Need to enable uart driver in optee in xavier nx


I’m working in optee. I need to get the data from the uart in the optee. So that uart driver needs to be enabled in the optee os. Is there any driver files available or need to write the new uart driver inorder to access the uart data from the optee. Please suggest reference to get started.

Hi sushmitha.sp,

Are you using the devkit or custom board for Xavier NX?
What’s your Jetpack version in use?

Which UART interface would you like to use?

You can refer to Failed to access UART registers from OP-TEE

Hi Kevin,

I’m using devkit and my jetpack version is 5.1.3.

I like to use uart1 which is connected to the 40 pin header.

I have referred that topic but it doesn’t contain UART driver

Maybe you can refer to optee_os/core/drivers/serial8250_uart.c at master · OP-TEE/optee_os · GitHub.

Hi Kevin,

Does this mean, serial8250 is the controller used in Jetson Xavier NX for UART1?
My main objective here is to read data from uart port in optee os. As per the previous issue thread you have referred we understand that it requires

  1. UART driver on OPTEE OS
  2. System call interface for TA
  3. A Trusted app to read data from uart device.

Is there any reference implementation for the same?

Yes, you can use 8250 driver for UART1.

We don’t have official resource for this, please try to implement it manually.