Linux/PROCESSOR-SDK-AM335X: Change The Debug Port From UART0 to USB0 on Beagle Bone Black Board

Narreddi Siva Prakash Reddy

Tool/software: Linux

Hello:

Can anyone help me in changing Debug Port in Beagle Bone Black (BBB) Board from UART0 to USB0.?

Recently I started working on Bare-metal Programming on BBB board. I am trying to understand U-Boot process of BBB board and all the logs in u-boot prompt are showing on UART0 port.

I want to see the u-boot prompt in USB0 port on BBB. To achieve this, the following are My thoughts..

1. Is it (UART0 as Debug Port) fixed in Boot ROM code only.?

2. What are all the necessary information should I know.?

3. Is it required to modify in u-boot source code.? if yes, where can I change.?

Please, respond as soon as possible.

Thanks and Regards,

Siva Prakash Reddy

over 6 years ago

0 Cvetolin Shulev-XID over 6 years ago

TI__Guru 65405 points

Hi Siva Prakash Reddy,

Configuration of debug port is not hard coded in the Boot ROM code. It is configurable and it is not necessary to change u-boot source code.
A possible way to change configuration of debug console is to modify "console" bootargs in u-boot configuration. Here is some details about how to do that:
processors.wiki.ti.com/.../Modifying_U-boot
processors.wiki.ti.com/.../Booting_Linux_kernel_using_U-Boot
www.denx.de/.../UBootEnvVariables
in general you should change console=ttyS0,115200n8 to console=ttyUSB0,115200n8

BR
Tsvetolin Shulev

0 Narreddi Siva Prakash Reddy over 6 years ago in reply to Cvetolin Shulev-XID

Prodigy 30 points

Hello:

Thanks for the valuable response.

In my case I had created only BOOT partition on my SD Card and I copied the MLO, U-boot.img and uEnv.txt files.

the content in the uEnv.txt is as follows:

uenvcmd=setenv bootargs console=ttyUSB0,115200n8 console=${console}
echo *** Booting To Baremetal_1 ***

Before applying USB power to BBB, SD card is inserted and I pressed and hold the Switch-2 to boot from SD Card.

But there is no response from the board at USB0 port.

Is it problem with uEnv.txt file.?

Are there required for any changes.?

Thanks And Regards,

Siva Prakash Reddy

0 Cvetolin Shulev-XID over 6 years ago in reply to Narreddi Siva Prakash Reddy

TI__Guru 65405 points

To ensure that setting the proper console configuration could you post output of "ls /dev/tty*" command.

BR
Tsvetolin Shulev

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Linux/PROCESSOR-SDK-AM335X: Change The Debug Port From UART0 to USB0 on Beagle Bone Black Board