NIOS II and Cyclone III Remote Update

I had difficulties to understand but I think I get it, you've the remote update core that enables to select the FPGA image, this FPGA image can includes the Nios firmware position defined by the Nios bootloader code (EPCS_boot_rom.hex) that will load this Nios firmware itself, remote update core can't change this one because it's integrated in EPCS controller core itself, in EPCS you have a base FPGA configuration at address 0 and others address, the default one is 0 if the Nios bootloader isn't changed. So for example, if I have two FPGA Images each included a Nios system, one at address 0 and the other one at address 0x400000, if I select the second FPGA image with the remote update core upon power up the default base configuration at address 0 is loaded, so my second FPGA image is selected but runs Nios firmware in the first FPGA image and not the Nios firmware in my second FPGA image.