[syslinux] Dir_FstClusHi being used for FAT16/12 fs types

[Ram Yalamanchili]

Hi,

I just found syslinux gives corrupt data when reading files from a
FAT16 partition. The fat16 implementation was using the reserved
Dir_FstClusHi (offset 20 in the directory entry, name quoted from VFAT
spec from Microsoft) which is supposed to be 0 for FAT12 and FAT16.
Linux ignores this and never uses the Dir_FstClusHi cluster with 0 for
FAT16/12, so it works fine.

>From the spec:
DIR_FstClusHI: High word of this entry's first cluster number (always
0 for a FAT12 or FAT16 volume).

If the value is non-zero, the data i get to read in mboot.c32 is
corrupt. Can this value be ignored for fat16/12 in syslinux?

thanks,
Ram