Running Android on a mainline graphics stack

Posted Sep 13, 2017 21:33 UTC (Wed) by roc (subscriber, #30627)
In reply to: Running Android on a mainline graphics stack by excors
Parent article: Running Android on a mainline graphics stack

FirefoxOS ran on really terrible hardware and all of those chipsets had dedicated 2D compositing.

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Running Android on a mainline graphics stack

Posted Sep 13, 2017 22:23 UTC (Wed) by excors (subscriber, #95769) [Link] (2 responses)

Your standards for "really terrible" might be excessively high :-) . I could be misremembering but I think some low-cost Broadcom chips (maybe BCM21664 or similar?), used in e.g. some Samsung phones a few years ago, had VideoCore 4 but with all the fun bits stripped out to minimise cost. That included removing the VPU and any clever display hardware, so compositing had to be done entirely in OpenGL. Admittedly that's a fairly old chip, I don't know if any more recent ones have similar limitations.

(Proper non-stripped-down VC4, like in Raspberry Pi, does compositing with HVS <https://dri.freedesktop.org/docs/drm/gpu/vc4.html>. The mainline vc4 driver uses that to implement DRM atomic mode setting.)

Running Android on a mainline graphics stack

Posted Sep 14, 2017 4:33 UTC (Thu) by roc (subscriber, #30627) [Link]

I think the lowest-end FirefoxOS phones were Qualcomm MSM7225A Snapdragon S1. The very lowest-end was 128MB RAM, so it really was terrible :-).

Running Android on a mainline graphics stack

Posted Sep 15, 2017 0:36 UTC (Fri) by anholt (subscriber, #52292) [Link]

I've wished before that I had some 21664 hardware (with a reasonable debug environment) that I could port the vc4 stack to. It's a shame to not cover it.