- Add VramManager (vram.rs): bump-allocator with free-list coalescing for BAR2 VRAM
aperture. gem_create auto-selects VRAM for scanout buffers (width>0 && height>0)
with fallback to system RAM on exhaustion. gem_close frees VRAM when gpu_addr is
within BAR2 range. ensure_gem_gpu_mapping detects VRAM-backed buffers and skips
GTT mapping.
- Add amdgpu_dc_upload_firmware() stub documenting DMUB firmware upload sequence
prerequisites (requires Linux DC tree compilation).
- Replace generic 'unavailable' CS ioctl/virgl error messages with specific
messages documenting what component is needed (amdgpu core driver, Mesa radeonsi/
iris cross-compilation, CS ioctl backend).
vasilito
61f758a881