Date: Tue, 24 Aug 1999 16:29:31 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: Matthew Dillon <dillon@apollo.backplane.com> Cc: David Greenman <dg@root.com>, FreeBSD Hackers List <freebsd-hackers@FreeBSD.ORG> Subject: more... Re: Possibility of increasing default MAXPARTITIONS from 8 to 16 Message-ID: <199908242329.QAA19447@apollo.backplane.com> References: <199908242254.PAA16075@implode.root.com> <199908242303.QAA19246@apollo.backplane.com> <199908242322.QAA19396@apollo.backplane.com>
next in thread | previous in thread | raw e-mail | index | archive | help
: minor device number:
:
: t = type
:
: u = unit (upper bits split off from lower)
:
: s = slice (assuming only 8 slices)
: 0 noslice
: 1 whole disk
: 2-5 s1,s2,s3,s4
: 6-8 unused
:
: p = partition
:
: - = cannot be used
:
:
: tttttttu uuusssss -------- uuuuuppp minor layout for disks
: 11111111 11111111 -------- 11111111 mask for uminor
:
: Our only hope as far as I can tell is to take the upper two bits of the
: slice (bits 19 and 20) and use them for the partition instead.
:
: As far as I can tell, only slices 0-5 are used, requiring only 3 bits.
:
: Can someone check my work? Are bits 19 and 20 unused by any disk
: devices?
:
: -Matt
Grrr. #ifdef PC98, NDOSPART is set to 16 instead of 4, requiring 5 bits
(0,1,2-17). This leaves one bit that we can usurp.
I'd rather have 2 bits, but I'll take 1 if I can get it.
-Matt
Matthew Dillon
<dillon@backplane.com>
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199908242329.QAA19447>