[syslinux] syslinux.com 5.01 pre3

[Ady]

> > E_ Under FreeDOS, SYSLINUX.COM doesn't seem to install ldlinux.* 
> > (specially when used with "--directory"), and there are no ([error]) 
> > messages; not even when executed with no parameters, or with 
> > "--help", or with "--version". The messages disappeared _after_ 
> > 5.00-pre7.
> 
> Right, as Peter pointed out on IRC, it seems unreasonable to expect
> 5.00's 496K syslinux.com to be loaded under real-mode DOS (-pre7 is when
> we started installing ldlinux.c32 automatically instead of requiring the
> user to manually copy it).
> 
> At this point I'm leaning towards marking real-mode DOS as Not Supported
> from Syslinux-5.00 onwards since 5.x's execution revolves around
> ldlinux.c32, which at 428K, is unlikely to ever execute in 1MB of RAM.
> Even if we compress ldlinux.c32, it has to be uncompresed in RAM at some
> point so that we can execute it, unless we only uncompressed chunks of
> ldlinux.c32 as and when it was needed. But partial decompression would
> be a major project.
> 
> Note that Syslinux-5.00 *does* run under FreeDOS provided that you load
> one of the memory managers.
> 
> -- 
> Matt Fleming, Intel Open Source Technology Center
> 
> 

I have only tested this under a VBox FreeDOS VM. Indeed, without 
memory managers, it can't finish the installation process, but it 
does return back to the DOS prompt.

But when I tried booting FreeDOS with different memory managers 
loaded (in the same VM), it fails. In some cases, ldlinux.* are 
copied to the destination directory. In others, they get to the root 
of the destination device but not to the destination directory (they 
are copied to the root of the device, but the second copy/move from 
there to the specified directory may or may not be completed).

For example, in one of my attempts I received:
Invalid Opcode at 11B1 89CF 0246 BA06 FFF8 0000 0000 0000 0000 1194 
0000 0000 0000

and the system hangs.

Whatever happens during the installation, when I tried to boot with 
the destination device, the boot failed to complete (so it seems the 
boot sector was not written by SYSLINUX.COM).

I don't know if this situation was specific to VBox, or to something 
specific in my system.

I would like to see what happens when all c32 files are stripped (and 
eventually also compressed).

If _then_ it still fails, instead of not supporting SYSLINUX.COM, the 
install could do what it did before: edit the VBR and copy 
ldlinux.sys. The instructions for installing with SYSLINUX.COM would 
just be different from other SYSLINUX installers, requiring from the 
user to manually copy ldlinux.c32. After all, the same happens with 
ISOLINUX and PXELINUX. This would allow the user to execute 
SYSLINUX.COM without memory managers (or any specific conditions of 
the OS) and a simple COPY command would finish the rest.

TIA,
Ady.