Where did my 128GB of video RAM go? AMD GPU BIOS gotcha for LLM builders

Adding amdgpu.gttsize=126976 and ttm.pages_limit=32505856 to the kernel parameters, while setting the VRAM in the BIOS to the minimum value, enables unified memory to work as expected on AMD Strix Halo running Linux.

The https://strixhalo.wiki has most of the info you need to get LLMs running on these machines.