8/7/2019 Building a Bootable GRUB Legacy Image for QEMU

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Building a Bootable GRUB Legacy Image for QEMU

Building a Bootable GRUB Legacy

Image for QEMUFinnbarr P. Murphy

(fpm@fpmurphy.com)

Recently, as a moderator on a Unix and GNU/Linux-related forum, I assisted a member who was

having a problem creating a bootable image for use with QEMU. As a result of this experience, I

decided to write this post to demonstrate to others how easy the process is.

Without further ado, here is a simple Bash shell script to create a bootable image containing only

the GRUB Legacy boot loader which is bootable using QEMU.

#!/bin/bash

#

# Finnbarr P. Murphy 01/03/2011

#

# Create a bootable image containing just Legacy Grub

# and use QEMU to test boot it if requested

#

if (( $(id -u) != 0 ))

then

echo "ERROR: This script must be run as root" 1>&2

exit 1

fi

GRUBFILEDIR=/usr/share/grub/x86_64-redhat

IMAGE=myimage

LOOPDEV=$(/sbin/losetup -f)

dd if=/dev/zero of=${IMAGE}.img bs=512 count=2880

if [[ -d ${IMAGE} ]]

then

rm -rf ${IMAGE}

fi

mkdir -p ${IMAGE}/boot/grub

cp ${GRUBFILEDIR}/stage1 ${IMAGE}/boot/grub

cp ${GRUBFILEDIR}/stage2 ${IMAGE}/boot/grub

/sbin/losetup ${LOOPDEV} ${IMAGE}.img

/sbin/mke2fs ${LOOPDEV}

mount ${LOOPDEV} -o loop /mnt

chmod 777 /mnt

cp -aR ${IMAGE}/* /mntumount /mnt

cat