bug#33656: Hard locks on boot (uefi system) via usb

[Keno Goertz <goertzke@informatik.hu-berlin.de>]

I think I just encountered the same bug today. I got stuck at some
completely irrelevant kernel message in the boot screen. Couldn't
switch to TTY, nada. I worked around it by adding

> modprobe.blacklist=amdgpu

To the kernel parameters in grub. But the graphical installer still
didn't work because the resolution wasn't right, so I also had to add

> vga=792

Now, I can see the installer. I hope this resolves the issue for you,
too. I also think that these kernel parameters should be included by
default, because

1) amdgpu does not work without binary blobs AFAIK, so it can just be
blacklisted
2) vga=792 corresponds to 1024×768x24, which is supported by pretty
much any screen I've ever encountered. I'm not sure what happens when
the screen doesn't support the resolution specified in the vga kernel
parameter, but I think it just falls back to the standard, so it
shouldn't do any harm