Setup and install OpenBSD in Qemu with a Virtual Risc-V Instance

risc-v_qemu.sh

#!/usr/bin/env bash
# vim: set sw=4 sts=4 et ft=sh :
# -*- mode:bash; -*-
# -------------------------------------------------------
# Copyright (C) 2025 by Anoduck, The Anonymous Duck
# -------------------------------------------------------
# https://anoduck.mit-license.org
# -------------------------------------------------------
# Installation method derived from the below blog post:
# https://briancallahan.net/blog/20220418.html
# -------------------------------------------------------
# mirror list: https://www.openbsd.org/ftp.html
MIRROR="https://cdn.openbsd.org/pub/OpenBSD"
RELEASE="snapshots"
MINIROOT="miniroot78.img"
VMROOT="/var/vmm/risc-v"
LIBDIR="/usr/local"
VMDISK="risc-v_disk.raw"
FWJUMP="${LIBDIR}/share/opensbi/generic/fw_jump.bin"
UBOOT="${LIBDIR}/share/u-boot/qemu-riscv64_smode/u-boot.bin"
INSTALLFILE="${VMROOT}/.riscv-install"

if ! [[ -d "$VMROOT" ]]; then
	sudo mkdir -m 770 -p "$VMROOT"
	sudo chown -R nobody:staff "$VMROOT"
fi

cd "$VMROOT" || return
if [[ "$PWD" != "$VMROOT" ]]; then
	cd "$VMROOT" || exit
fi

miniroot() {
	test -f "${VMROOT}/${MINIROOT}" && return # download once
	url="${MIRROR}/${RELEASE}/riscv64/${MINIROOT}"
	curl -o "${MINIROOT}" "${url}"
}

createrootdisk() {
	test -f "${VMROOT}/${VMDISK}" && return # create once
	qemu-img create -f qcow2 "$VMDISK" 60G # create 10 GB disk
}

opensbi() {
	test -f ${FWJUMP} && return # Do not install if already present
	if [[ $(uname -s) == "OpenBSD" ]]; then
		sudo pkg_add -U "opensbi"
	else
		f="opensbi.tgz"
		test -f "${f}" && return # download and extract once.

		url="${MIRROR}/${RELEASE}/packages/amd64/opensbi-0.9p0.tgz"
		curl -o "${f}" "${url}"

		tar -xzf "${f}" "${LIBDIR}share/opensbi/generic/fw_jump.bin"
	fi
}

uboot() {
	test -f ${UBOOT} && return # Do not install if already present
	if [[ $(uname -s) == "OpenBSD" ]]; then
		sudo pkg_add -U "u-boot-riscv64"
	else
		f="uboot.tgz"
		test -f "${f}" && return # download and extract once.

		url="${MIRROR}/${RELEASE}/packages/amd64/u-boot-riscv64-2021.07p0.tgz"
		curl -o "${f}" "${url}"

		tar -xzf "${f}" "${LIBDIR}share/u-boot/qemu-riscv64_smode/u-boot.bin"
	fi
}

setup() {
	test -f ${INSTALLFILE} && return # Do not setup is already setup.

	miniroot
	createrootdisk
	opensbi
	uboot
	touch "${INSTALLFILE}"
	echo "Your image is ready to run"
}

run() {
	qemu-system-riscv64 \
		-machine virt \
		-nographic \
		-m 2048M \
		-smp 2 \
		-bios "${FWJUMP}" \
		-kernel "${UBOOT}" \
		-device virtio-net-device,netdev=net -netdev user,id=net \
		-device virtio-blk-device,drive=sd -drive file=${MINIROOT},if=none,id=sd \
		-device virtio-blk-device,drive=hd -drive file=${VMDISK},if=none,id=hd
}

clean() {
	rm "${INSTALLFILE}"
	rm "${VMDISK}"
	echo "Your Cleaned"
}

case $1 in
    setup)
        setup
        ;;
    run)
		run
		;;
	clean)
		clean
		;;
	*)
		echo "Your choices are setup, run, and clean"
esac