Jetson TX2 flickering image during boot when connected to small hdmi display

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX2
1

I’m using JetPack3.3 to flash the jetson TX2. When it’s connected to 1024X600 resolution HDMI display, the image is flickering during boot. After boot to kernel, the image turns to normal. I’m wondering how to change cboot to send lower resolution splash image.

2

Here is the further interesting log messages from cboot and kernel:
For connecting working monitors:

[0002.523] I> Best mode Width = 1920, Height = 1080, freq = 148351648
...
[    1.806671] tegradc 15210000.nvdisplay: Bootloader disp_param detected. Detected mode: 1920x1080 (on 0x0mm) pclk=148350937

For the small display having trouble in the cboot:

[0002.432] I> Best mode Width = 640, Height = 480, freq = 25174825
...
[    1.807060] tegradc 15210000.nvdisplay: Bootloader disp_param detected. Detected mode: 640x480 (on 0x0mm) pclk=50347983

I see the frequency is doubled in kernel and the display works fine after kernel boot. Does that mean the cboot didn’t set clock right?

3

I think cboot does not support splash logo with this mode. Does your monitor support 640x480 mode?

4

Hi WayneWWW,

The working monitor doesn’t support 640X480 mode. For the small display with 1024X600 resolution, the kernel log said the best mode is 640X480, so I assume it supports this mode.

Did you mean the cboot doesn’t support 640X480? From https://devtalk.nvidia.com/default/topic/1031327/jetson-tx2/change-cboot-boot-logo-l4t-28-2-/, I thought it support 1920x1080, 1280x720 and 640X480 three modes.

Thanks!

5

lib5y15,

Could you check the display mode list on your 1024x600 display with xrandr?
You could use this command after boot up

export DISPLAY=:0
xrandr
6

Hi WayneWWW,

Here is the result:

nvidia@tegra-ubuntu:~$ export DISPLAY=:0
nvidia@tegra-ubuntu:~$ xrandr
Screen 0: minimum 8 x 8, current 1024 x 600, maximum 32767 x 32767
HDMI-0 connected primary 1024x600+0+0 (normal left inverted right x axis y axis) 150mm x 100mm
   1024x600      43.07*+
7

lib5y15,

I think the reason is obvious here. Your monitor does not support 640x480 mode. That is why it gets flicker.

8

Thanks WayneWWW,

You mean the cboot doesn’t support this mode but kernel does? Is there any way to modify cboot?

9

Actually, I think it is more precise to say the bmp.blob we provided for boot logo only supports this 3 modes.
Cboot is able to support those modes. If you look into the cboot log, you should see it prints out a list of your monitor mode when boot up.

For changing the boot logo, current way is to follow up this thread. There is no official method yet.
If you need official support for it, please contact nvidia sales to highlight it.
https://devtalk.nvidia.com/default/topic/1031327/jetson-tx2/change-cboot-boot-logo-l4t-28-2-/