Re: [meta-raspberrypi] Would like to run xterm on Raspberry Pi 4 but Xorg fails with "module fbdev not found"


Manuel Wagesreither
 

Hello all,

Am So, 15. Aug 2021, um 22:36, schrieb Manuel Wagesreither:
I'm building my project for qemux86-64 and Raspberry Pi 4. Currently,
when booted, it displays a textual root shell. I can work with it in
both qemu and Raspi and all is good. Now I want to change my image to
display a graphical terminal when booted.

On qemu, this already works. In Raspberry Pi, not yet. It still
provides me the textual root shell.

On Raspberry Pi, `/var/log/Xorg.0.log` contains the following:
```
[ 1049.676] (II) LoadModule: "fbdev"
[ 1049.681] (WW) Warning, couldn't open module fbdev
[ 1049.681] (EE) Failed to load module "fbdev" (module does not exist, 0)
[ 1049.681] (II) modesetting: Driver for Modesetting Kernel Drivers: kms
[ 1049.684] (WW) Falling back to old probe method for modesetting
[ 1049.684] (EE) open /dev/dri/card0: No such file or directory
[ 1049.684] (WW) Falling back to old probe method for modesetting
[ 1049.684] (EE) open /dev/dri/card0: No such file or directory
[ 1049.684] (EE) No devices detected.
```

`/dev/fb0` does exist, so something like a framebuffer does at least
seem to exist.

So how can I install the fbdev module on my Raspberry Pi? I looked
around a bit and found this: https://elinux.org/RPi_Xorg_rpi_Driver I
tried it out and installed the
`/usr/lib/xorg/modules/drivers/fbdev_drv.so` file provided in the page,
but it's 32bit armhf architecture. My Raspi image is built for aarch64
architecture, so it naturally doesn't run there.

I googled a bit and there seem to be quite a few technologies around to
hw-accelerate output rendering. Read about EGL, GLX, OpenGL and DRI.
Are some of these options available on RasperryPi or qemux86_64? I
runqemu with the kvm option. Booting is fast, but the GUI terminal
window doesn't even catch the keypresses in time.

My image is a core-image-minimal with IMAGE_FEATURES x11-base.
(https://gitlab.com/manuel_wagesreither/bora-proj/-/blob/master/meta-manwag/recipes-core/images/bora-image.bb)

The distro is a modified Poky with DISTRO_FEATURES x11.
(https://gitlab.com/manuel_wagesreither/bora-proj/-/blob/master/meta-manwag/conf/distro/bora-device.conf) To work around https://github.com/agherzan/meta-raspberrypi/issues/228 I made DISTRO_FEATURES_append = " opengl".
just for documentational purposes, if I recall correctly, adding package "kernel-features" to IMAGE_INSTALL did the trick.

Regards,
Manuel

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