how to configure to compile from source on wheezy

Hello:
I started off a few years ago with pre-compiled emc2 on Lucid 10.04 and I made good progress with cheap hardware.
I took on an ambitious project and started to compile from source, still on Lucid. At that time, the script src/configure took care of modifying a few files so that I could compile for RTAI on my cheap computer. It worked, and I didn't try to understand it.

My project got complicated, and I could see that I would need a 64-bit OS. I bought better hardware and tried installing Wheezy, but nothing worked, and I settled for installing on 64-bit Ubuntu 12.04 and configured my compiles for simulation mode. This kept my project happy for another year or so.

Now, I need to finally start driving motors again, so I need a 64-bit RT system. I followed the directions and managed to install debian 7.11 3.2.0-4-rt-amd64. When I try to make linuxcnc from source, it still wants to compile for simulation mode because several variables in src/Makefile.inc are set wrong.
src/configure tells me "error: RT not found" and wants a --with-realtime path which I can't find.
debian/configure tells me "your kernel '3.2.0-4-rt-amd64; is not known ........ successfully configured for 'Debian-7.11 3.2.0-4-4t-amd64.
Neither script changes the Makefile.inc for me.

So finally, my question:
What are the values I should set in src/Makefile.inc for BUILD_SYS and RT* for a compile-from-source in wheezy? And why don't the configure scripts do this for me? (Please don't tell me I need to compile my linux kernel from source!!)

Thanks,
Reid Wistort

I'm trying to servo toward a moving target, and there's a vision component that uses a lot of memory, so I (think I) need a 64-bit system. And if I don't, I'm pretty sure I will pretty soon.
It's also my main office machine, so why not?

In a nutshell, I'm using a frame grabber and opencv to collect and process stereo images as fast as I can within a user-space hal component. The target's location is updated onto hal at the frame rate and polled by a 'flight simulator' at the servo rate. Fsim talks to emc and, if all goes well, we hit the target.

A lot of this works, but a lot of it doesn't. Right now, I need to go back to an RT system and, with only one stone to throw, I think I've been trying to kill too many birds, and the birds have been killing me instead.
So I'm going to go with the flow and give rt-i386 another try instead, and see what happens.

Reid

before you build linuxcnc you must:

./configure --with-realtime=uspace

to generate a Preempt-RT compatible LinuxCNC version

(build instructions are in the README.md file in the top level LinuxCNC source tree)