Spi codes unclear and no output

[Bhargav607]

There is an error in "loopback design" . And the testbench doesn't match with the output waveform pic in this. And there is nothing related to slave other than main program(no testbench and no output waveform), so how to execute the codes in order and what's the use of loopback code.
Can you let me the order in which to execute this whole spi protocol and in how many scripts/source file should we write this code.
It would be helpful if you reply with necessary solutions.
Thank you