Do we even know how to access the GPU? On x86-based systems there would be a standard bus (PCI/AGP/PCIe) to enumerate the the graphics device, but my impression is ARM doesn't have such things.
A lot of the recent improvement in graphics on Linux has come from manufacturers deciding to become cooperative rather than there being more people reverse-engineering graphics drivers. (Broadcom is contributing support for the Pi 4; AMD added its drivers to upstream; nVidia releases binary drivers to support enterprise customers.)
A lot of the recent improvement in graphics on Linux has come from manufacturers deciding to become cooperative rather than there being more people reverse-engineering graphics drivers. (Broadcom is contributing support for the Pi 4; AMD added its drivers to upstream; nVidia releases binary drivers to support enterprise customers.)