntu.com/questions/797599/how-to-run-ubuntu-16-04-arm-in-qemu

# Parameters.
# This filename may need updating, check http://cdimage.ubuntu.com/releases/18.04/release/
id=ubuntu-18.04.3-server-arm64   
#id=debian-9.6.0-arm64-xfce-CD-1
img="${id}.img.qcow2"
img_snapshot="${id}.img.snapshot.qcow2"
iso="${id}.iso"
flash0="${id}-flash0.img"
flash1="${id}-flash1.img"

# Images.
if [ ! -f "$iso" ]; then
  wget "http://cdimage.ubuntu.com/releases/18.04/release/${iso}"
fi
if [ ! -f "$img" ]; then
  qemu-img create -f qcow2 "$img" 1T
fi
if [ ! -f "$img_snapshot" ]; then
  qemu-img \
    create \
    -b "$img" \
    -f qcow2 \
    "$img_snapshot" \
  ;
fi
if [ ! -f "$flash0" ]; then
  dd if=/dev/zero of="$flash0" bs=1M count=64
  dd if=/usr/share/qemu-efi/QEMU_EFI.fd of="$flash0" conv=notrunc
fi
if [ ! -f "$flash1" ]; then
  dd if=/dev/zero of="$flash1" bs=1M count=64
fi

# Run.
#
# cdrom must be scsi or else the installation fails midway with:
#
# > Detect and mount CD-ROM
# >
# > Your installation CD-ROM couldn't be mounted. This probably means
# > that the CD-ROM was not in the drive. If so you can insert it and try
# > again.
# >
# > Retry mounting the CD-ROM?
# > Your installation CD-ROM couldn't be mounted.
#
# This is because the drivers for the default virtio are not installed in the ISO,
# because in the past it was not reliable on qemu-system-aarch64.
#
# See also:
# https://bazaar.launchpad.net/~ubuntu-testcase/ubuntu-manual-tests/trunk/view/head:/testcases/image/1688_ARM64_Headless_KVM_Guest
qemu-system-aarch64 \
  -cpu cortex-a57 \
  -device rtl8139,netdev=net0 \
  -device virtio-scsi-device \
  -device scsi-cd,drive=cdrom \
  -device virtio-blk-device,drive=hd0 \
  -drive "file=${iso},id=cdrom,if=none,media=cdrom" \
  -drive "if=none,file=${img_snapshot},id=hd0" \
  -m 2G \
  -machine virt \
  -netdev user,id=net0 \
  -nographic \
  -pflash "$flash0" \
  -pflash "$flash1" \
  -smp 2 \
;

GitHub upstream.

See also this for Raspberry Pi emulation: https://stackoverflow.com/questions/28880833/how-to-emulate-the-raspberry-pi-2-on-qemu/45814913#45814913

amd64 desktop shown at: https://askubuntu.com/questions/884534/how-to-run-ubuntu-16-04-desktop-on-qemu/1046792#1046792