First of all, I want to add a new sensor in device tree. So according to the Linux Driver Package Development Guide, I plan to download the kernel source code and build out the image and dts files. I have done the above and I don’t know what this means in the Guide:
-On T210 (Nano and TX1) devices only, connect the Jetson device’s recovery USB port to your host. Enter this command at the U‑Boot command prompt:
-ums 0 mmc 1
-This connects eMMC (or the Jetson Nano SD Card) to the host as a set of USB mass storage devices (each partition as a device). You then can copy your custom kernel to /boot/Image directly.
What does “enter this command at the U-Boot command prompt” means? In addition,I have tried to use the sdkmanager to flash the jetson nano. Sdkmanager will automatically download and creat the os image and driver files so I replace the kernel image and dts files with these built from new kernel source code. After flashing, the jetson nano can be configed the user name and password, but it didn’t entering the operating interface after thar and stuck in “started Update UTMP about System Runlevel Changes”.
I don’t know if this way is wrong and I want to try U-Boot way but I don’t how to do it?