Tegra Mesa GLES without X

Question

I am trying to setup a Tegra 3 (Toradex Apalis T30) based system that will have an OpenGL ES based user interface on a touch screen. Unfortunately the standard Linux4Tegra kernel is seriously outdated and the provided graphics driver requires X11 integration. I have found though that I can build the Vanilla Linux kernel and get it running just fine on my board (tested 3.18). I have also found that a DRM Tegra driver is included in the kernel these days and I enabled it in menuconfig and built the kernel using it. I have also managed to get many distros working with the kernel (though I haven't really tried getting X working on any one).

My problem is that beyond this point, I am stuck. I cannot figure out what to do next in order to get GLES rendering up and running with the DRM driver. I have looked around a bit and have seen that Mesa might support GLES via DRM but I am not sure if this will allow me to do so without X? Also, how on earth to I get Mesa configured and compiled for the Tegra DRM driver?

Also, how does one go about configuring the output display using this DRM driver? My target screen is a 24bit parallel RGB display but I have not got that hooked up yet and would like to test with HDMI first. I have literally no idea how one should go about configuring the output display. The only information that I can find that might help involves X and xorg.conf which I will hopefully not be using. My device does output the console correctly on the HDMI display, how does it know to do that? Might this process somehow involve the device tree?

PS. I guess this question is a bit stupid but I am very new to embedded Linux and have just figured out how to build the vanilla kernel etc. and have really no idea of how the Linux display system works beyond just configuring X. Finding information regarding this is also proving hard.

EDIT: I have gotten XFCE sort of running on HDMI (login does not work and the login windows is very tiny) on Fedora using the OpenTegra driver which in term uses the DRM driver if I am not mistaken so hopefully that is good news?

Answer 1

Nvidia-setting can usually clear things up if you've gotten this far. Typically the video will work if the kernel has been given the correct vesa mode to show the system bootup messages. These are somewhat cryptic but they simple turn into an argument you append to the kernel boot parameters "vga=###".