@dc42 Thank you very much for this fast response.
I did choose your 4 recommendation. And every thinf build with out problem.
Now i will try, your just released 2.0.2RC3, to get Build for RADDS.
One more question: in Wiring.c the excluded part for micros, which you not recommend to use, what can be used instead?
Regrards

I'm new to Eclipse and GCC. Please be patient.
I using 3D printer with Repetier and want try to use other Software. One of this is REPRAP.
But befor i change i did try to Build REPRAP for RADDS. I using DUE with my own designed Shield. So i must change some Pinout later.
Lets Start with my Problem:
I was following exactly the Buildinstructions from DC42 for the Master Branch.
Installed Eclipse Oxygen. GCC, CoreNG and the Firmware.
Import of the Project CoreNG and Firmware into Eclipse.
Setup the Path for GCC and using the Internal Builder.
CoreNG was build from the beginning and i got the libCoreNG.a
Then i start the Build for the Firmware, but different problems happen.
1.GCC complains about the micros and delay definitions.
This was fixed by change all the delay to coreDelay. For the micros it was neccesary to enable some part of the code in Wiring.c.
So far so good.
Now he build all modules but failed at the Linker step with following error:
F:\Eclipse\Firmware\CoreNG\RADDS\libCoreNG.a(startup_sam3x.o): In function Reset_Handler': startup_sam3x.c:(.text.Reset_Handler+0x6a): warning: undefined reference to UrgentInit'
startup_sam3x.c:(.text.Reset_Handler+0xa4): warning: undefined reference to `AppMain'
collect2.exe: error: ld returned 1 exit status

I selected the RADDS Build in CoreNG and ReprapFirmware.
Thank you in advance for your support.