TK1 Remote Display

Is there any way to bring up a remote display via a connection to the Apalis TK1 under Angstrom?

Are there any kind of supported VNC applications which would allow a Windows machine (or Ubuntu) to connect to the TK1 via Ethernet/Wi-Fi or USB?

you can install vnc using below commands. Apalis TK1 should be able to access Internet.

opkg update
opkg install x11vnc

Now start vnc

root@apalis-tk1:~# x11vnc

Hi @benjamin.tx, thank you for your response. I’ve followed your instructions but when it comes to starting the x11vnc, the following error message is displayed:

XOpenDisplay(":0.0") failed.
Trying again with XAUTHLOCALHOSTNAME=localhost
************************************************************
*** XOpenDisplay failed (:0.0)

x11vnc was unable to open the X DISPLAY: ":0.0", it cannot continue. There may be "Xlib:" error messages above with details about the failure.

I also need to add that the Apalis TK1 is running headless, there are no display interfaces available

If JetPack is not needed, you can install our latest image on TK1 according this article. By default, lvds is enabled. So a real monitor is not necessary connected to TK1.

root@apalis-tk1:~# xrandr
Screen 0: minimum 8 x 8, current 1024 x 768, maximum 16384 x 16384
LVDS-0 connected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   1024x768      60.01*+
HDMI-0 disconnected primary (normal left inverted right x axis y axis)
root@apalis-tk1:~# echo $DISPLAY
:0.0

Hi @benjamin.tx, how can I enable a default display in our deployment?

Do you use our standard image v2.7beta2 ? LVDS is already enabled there including DISPLAY variable(DISPLAY=:0.0).

Hi @benjamin.tx, yes, I am using the v2.7beta2 image.

I seem to have a default display but I can’t access it!

root@apalis-tk1:~# xrandr
Can't open display :0.0

root@apalis-tk1:~# echo $DISPLAY
:0.0

My vidargs are set to the following:

root@apalis-tk1:~# fw_printenv vidargs
vidargs=video=tegrafb0:1024x600-16@60 fbcon=map:1

could you share dmesg output of TK1? You can upload it here.

Hi @benjamin.tx, here’s the dmesg output:

output

From the log(Linux version 3.10.40-g19722d4-dirty (blueprint@Phoenix) ), your kernel is modified. But I can’t tell what have been changed. You can use our latest kernel from git and the default configuration.See this.

git clone -b  toradex_tk1_l4t_r21.5 git://git.toradex.com/linux-toradex.git

Hi @benjamin.tx, the only extra added is the driver support for the ADV7280-M and the backports used for the Intel 7260 Wi-Fi module. Nothing else is different

tegradc doesn’t parse vidargs in your log. This is what at my side.

[    0.958581] tegradc tegradc.0: probed
[    0.958812] tegradc tegradc.0: parse cmd options for tegrafb0: 1024x768-16@60
[    0.958860] tegradc tegradc.0: switching framebuffer to 1024x768
[    0.958887] tegradc tegradc.0: Calculated sync href=0 vref=2
[    0.958916] tegradc tegradc.0: using mode 1024x768 pclk=65002000 href=0 vref=2
[    0.992582] tegradc tegradc.0: nominal-pclk:65002000 parent:65000000 div:1.0 pclk:65000000 64351980~70852180
[    1.010243] tegradc tegradc.0: fb registered
[    1.011965] tegradc tegradc.1: probed

Can you check if vidargs is passed to kernel?

root@apalis-tk1:~# cat /proc/cmdline

Here is the output:

root@apalis-tk1:~# cat /proc/cmdline
lp0_vec=2064@0xf46ff000 core_edp_mv=1150 core_edp_ma=4000 usb_port_owner_info=2 lane_owner_info=6 emc_max_dvfs=0 ip=off root=/dev/mmcblk0p2 rw rootfstype=ext3 rootwait igb_mac=00:14:2d:2b:d8:1b consoleblank=0 no_console_suspend=1 console=tty1 console=ttyS0,115200n8 debug_uartport=lsport,0 video=tegrafb0:1024x600-16@60 fbcon=map:1
root@apalis-tk1:~#

@kwebster83 is still based on g19722d4 which did not include the vidargs parsing as of yet. Please update to our latest 2.7b2 Linux kernel sources.

Hi @marcel.tx, I double-checked my vidargs, removing the fbcon=map:1 and this seems to have fixed the lack of default display. I can now install and run x11vnc as well as connecting to it from TightVNC within Windows.

Perfect!

And just as I said it, a reboot then caused a default display to “disappear” and I can no longer start x11vnc. Ok, I shall update to 2.7b2 sources