[syslinux] boot Soekris 4801 with EXTLINUX

[Evan Webb]

Success! 

Altering cache.inc and changed 65536 in the size calculation to 4096
makes EXTLINUX work properly (I changed it in all 3 places). Whats
strange is that syslinux seems to work fine with a value of 65536, so
I'm wondering if maybe the code to read the ext2 data just before doing
initcache takes up a lot more room on the stack than the same syslinux
code. 

Then again, I could easily be completely off base, as this qualifies as
my first crack at debugging x86 bootloader assembly. At any rate, Peter
if you need me to test any code or help to debug this more, let me know,
I'd be happy to.

Evan Webb // evan at lockdownnetworks.com

On Wed, 2005-05-25 at 15:38 -0700, Evan Webb wrote:
> EXTLINUX seems to crash trying to return from initcache, I'm wondering
> if it's allocating too much cache. I'm going to try adjust the settings
> a little and see if there is any change.
> 
> Evan
> 
> On Wed, 2005-05-25 at 15:26 -0700, Evan Webb wrote:
> > You are correct. I added a jmp .noedd as the first command of eddcheck
> > and syslinux now works. EXTLINUX now shows the copyright, but then stop,
> > no prompt or anything. I'm adding a bit of debug code now to try and
> > figure out where it might have gotten hung up. Is there EDD dependent
> > read code thats used to read the ext2 sectors?
> > 
> > Evan
> > 
> > On Wed, 2005-05-25 at 13:11 -0700, H. Peter Anvin wrote:
> > > Evan Webb wrote:
> > > > I suspect that the net4801 has the same problem as the net45xx that I
> > > > reported on Monday. I tested some more of the code, and it appears that,
> > > > strangely, the jump to the code in the 2nd sector (jz all_read) of
> > > > ldlinux.sys fails.
> > > > 
> > > > Peter, any ideas?
> > > 
> > > That would mean that the second sector didn't get read correctly, which 
> > > implies a fundamental bug in the BIOS.  One thing I would suggest is to 
> > > hard-wire the CBIOS/EBIOS selection, and see if one works and not the other.
> > > 
> > > 	-hpa
-- 
Evan Webb <evan at lockdownnetworks.com>
Lockdown Networks