Subject: Re: General Disk Info
To: Kevin Wilson 315-456-1404 <kevin@spef8.spef.syr.ge.com>
From: Michael Finch <finchm@cray-ymp.acm.stuorg.vt.edu>
List: macbsd-general
Date: 04/09/1994 22:51:48
Kevin Wilson 315-456-1404 wrote:
>   The Apple HD SC Setup showed me that there were two additional partitions
> on the disk that non of the other formatters told me about.  They were
> the partion table itself, and a MacOS boot partion.  This meant that my swap
> partion was at partion 8 (beyond the 0-7 range I was trying to stay within).
>   I have fixed my imediate problem by removeing an almost unused MacOS partion
> and giving it to MacBSD.
> 
>   I hope this will help people in the future.
> 
> ????
>   Is there a possible fix for this problem in MacBSD?  It seems to me that
> at some point during the boot phase a logical to physical mapping of the
> drive partions must occur.  I saw this because my partion 6 shows up as 
> MacBSD partion a: and 7 as b:.  It seems as though disklabel and the mapping
> process only look at upto the first 8 tabel entries.  Could this me fixed
> to look at the entire tabel and stop when either there are no more enties
> in the partion table of the disk or unix?

I looked at the code, and you are correct it only reads MAXPARTITIONS
from the disk partition table.  The change is simple to make it
read more than that.  I never expected Mac owners to have more than
8 partitions, ooh well.  I tried to keep the number down since it
holds the entire partition table in memory, and each entry is the
size of a disk sector.  As I recall, Silverlining's disk partition
table was 63 sectors in length, with Apple suggesting >100 on page
578 of IM-V.  So, loading the entire table is OUT of the question.


-Mike

-- 
finchm@cray-ymp.acm.stuorg.vt.edu   | Ask me how to awaken the sexual
                                    | beast that lies dormant in
                                    | every woman's soul.

------------------------------------------------------------------------------