On Sun, May 01, 2005 at 08:52:04PM +0200, malebe@numericable.fr wrote:
> On Sunday,  1 May 2005 at  9:22:12 +0100, David Laight wrote:
> > > When i want to install NetBSD 2.0, after 5 secondes i have this message:
> > > 3692492/
> > 
> > Does the '/' rotate (through /, -, \ and |) at all ?
> 
> yes, the '/' rotate fast during 2-3 seconds with all version i try.

ok, so it isn't failing on the first read, but gets well into reading
(and uncompressing) the install kernel before dieing horribly.

> But after, it's different:
> 
> With 1.6.1 (i386 bios boot revision 2.13):
> 3207712/ (/-\|) and nothing more after stop rotating.

Good - that means it isn't something affected by my rototil of the boot code!

> With 2.0 (i386 bios boot revision 3.1):
> 3692492/ (/-\|) and hundreds lines 'exit'.
> 
> With 2.0.2 (i386 bios boot revision 3.1):
> 3695248/ (/-\|) and @@@@@@ (about 5-6) and reboot.
> 
> With snapshot 20050408-3.0_BETA (i386 bios boot revision 3.2):
> 2461888/ (/-\|), and '+' , and number (so fast=51....) and /-\| and
> hundreds lines 'exit'

Now some guesswork...

The 3.0_BETA install image seems to only have 2.4MB of code, not 3.6MB (dunno
what got removed, but that isn't relevant) so that static data starts to be
loaded (the second number displayed during load).

So somewhere, maybe at 3MB of loaded data - 4MB absolute - the data reads
start overwriting some important data.

What, why and exactly where is more difficult to guess.  But it could be
determined by a serious debugging session.

Some things that you might be able to try:

1) booting from the boot[12].fs floppies
2) interrupting the boot and trying to boot a kernel from within a ufs
   filesystem.  The filesystem may only need start at the beginning
   of the the mbr partition being booted, try 'boot hd0i:netbsd' to get
   the first mbr partition on a disk without a netbsd disklabel.

Both of those would remove any issues with the bios floppy emulation.

Actually it may be worth checking all the BIOS setup screens to ensure
that memory at 4MB is reserved for (say) the VGA display.

	David

-- 
David Laight: david@l8s.co.uk