Have you modified the flash content in any other way? Which L4T release version is it?
I have no idea if this is related, but what is the exact byte size of the
system.img file you created? It should be an integer multiple of either MiB (1024*1024) or GiB (1024*1024*1024). The “size” parameter to
flash.sh could be used in case it is an issue of a non-default size. As an example, if the file is 16106127360 bytes (15 * 1024 * 1024 * 1024), then it is 15GiB, and you might use:
sudo ./flash.sh -r -S 15GiB jetson-tx2-devkit mmcblk0p1
(note that I’m also including the “
-r” so it reuses your image)