Date: Wed, 12 Nov 1997 22:01:37 +0000 (GMT) From: Terry Lambert <tlambert@primenet.com> To: tlambert@primenet.com (Terry Lambert) Cc: handy@sag.space.lockheed.com, roberto@keltia.freenix.fr, current@FreeBSD.ORG Subject: Re: make world time???/ Message-ID: <199711122201.PAA20601@usr05.primenet.com> In-Reply-To: <199711122019.NAA07092@usr09.primenet.com> from "Terry Lambert" at Nov 12, 97 08:19:03 pm
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> 1) Allocate a buffer in low memory at some offset "x". > 2) Allocate a buffer in high memory at 16M + x > 3) Allocate a compare buffer somewhere. > 4) Schedule a bus mastering DMA read into the low memory > buffer; wait for it to complete > 5) Copy the low memory buffer contents to the compare buffer > 6) XOR some non-zero pattern into the low memory buffer > 7) Copy the low memory buffer contents to the high memory buffer > 8) Schedule a bus mastering DMA read into the low memory ^^^^ - UGH! I meant to say "high" here... > buffer; wait for it to complete > 9) Compare the compare buffer contents against the low memory > and high memory buffer contents. > 10) If the compare buffer contents matches the low memory buffer > contents, set the "USEBOUNCEBUFFERS" flag on the controller. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.
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