Not sure if there is a jetson support email, all I could see was CUDA. I’d successfully flashed a new kernel in R19.2 jetson, and decided to flash R19.3 as a whole (not just a kernel). I ended up with this after a few attempts (since none of the attempts worked):
R19.3/Linux_for_Tegra# ./flash.sh -S 15GiB jetson-tk1 mmcblk0p1 copying dtbfile(/home/dan/Documents/embedded/L4T/R19.3/Linux_for_Tegra/kernel/dtb/tegra124-pm375.dtb) to tegra124-pm375.dtb... done. Making system.img... /home/dan/Documents/embedded/L4T/R19.3/Linux_for_Tegra/rootfs 16106127360 mapping system.img to loop device failed.
One attempt used the u-boot option, another without any size (no -S). So far, no listings found for mapping system.img failure. Is there an L4T/jetson support email at nVidia, or does the CUDA one handle L4T/jetson?