I've read your other thread, about Hello World on Nios II and nowhere do you mention that you configure the FPGA for running the NIOS II, so maybe that's the problem?
I quote from Nios II handbook (see page 2-5 and 2-6): "Configuring the FPGA. Before you can run your software, you must ensure that the correct hardware design is running on the FPGA. To configure the FPGA, you use the Quartus® II Programmer. In the Windows operating system, you start the Quartus II Programmer from the Nios II SBT for Eclipse, through the Nios II menu. In the Linux operating system, you start Quartus II Programmer from the Quartus II software. The project directory for your hardware design contains an SRAM Object File (.sof) along with the .sopcinfo file. The .sof file contains the hardware design to be programmed in the FPGA."
Also se the Qartus II FPGA programmer handbook for info on how to program your FPGA.