[syslinux] Allowed code pages and encodings to write f0.txt through f1.txt?

[Thomas Schmitt]

Hi,

> Implementing Rock Ridge and/or Joliet for ISO 9660 would be nice, too.

That would be in my sandbox ... if i only had a clue of syslinux.

Nevertheless i tried to find the source and ended up at
  http://git.kernel.org/cgit/boot/syslinux/syslinux.git/tree/core/fs/iso9660/iso9660.c
Is that the current ISO 9660 code ?

If so, then Rock Ridge would affect function iso_find_entry().
It would need a SUSP decoder loop which looks for NM entries and
combines them to candidates for e.g. strcmp().
There would be the need for a second data block buffer into which
the target blocks of CE entries will be read.

A similar change would be needed in function iso_readdir().
It seems worthwhile to create a common Rock Ridge name retriever
function.

Function iso_convert_name() would not be needed for Rock Ridge names.

The existence of Rock Ridge would be announced by an ER entry
in the root directory record. But one could as well always look
whether the System Use field of an ISO 9660 directory record
contains SUSP and RRIP entries.


The existence of Joliet in an ISO image is announced by a Joliet
volume descriptor. The filesystem reader should then take the
root directory record from the Joliet descriptor rather than from
the Primary Volume Descriptor.
Functions iso_compar_name() and iso_convert_name() would have to
deal with UCS-2 strings rather than byte strings. Elsewise, Joliet
and ECMA-119 have the same structure.

Interpretation of Joliet and Rock Ridge is mutually exclusive.
One would have to decide early, which one to use, if both are
present.


References:
ECMA-119 aka ISO 9660
  http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-119.pdf
SUSP 1.12 (entries CE , PD , SP , ST , ER , ES)
  ftp://ftp.ymi.com/pub/rockridge/susp112.ps
RRIP 1.12 (entries PX , PN , SL , NM , CL , PL , RE , TF , SF , obsolete: RR)
  ftp://ftp.ymi.com/pub/rockridge/rrip112.ps
Joliet:
  http://www.buildorbuy.org/pdf/joliet.pdf


Have a nice day :)

Thomas