Hi Robert, thank you for your message. I used the configuration from bb.org_defconfig and compiled again the kernel. I noticed that the default configuration enables CONFIG_DRM_FBDEV_EMULATION by default. I compiled the kernel, and I have video out to my LCD screen, but I still have problems with Retroarch to run on my board.
As this fbdev emulation is a default configuration I returned to the original kernel (4.14.71-ti-r80) and now I don't really know why I cannot run Retroarch with the standard video support on my board. I installed retroarch from the repository with (apt-get install retroarch) in a clean Debian 9.5 IOT image. I had video error problems, so I followed the instructions from here: https://elinux.org/BeagleBoneBlack/SGX_%2B_Qt_EGLFS_%2B_Weston to install the accelerated video driver, and I managed to get the 3D examples working nicely. But I still getting errors on the Retroarch log: --------------- .... RetroArch [INFO] :: [DRM]: Mode 0: (480x272) 480 x 272, 59 Hz gbm: failed to open any driver (search paths /usr/lib/arm-linux-gnueabihf/dri:${ORIGIN}/dri:/usr/lib/dri) gbm: Last dlopen error: /usr/lib/dri/tilcdc_dri.so: cannot open shared object file: No such file or directory failed to load driver: tilcdc RetroArch [INFO] :: Found GL context: kms RetroArch [INFO] :: Detecting screen resolution 480x272. RetroArch [INFO] :: [EGL]: EGL version: 1.4 Segmentation fault -------------- Now Retroarch seems to be able to detect the video configurations but still giving errors, and craches. I also tried to compile retroarch from the source with more video driver support like SDL, SDL2, and I found that they have an old driver dedicated to OMAP processors from 2014 that needs /sys/devices/platform/omapdss populated (https://github.com/libretro/RetroArch/blob/master/README-OMAP.md), but none of the drivers that I tried worked. This driver was probably written before DRM support to the beaglebone boards. So, that's why I would like to have the standard fbdev working without any acceleration driver to test the program. I expect that Retroarch won't work well with the PowerVR GPU anyway. I tried to use old debian images but all images with the beagleboneblack wireless support already have the DRM enabled, and with the CONFIG_DRM_FBDEV_EMULATION enabled I'm confused, and I don't nkow how to make Retroarch work. Do you have any suggestion? Best regards Em sábado, 13 de julho de 2019 19:23:30 UTC+2, RobertCNelson escreveu: > > On Sat, Jul 13, 2019 at 3:54 AM João Manoel <[email protected] > <javascript:>> wrote: > > > > Hi, > > > > I would like to make a program that uses the fbdev to work and I need to > compile the kernel to add this functionality and remove the DRM support. > > I managed to compile a bootable kernel but I'm failing to get the fbdev > working. I would like to know what is the easiest way to get the fbdev > working. > > > > The things that I modified to the kernel config are: > > > > - enable: > > CONFIG_FB_DA8XX=y > > - disable: > > CONFIG_DRM > > CONFIG_DRM_I2C_NXP_TDA998X > > CONFIG_DRM_TILCDC > > > > What is missing to get video out with fbdev? > > > > My board is a Beagleboard black wireless, and I couldn't see any error > on the dmesg or anything related to the video after booting without video. > I'm compiling the kernel 4.14.108. I have an HDMI cable attached, but I'm > also trying to get video out with an LCD cape (from farnell element14) > > > > Thank you in advance for the help :) > > CONFIG_DRM_FBDEV_EMULATION > > Then re-enable: > > CONFIG_DRM > CONFIG_DRM_I2C_NXP_TDA998X > CONFIG_DRM_TILCDC > > Regards, > > -- > Robert Nelson > https://rcn-ee.com/ > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/8dc35a7d-0b64-4a54-9a47-63b1da104ceb%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
