Re: pinebook status update (20230721)

[Robert Swindells <rjs%fdy2.co.uk@localhost>]

Jun Ebihara <jun%soum.co.jp@localhost> wrote:
> Topics:
> - Tow-Boot on Pinebook Pro
>   https://tow-boot.org/devices/pine64-pinebookPro.html
>   need more testing on NetBSD.

My Pinebook Pro has been totally reliable booting NetBSD from NVMe using
Tow-Boot.

> - Pinebook GPU
>  "I think I am making a bit of progress with the DRM driver 
>   for the Pinebook."
>   http://mail-index.netbsd.org/port-arm/2022/05/12/msg007650.html

This hasn't gone backwards but haven't made much progress since then.

There are two DRM/KMS drivers for ARM GPUs, Lima and Panfrost. The
Pinebook needs Lima, Pinebook Pro needs Panfrost.

We need to import the original sources for both into the NetBSD tree
then add patches on top. Also need to add extra patches for our Linux
emulation layer.

Both require an extra component of the core DRM code that isn't in our
tree, it is currently GPL. I tried to get this dual-licenced in Linux
but didn't get consensus on doing it. A fallback could be to ask them to
dual-licence just the header then write our own implementation of the
source for it.

I broke the screen on my Pinebook and can't get the HDMI port to work
with an external display. My other dev boards with a GPU supported by
the lima driver don't have a DRM console, I have a Cubietruck and an
Odroid-C2. The lima driver does initialize but crashes when running X11
with it.

Panfrost needs one extra piece writing for our Linux emulation layer to
setup the MMU of the GPU, after this it will be ready to start debugging
on the Pinebook Pro.

I think debugging both drivers probably needs simpler tests than
starting up X11 and seeing what happens.

One of the Linux developers suggested kmscube as a test app, but it
needs OpenGL ESv2 and we don't currently build that library natively.

I have the userland Mesa code for Lima and Panfrost building in my local
tree using xsrc MesaLib.old (19.1.17), not tried adding them to MesaLib
(21.3.7) yet.