osk-sdl port for Moto X (ghost)

I've debugged osk-sdl on the motorola-ghost device, which I'm trying to port pmOS to. I've noticed that while generating a fb.modes file, the device has a 32 bits framebuffer, but, according to the wiki, it isn't supported. I've changed the depth to 16 bits and tried setting a 24/32 bit pixel format, but none worked. I later realized that, from the output of fbset that the actual pixel format for the device is ABGR, by looking at DirectFB's source code.

If I set the pixel format to none (which would use the default) or RGB16, the osk-sdl application "works". I get a mirrored screen and a pink background. Touchscreen works.

If I set the pixel format to ABGR, osk-sdl exits with the following error:

ERROR: Unknown dfb pixelformat 418c25 !
INFO: Keyboard 0 - Keyboard
ERROR: SDL_Init failed: The video driver did not add any displays

There are other two phones that have the same offsets as the Moto X, but I don't know if they faced the same issues I'm facing right now. They are xiaomi-ido and sony-nicki.

EDIT: I forgot to mention that I've looked at the SDL source code as well and it seems like ABGR mode isn't supported. Is this expected?

changed the description

By Xinayder on 2018-08-01T01:01:36

changed the description

By Xinayder on 2018-08-01T01:11:52

changed title from osk-sdl port for Moto X (motorola-ghost) to osk-sdl port for Moto X (ghost)

By Xinayder on 2018-08-01T03:19:35

Excellent research you did there, @Xinayder! I think you are pretty close to making it work properly.

I've taken a look at the links you have sent, and from my understanding, the following line from SDL_DirectFB_video.c means, that the SDL2 mode is not mapped to a DirectFB mode:

{ DSPF_UNKNOWN, SDL_PIXELFORMAT_ABGR8888 },

Here's another line in the same file, which does have a proper mapping:

{ DSPF_ARGB, SDL_PIXELFORMAT_ARGB8888 },

So it seems to me, we need to replace DSPF_UNKNOWN with the proper value at this point, then it is no longer unknown and SDL2 won't throw this error anymore. The DSPF_ variables are defined in the directfb.h of the DirectFB source code. And it seems like we're lucky, there's already a variable for ABGR:

/* 32 bit  ABGR (4 byte, alpha 8@24, blue 8@16, green 8@8, red 8@0) */
DSPF_ABGR = DFB_SURFACE_PIXELFORMAT( 37, 24, 8, 1, 0, 4, 0, 0, 0, 0, 0 ),

Now I would recommend to compile your own SDL2 package, where you replace DSPF_UNKNOWN with DSPF_ABGR, and then test if that works on the device.

How to patch packages is explained here: https://wiki.postmarketos.org/wiki/Patching (just updated with pmbootstrap build --src instructions, please extend if you figure out something useful)

By Oliver Smith on 2018-08-02T22:23:18

@Xinayder, you mentioned in #postmarketOS, that building sdl2 failed, because the check function failed. You could add options="!check" to the APKBUILD as a workaround.

By Oliver Smith on 2018-08-05T19:34:40

Excluding the check function (I'm assuming that's what !check does) from the APKBUILD solved the problem, but now I need to figure out how to compile with the correct arch.

EDIT: I managed to get a workaround to build for armhf, but the problem is still there. I think the package wasn't updated in my phone, even with apk add -u sdl2.

By Xinayder on 2018-08-05T22:05:54

So, I found out why the package wasn't updated at all. I installed my own, recently-built SDL2 package, but forgot to patch it. Now, I get a blue background, which I think is correct, and the display is no longer duplicated.

The animation is a bit slow, but I think this is okay, right? EDIT: please ignore the burn-in on the display

Snapchat-1595092422

By Xinayder on 2018-08-12T21:12:20

but now I need to figure out how to compile with the correct arch.

like this (can be combined with --src)? pmbootstrap build --arch=armhf ...

Now, I get a blue background, which I think is correct, and the display is no longer duplicated.

Yep, this is how it's supposed to look like. Great work \o/

Would you like to upstream your patch to SDL2? From their FAQ:

Where do I send bug reports / patches?

You can submit bug reports and patches to the SDL bugzilla bug tracking system: https://bugzilla.libsdl.org/

By Oliver Smith on 2018-08-14T17:10:14

mentioned in commit wiki@6219ddc7

By postmarketOS Wiki bot on 2018-08-14T17:42:41

I've submitted the patch, it's at https://bugzilla.libsdl.org/show_bug.cgi?id=4229

I have another question. Should I be able to successfully unlock the device with the osk-sdl app, or am I typing the wrong password?

By Xinayder on 2018-08-15T02:45:07

Thanks for creating the patch! Consider also mentioning in the comments of the patch that you have tested this on your device, and it's working (possibly with a link to this issue). Because it's likely that they won't be able to test this on a real device.

Should I be able to successfully unlock the device with the osk-sdl app, or am I typing the wrong password?

Yes, that should work. If it doesn't accept yours after multiple tries, could you try it with a simple one (e.g. a one letter password) for debugging? There's a small chance that you typed it wrong twice during the setup.

By Oliver Smith on 2018-08-15T20:04:19

added needs more info label

Closing, this doesn't seem like any specific osk-sdl issues remain here.

By clayton craft on 2021-01-31T06:37:04

closed