Re: port-sparc64/56363: boot: Inode not directory

[David Holland <dholland-bugs%netbsd.org@localhost>]

The following reply was made to PR port-sparc64/56363; it has been noted by GNATS.

From: David Holland <dholland-bugs%netbsd.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: port-sparc64/56363: boot: Inode not directory
Date: Fri, 20 Aug 2021 04:17:27 +0000

 On Thu, Aug 19, 2021 at 02:00:03PM +0000, Martin Husemann wrote:
  >  On Thu, Aug 19, 2021 at 01:53:26PM +0100, David Brownlee wrote:
  >  > Is there any way to ensure that the blocks loaded from /ofwboot are at
  >  > the end of a partition for testing purposes? Maybe have a some code
  >  > create repeated copies of ofwboot until it finds one with a block over
  >  > a required limit, then remove the others and use that one?
  >  
  >  I am not sure I understand your idea - I don't think there is any 
  >  non-destructive way to probe for this kind of limits.
 
 I think the idea was to rerun installboot repeatedly until you get an
 installation that has blocks outside some suspect test range, see if
 it works, and then repeat, bisecting to find the limit.
 
 You don't really want to fill the disk with copies of the bootblock
 for that, though, since if it silently reads the wrong block you stand
 a decent chance of getting the right material anyway. Better to fill
 the disk with blocks of illegal instructions.
 
 There's still no good way to control where things end up, though, but
 I guess you could introduce a hack to ffs to always pick cylinder
 groups in reverse order from the end. Or since you're going to be
 booting from alternate media anyway, just use makefs to prepare a
 suitable image and then dd it on.
 
 -- 
 David A. Holland
 dholland%netbsd.org@localhost