@JustinBlaber After writing 2 comments about it, I choose to just write a answer...

Even tho my response is kinda late... There is really good github repository from a guy called Obko. (https://github.com/ObKo/stm32-cmake/tree/master) There is everything except the OBJECT stuff in there, but it might be helpful still. In order to understand the usage of the OBJECT libraries more better you could just create some test-project with your STM32CubeMX. Just create for the board of your choice a little project, but make sure you select "CMake" as Toolchain and create it once.

It doesnt matter if you use the STM32IDE or VSCode with the original STM32 Extension for it. Then you will see a folder named cmake/stm32cubemx// with one toolchain file and one bigger file. The bigger file is the one you are looking for. There is everything ST uses split up into OBJECT libraries which are circuarly depending on each other. Pretty neat.