[coreboot] What's the relationship between ACPI and SMM?

[Iru Cai]

Hello,

I'm trying to write some ACPI code to support an EC. I don't know if I need
to write an smihandler.c for the boards.

I saw some mainboard code. Older boards such as lenovo/x200 have no
smihandler.c, but newer boards such as lenovo/x220 have. Also, I don't know
much about things like GPE, SCI, ..., even after I look at the ACPI
specification.

So can some one sort out what happens when there is a event (e.g. Lid
open/close), and what the EC and ACPI OS should do. What needs to be added
in the mainboard code?

Thanks,
Iru