Date: Wed, 26 Aug 2009 15:53:36 -0700 From: steve@Watt.COM (Steve Watt) To: hackers@freebsd.org Subject: Re: enable ECC in OS code? Message-ID: <200908262253.n7QMrauP063683@wattres.watt.com> In-Reply-To: <4A954A35.4030207@icyb.net.ua>
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In <4A954A35.4030207@icyb.net.ua>, avg@icyb.net.ua wrote: > >Here is a question that I am afraid I know an answer for. >I have some ECC capable hardware: >1) Athlon II with embedded memory controller that can do ECC >2) DRAM modules with ECC >Assuming that ECC data lanes are connected between the two on motherboard, and >given that BIOS doesn't perform any ECC setup (nor there is any option to control >that) - would it be possible to turn on ECC from OS code? >Or is it too late in the game already? It's about 100 times easier to have the BIOS do this. First off, it's usually quite specific to the chip set exactly how to do it. Next, if ECC wasn't enabled previously, the ECC bytes will all be wrong, which means that you'll have to rewrite all of memory after you've turned it on. Oh, and you have to fetch the code that rewrites the ECC from the memory with incorrect ECC to do that. If the BIOS is broken to the extent that it doesn't enable ECC on a system that it should be available, whine at the vendor. -- Steve Watt KD6GGD PP-ASEL-IA ICBM: 121W 56' 57.5" / 37N 20' 15.3" Internet: steve @ Watt.COM Whois: SW32-ARIN Free time? There's no such thing. It just comes in varying prices...
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