Getting Fedora on this is hard work, but I managed it in the end.
To save you some time, I’ll tell you that you need to get a null modem cable, a Linux computer with a serial port, and a USB drive (anything 1GB or over).
Who uses serial ports? Evidently the manufacturers of modern PCs don’t think we need them because I discovered that I have only one working PC in the house left that has a serial port. USB-to-serial adapters and null modem cables are esoteric pieces of equipment, which tells me that ARM / Fedora / Fedora-on-ARM has a long way to go to make this usable for the common man.
There is also no Anaconda or installer for Fedora yet, so installation is quite unlike installing Fedora on a PC. It starts with a root filesystem which contains a minimal set of RPMs already installed, and you somehow have to get that on to the machine yourself.
Luckily the U-Boot ROM that comes with the Trim Slice is simple to understand (relatively speaking) and I managed to get Fedora/ARM to boot first time, even with my custom boot script. I followed the instructions here.
To get the root filesystem onto the internal SD card, I first installed it on the external USB drive, then booted Fedora from that, then copied it over the internal Ubuntu, then rebooted into that.
Finally, the SD drive is slooowwww (although the dual core Tegra 2 processor is pretty nippy). Running yum is much slower than normal (which is saying something). To get around this I’m using NFSv4
/home and temporary directories, so I can do things like builds in a faster place.
In the end, I do have a good, quite fast, ARM build server on my network.