[Freedreno] [GSoC-15] Enabling Freedreno on Android

[Emil Velikov]

On 18/03/15 11:12, Varad Gautam wrote:
> On 03/16/2015 11:59 PM, Emil Velikov wrote:
>> On 16/03/15 16:11, Rob Clark wrote:
>>> If you have access to an ifc6410 board, that would probably be a
>>> pretty good way to start.. on that device, the primary display is HDMI
>>> (which is already well supported in drm/msm), and we can use something
>>> very close to a mainline kernel[1].
>>>
>>> Obviously in the long run, it would be nice to get this working on
>>> some phones/tablets.. which would require backporting the upstream drm
>>> + DSI code, and writing panel drivers for the specific LCD panel in
>>> whichever phone/tablet.. but starting on ifc6410 could allow for some
>>> of that to happen in parallel, depending on exactly how much work is
>>> needed to get drm_gralloc working.
> 
> I'll get an ifc6410 right away. CyanogenMod doesn't support the board
> yet, but I think we can find a similar phone while doing the distro
> integration later.
> 
Pardon my ignorance, but I thought that most of the "supports board X"
boils down to drivers (kernel + userspace graphics ones) + firmware. Are
there (m)any other bits ?

> 
>>
>> I would strongly suggest that as a preparation (although I'll let Rob be
>> the judge)
>>  - checkout android-x86/kitkat-x86
>>  - rebase their mesa kitkat-x86 branch on top of upstream 10.4 [3], and
>> add it to the build.
>>  - get the kernel Rob mentioned, and integrate it into the build (manifest)
>>  - grep through the code for "nouveaufb" and "inteldrmfb". Check the
>> "offending" commits and prep similar patch(es) for freedreno. It should
>> be trivial 5 line patch. Iirc there are initscripts (+ other?) which do
>> funny things depending on the framebuffer. Don't forget to update your
>> manifest :)
>>  - set BOARD_GPU_DRIVERS=freedreno and leave it build a complete image.
>> Note it will take quite some time.
>>  - If it builds try booting it up :)
>>
>> With the above information at hand I believe you'll be OK with setting
>> up a plan/proposal. How much you'll focus on the kernel,
>> gralloc/hwcomposer or mesa depends on what you'll uncover :-)
> 
> Thanks for breaking it down, I'm on it. Will the kitkat-x86 build work
> with ifc6410 (or do I need a patched CodeAurora build [1])?
> 
I fear it's the first time I hear of this Android (flavour). Don't have
a clue about it.

kitkat-x86 builds and runs on x86 platforms, so modulo a x86 hack or two
it should be ok for arm. It has the arm compiler toolchain.

If I were you I would leave the system checkout other androids (QAEP,
CM) while I'm out/asleep. Just in case.

Cheers,
Emil