[syslinux] Reports from 5.00

[Bernd Blaauw]

Op 16-1-2013 13:30, Matt Fleming schreef:

>> 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.

Is this specific to the installer or to the used flavor of DOS?


> 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).

There's a LDLINUX.C32 already in the download archive (needed for 
ISOLINUX.BIN), might as well let the DOS installer require it also, 
keeps the installer smaller. That would be inconsistent though with the 
other (Windows/Linux) installers which already embed the file.

> 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.

Imagine a 4MB machine but clean-booted DOS. Syslinux would work, but you 
can't get it installed unless your DOS disk has a commandline-loadable 
XMS-driver present (like XMSMMGR in MSDOS/Win32, or JEMMEX by Japheth). 
Not friendly. Perhaps a DJGPP version then, or a HX-stubbed Windows 
installer.
If the machine really has only 1 MB of RAM then ouch.
(easy to simulate in Bochs and QEMU). Pretty sure Syslinux requires a 
tiny amount of extended memory anyway.

> 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.

Mentioned above: require the external file. Or perhaps UPX 
executable-compressor is smart enough to keep things working.

> Note that Syslinux-5.00 *does* run under FreeDOS provided that you load
> one of the memory managers.

Good to know. Is that ability to run caused by the increased amount of 
conventional memory after loading a memory driver (shell's memory print 
gets lot lower in low memory due to moving parts to XMS) ?
Or from the availability of extended memory?

Was there an 8.3-version of the (vesa)menu.c32 libraries already?

Bernd