On Wednesday, 29 November 2000 at 20:58:16 -0800, Peter Wemm wrote:
> Frank van der Linden wrote:
>> On Thu, Nov 30, 2000 at 09:05:55AM +1030, Greg Lehey wrote:
>>> In the last couple of days we've been having a discussion in the
>>> FreeBSD mobile list about a bug in newer IBM laptops.  See
>>> http://www.pc.ibm.com/qtechinfo/MIGR-4QHLS4.html for more details.
>>> Basically, it seems that the IBM BIOS uses partition type 165 for its
>>> own purposes, and goes crazy if it doesn't find what it wants in it:
>>
>> If type 165 is the problem, then NetBSD will certainly not have that problem,
>> since it uses 169 these days.
>
> I half wonder if we should make FreeBSD recognize a secondary partition type
> as well, just in case.  For example, our fdisk.c suggests that 168 (0xA8)
> and 175 (0xAF) are free.. Maybe one of them?  Then we can try using the
> alternate on the wretched thinkpads (sysinstall will let the user put in
> any partition type they want).

Well, in fact I just blew away my laptop with some experiments :-(

Here's what I discovered:

1.  FreeBSD will happily mount FreeBSD partitions in NetBSD or OpenBSD
    slices.  It's just the boot which silently ignores them and boots
    from the first FreeBSD partition it finds, and complains if it
    can't find one.  Correct me if I misunderstand, but I think the
    process is something like this:

    a.  Boot manager prompts:

	F1: Microsoft
	F2: FreeBSD
	F3: OpenBSD
	F4: NetBSD

    b.  Press F3 or F4.  Boot manager goes looking for the boot block
        on this slice and loads it.
   
    c.  The boot block goes and looks at the slice, says "nah!  That's
        not FreeBSD", finds slice 2 and boots it.

    Is this reasonable?  In that case, we just need to change the
    boot.

2.  Don't use /stand/sysinstall's partition manager to rewrite the
    partition type of a partition you care about.  It seems to create
    an empty partition table as well.  Use fdisk(8) instead.

Greg
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