Re: [Qemu-devel] Booting a guest with OVMF

[Laszlo Ersek <lersek@redhat.com>]

Alright, so we've already dealt with case #3 (--> the disk image was not
appropriate for a UEFI VM); let's see cases #1 and #2 (I downloaded and
tested the gummiboot rawhide image that you gave me).

What I did as preparation was:
- I converted the raw image to qcow2:

  qemu-img convert -p -f raw -O qcow2 \
      fedora-rawhide.iso fedora-rawhide.qcow2

- then I created an overlay so that the original never be modified:

  qemu-img create -f qcow2 -o backing_file=fedora-rawhide.qcow2 \
      overlay.qcow2

And I tested with "overlay.qcow2" (rather than /dev/sdb), always
recreating it from scratch before a test.

On 06/10/14 15:04, Kashyap Chamarthy wrote:
> Heya,
> 
> Laszlo pointed out OVMF packages for Fedora from here[1]. I tried a
> simple test using this[2] by installing Fedora onto a USB stick.
> 
> Once Fedora is installed on the USB stick (/dev/sdb), and I attempt to
> boot into the USB device as below, I get the Fedora serial console login
> prompt just fine through a QEMU vnc display:
> 
>     $ sudo qemu-system-x86_64 -machine accel=kvm -m 256 -bios \
>       /usr/share/OVMF/OVMFX64.fd  /dev/sdb)

So, this "just works (TM)" for me too, same as for you.

> However, when I try with the below QEMU invocation, I get "Boot Failed.
> EFI Floppy":
> 
>     $ sudo qemu-system-x86_64 -machine accel=kvm -m 512 -nographic \
>       -nodefconfig -nodefaults  -serial stdio \
>       -bios /usr/share/OVMF/OVMFX64.fd /dev/sdb
>     Boot Failed. EFI Floppy
>     Boot Failed. EFI Floppy 1

This happens because the image is incorrectly built. One "trick" that
you should always use is the following two options:

  -debugcon file:debug.log \
  -global isa-debugcon.iobase=0x402

(This is documented in the OVMF README.)

This will place the debug console at guest ioport 0x402, and redirect it
to the debug.log host-side file. OVMF writes a pretty verbose log to
that port.

Looking at that log, it's clear that gummiboot is actually started:

[...]
Booting EFI Floppy
PlatformBdsBootFail
[...]
Booting EFI Floppy 1
PlatformBdsBootFail
[...]
Booting EFI Hard Drive
[...]

The first two floppy boot failures are also displayed on serial (that's
what you quoted).

No hard disk boot failure is logged to serial because that boot actually
succeeds.

So, the question is, why don't you see anything on serial then? Well
because in the image file neither gummiboot nor the kernel are
configured to care about serial at all. And, in case #2, you have no VGA
etc; only a serial line.

Try this:
- boot the image like in case #1 (== normal VGA),
- log in, and navigate to /boot/loader/entries/
- edit the gummiboot conf file you find there,
- append "console=tty console=ttyS0" to the "options" line
- shut down the guest cleanly (shutdown -h now)
- start the guest again, like in case #2 (== headless).
- You should get a login prompt on serial. (I do.)

Thanks
Laszlo