When I boot up the TX2, there is a ~7 seconds that kernel console output has not shown up, and due to the default video setting of the tx2 there are strange looking stripes on the monitor. My initial guess is that it is due to uboot waiting timeout, and as soons as Ubuntu loads video will look ok. The attached gif illustrates the issue I am having.
I’ve looked at the git://nv-tegra.nvidia.com/3rdparty/u-boot.git (l4t 32.5) and tried to add either of the following to the /boot/extlinux/extlinux.conf. These did not change anything.
I have also tried to remove parameters like TIMEOUT and rootwait, but they also didn’t change anything.
I next consider the possibility of uboot timeout being too long. This is based on an assumption that when Linux kernel loads the stripes disappear and console show up properly (with dmesg). I proceed to connect to uart0 and expect to see uboot output and be able to enter into menu to change timeout option. However, I could not observe any uboot output from the uart0 debug output. The attached uart0_output.txt illustrates this. I also attach the dmesg from the booting system (dmesg.txt) for comparison. I made an assumption that perhaps uboot’s message was hidden due to some setting, and trie clicking on various keys at boot up to enter into uboot menu. All my keystrokes seemed ignored and the system still booted to Ubuntu.
So I have two questions:
- Is there a way to set default video output setting to match HDMI output of 1280x800?
- Is there a way to show uboot output on console and enter into uboot menu on TX2 so I can change timeout settings?
Lastly, if it’s very obvious that I’m on the wrong track to solve my problem, please enlighten me.
Reference - feedback from monitor vendor:
This is a common issue that is caused when your SBC BIOS initially boots up with a temporary default video output setting (most likely VGA) that is not compatible with the ELI101-IPHW WXGA requirements of 1280 x 800. Since ELI units don’t upscale or downscale video inputs, they often can’t properly display video resolutions that are outside of their expected range or resolution. Since your BIOS is temporarily giving the ELI101-IPHW a VGA resolution signal, and ELI is expecting WXGA resolution, the distortion that you are seeing can possibly occur.
Once the SBC is up and running the OS (Windows or Linux) typically reads the EDID file from the ELI unit and properly sets the video output and timing, so the display is then correct.