Transitioning from other version control system to github

[sjs-dogsrule]

I work on a large ASIC that has a mix of VHDL and verilog HDL.
Previously we used an older version control system that had a notion of components. We now need to transition to enterprise github and we are trying to decide how best to set everything up.

We have a TOP component, and then we have other components. For example, we had components like WriteFormatter, ReadFormatter, BufferManager, and SOC, and many more
The SOC files are in a directory of their own, but the other files from the components I mentioned above are all in the same main directory.

In going forward to github, I am thinking of the following setup.
Main repository in the main directory named TOP
And then create a submodule for each component. (In that case does each submodule need to have its own directory? Cannot be shared with the main repository directory?)

Would this work, or is there a better way? I am not familiar with all the github terms, so I may be missing other alternatives.

Thanks for any input.
Scott

[joshjohanning]

If starting fresh with git, I wouldn't really recommend submodules. They have their place, but can overly complicate things quite quickly.

What's the build / deployment flow look like? Does everything need to be compiled and deployed "as one"? Or better said, if you take one of the components out of the equation, does everything break/fall apart?

Monorepos aren't necessarily recommended either, but they can make sense in some situations if the entire app is developed, built, and deployed as one unit (a monolith essentially). Make sure you are familiar with some of the downsides of a monorepo though: https://monorepo-book.github.io/. Assuming you don't have thousands of developers making thousands of changes a day with GB's of git repo size, I would prefer a monorepo over a submodule.

[sjs-dogsrule]

Thanks, I can take a look at monorepos. I need to understand the difference between monorepos and submodules. Never having used either.
We only have 10-15 developers. Each working on their own component. A working component is needed for the other developers so they can run simulations at the entire ASIC scope. Each developer would compile and simulate using a configuration file to use their own component for their testing without affecting anyone else.

[joshjohanning]

A monorepo will have shared history, a submodule will have history split. Although I highly recommend against submodules :)

I would prefer either:

1. monorepo
2. A repo per component, and create a bootstrap script to clone/pull (update) all of the components at will