I used the pynq sdbuild process (3.0.1) to create an image for my DIY board, aiming to achieve the function of displaying the GUI via HDMI.
I followed this tutorial: Zybo z7 の Linux で SimpleDRM を実装する #FPGA - Qiita
The method is to read the fb0 through the “video framebuffer read” ip.It seems that the author easily accomplished this function, but I encountered an error.
Without installing any other software, the following error occurred:
xilinx@pynq:~$ cat /var/log/Xorg.0.log
[ 146.739]
X.Org X Server 1.21.1.3
X Protocol Version 11, Revision 0
[ 146.740] Current Operating System: Linux pynq 5.15.19-xilinx-v2022.1 #1 SMP PREEMPT Mon Apr 11 17:52:14 UTC 2022 armv7l
[ 146.740] Kernel command line: root=/dev/mmcblk0p2 rw earlyprintk rootfstype=ext4 rootwait devtmpfs.mount=1 uio_pdrv_genirq.of_id="generic-uio" clk_ignore_unused
[ 146.742] xorg-server 2:21.1.3-2ubuntu2 (For technical support please see http://www.ubuntu.com/support)
[ 146.742] Current version of pixman: 0.40.0
[ 146.743] Before reporting problems, check http://wiki.x.org
to make sure that you have the latest version.
[ 146.743] Markers: (--) probed, (**) from config file, (==) default setting,
(++) from command line, (!!) notice, (II) informational,
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[ 146.745] (==) Log file: "/var/log/Xorg.0.log", Time: Mon Oct 27 07:03:19 2025
[ 146.750] (==) Using system config directory "/usr/share/X11/xorg.conf.d"
[ 146.762] (==) ServerLayout "Layout0"
[ 146.762] (**) |-->Screen "Screen0" (0)
[ 146.763] (**) | |-->Monitor "Monitor0"
[ 146.765] (**) | |-->Device "Framebuffer"
[ 146.765] (==) Automatically adding devices
[ 146.765] (==) Automatically enabling devices
[ 146.765] (==) Automatically adding GPU devices
[ 146.765] (==) Automatically binding GPU devices
[ 146.766] (==) Max clients allowed: 256, resource mask: 0x1fffff
[ 146.779] (WW) `fonts.dir' not found (or not valid) in "/usr/share/fonts/X11/misc".
[ 146.779] Entry deleted from font path.
[ 146.779] (Run 'mkfontdir' on "/usr/share/fonts/X11/misc").
[ 146.779] (WW) The directory "/usr/share/fonts/X11/cyrillic" does not exist.
[ 146.779] Entry deleted from font path.
[ 146.779] (WW) The directory "/usr/share/fonts/X11/100dpi/" does not exist.
[ 146.779] Entry deleted from font path.
[ 146.779] (WW) The directory "/usr/share/fonts/X11/75dpi/" does not exist.
[ 146.779] Entry deleted from font path.
[ 146.780] (WW) The directory "/usr/share/fonts/X11/100dpi" does not exist.
[ 146.781] Entry deleted from font path.
[ 146.781] (WW) The directory "/usr/share/fonts/X11/75dpi" does not exist.
[ 146.781] Entry deleted from font path.
[ 146.781] (==) FontPath set to:
/usr/share/fonts/X11/Type1,
built-ins
[ 146.781] (==) ModulePath set to "/usr/lib/xorg/modules"
[ 146.781] (II) The server relies on udev to provide the list of input devices.
If no devices become available, reconfigure udev or disable AutoAddDevices.
[ 146.781] (II) Loader magic: 0x5e1008
[ 146.781] (II) Module ABI versions:
[ 146.781] X.Org ANSI C Emulation: 0.4
[ 146.781] X.Org Video Driver: 25.2
[ 146.781] X.Org XInput driver : 24.4
[ 146.781] X.Org Server Extension : 10.0
[ 146.785] (++) using VT number 1
[ 146.793] (II) systemd-logind: took control of session /org/freedesktop/login1/session/c2
[ 146.796] (II) xfree86: Adding drm device (/dev/dri/card0)
[ 146.796] (II) Platform probe for /sys/devices/soc0/axi/axi:zyxclmm_drm/drm/card0
[ 146.801] (II) systemd-logind: got fd for /dev/dri/card0 226:0 fd 11 paused 0
[ 146.801] (EE)
[ 146.801] (EE) Backtrace:
[ 146.803] (EE)
[ 146.804] (EE) Segmentation fault at address 0x0
[ 146.804] (EE)
Fatal server error:
[ 146.804] (EE) Caught signal 11 (Segmentation fault). Server aborting
[ 146.804] (EE)
[ 146.804] (EE)
Please consult the The X.Org Foundation support
at http://wiki.x.org
for help.
[ 146.805] (EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information.
[ 146.805] (EE)
[ 146.827] (EE) Server terminated with error (1). Closing log file.
In that totorial,author add /delete-node/ &v_frmbuf_rd_0; in device tree,I think pynq does not include the PL device tree,perhaps this difference is what caused the error?
My screen can display the command line, but entering “startx” fails and show error like above.