Problem when downloading zImage to DE2-115 (cont.)

The error you are getting is not related to your zImage. The process of resetting the processor should work with any image, even a nios2-elf (though it would fail afterwards).

I'm attaching the sof I compiled from your project, try and see if it works for you, it is the one which is working here.

Unfortunatelly I can't send you the zImage, but it must work with yours. If not, I'd advice you to check your board (with other designs, maybe the board test system).

Here is the command I used and its output.

~/Downloads/onur_restored$ nios2-configure-sof output_files/onur.sof && nios2-download -g ~/nios2-linux/uClinux-dist/images/zImage
Info: *******************************************************************
Info: Running Quartus II 64-Bit Programmer
Info: Command: quartus_pgm --no_banner --mode=jtag -o p;./output_files/onur.sof
Info (213045): Using programming cable "USB-Blaster "
Info (213011): Using programming file ./output_files/onur.sof with checksum 0x008EA0A1 for device EP4CE115F29@1
Info (209060): Started Programmer operation at Mon May  6 09:39:28 2013
Info (209016): Configuring device index 1
Info (209017): Device 1 contains JTAG ID code 0x020F70DD
Info (209007): Configuration succeeded -- 1 device(s) configured
Info (209011): Successfully performed operation(s)
Info (209061): Ended Programmer operation at Mon May  6 09:39:34 2013
Info: Quartus II 64-Bit Programmer was successful. 0 errors, 0 warnings
    Info: Peak virtual memory: 281 megabytes
    Info: Processing ended: Mon May  6 09:39:34 2013
    Info: Elapsed time: 00:00:07
    Info: Total CPU time (on all processors): 00:00:01
Using cable "USB-Blaster ", device 1, instance 0x00
Pausing target processor: OK
Initializing CPU cache (if present)
OK
Downloading D13E0000 (76%)