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olofk / fusesoc

Package manager and build abstraction tool for FPGA/ASIC development
BSD 2-Clause "Simplified" License
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vlogdefine not passed to verilator #179

Closed lucasasselli closed 6 years ago

lucasasselli commented 6 years ago

I have noticed that a parameter passed with vlogdefine is not passed to verilator. It works fine in modelsim and icarus.

olofk commented 6 years ago

Interesting. That is supposed to work. I'll take a look. Are you using the latest version? Do you have any examples?

olofk commented 6 years ago

Aha! I found out why. For historical reasons, when using verilator, all parameters are sent the verilated model as command-line parameters. To get the same behaviour as for the other simulator backends, you need to set cli_parser = fusesoc in the verilator section.

This is really badly documented. So bad that I had forgot about it myself :/

lucasasselli commented 6 years ago

It seems to work, but using or1200-generic the elf file is no longer loaded in the simulation.

olofk commented 6 years ago

Hmm... you're right. The problem is that the file used by --elf-load is sent to the verilated model as a plusarg, but it expects it to be a command-line parameter. It's not trivial to fix this properly, so I recommend doing a workaround for now. The easist work-around would be to run fusesoc sim --build-only ... to just build the model without running it, and then launch it manually from build/or1200_generic_0/sim-verilator/Vorpsoc_top --elf-load=/path/to/elf-file

Another way would be to change the testbench to get the elf-file from a plusarg instead. Not sure if that also requires hacking verilator_tb_utils (this part is a bit messy unfortunately).

I need to think a bit how to improve this in a good way

lucasasselli commented 6 years ago

Nice workaround, it worked perfectly!

olofk commented 6 years ago

Can we close this?

lucasasselli commented 6 years ago

Of course, sorry!