> burn the .img into an sdcard and try it out.

The current SD card image https://9p.io/sources/contrib/miller/9pi.img.gz
has a flaw in the bootable kernel which makes it wait forever for a
usb ethernet adapter, which isn't there on the pi zero.  So, after burning
the SD card, please copy https://9p.io/sources/contrib/miller/9pi to the
DOS partition - this is a newer kernel which fixes the problem.

I will get around to updating the 9pi.img.gz Real Soon Now.