Tomato and Cherry Support in Mainline Linux

[Dylanger Daly]

Hi All,

I'm trying to get my Acer Spin 513 (Tomato) booting vanilla Linux Kernel/Mainline Linux however I don't see Device Trees for Tomato or the Cherry baseboard in https://github.com/torvalds/linux/tree/master/arch/arm64/boot/dts/mediatek yet, from what I can tell MediaTek are currently up-streaming better MT8195 support as we speak - https://lkml.org/lkml/2022/6/23/2046.

I just wanted to ask if it would be possible to upstream the Device Tree for Tomato and Cherry?

Thank you ChromiumOS developers! :)

[Nicolas Dufresne]

Hi Dylan,

upstreaming is actively being worked on by Mediatek indeed, but takes time. In order to test the progress, my colleague maintains a tracking branch of linux-next and any missing mailing patches that aren't accepted yet, plus some quick integration fix for the things that didn't work out-of-the-box together. Be aware that this branch is rebased often (forced pushed) and breaks often for a day or two. This is not suitable of production use.

https://gitlab.collabora.com/google/chromeos-kernel/-/tree/mt8195-tracking-master-rollin

Not everything works correctly yet, I will let you discover since there is too much on a laptop to list them all. Though, by building mesa and gstreamer from git, I get Gnome 42 working very well, and accelerated video playback works too (you need special GStreamer branch for AV1, as that will take more time to reach mainline). Audio is not yet working, in current tree, the display never come back if it get powered off (e.g. by dpms).

Nicolas

[Dylanger Daly]

Hi Nicolas,

This is fantastic! Thank you, I'll have a play with this tonight.

What CONFIG are you using? I've managed to build a Cadmium image with your kernel branch and added the DTBs for Cherry Tomato into the .its for depthcharge however I just get a black screen and no UART output on AP with SuzyQ.

I do however get BROM out

```

F0: 102B 0000
F3: 1001 0000 [0200]
F3: 1001 0000
F7: 4C0B 0027
F6: 102C 0000
F1: 0000 0000
V0: 0000 0000 [0001]
00: 0007 8000
01: 0000 0000
BP: 0C00 0209 [0000]
G0: 1182 0000
EC: 0080 0001 [3000]
S7: 0114 0A0F [0108]
T0: 0000 03A8 [010F]
Jump to BL

```

I think Cadmium's config mightn't have the correct things switched on for Cherry Tomato

[Dylanger Daly]

Hi Nicolas,

Quick update, simply using the defconfig with Cadmium I have a display!

Appears to be some issues with it finding rootfs, I'll continue playing tomorrow, fantastic work!

[Nicolas Dufresne]

Nice work, keep us posted. Was there more Tux then that ? I expected 8 tux to show up. I'm sure you'll figure-out the boot params for the rootfs (everyone hits that at first) :-D

Nicolas