[syslinux] cbios disk read problems

[H. Peter Anvin]

Ram Yalamanchili wrote:
> 
> Hmm, I actually see this issue on both the machines I have here (Dell
> laptop D410 and an AMI bios box). I think, in general there is
> something wrong in the code. The algorithm to calculate CHS for reads
> is the same one Peter wrote for chain.c32, and I confirmed from
> wikipedia.
> 
> The disk was made entirely with mkdiskimage and mtools/mkfs.vfat. I
> think this is unlikely, but is it possible that the cbios reads dont
> support reading after certain disk region? Reading the 70k'ish sector
> is around offset 34MB.. hmm..
> 

34 MB sounds suspicious, since it's just above the 32 MB mark for 16-bit
linear sector numbers, by the way.

	-hpa