I do see something which might be an issue. The command line was this:
sudo ./flash.sh <b>-k kernel</b> jetson-tx2 mmcblk0p1
If using lower case “-k”, then you name a partition ID, e.g., “-k EBT” or “-k LNX”. The word “kernel” is not defined. If you use the “-K” upper case, then it is for the name of an actual kernel Image file.