Zybo Z7-10 with Linaro

[Scarlet]

I am trying to boot Linux with Linaro file system on Zybo Z7-10 without Petalinux. I would like to connect a monitor to HDMI TX output to be able to see Linaro graphical interface but I am getting errors while Linaro Ubuntu is booting, and nothing is being shown on the monitor.

I am sure that HDMI output works on my board since I got HDMI demo project to work.

I am using Zybo base system design from here, adapted to Zybo Z7 on Vivado 2018.2. I have generated device tree from this design using Xilinx SDK following this tutorial.

I am using Digilent's u-boot and Linux kernel and I've downloaded Linaro file system from here (last file).

These are the errors that are showing up when Linaro Ubuntu is booting:

systemd-bootchart.service failed.
[  OK  ] Started Remount Root and Kernel File Systems.
[  OK  ] Started Create Static Device Nodes in /dev.
         Starting udev Kernel Device Manager...
         Starting Load/Save Random Seed...
[  OK  ] Reached target Local File Systems (Pre).
[FAILED] Failed to start Load Kernel Modules.
See "systemctl status systemd-modules-load.service" for details.
systemd-modules-load.service failed.
         Starting Apply Kernel Variables...
[  OK  ] Started udev Coldplug all Devices.
[  OK  ] Started Increase datagram queue length.
[FAILED] Failed to mount Temporary Directory.
See "systemctl status tmp.mount" for details.

[FAILED] Failed to start RealtimeKit Scheduling Policy Service.
See "systemctl status rtkit-daemon.service" for details.

My goal is to enable HDMI output on Zybo Z7. I suspect that these errors are the cause of the problem, but I am not sure if there is any additional step I need to perform to get HDMI to work, like enabling some drivers in Linux kernel, or configuring the device tree.

I have tried using different  Linux kernel versions (by checking out different tags from Digilent's repository), using different versions of Linaro file system, using default device tree for Zybo Z7 provided with Linux kernel, but I've had no success since various errors are always showing up.

I would appreciate any help or someone pointing me in the right direction, since I am not sure what is the cause of the problem.

Thank you!

[jpeyron]

Hi @Scarlet,

We have reached out to a more experience embedded linux engineer about this thread. It may be a few days before you receive a response.

thank you,

Jon

[Scarlet]

Hi Jon,

Thank you for your response.

I would like to add that I managed to get HDMI and Linaro file system to work using Petalinux. Even though errors that I posted above still show up when using Petalinux, I can see output on my monitor. That suggests that those errors are not the problem which causes HDMI not to work without Petalinux, but rather something else.

I would still like to get HDMI to work without using Petalinux to generate files, so any help figuring out the problem is still appreciated.

 

Thank you.

[vicentiu]

Can you do a diff between the device trees and kernel configs when it's working and when it's not and see what the differences are?

[Scarlet]

Diff between kernel configs is in the attachment. I noticed that CONFIG_DRM_DIGILENT_ENCODER option is not set in Digilent kernel config, and it is set to "y" in Petalinux kernel config which works. Perhaps that is the problem?

Device trees are very different and there are several files so I did not do a diff between them, I attached all of them in the tar if you wanted to take a look.

 

Another question, when using Petalinux with Linaro Gnome (Ubunutu version 15.04, downloaded from here), I can only get console output and not GUI. I try to start gdm but nothing happens, and this shows up in /var/log/Xorg.0.log :

[    20.448] (II) xfree86: Adding drm device (/dev/dri/card0)
[    20.449] (EE) 
[    20.449] (EE) Backtrace:
[    20.449] (EE) 
[    20.449] (EE) Segmentation fault at address 0x0
[    20.449] (EE) 
Fatal server error:
[    20.450] (EE) Caught signal 11 (Segmentation fault). Server aborting

Do you have any idea why this happens?

 

Thank you.

Device tree.tar.gz

Digilent vs Petalinux kernel config diff

[vicentiu]

Yes, CONFIG_DRM_DIGILENT_ENCODER  is necessary along with CONFIG_COMMON_CLK_DGLNT_DYNCLK.

For the device tree, the petalinux pl.dtsi has the correct definitions some of which are missing from the kernel build pl.dtsi.

Also, you mentioned in the OP you're using the Zybo base system. You should be using the Zybo Z7 base system.