How AGX xavier debug uart can only use uart3

Autonomous Machines Jetson & Embedded Systems Jetson AGX Xavier
1

Hi everyone
I found that uart3 is the console during the initial boot, and uart1 is the console after the image is booted. I want to change it to only use uart3 as the console, because the hardware has no uart1 interface.
please give me some advice,best wishes!

3

hello zhangxiaodong ,

you’ll need to update board configuration file to change the debug console,
please also refer to Topic 54744 for an example,
thanks

4

Hi JerryChang
Thanks for your reply,the topic you send is base on tx2 28.x.But I’m working on xavier R32.4.3.some cfg file doesn’t have.

5

hello zhangxiaodong ,

you may also refer to Topic 122047,
please modify cfg file as below to do the trick for disabling UART logs.
for example,

enable_combined_uart = 0;
spe_uart_instance = 0xff;

you may looking for kernel init messages, $ dmesg | grep -i THS
and please compare it with $L4T_Sources/r32.5/Linux_for_Tegra/source/public/hardware/nvidia/soc/t19x/kernel-dts/tegra194-soc/tegra194-soc-uart.dtsi
you should program it to output logs to uart3, uartc: serial@c280000 {...}.
there’s also pinmux cfg you should check for reference, uart3_tx_pcc5, and uart3_rx_pcc6.
thanks

7

Hi
use follow cmmand can disable the uart1? how can I use uart3 to show the kernel starting log.
enable_combined_uart = 0;
spe_uart_instance = 0xff;

how to program the dts as you mentioned the step:
“should program it to output logs to uart3, uartc: serial@c280000 {…}”

8

hello zhangxiaodong,

please check your kernel message for confirmation uart mapping to which ttyTHS,
then, modify the bootargs to assign the destination.
for example, bootargs =“console=ttyTHS2,115200”;
you should access Jetson AGX Xavier OEM Product Design Guide, and refer to [Jetson AGX Xavier UART Pin Description] to have correct signal connection.
thanks

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