Date: Wed, 22 Sep 2004 02:04:06 -0700 From: Bruce M Simpson <bms@spc.org> To: John Baldwin <jhb@FreeBSD.org> Cc: Nate Lawson <nate@root.org> Subject: Re: mp_machdep.c (was Re: [Fwd: Re: Bug reports requested - acpi]) Message-ID: <20040922090406.GF4985@empiric.icir.org> In-Reply-To: <200409211441.42325.jhb@FreeBSD.org> References: <41421D6A.8070805@cronyx.ru> <41505663.40407@cronyx.ru> <4150607D.3020900@root.org> <200409211441.42325.jhb@FreeBSD.org>
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Just FYI... On Tue, Sep 21, 2004 at 02:41:42PM -0400, John Baldwin wrote: > Umm, 0xa0000 is the start of Video RAM, so I sure hope the ACPI wake code > doesn't try to write code into Video memory. The pmap_invalidate_page is > certainly needed. This is more common than you'd think, by the way. The 0xA0000 range is sometimes used as a place to hold 'hidden memory' used whilst servicing an SMI; ie the pages are 'stolen' from main memory by the during BIOS initialization using registers for APM/ACPI support in the chipset. Sometimes this is referred to as SMRAM or Systems Management Memory (SMM). I posted some code just over a year ago illustrating how to access this 'hidden segment' on the i440BX to the lists. BMS
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