I hate peecees
Well I was up till 3am fucking around with this bloody machine.
After verifying the hardware actually works it seems that the whole problem with my RAM not being found is the damn BIOS. I downloaded a bunch of BIOSs intending to try an older one and realised I hadn't installed the latest anyway. So I dropped than in and low and behold the memory came back. Yay.
So now I had that, I thought i'd try and get OpenCL working again. Ok, installed the latest (17.40) amdgpu-pro ... and fuck. Unsupported something or other in the kernel module. Sigh. I discovered that 17.30 did apparently work ... but it took a bit of digging to find a download link for it as AMD doesn't link to older releases (at this point i also found out midori has utterly shithouse network code. sigh). I finally found the right one (that wasn't corrupt), installed it and finally ...
Oh, back to 3.5G ram again. FAAARK.
At this point the power went out for the whole street so I had a shower using my phone's torch and went to bed.
Did some more digging when I got up (I was going to give up and say fuck it, but i've come this far), tried manually adding the ram using memmap, and finally confirmed the problem was the BIOS. So i tried an older one. That worked.
But only for a while, and then that broke as well. So trying the previous one ... groan.
Mabye it's time to cut my losses, it's already 1pm, the sun is out, heading for a lovely 31 degrees.
I also got rocm installed but i don't know if it works on this hardware, although at least the kernel is running ok so far.