XC7 Startupe2 primitive

[onestacked]

I wanted to write a controller for the qspi flash on the Nexys 4 DDR / Nexys A7. To do that i need to instantiate a STARTUPE2 primitive to control the serial clock port that is also used for initial configuration.

I noticed that (at least parts of it) were already fuzzed by project xray (038-cfg) but it wasn't in this repo and tried adding it myself but failed.

I'd like to get some pointer to what is needed for me to be able to add it myself (or that someone else just adds it themselves)