Create jammy rootfs image for QEMU in command-line

qemu-create-rootfs.sh

#!/bin/sh

# check file exists
if [ -f "rootfs.qcow2" ]; then
        echo -n "Overwrite existing rootfs.qcow2? [y/N] > "
        read ans
        if [ "$ans" != "y" ]; then
                exit 0
        fi
fi
qemu-img create -f qcow2 rootfs.qcow2 30G

echo ""
echo "===================================================================================="
echo "Type 'e' in GRUB menu and add 'console=ttyS0' at the end of line starts with 'linux'"
echo "===================================================================================="
echo ""

# check file exists
if [ ! -f "ubuntu-22.04.5-live-server-amd64.iso" ]; then
        echo "Downloading ubuntu-22.04.4-live-server-amd64.iso..."
        # wget https://mirror.kakao.com/ubuntu-releases/jammy/ubuntu-22.04.5-live-server-amd64.iso
        wget https://releases.ubuntu.com/jammy/ubuntu-22.04.5-live-server-amd64.iso
fi

echo "Verifying..."
echo "9bc6028870aef3f74f4e16b900008179e78b130e6b0b9a140635434a46aa98b0 *ubuntu-22.04.5-live-server-amd64.iso" | sha256sum -c
if [ $? -ne 0 ]; then
        exit 1
fi

echo ""
echo "Require root permission to enable KVM"
sudo qemu-system-x86_64 \
-enable-kvm \
-smp 2 \
-m 4G \
-drive file=rootfs.qcow2,if=virtio,id=disk0 \
-cdrom ubuntu-22.04.5-live-server-amd64.iso \
-nographic