[syslinux] isolinux.bin checksum

[Ady Ady]

Until Syslinux 3.86, isolinux.bin contained a checksum that was 
calculated by 'core/checksumiso.pl'. The checksum is related to the 
patching of the boot info table.

During May 2009, a commit by Peter deleted the checksumiso.pl file. The 
commit is:

 core: LZO compress the PM part of the core 

 
repo.or.cz/syslinux.git/commit/0d82b71304d596d80f3c4520f9dcf90048ca50b7 


And so, since version 4.00, the 'code/checksumiso.pl' file is no longer 
included.

How is the checksum of isolinux.bin calculated since then?

How is it introduced in isolinux.bin?

Reason to ask: the checksum (within isolinux.bin) for version 3.86 
seems to be correct, but it seems to be "wrong" since then.

Until version 3.86, the checksum was calculated based on a certain 
range of values within isolinux.bin. Since v.4.00, the checksum seems 
to be calculated on a different range of values than before.

Could someone please confirm this? Was/is this intentional? What was/is 
the purpose of this range change? Or, is this a 
mistake/bug/unintentional?

TIA,
Ady.