Date: Wed, 21 Sep 2011 13:47:26 -0400 From: Lucas Holt <luke@foolishgames.com> To: Thomas Mueller <mueller6727@bellsouth.net> Cc: "freebsd-current@freebsd.org" <freebsd-current@freebsd.org> Subject: Re: 9.0 beta2 & the new bsdinstaller Message-ID: <FBC78CBB-359D-40B4-B7E7-04C56486710A@foolishgames.com> In-Reply-To: <20110921082649.9616D1065672@hub.freebsd.org> References: <20110920210906.GG14862@over-yonder.net> <20110921082649.9616D1065672@hub.freebsd.org>
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1MB is a magic number. It works with advanced format disks, traditional disk= s, some odd SSD and most raid configurations.=20 Lucas Holt On Sep 21, 2011, at 4:26 AM, "Thomas Mueller" <mueller6727@bellsouth.net> wr= ote: >> =46rom "Matthew D. Fuller" <fullermd@over-yonder.net>: >=20 >> I've been meaning to mention this, but we really should document >> somewhere that it has a _MAXIMUM_ size. >=20 >> I setup a system a few weeks back with GPT, and figured I'd just make >> the first 'real' partition start at the 1 meg mark. And make >> everything before that (1 meg - the however many sectors for the pmbr) >> the freebsd-boot partition. >=20 >> It worked fine, up 'till the point that I tried to boot, and it >> completely failed to, complaining that the boot code was too big. I >> had to track around in pmbr to find >=20 >> . . cmp $0x9000,%ax.. . # Don't load past 0x90000, >> . . jae err_big.. . # 545k should be enough for >> . . mov %ax,%es.. . # any boot code. :) >=20 >> and redo the partition to 512k (leaving a few hundred k unused before >> the next partition started) before it would boot. That's a little >> nerve-wracking to hit on a critical system... >=20 > I don't think there is any particular advantage in aligning GPT partitions= on 1 MB boundaries. >=20 > Nothing sacred about being an integer power of 2, wouldn't it be sufficien= t for boot partition size to be divisible by 4096 bytes, when the hard drive= sector size is 4096 bytes? >=20 >=20 > Tom >=20 > _______________________________________________ > freebsd-current@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org"=
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