Date: Tue, 10 Mar 1998 21:00:28 +1100 From: Bruce Evans <bde@zeta.org.au> To: bde@zeta.org.au, luoqi@watermarkgroup.com, mike@smith.net.au Cc: current@FreeBSD.ORG, stable@FreeBSD.ORG Subject: Re: *HEADS UP* Correction to previous postings. Message-ID: <199803101000.VAA13596@godzilla.zeta.org.au>
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>> > Summary of the 3 cases where the whole disk is used for FreeBSD: >> > >> > Partition table config Slice# passed by bootblocks Slice# to use for "/" >> > ---------------------- --------------------------- ------------------------- >> > Signature != 0xAA55 WHOLE_DISK_SLICE (= 1) COMPATIBILITY_SLICE (= 0) >> > Historical invalid BASE_SLICE + 3 (= 5) COMPATIBILITY_SLICE (= 0) >> > "Valid" (1 big part.) BASE_SLICE + N (0 <= N < 4) BASE_SLICE + N >> ... >I managed to modify boot2 so I was able to boot with -r1.87 autoconf.c >from my dedicated disk (historical invalid). My solution was to leave slice >to be WHOLE_DISK_SLICE for a BSD partition starts at sector 0 (this would >bloat boot2 by two bytes: a je rel8). This test would misdetect case 3 as dedicated (which may be best :-) and would also misdetect cases where there are multiple nonempty partitions with the first BSD one starting at sector 0. For complete compatility with the kernel, the boot blocks would have to do a bcmp() of the historical table with the actual table. This takes 0x40 bytes for the table and about 0x20 bytes for the test. I don't think this can be compressed much. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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