U-Boot environment variable change

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX2
1

Hi,

I want to change the U-Boot environment variable (specifically only “bootdelay”) without using uart connected to serial console. I have looked at the forum and found “u-boot-tools” package. From what I’ve seen, people can change the variable by using fw_setenv. In order to use fw_setenv, /etc/fw_env.config file must be set correctly. What is the content of this file should be? Someone posted his config file (https://devtalk.nvidia.com/default/topic/1037561/jetson-tx2/fw_printenv-and-fw_setenv-in-tx2/post/5272612/#5272612)

/dev/mmcblk0boot1   0x3FE000  0x2000

But this one still gives me the following error and shows the default uboot variables:

Warning: Bad CRC, using default environment

This will be the first time I am going to change the uboot variable after flashing. Can I do this without using serial console?

Thanks in advance.

2

You could put CONFIG_BOOTDELAY= in defconfig and rebuild the u-boot.

3

I have followed the instructions in this link https://docs.nvidia.com/jetson/l4t/index.html#page/Tegra%20Linux%20Driver%20Package%20Development%20Guide/uboot_guide.html#wwpID0E0UK0HA

On To download and build U-Boot section, part 4, I’ve build the U-Boot with

make distclean
make p2771-0000-500_defconfig
make

Following files are created dts/dt.dtb, u-boot-dtb.bin, u-boot.bin, u-boot.sym, u-boot.cfg, u-boot.dtb.

From my understanding according to your reply, I need to add CONFIG_BOOTDELAY= to the u-boot/configs/p2771-0000-500_defconfig (since there is no CONFIG_BOOTDELAY variable in this _defconfig) file while keeping other variables as it is and build again?