You need either command line flash (uses driver package plus sample rootfs package), or JetPack (current version for a TK1 is JetPack3.1…not sure if 3.2 has a TK1 in it, but if it does, then the L4T version would be the same…L4T is just Ubuntu plus hardware drivers). This has to be run on a host with Ubuntu 14.04 or 16.04 with the flash over USB to the micro-USB connector. There is no bootable USB with embedded systems such as this. Also beware that host PCs with VMs usually fail due to USB issues…they can be made to work with much effort. PCs booted to Linux on live DVD distributions will also fail because they lack some of the normal features.
If you use command line to flash, then you just need any x86_64 PC with any flavor of Linux. If you use JetPack, then the host must specifically be Ubuntu 14.04 or 16.04. The advantages of JetPack include automatic download of packages (JetPack is a front end to command line…it downloads driver package and sample rootfs for you) and the ability to install extra software packages after the flash. You can flash command line and then run JetPack for extra packages. You can re-run JetPack at any time to work with optional packages if you just deselect the flash step. Flash goes through USB, extra packages go through wired ethernet.
You can look at the most recent (and recommended) release of R21.6 for a TK1 here:
Take a look at that and just ask if you have questions. The gist is that you run JetPack as your regular user and it will ask for a password for sudo when needed. Or if you use command line you unpack driver package as a regular user (creates a “Linux_for_Tegra/” subdirectory), then unpack sample rootfs with sudo (as root) in the rootfs subdirectory (“Linux_for_Tegra/rootfs/”), followed by cd back up one directory and “sudo ./apply_binaries.sh” (it’s in the “Linux_for_Tegra/” subdirectory)…then command line is ready for flash. A sample command line flash:
sudo ./flash.sh -S 14580MiB jetson-tk1 mmcblk0p1