How to update u-boot?

Dear All,
I’m about to add some modifications to U-Boot on the Jetson Nano 2GB board. I’m working with Yocto and usually do the following steps to test a given modification:

  • bitbake u-boot-tegra -C compile -f
  • bitbake core-image-weston
  • then extract tegraflash and execute “sudo ./doflash.sh --spi-only”

This whole process takes several minutes to complete. Is there maybe a faster way of rebuilding and updating U-Boot in the SPI flash?

Thanks for any hint!

No, there is no faster way since “dd” command no longer works on jetson nano.

Thanks!
When I update the devicetree only there is a slightly faster way. After Linux has been built the .dtb file can be written directly to the SPI flash with the “flash.sh -k DTB …” command. (flash.sh comes from L4T-tegra210-32.5.2-r0/Linux_for_Tegra) Isn’t there something similar for U-Boot?

Yes, there is similar case for uboot. -k LNX may flash the uboot.

Do you happen to know the exact syntax?
I tried

  • sudo ./flash.sh -k LNX -L boot.img jetson-nano-2gb-devkit mmcblk0p1

and it failed with “Error: Return value 4
Command tegrarcm --download ebt cboot.bin 0 0 --download rp1 kernel_tegra210-p3448-0003-p3542-0000.dtb 0”

I took “boot.bin” from work/jetson_nano_2gb_devkit-poky-linux/core-image-weston/1.0-r0/tegraflash

Please try

sudo ./flash.sh -r -k LNX -board name- mmcblk0p1

Witch the board name to what you are using.