Jetson TK1 - Command line boot?

Traditionally, to start Ubuntu with the command line it’s a simple modification of /etc/default/grub by changing some text with nano. Should there be any differences considering this is Tegra Ubuntu?

Is it suggested that the fan be used even during basic tasks solely using the command line? At what point should the fan be used with a non-GUI boot?

How about this? Unfortunately I didn’t test this yet.
https://devtalk.nvidia.com/default/topic/718956/embedded-systems/-linux-for-tegra-r19/post/4258401/#4258401

Jetson does not have grub, I doubt any embedded system comes with grub. Jetson comes with fastboot which has no easily changed options (fastboot uses the flash.sh -K 6 option for setting a boot partition, u-boot instead looks for the /boot subdirectory of rootfs and finds zImage via extlinux.conf).

If you flash to L4T R19.3, you can choose u-boot during flash, and u-boot can easily be edited to change command line to the kernel, as well as adding multiple kernels. Tegra’s L4T and the Ubuntu on it is no different from anyone else…except for the boot loader (which is basically the same as other embedded systems). Here is a recent entry on this, but there are a lot of good threads on this if you look around:
https://devtalk.nvidia.com/default/topic/747933/embedded-systems/is-it-possible-to-boot-from-sd-or-usb-hdd-and-how-jetson-tk1-/

You’ll see in the flash.sh command options about the location where to install during flash. Assuming devices are plugged into Jetson, mmcblk0p1 corresponds to the internal eMMC flash; mmcblk1p1 corresponds to the SD card slot (better have an SD card plugged in!); sda1 corresponds to the SATA slot. Not sure what one would use to refer to the USB thumb drive or NFS.