Following,
http://fedoraproject.org/wiki/Architectures/ARM/F21/Installation
I tested
Fedora-SoaS-armhfp-rawhide-20150129-sda.raw.xz
Booting with display direct to HDMI proceeds ok, except I notice that
the connected optical mouse does not illuminate.
If it is first boot, an initial setup screen appears, (which displays
fine, 4:3) neither keyboard or mouse will produce a reaction. (This is a
standard wired keyboard and optical mouse occupying the 2xUSB ports.)
If it is a boot subsequent to running first boot over serial cable,
login screen displays fine 4:3, but cannot login, due to no keyboard or
mouse working.
Another USB device with a LED indicates that the USB ports seem to be
unpowered, except for a short pulse at about the point where the boot
trace gives way to a black screen, say 5 seconds from power on.
By comparison, by the same LED test, Fedora20 Remix powers the USB ports
at about 3 seconds from power on, and same keyboard and mouse work fine.
Booting with serial cable is successful to login and performing simple
commands.
Tested Fedora-Xfce-armhfp-rawhide-20150129-sda.raw.xz and got basically
same results.