[syslinux] [PATCH] core/diskboot.inc: fix handover info sanity checks

[Michal Soltys]

On 11-02-22 22:23, H. Peter Anvin wrote:
> On 02/22/2011 12:18 AM, rasengan rootish wrote:

uups...

>>
>>  Not too pretty - I can stuff it to +5 bytes with one extra change.
>>
>>  After that, 11 free bytes remain overall.
>>
> 
> That hurts.  A lot.  I think I would rather have that extra wiggle room.
> 
> 	-hpa

Yea, now that you pointed that out I realized how little space was left.

So better fix: allow an occasional false negative (if the distance is less
than paragraph from PartInfo), but make sure no false positive is
possible, for the area. No size changes this way.

I'd also test against 50h:0 on the low side, not only 40h:0 - it would be
bad if the handover was stuffed into bios data area. With that, test for
SI == 0 could probably be removed.