Flash a XC6SLX9 dev board as a 7i90HD

It probably works, but I'd still have to invent something to replace the convenience of the 7i42TA's for connection to the real world. I may have been the first user of the 7i90HD, doing it just to see if t could be done. Peter hasn't said. And because I mentioned an rt kernel I'm banned from the pi forum. So I had to compile it myself, and figure out how to install it, which actually turned out to be a piece of cake. The uncompressed tarball is about 28 megs, and installed by untaring its two directors to the same directories in the sd card the pi boots from. Done and apt doesn't mess with it.