Some how,when I first used the installer iso, it didn't actually install the basic system and the amd-firmware files, so when it came back to reboot/finish the install, it hung up with the scrambled amd graphics problem. At best. I could get a grub prompt which enabled me to see that there was no kernel, etc files.

The  problem then was that every time I tried the installer iso, it was scrambled graphics, which was why I was using attempting an install with the desktop-live, which also kept on failing.

The motherboard is an ASUS B550M-A and I expected it to be like the ASUS B350 which has a very clear bios setting of legacy or UEFI boot. Lucked out there with the new motherboard.  I've stuck with legacy boot as previous attempts to use UEFI boots have been repeatedly unsuccessful.

I usually stick with stable as this is my main/only "work" computer and I have tasks to carry out.
Went to backports  when the 'present" was a AMD RX 5700 XT gpu with dual 2K monitors. Really could have used that decades ago when crunching text/documents.

Any way, thanks everyone for their ideas. As usual, a solution is eventually arrived at..

Can anyone give me some tips to overcome this?

Please stop posting vague, confusing descriptions. Instead post clear explanations of what you actually see.

Do not ask about XY problems. Instead simply state the actual issue, which in this case is that your AMD graphics are not working. UEFI has *nothing* to do with that and installing a non-UEFI system will not help. Please change the thread title to reflect this and help prevent further confusion and noise.

@fsmithred's suggestion to try a newer kernel might help. Brand new hardware might not be supported by chimaera's six month old kernel.

Unfortunately though the AMD graphics firmware hasn't been updated since 2021-08-18, even in ceres, so you might have to draw it directly from upstream:

apt install git
git clone https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git
cp -r linux-firmware/amdgpu /lib/firmware

If a newer kernel is needed try one of the daedalus isos or try this iso with a backports kernel that I made for testing new hardware: https://get.refracta.org/files/experime … 0_2148.iso

BTW: I have stumbled across an effect that Chimaera in efi mode does not mount the efivars on first real boot. You have to do that manually once I think, then it works.

rolfie

I had another go at an install with live iso, blowing all the previous install away and all I ended yo was GRUB being continually streamed across the screen, which required a power olf to clear it.

I dont quite understand what you need to do, you say here:

So are you looking to wipe the hard drive clean an install a new devuan chimaera system or no?

If you are looking to clear partitions on the drive and start again, use below command.

sudo sgdisk -Z /dev/sda

As this system has a amdgpu installed installed it isn't possible to simple attempt a fresh install as the graphics are scambled and unreadable. Previously, i could swap out the gpu to something non-amd, but I have no other gpu/videos ion stock and it would be about a fortnight delay and rather expensive.

Unfortunatly, there is nothing of the kernel.image.vmlinuz installed so I can not follow the set-root/linux/initrd/boot proceedure and I know of no way of moving file via the grub prompt.

So, I'm trying to get a system installed via the devuan-live iso install script.
The problem is an efi boot partition and once again, efi booting will not work.
So I need to wipe out the efi-boot setting and hopefully replace it with a legacy-grub boot.
Unfortunately, repeated attempts to do this alway reach a stage where it wants to set an efit boot. at which point i exit and try again.

Can anyone give me some tips to overcome this?  T.I.A.