[cs]What are the `some_name.o.cmd` files?

Basically, this is kernel compilation optimisation. These files are used to prevent make from working too much when unnecessary. As you can read above, a some_name.o.cmd file would be there to keep tracks of what's been done already/needs to be done when it comes to the compilation of some_name.o.
For more information, see section 4.5 of the document I linked earlier (What is new in Linux-2.5/2.6’s kbuild?).

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