[coreboot] Question about smm handler bin

Patrick Georgi patrick at georgi-clan.de
Wed Nov 10 18:34:00 CET 2010

Am 10.11.2010 18:30, schrieb fengwei zhang:
> Suppose I just want to put RSM instruction in the smmhandler, can I just
> write instruction "0f aa"(bianry code of RSM) to location 0xa0000 and
> 0xa0001. I tried this, but my machine went freeze after I invoke SMI.
I think the SMI entry point is usually 0x8000 into the SMM segment, so
you'd need to put rsm at 0xa8000, not at 0xa0000.

> I am thinking I may need to more instructons, because the SMM start with
> 16 bits real mode, it may not recongnize the instruction, right?
That could be accomodated by ".code16" in the assembly code. We have
some semi-generic SMI handler, originally built to support i945/ICH7.
Not sure how much more generic it can be, Stefan might be able to answer


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