Tidy up Makefiles and expand README

Author: matiasilva

README.md

@@ -1,3 +1,17 @@
 # FPGA projects
 
-This repo houses a collection of projects that use the iCEBreaker FPGA and the open source suite of tools for simulation, synthesis and place-and-route.
+This repo houses a collection of projects on FPGA boards that I've used. These are:
+
+* the iCEBreaker FPGA
+* the TangNano 9kandand
+* the Xilinx Zynq-7000
+
+Most projects use the open source suite of tools for simulation, synthesis and place-and-route.
+
+## Development
+
+1. Source the OSS CAD suite environment:
+```bash
+source $CAD_SUITE_DIR/oss-cad-suite/environment
+```
+