Check if an ISO or USB Drive is Bootable using QEMU

Qemu is a generic and open source machine emulator and virtualizer. This article will show you how to check and test if an ISO or USB Drive is bootable using Qemu in the Linux operating system. In my opinion this is a cool way to confirm whether or not image files (ISO) and USB drives/devices should be expected to be bootable during boot of a normal x86/x64 desktop/laptop/server.

With a Bootable drive, you can not only install distro applications, you can also use the disk to test the desktop experience of Ubuntu without needing to meddle with your computer’s configuration or even help in fixing any configuration issues.

Full-system

emulation

Run operating systems for any machine, on any supported architecture

User-mode

emulation

Run programs for another Linux/BSD target, on any supported architecture

Virtualization

Run KVM and Xen virtual machines with near native performance

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Install Qemu if you have not already:

• Arch: pacman -S qemu
• Debian/Ubuntu: apt-get install qemu
• Fedora: dnf install @virtualization
• Gentoo: emerge --ask app-emulation/qemu
• RHEL/CentOS: yum install qemu-kvm
• SUSE: zypper install qemu

You can also download Qemu directly from their website for various platforms.

The following packages were installed on my machine after apt install qemu.

ipxe-qemu-256k-compat-efi-roms/focal,focal,now 1.0.0+git-20150424.a25a16d-0ubuntu4 all [installed]
ipxe-qemu/focal-updates,focal-updates,now 1.0.0+git-20190109.133f4c4-0ubuntu3.2 all [installed]
libvirt-daemon-driver-qemu/focal-updates,now 6.0.0-0ubuntu8.11 amd64 [installed]
qemu-block-extra/focal-updates,focal-security,now 1:4.2-3ubuntu6.17 amd64 [installed]
qemu-kvm/focal-updates,focal-security,now 1:4.2-3ubuntu6.17 amd64 [installed]
qemu-system-common/focal-updates,focal-security,now 1:4.2-3ubuntu6.17 amd64 [installed]
qemu-system-data/focal-updates,focal-updates,focal-security,focal-security,now 1:4.2-3ubuntu6.17 all [installed]
qemu-system-gui/focal-updates,focal-security,now 1:4.2-3ubuntu6.17 amd64 [installed]
qemu-system-x86/focal-updates,focal-security,now 1:4.2-3ubuntu6.17 amd64 [installed]
qemu-utils/focal-updates,focal-security,now 1:4.2-3ubuntu6.17 amd64 [installed]
qemu/focal-updates,focal-security,now 1:4.2-3ubuntu6.17 amd64 [installed]

 

Check if an image file (ISO, etc) is bootable

The -m parameter controls how much memory in MB is to be allocated.

sudo qemu-system-x86_64 -boot d -cdrom "image.iso" -m 512

Check if your real cdrom is bootable

It is also possible to use your regular cdrom device too. If the device is /dev/cdrom you can boot a cd in the device like that:

sudo qemu-system-x86_64 -boot d -cdrom /dev/cdrom -m 512

 

Check if a USB drive is bootable

Method 1:

This first method will be using the block device path (/dev/sdx):

sudo qemu-system-x86_64 -hda /dev/sdx

Method 2:

Get the host bus and host address identifiers from your USB drive:

lsusb

# Output from lsusb command
Bus 002 Device 005: ID 090c:1000 Silicon Motion, Inc. - Taiwan (formerly Feiya Technology Corp.) Flash Drive
Bus 002 Device 004: ID 05e3:0616 Genesys Logic, Inc. hub
Bus 002 Device 003: ID 0bda:0411 Realtek Semiconductor Corp. 4-Port USB 3.0 Hub
Bus 002 Device 002: ID 0bc2:ab28 Seagate RSS LLC BUP BK
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub

The thumb drive I’m targeting is the Silicon Motion at bus 002, device 005.

sudo qemu-system-x86_64 -m 512 -enable-kvm -usb -device usb-host,hostbus=2,hostaddr=005

 

Check if a USB drive is bootable and install to disk image

If you want to install a distribution to a harddisk image file, you need to create harddisk image file first.

Create the raw disk image file to install onto:

qemu-img create mydisk.img 15G
sudo qemu-system-x86_64 -boot d -cdrom image.iso -m 512 -hda mydisk.img

 

Check if an ISO image is bootable plus control CPU-related resources

sudo qemu-system-x86_64 -boot d -drive format=raw,file=$HOME/mydisk.img \
-enable-kvm -bios /usr/share/qemu/OVMF.fd -cpu host -smp cpus=8,cores=4,\
threads=2,sockets=1 -m 1024 -cdrom image.iso