David Laight wrote:

> On Wed, Jul 02, 2003 at 12:03:57AM +1000, Simon Burge wrote:
> > With the following ugly diff I was able to boot successfully off a disk
> > that had the raid0 set at the start of the disk and without the need
> > for mucking about with boot partitions or wierd offsets for the 'a'
> > partition.
> > 
> > The "64" should at least be
> > 
> > 	#define RF_PROTECTED_SECTORS    64      /* XXX refer to <.../rf_optnames.h> */
> > 
> > and I don't know (read - "this works and that's all I needed") if
> > there's a better way of doing this.
> > 
> > Anyone more savvy with the i386 bootblocks care to comment?
> 
> I had a feeleng that my 'new' bootcode should make this easy!
> However I think the 64 should be added on at a different point
> - based on some property of the filesystem.
> 
> I don't know the actual layout of the raid0 system, but I recall there
> is code somewhere that adds in 64 - does that code work?

Very roughly here is the layout (for i386):

	block 0			start of real "a" partition
	block 1			disklabel for real disk
	block 0-16		space for "bootxx_*" first stage
	block 32 (maybe?)	raid label
	block 64		start of raid space
	block 65		disklabel for raid space
	block 80 (64+16)	start of FFS (or other) filesystem

> Is that in the code that loads the kernel?

This is in the bootxx_* code that loads /boot.  /boot itself is fine (it
uses .../lib/biosdisk.c which deals with adding 64 if the partition type
in the disk label is RAID) but bootxx_* needs to know whether or not to
add 64 as well, but currently the code doesn't look at the disklabel
(space constraints I guess).  So I just took the approach of "if the
open fails, try adding 64 to all read offsets and try again."

Simon.
--
Simon Burge                            <simonb@wasabisystems.com>
NetBSD Support and Service:         http://www.wasabisystems.com/