How to disable debug UART completely on AGX Orin

[kaichu.wu]

Hello forks,

We are trying to use the 5x UART interface of AGX Orin as COM ports. With debug UART enabled, we have noticed that:

• UART C (serial@c280000) is linked to /dev/ttyTCU0
• UART E (serial@3140000) is linked to /dev/ttyAMA0

We tried to remove the “console” related arguments under /boot/extlinux/extlinux.conf, which becomes

      APPEND ${cbootargs} root=/dev/mmcblk0p1 rw rootwait rootfstype=ext4 mminit_loglevel=8 firmware_class.path=/etc/firmware fbcon=map:0 net.ifnames=0

But we still get the following information in the boot-up process

**  WARNING: Test Key is used.  **
L4TLauncher: Attempting GRUB Boot
L4TLauncher: Attempting Direct Boot
EFI stub: Booting Linux Kernel...
EFI stub: Using DTB from configuration table
EFI stub: Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path
EFI stub: Exiting boot services and installing virtual address map...

We are grateful if you would share any related experience or feedback.

Thanks!

[kaichu.wu]

We also found that, after removing the console arguments of the extlinux.conf, UART C will be linked to /dev/ttyTHS2.

However, when we try to send characters from /dev/ttyTHS2 via minicom, the receiver needs to press an additional “new line” to receive the characters . On the other hand, AGX Orin is not able to receive any character from another computer.

[JerryChang]

hello kaichu.wu,

there’re only UART1/2/5 were used as UART ports on DevKit.
in addition, Orin series is same as Xavier series that using combine UART.

however,
we have not verify the use-case by disabling that. we cannot guarantee the real use-case for transferring data as it’s not in our supported use cases/features, there is no suggestion currently.

[kaichu.wu]

@JerryChang
Thanks for your quick response. We will try to figure out a solution for our usage.