Comment 20 for bug 1298894

Hi,

> Your little C program works for me

So if maintainance of the separate amd64+mac image becomes
cumbersome, it would be possible to replace it by some ISO 9660
patching service for the current amd64 images.
Possible occasions for patching:
- After production of standard ISO (making obsolete the need
  for maintaining separate production scripts).
- At download time on the server (if it is economic to do it
  on-the-fly).
- After download by help of a program that is executable
  (or can be copied) from the mounted ISO.

The byte manipulation procedure is based on El Torito specs:
Version 1.0, January 25, 1995, IBM and Phoenix Technologies.
(Read underlined text in paragraph 2.0, hop to figure 7,
 see what shall stay preserved in figures 2 and 3, see what shall
 be erased in figures 4 and 5.)
It assumes that not more than 32 boot images are announced by the
boot catalog, or that it suffices to deface the first additional
boot section in order to truncate the catalog.

As for the name "amd64+mac": Wouldn't "amd64-bios-only" be more
appropriate ?
We know by now that there is nothing Mac-specific in the image
compared with the standard "amd64" image. It just does not step into
a known Mac firmware bug by restricting itself to amd64 pre-UEFI.

Have a nice day :)

Thomas