I did use also Mock components, in first version of FPGAmstrad, FPGA platforms was too small, so I could have FPGAmstrad only with cool sound and low graphics, or else FPGAmstrad with cool graphics and no sound. Both using 100% of this old FPGA platform. A Mock component is a fake component, an empty one, just telling back "I'm OK, please thrust me I do exist" to others components trying to communicate with me (it's a entity with same in out ports as original but using constant output values)
* *for programming a FPGA, the compiled binary is around 180KB, so do not expect about creating a RAM in FPGA itself. FPGA does contains also internal RAM (seduce ones, that can using two clock entries : one clock for data in an another for data out <3), but it is about 32KB. So an external 600KB RAM is best friend of FPGA.
=== Bootloader ===