Hi,
Sorry for the delay.
The fmc_spi node refers to the hardmacro SPI controller that is in the PS portion of the Zynq. The addresses you see in the address editor are only for peripherals that are in the programmable logic section of the Zynq.
When you download the pre-build image you can copy it to you SD card without having a already working environment.
The source code for the kernel and devicetree can be found in the xcomm_zynq branch. The u-boot used is a (mostly) unmodified version of the Xilinx u-boot. The only change is the this patch.
- Lars