[syslinux] isolinux needing mkisofs

[H. Peter Anvin]

David Bond wrote:
> Due to limitations of equipment, I have need of using the isolinux boot 
> loader with .iso files generated by roxio.
> 
> After trying (and of course failing) with an off the shelf version of 
> isolinux, I grabbed the source for isolinux (syslinux 2.11 package) and 
> started looking.
> 
> It took a few hours to orient myself, but I ended up doing the 
> modification below to isolinux.asm.  I then had to write a small C 
> program to take the .bin file and patch offset 0x14 with the proper 
> checksum info.  With that I now have a isolinux.bin file suitable for 
> roxio - and probably other software.
> 
> Is there any interest in this, or is the dependency on mkisofs there for 
> another reason?
> 

Could you please send that as a unified diff?

The dependency on mkisofs is because the assumption that the BRV is at 
sector 17 isn't inherently valid.  The spec is that it's at sector 17 OF 
THE LAST SESSION WRITTEN, which isn't the same thing.  This is basically 
a screwup in the El Torito specification, which is why the boot info 
block option to mkisofs exists to make up for it.

I don't know what you mean with "limitations of equipment"; mkisofs 
should be able to run on pretty much anything, especially these days 
with MacOS being Unix and there being Cygwin for 'doze.

Or you can lobby the Roxio people for adding this extension, it's fully 
documented.

That being said, it wouldn't be a bad idea at all to add something like 
this as a fallback option; it's certainly easy to find if the info block 
hasn't already been patched, and it's better than failing completely. 
After all, it should work as long as it's not a multisession disk. 
Hence the request for a unified diff.

	-hpa