Synthesis configuration and use

[LudwigCRON]

In current run operation, there is no configuration file to define parameters or macro
for a platform instantiating several IP blocks and custom blocks.

• Would be nice to have such configuration file
• Parameters can be used in yosys (resp. genus)

# Yosys
chparam -set name value

• Defines can be used in yosys (resp. genus)

# Yosys
read -define macro[=value] file(s)

In the configuration file, a parameter could be reserved to specify
a custom synthesis script after read of all files.

So that user can specify:

• freduce (remove redundancy)
• rmports (remove unconnected ports)
• opt -undriven -fine
• set_dont_touch
  ...