# How to update u-boot? **URL:** \ **Category:** Jetson Nano\ **Tags:** nano2gb, uboot\ **Created:** [January 5, 2022, 4:25pm UTC](https://forums.developer.nvidia.com/t/how-to-update-u-boot/199678 "2022-01-05T16:25:19Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![botond.kardos](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@botond.kardos](https://forums.developer.nvidia.com/u/botond.kardos)\ **Post date:** [January 5, 2022, 4:25pm UTC](https://forums.developer.nvidia.com/t/how-to-update-u-boot/199678/1 "2022-01-05T16:25:20Z")
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! ---
**Author:** ![WayneWWW](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/waynewww/32/14043_2.png) [@WayneWWW](https://forums.developer.nvidia.com/u/WayneWWW)\ **Post date:** [January 6, 2022, 3:02am UTC](https://forums.developer.nvidia.com/t/how-to-update-u-boot/199678/3 "2022-01-06T03:02:10Z")
No, there is no faster way since “dd” command no longer works on jetson nano. ---
**Author:** ![botond.kardos](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@botond.kardos](https://forums.developer.nvidia.com/u/botond.kardos)\ **Post date:** [January 6, 2022, 7:56am UTC](https://forums.developer.nvidia.com/t/how-to-update-u-boot/199678/4 "2022-01-06T07:56:17Z")
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? ---
**Author:** ![WayneWWW](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/waynewww/32/14043_2.png) [@WayneWWW](https://forums.developer.nvidia.com/u/WayneWWW)\ **Post date:** [January 6, 2022, 8:16am UTC](https://forums.developer.nvidia.com/t/how-to-update-u-boot/199678/5 "2022-01-06T08:16:48Z")
Yes, there is similar case for uboot. -k LNX may flash the uboot. ---
**Author:** ![botond.kardos](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@botond.kardos](https://forums.developer.nvidia.com/u/botond.kardos)\ **Post date:** [January 6, 2022, 1:00pm UTC](https://forums.developer.nvidia.com/t/how-to-update-u-boot/199678/6 "2022-01-06T13:00:06Z")
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 ---
**Author:** ![WayneWWW](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/waynewww/32/14043_2.png) [@WayneWWW](https://forums.developer.nvidia.com/u/WayneWWW)\ **Post date:** [January 6, 2022, 3:48pm UTC](https://forums.developer.nvidia.com/t/how-to-update-u-boot/199678/7 "2022-01-06T15:48:06Z")
Please try > sudo ./flash.sh -r -k LNX _-board name-_ mmcblk0p1 Witch the board name to what you are using. ---
**Author:** ![system](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/system/32/68080_2.png) [@system](https://forums.developer.nvidia.com/u/system)\ **Post date:** [January 26, 2022, 6:28am UTC](https://forums.developer.nvidia.com/t/how-to-update-u-boot/199678/9 "2022-01-26T06:28:17Z")
Closed on January 26, 2022, 6:28am UTC This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.