removing building.txt, now all the information is on wiki pages

building.txt

-Building the WR Switch gateware
--------------------------------
-
-Disclaimer: this readme assumes that you know the basic UNIX commands.
-						Otherwise, we recommend downloading the FPGA binaries from 
-            the 'Files' section of WR Switch HDL project.
-
-1. Environment setup:
-  1a. Make sure you have git & make installed.
-  1b. Make sure you have Xilinx ISE installed (64-bit version ONLY, version 14.5 or above). 
-  1c. Check ISE-related environment variables:
-    - Xilinx binaries (xst, map, par) must be in PATH environmental variable.
-    - XILINX environmental variable must be correctly set (for example: 
-      XILINX=/opt/Xilinx/14.5/ISE_DS for ISE suite installed in /opt/Xilinx)
-
-2. Install and build hdlmake ("isyp" branch)
-  2a. Download the sources and build hdlmake
-    $ git clone git://ohwr.org/misc/hdl-make.git
-    $ cd hdl-make
-    $ git checkout isyp
-    $ make
-  2b. Put hdlmake in a directory listed in PATH, for example:
-    $ sudo ln -sf `readlink -f hdlmake` /usr/bin/hdlmake
-
-3. Download WR Switch HDL sources
-  $ git clone --recursive git://ohwr.org/white-rabbit/wr-switch-hdl.git
-  $ cd wr-switch-hdl
-  $ git checkout wr-switch-sw-v4.2
-  $ git submodule update
-
-4. Generate SDB Metadata package with synthesis information
-  $ cd top/bare_top
-  $ ./gen_sdbsyn.py --user <your name> --project WRS_18p --ver <ISE version>
-
-5. Build it
-  5a. Generate the Makefiles
-    $ cd ../../syn/scb_18ports
-    $ hdlmake --ise-proj --make-ise
-  5b. Synthesize:
-    $ make
-
-6. Deploy the firmware
-  Copy the freshly build firmware to the switch filesystem:
-  scp scb_top_synthesis.bin root@<your_switch_ip_address>:/wr/lib/firmware/18p_mb-LX240T.bin
-  Reboot the switch.
-
-7. Good luck!
-
-Frequently Asked Questions
---------------------------
-
-Q: I'm getting PAR timing errors!
-A: If only this constraint is failing:
-   NET "clk_dmtd" MAXSKEW = 0.5 ns
-   It's acceptable (I used ridiculously low skew value to force PAR to put more effort on routing this signal).
-   For reasons yet unknown, ISE refuses to route this signal on a global clock net, resulting in larger skew.
-   Fortunately, the skew on clk_dmtd net is equal to port-to-port clock offset, which can be 
-   measured on a scope and compensated in delta_tx/delta_rx parameters in wrsw_hal.conf.
-
-Q: It takes so long to synthesize!
-A: The synthesis takes approx 2 hours on a Core i7-980x machine. If you don't need all 18 ports, you can
-   synthesize scb_8ports project instead (~30 mins on the same PC)
-
-Q: ISE appears to have frozen during MAP/PAR!
-A: Did you install a 64-bit version of ISE? It needs up to 4 GB of free RAM during mapping/routing the design.
-   32-bit version can't use more than 3 GBs and sometimes freezes instead of throwing an error.
-