NixOS on ARM/Jetson TK1
@dezgeg's porting efforts to ARMv7 should work.
Board-specific installation notes
The proprietary NVIDIA bootloader can only boot NVIDIA's L4T kernel, so it needs to be replaced by flashing U-Boot on the board's eMMC via the recovery USB port. The easiest way to do that is to use tegra-uboot-flasher-scripts, though unfortunately that's currently not packaged in NixOS. Once U-Boot is flashed, the ARMv7 image will boot out-of-the-box.
To get the ARMv7 image, follow the generic installation steps.
Finally, install using the installation and configuration steps.
Notes about the boot process
Only serial console (via the DB-9 connector) is supported.