Skip to main content

Get QEMU to boot EFI

It took me some Googling and experiments before I saw it work the first time: an EFI boot inside QEMU. I was blown away.

What is an EFI boot in QEMU good for? Two things:

  1. To predict about future bootability on actual EFI hardware.

  2. To make a Linux installer work with WLAN as if it's LAN.

My case was a bit of both combined, but that's a story for another post.

To have QEMU do an EFI boot, besides QEMU it takes:

  • OVMF installed (e.g. package sys-firmware/edk2-ovmf on Gentoo)

  • An EFI-only test image for proof (e.g. MemTest86 5.x or later)

Then:

wget https://www.memtest86.com/downloads/memtest86-usb.zip
unzip memtest86-usb.zip

sudo qemu-system-x86_64 \
    -enable-kvm -m 2G \
    -bios /usr/share/edk2-ovmf/OVMF_CODE.fd \
    -drive file=memtest86-usb.img,format=raw

Nice!

Arguments -enable-kvm -m 2G are optional and just make things run faster. The location of BIOS file OVMF_CODE.fd depends on your Linux distrubution:

  • Debian: /usr/share/OVMF/OVMF_CODE.fd (not /usr/share/qemu/OVMF.fd)

  • Gentoo: /usr/share/edk2-ovmf/OVMF_CODE.fd

  • Ubuntu: /usr/share/OVMF/OVMF_CODE.fd (not /usr/share/qemu/OVMF.fd)

Enough EFI for today.

Best, Sebastian