Is there some way to pass parameters (or command line arguments) to a Yosys script?
I see in this quetion (Can we have variables in a Yosys script?) you can run the Yosys script within a TCL interpreter. Is there some way to pass in an argument?
The reason I am doing this is that I have a script, and I want to be able to call the script with a parameterized path to a Verilog file. Surely this is a common need, and there must be some easy way to do this, but I'm not seeing it.
The only way to do that at the moment is using environment variables and TCL scripts. For example, you can write a TCL script test.tcl:
yosys read_verilog $::env(VLOG_FILE_NAME)
yosys synth -top $::env(TOP_MODULE)
yosys write_verilog output.v
And then call if with VLOG_FILE_NAME and TOP_MODULE set in the environment:
VLOG_FILE_NAME=tests/simple/fiedler-cooley.v TOP_MODULE=up3down5 yosys test.tcl
If you are running Yosys from a shell script you can also simply run something like export VLOG_FILE_NAME=... at the top of your script. Similarly you can use the export Makefile statement when you are running Yosys from a Makefile.
I was facing a similar case. This question showed up while I was working on a solution. I ended up with a different approach though:
I'm creating a wrapper to my top module, written in m4 language. It's very simple, it overrides the parameters value, and then includes my top module definition.
Then in the Makefile, I process the wrapper.m4 file, to create the resulting wrapper.v file, that will be input to yosys.
I have detailled the solution here.
