Could not upate kernel

Problem Description:
We have a Xavier 16G eMMC module and we design a carrier board . We Modified the kernel, reborn the kernel to the module, and found that the kernel could not be updated

Operation process:

  1. Using sdkmanager, version jp4.4dp
  2. Clone image file- system.img clone- system.img.raw
  3. Replace / bootloader/ system.img : cp clone- system.img.raw system.img
  4. Modify the kernel source code (corresponding to version r32.4.2) and compile the kernel
  5. Copy the generated image and DTB files from the kernel output directory to Linux_ for_ Tegra / kernel / image and Linux_ for_ Tegra/kernel/dtb
  6. Burn kernel: sudo/ -r -K kernel/Image jetson-xavier mmcblk0p1

Other methods tried to update the kernel:
Replace / boot / image (this method fails, the system cannot be started, and cannot enter the desktop system)

None of the above operations can update the kernel.Would you please help us how to do

This won’t cover everything, but realize that some of the files in “Linux_for_Tegra/kernel/” get copied into the “rootfs” prior to generating a new filesystem image. Other files may end up in other partitions. When you flash a clone using “-r”, this implies your rootfs image file will be used without any modification. If the flash command adds or edits content to non-rootfs partitions, then things will do as you expect. If the flash command would normally add Image to “rootfs/boot/Image”, then what you expect to update will not update. You could also copy the Image file to the loopback mounted raw clone within its “/boot” directory. Not sure if that will help or not.

thanks for you reply.