[ci] Switch to distro Verilator

[jackkoenig]

This debumps slightly to Verilator 5.020 2024-01-01 rev (Debian 5.020-1) (from currently build from source v5.022) but it seems to work and is simpler, especially as an example for users. What do you think @seldridge?

[tymcauley]

FWIW, I ran into some ChiselSim segfaults after the bump to firtool-1.115.0 while using Verilator 5.030, which were resolved by updating to Verilator 5.034.

[jackkoenig]

FWIW, I ran into some ChiselSim segfaults after the bump to firtool-1.115.0 while using Verilator 5.030, which were resolved by updating to Verilator 5.034.

Good to know, thanks. Installing from source causes issues with giter8¹ due to $, but I will figure something out.

Footnotes

1. experimenting with giter8 in https://github.com/jackkoenig/chisel-template.g8 ↩

[seldridge]

This is probably fine.

There are (as Tynan states) some problems with older Verilator versions. Also, if you want force to work, you need 5.036 (which even the newest Ubuntu doesn't have).

Maybe what we want here is our own GitHub action just for installing Verilator. There are a couple on the Actions Marketplace already. However, this installation is so simple, that it may be easier (and safer) to roll it ourselves.