Linux/PROCESSOR-SDK-AM335X: uEnv.txt upload

yingjie gu

Tool/software: Linux

Hi ,

I met similar problem with https://e2e.ti.com/support/arm/sitara_arm/f/791/t/241286#pi316653=2, and I learned from this post that I should edit the uEnv.txt file. The problem is I don't want to use any SD during booting

up am335x starter kit. In my real project, I will not use SD, but plan to use UART to upload u-boot and use ethernet to upload kernel and file system.

I uploaded u-boot-spl and u-boot.img through minicom xmoderm and ymoderm on Ubuntu 16. Then the u-boot tried to find kernel on my DHCP server and, of course, always

failed since kernel and file system is on another PC. In this case how can I upload the modified uEnv.txt to starter kit to make it download from my PC?

Also, I am able to run some commands on u-boot mode to load kernel and succeed from PC, but after that I don't know which command shall I use to let the board run from the kernel.

over 6 years ago

0 Biser Gatchev-XID over 6 years ago

TI__Guru**** 393215 points

Hi,

Please read processors.wiki.ti.com/.../Linux_Core_U-Boot_User's_Guide

0 yingjie gu over 6 years ago in reply to Biser Gatchev-XID

Intellectual 810 points

Hi Biser,
Thank you for the reply. But it doesn't answer my question.
I read the file before, and this file has no answer to my question. I ran the command in the file to download kernel, it works.
But
1. The file doesn't show how to upload uEnv.txt without SD card. It seems that I must use a SD card in order to enable a auto load from the correct PC. Without the SD card, I have to manually set env every time I connect a new board, or reconnect the same board. (I did not flash boot to NAND)
2. The file didn't show how to run from kernel after it is loaded to 0x82000000.

0 Dwarakesh Radhakrishnan over 6 years ago in reply to yingjie gu

Guru 13620 points

Hi,

One option is You can hardcode the bootargs into the code in bootloader.

0 yingjie gu over 6 years ago in reply to Dwarakesh Radhakrishnan

Intellectual 810 points

Dwarakesh, could you please provide more information? Which file should I change to hardcode the bootargs? Thank you.

0 Dwarakesh Radhakrishnan over 6 years ago in reply to yingjie gu

Guru 13620 points

Hi,
In uboot code:

Can you try:

macro CONFIG_EXTRA_ENV_SETTINGS in include/configs/am335x_evm.h
macro NETARGS in include/configs/ti_armv7_common.h

I have not tried myself. It is been long since I worked in AM335x and not much familiar. So not sure of the exact place. This is just a suggestion.

0 Kemal R. Shakir over 6 years ago in reply to Dwarakesh Radhakrishnan

TI__Guru 55345 points

I confirm, this should work.

0 yingjie gu over 6 years ago in reply to Dwarakesh Radhakrishnan

Intellectual 810 points

Thanks, Dwarakesh. It works.
This is what I did.
in board_support/u-bootxxx/include/configs/am335x_evm.h, modify the CONFIG_BOOTCOMMAND as
#define CONFIG_BOOTCOMMAND \
"setenv autoload no; " \
"setenv serverip 10.0.0.132; " \
"dhcp; " \
"tftp 0x81000000 10.0.0.132:uImage" \
"bootm 0x81000000"

I didn't change NETARGS since, for now, I just plan to try UART loading u-boot and Ethernet loading uImage. The above changes already make it works.
But I still met new problem. By using the pre-built u-boot.img and zImage provided in board_support/prebuilt-images, my am335x-SK stuck at starting kernel. Although I open the Debug_LL, nothing is printed after that.
I will post a new question with detail information. But thank you for helping me out of this uEnv problem.

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Linux/PROCESSOR-SDK-AM335X: uEnv.txt upload