Support for GOWIN (and other EDAs/FPGAs)

[tiagosr]

Hi! Is there a specific way someone would go about adding support for a new EDA tool within PipelineC? I'm aiming at using PipelineC with GOWIN FPGAs.

I have some boards with GW1, GW2 and GW5 series FPGAs that I'm very interested in using with PipelineC. I saw that the OPEN_TOOLS.py backend plugs into nextpnr-ecp5, nextpnr currently also has support for most GW1 and one particular GW2 FPGA - this could be an easier backend to port, but would it be a lot more work to support another tool like GOWIN's EDA command line tools?

[JulianKemmerer]

It's absolutely possible, and only a question is to what extent the Gowin tools support what you want to do. If they are based on some of the open tools like nextpnr then hopefully is easy.

Essentially the PipelineC tool does:

1. write a script file with synthesis pnr and timing report commands + list of vhdl files
2. run the script
3. parse the script output for timing result

and its that for Lattice ghdl yosys and nextpnr that you see in OPEN_TOOLS.py

So I would love to see as a start 'here is how to run Gowin tool flow on command line'
for like a single VHDL file example + what timing report looks like etc

Then I'd probably make a GOWIN.py file and try to have it reference OPEN_TOOLS.py if possible, but otherwise just some python code to take the single VHDL file example and automate it into doing 1,2,3 from above.

What are your thoughts? 🤓

[JulianKemmerer]

OK making progress

If you check out the gowin branch https://github.com/JulianKemmerer/PipelineC/tree/gowin

and run
./src/pipelinec examples/tool_tests/gowin.c

It should print part of the log you provided and an error message about needing to parse the log.

Ex. Need to extract the delay in nano sec from each path in the report (and start and end registers etc). There is dumb example code from another tool (Efinix Efinty) there line by line searching for tokens - but feels like there should be a better way...

If you have some time to hack some python, go at giving it a go 🤓 - otherwise ill be getting back to this again in a bit...

[JulianKemmerer]

OK now in theory parsing the gowin timing report is done now.

I merged the code into main branch since footprint outside of gowin specific stuff was minimal.

Whats really left to do is install the gowin tools and try it out.

Do you have the gowin tools installed? @tiagosr care to give ./src/pipelinec examples/tool_tests/gowin.c a try?

[tiagosr]

Sure! I was just now starting to work on some fixes on your previous commit to run with the tools - some of the file locations in your version ended up slightly displaced when gw_sh was finally triggered. I'll report once I get the file parsing well (or if I find some more complicated issues 😅 )

[JulianKemmerer]

Surely other issues exist 😅

Sorry if I stepped on what you were trying to do with my quick commit ✊

Look forward to hearing for ya, no rush though, have a good weekend

[tiagosr]

Just created a pull request with some changes there #190 - I think all is working well with it! The previous version was not stopping at the end of the Setup Path Report in the .tr file, so it started generating negative timings and entering an infinite loop.

I'll try making some LEDs in my board blink via PipelineC soon 💡