qemu-efiboot

#!/bin/bash
# SPDX-License-Identifier: LGPL-2.1-or-later

set -euo pipefail

SCRIPT_FILENAME=$(basename "${BASH_SOURCE[0]}")
DISK=
QEMU_EXTRA_ARGS=()

usage() {
	cat - <<-EOF
	USAGE:
	$SCRIPT_FILENAME [image] [options|qemu-options]

	Wrapper with some default arguments to boot a raw/qcow2 image in efi

	DISK must be the first non-positinal argument. The VARS file from edk2
	will be copied to the same directory as the vm is located.
	All options not specific to this wrapper are forwarded to qemu.

	OPTIONS:
	    -h, --help		Show this help

	EXAMPLES:

	Boot image:

	    $ sudo $SCRIPT_FILENAME disk.qcow2

	Create new image "layer" and boot:

	    $ qemu-image create -f qcow2 -F qcow2 -b base.qcow2 dev.qcow2
	    $ sudo $SCRIPT_FILENAME dev.qcow

EOF
}

argerr() {
	echo "invalid argument: $*" >&2
	echo >&2
	usage >&2
	exit 1
}

err() {
	echo "error: $*" >&2
	exit 1
}

parse_args() {
	DISK=$1
	shift

	while [[ $# -gt 0 ]]; do
		case "$1" in
		-h|--help)
			usage
			exit 0
			;;
		*)
			QEMU_EXTRA_ARGS+=("$1")
			;;
		esac
		shift
	done

	if [[ ! -e "$DISK" ]]; then
		argerr "Missing image to boot - $DISK does not exist"
	fi
}

parse_args "$@"

# Inspect options to avoid setting incompatible default options.
uses_daemonize=no
uses_nic=no
for option; do
	if [[ "$option" == "-daemonize" ]]; then
		uses_daemonize=yes
	elif [[ "$option" == "-nic" ]]; then
		uses_nic=yes
	fi
done

#
# Disk and format
#
if [[ "$DISK" == *.qcow2 ]]; then
	image_format=qcow2
else
	image_format=raw
fi

qemu_args=(
	"-machine" "accel=kvm"
	"-smp" "2"
	"-m" "2048"
	"-drive" "if=virtio,id=hd,file=$DISK,format=$image_format"
	"-object" "rng-random,filename=/dev/urandom,id=rng0"
	"-device" "virtio-rng-pci,rng=rng0,id=rng-device0"
)

#
# Network
#
if [[ "$uses_nic" != "yes" ]]; then
	port_mapping=(
		"4022" "22" # ssh
	)
	hostfwd=$(printf ",hostfwd=tcp::%s-:%s" "${port_mapping[@]}")
	qemu_args+=("-nic" "user,model=virtio$hostfwd")
fi

# 
# Firmware files
# 
ovmf_paths=(
	"/usr/share/edk2/x64/OVMF_CODE.fd"
	"/usr/share/edk2/x64/OVMF.fd"
	"/usr/share/qemu/OVMF.fd"
	"/dev/null"
)

for ovmf_code in "${ovmf_paths[@]}"; do
	if [[ -f "$ovmf_code" ]]; then
		break
	fi
done
if [[ "$ovmf_code" == "/dev/null" ]]; then
	err "No suitable OVMF firmware found."
fi

ovmf_vars="${ovmf_code/.fd}"
ovmf_vars="${ovmf_vars/_CODE}"
ovmf_vars="${ovmf_vars}_VARS.fd"
local_ovmf_vars="$(dirname "$DISK")/$(basename "$ovmf_vars")"
if [[ ! -e "$local_ovmf_vars" ]]; then
	cp "$ovmf_vars" "$local_ovmf_vars"
fi

qemu_args+=(
	"-drive" "if=pflash,format=raw,readonly=on,file=$ovmf_code"
	"-drive" "if=pflash,format=raw,file=$local_ovmf_vars"
)

qemu_args+=("${QEMU_EXTRA_ARGS[@]}")

echo Running qemu with:
echo "    qemu-system-x86_64" "${qemu_args[@]}"
exec qemu-system-x86_64 "${qemu_args[@]}"