Syslinux - Mar 2010 - Request: port syslinux isohybrid perl script to C

I'll file a ticket once fedorahosted is back online.

The request is to port the isohybrid script, in the syslinux package,
from perl to C (and of course submit it upstream).  This would let
syslinux drop its dependency on perl, which would save considerable
space.

$ wc -l git/syslinux/utils/isohybrid.in 
258 git/syslinux/utils/isohybrid.in

As this is doing some simple structure unpacking and validation, and
simple binary writes, this should be straightforward to implement in
C.

Thanks,
Matt


----- Forwarded message from Peter Robinson <pbrobinson at gmail.com>
-----

Date: Tue, 30 Mar 2010 17:08:06 +0100
From: Peter Robinson <pbrobinson at gmail.com>
To: The Spin Special Interest Group mailing list <spins at
lists.fedoraproject.org>
Subject: Re: [Fedora-spins] Board SWG questions for Spins Owners

[snip]
I'd also like to see the removal of the requirement of perl (via perl
scripts in syslinux) as it added about 10% to the F-12 test LiveCDs I
did off Moblin. Anaconda uses a single of these scripts and only for
the creation of hybrid boot cds (see bugs 544136 and 559644 ), This is
also relevant for the Sugar on a Stick spin as well. Its the last dep
remaining on perl in both those spins (and I suspect the desktop spins
as well).

Peter
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----- End forwarded message -----

Good day Matt,

In regards to Syslinux dependencies on Perl: I believe that MEMDISK
building also involves Perl...  Is this a non-issue for your
distribution?

- Shao Miller

Never mind.  I didn't understand the context at first.  I guess you are
trying to remove the Perl requirement for the end results (binaries,
utilities) rather than for building.  Sorry about that.  - Shao

-----Original Message-----
From: Miller, Shao 
Sent: Tuesday, March 30, 2010 15:32
To: For discussion of Syslinux and tftp-hpa
Subject: RE: [syslinux] Request: port syslinux isohybrid perl script to
C

Good day Matt,

In regards to Syslinux dependencies on Perl: I believe that MEMDISK
building also involves Perl...  Is this a non-issue for your
distribution?

- Shao Miller

Hi,
> The request is to port the isohybrid script, in the syslinux package,
> from perl to C
If a major overhaul of isohybrid is done, then
please also consider my proposal to produce MBR
template files as alternative to image patching

  http://syslinux.zytor.com/archives/2010-March/013905.html

I just see that hpa has resumed our discussion.

It seems the isohybrid issues should be decided
in a coordinated way:
- There is interest of genisoimage to do what
  libisofs does.
- There is interest of libisofs to get a more
  stable interface to the SYSLINUX realm.
- There is interest to get rid of perl at
  runtime.

> As this is doing some simple structure unpacking and validation, and
> simple binary writes, this should be straightforward to implement in
> C.
Yes. It is no big deal. I did this in libisofs
with isohybrid from 3.72
 
http://bazaar.launchpad.net/%7Elibburnia-team/libisofs/scdbackup/annotate/head%3A/libisofs/make_isohybrid_mbr.c


The fundamental problem is that the souvereignty
over the MBR code is with SYSLINUX, but the
souvereignty over the inner addresses of the ISO
image is with the ISO formatter program.

So isohybrid cannot patch ISO images on-the-fly
and libisofs has to expect at any time that its
outdated MBR template does not match isolinux.bin
any more.
(It is a little wonder that it still works.)


It appears to me, that isohybrid already contains
most of the code needed for MBR templates.
One has to split the random access i/o on the
ISO file from the preparation of the MBR data.
Then it is possible to produce an MBR with some
dummy addresses.


Have a nice day :)

Thomas

On Tue, 30 Mar 2010, Matt Domsch wrote:
> I'll file a ticket once fedorahosted is back online.
>
> The request is to port the isohybrid script, in the syslinux package,
> from perl to C (and of course submit it upstream).  This would let
> syslinux drop its dependency on perl, which would save considerable
> space.
>
> $ wc -l git/syslinux/utils/isohybrid.in
> 258 git/syslinux/utils/isohybrid.in
>
> As this is doing some simple structure unpacking and validation, and
> simple binary writes, this should be straightforward to implement in
> C.
>
Just following up Matt, will this work for you?

https://fedorahosted.org/fedora-engineering-services/ticket/15

	-Mike