file format for writing epcs-flash directly from nios sw

Hello to all,

i am working on a project with cyclone iv e-fpga and an epcs-configuration device.

The customer needs the ability to transmit a new fpga-configuration over a custom serial bus to the fpga.

So the nios have to receive the configuration data and write it to the epcs-device.

Reading and writing the epcs is not a problem, but i don't know in which format the configuration data has to be.

Can anyone here tell me which format is the right, and how i can get it?

Thanks