Could you help to disconnect them one by one to narrow down which peripheral might cause this assertion?
The assertion of UEFI is under Universal/Console.
It appears that UART0 is causing the assertion since booting is normal with UART0 disconnected. Is there a way to ignore UART0 until booting is complete
I have setup the environment to recompile UEFI now, can you tell me specifically which edits are required to disable UART0. The link you provided is not clear.
You don’t need to build UEFI. The device tree is in the link shared by Kevin.
I don’t know which part is unclear to you. Please tell more about what you want to ask. For example, do you know how the device tree works here or not.
In brief, kernel dtb and uefi dtb by default is using same file. But we want you to create a new one and make them read from different dtb.
I assumed we needed to modify UEFI to change behavior of UART0 at OS level.
I have modified the dtb, disabled UART0 via 3110000.serial and reflashed. I do not have the booting problem anymore with UART0 disabled. We also dont see /dev/ttyTHS1 and so UART0 no longer exists.
How do we enable UART0 ( SOM pins 99/101) to talk to our GPS without interference from UEFI
First, I would like to address again. The boot process is UEFI->kernel. Most of use case should be done in kernel, not UEFI. Your case is this kind too.
What you got stuck is “UEFI does not let you pass”. The solution Kevin shared is we disable the UART0 in “UEFI” and still keep UART0 enabled in “Kernel”.
The reason we showed you there is a field called ““TBCDTB_FILE” in your board config is because this is where the UEFI reads the dtb.
UEFI has its own location to load dtb file and kernel has another location to read its dtb file. By default, these two are using same content. But now we want you to change it.
Your problem is you are still changing the content of both sides…
Could you understand what we try to say here? If you still not get it, I can share more examples…
do I need the full file path in TBCDTB_FILE. From Kevins post, I am guessing that it already looks in /bootloader/ directory for anything specified in TBCDTB_FILE
should I delete the existing tegra194-p3668-all-p3509-0000.dtb file from /bootloader directory
am I editing the correct board file. My initrd flash command is referencing p3509-0000+p3668-0001-qspi-emmc