What are the steps to create an ELF file for project in command-line?

The Nios II application is first compiled into an ELF file and then this is combined with SOF to create POF which is then downloaded into the FPGA. All this is well and good.

I want to know, the specific applications and steps to use to do this process through command-line. My main confusion is related to the very first step.

In order to create an ELF, I shall have to first create a bsp and then compile the BSP files together with the Nios II program source files to create the final ELF file output. How do I do all of this through command-line? The documents I have looked at gives such a long list or programs and mentioned "make" that I am totally confused. I would be grateful if someone can make this simple for me. Or maybe there is a course on Intel website that I am not aware of yet.