Bug#751730: please use syslinux-utils instead of isolinux for isohybird

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

> these programs are usable on
> all architectures even if the bootloader isn't available,

Be aware that neither old isohybrid.pl nor new isohybrid.c are
independent of the SYSLINUX version.

I can forward this warning by H. Peter Anvin (hpa), the author
of ISOLINUX, from personal experience a few years ago.
I had implemented isohybrid in libisofs and got urged to use
the  isohdp*x.bin  files of the individual ISOLINUX installation
instead of a hardcoded MBR copied from some version of
isohybrid.pl.

  http://git.kernel.org/cgit/boot/syslinux/syslinux.git/tree/utils/Makefile
shows that the isohdpfx.o module of isohybrid.c stems from
isohdp*x.bin and isohdp*x_[fc].bin of the installed SYSLINUX
suite.

Maybe this problem is insignificant in the light of the known
bugs of isohybrid.c. Worst one is with GPT production:
memcpy() of twice as many bytes than provided by the constant
text that is the copy source:
  http://git.kernel.org/cgit/boot/syslinux/syslinux.git/tree/utils/isohybrid.c#n795
  http://git.kernel.org/cgit/boot/syslinux/syslinux.git/tree/utils/isohybrid.c#n804
This and more bugs are reported in
  http://www.syslinux.org/archives/2012-May/017843.html
  http://www.syslinux.org/archives/2012-May/017871.html


Further (to be obviously nitpicking) isohybrid is suitable only
for architectures which boot via PC-BIOS. That would be amd64
and i386. Since amd64 for EFI could well need digestible UTF-16
names in the GPT, the advisable scope of isohybrid.c is i386 alone.


Have a nice day :)

Thomas