(In reply to JerryD from comment #35)
> Well, I just ran Fedora updates which brought kernel to 5.0.7-200.fc29 and
> there was also an update to mesa-dri-drivers.x86_64 18.3.6-1.fc29. My laptop
> failed to boot with or without the raven_dmcu.bin file after this update.
> 
> I then also noted that the 5.06 kernel will boot with or without the
> raven_dmcu.bin file.  I am leaving that firmware file in place and using
> 5.06 kernel at the moment.
> 
> I suspect we have a "whack-a-mole" bug, also affectionately known as a
> Heisenbug. Or at least more than one problem overlapping another. Hard to
> say whether the problem is in the kernel or somewhere else. For sure, I can
> not boot the 5.07.

I also updated my system to kernel 5.0.7-200.fc29 and mesa-dri-drivers.x86_64
version 18.3.6-1.fc29, and here are the results for me:
original initramfs image with raven_dmcu.bin file: Unable to boot, same issue
as before.
updated initramfs image without raven_dmcu.bin file: able to boot fine.

It's unfortunate that the issue is so hard to reproduce.