How can I used UARTC as debug serial instead of UARTA in u-boot

Autonomous Machines Jetson & Embedded Systems Jetson TX2
,
#1

I want to use UARTC as serial console in u-boot before start kernel, but I don’t know how to setting it.
u-boot VERSION:2020,04
modify:arch\arm\dts\tegra186-p2771-0000.dtsi
chosen {
-stdout-path = &uarta;
+stdout-path = &uartc;
};
-&uarta {
+&uartc {
status = “okay”;
};

arch\arm\dts\tegra186.dtsi:

  • uartc: serial@c280000 {
  •   compatible = "nvidia,tegra186-uart", "nvidia,tegra20-uart";

  •   reg = <0x0 0x0c280000 0x0 0x40>;

  •   reg-shift = <2>;

  •   status = "disabled";
  • };

4.log (25.2 KB)

#3

hello 396806033,

please access Jetson TX2 Series OEM Product Design Guide via download center.
please refer to [Table 74. UART Pin Descriptions] for more details of hardware connections.
thanks

#4

hardware connection is ok, when I running in kernel, I can use ttyTHS2 to receive or transfer, but I want use serial@c280000 in u-boot.

#5

hello 396806033,

could you please modify uart_instance in the misc configure for verification,
for example,
$OUT/Linux_for_Tegra/bootloader/t186ref/BCT/tegra186-mb1-bct-misc-si-l4t.cfg

##### debug variables #####
debug.enable_log = 1;
- debug.uart_instance = 0;
+ debug.uart_instance = 2;