Hi Mike!
I only know one board where the IMC is used for fan control - gizmo2
Could you please clarify the IMC status for ASUS AM1I-A (AMD 16h mini-ITX board) ? Because at coreboot's "menuconfig" I see this dependency
I'm pretty sure that the fan control is done by the superio on that board. The registers of the environment controller of the superio chip get written and HUDSON_IMC_FWM defaults to n in the board kconfig file. Not sure if the board kconfig file has precedence over the southbridge one; I'd guess so, but haven't checked.
Regards Felix