How to Debug RTEMS

[mfg]

Hello,
It's my first message and I'm not sure how this maillist works.
I would like to know if anyone has been able to debug an aplication of 
RTEMS (one simple hello world) in a Zedboard and how to do it.
I have tried many things and all have failed for one reason or 
another,Qemu, openOCD-GDB, Xilinx SDK, XSDK XMD console-GDB.

The closest thing I've been debugging it is when I've put breakpoints 
in the start.S file (rtems/c/src/lib/libbsp/arm/shared/start/start.S) 
and the code has reached the 350 line. At that time the blue led goes 
out, the orange led comes on (Something is sent by UART, but nothing is 
received.) And it crashes.

I can run a program using the SD (with SD Card boot), but I do not know 
how to debug with a JTAG.

Thanks in advance.