Syslinux - Aug 2002 - How to unload memdisk within DOS?

Hi SysLinux,
i'm using pxelinux.0 and memdisk to successfully boot dos on my PXE capable
workstation.
But aber the DOS boot I need to get access to Drive A: again. My DOS
bootimage is putting all necessary stuff into it's own RAMdisk.
How can I disable memdisk, so that it releases drive A: (does not
necessarily free the allocated memory for it's RAMdisk ..)

with kind regards / mit freundlichen Gr??en

Bernd von Osten
BCcomponents Beyschlag GmbH
Rungholtstrasse 8-10
D-25746 Heide
Germany
Tel. +49  (0)481/95-521
Fax: +49 (0)481/95-203
E-Mail: Bernd.von.Osten at bccomponents.com

Bernd.von.Osten at bccomponents.com wrote:
> Hi SysLinux,
> i'm using pxelinux.0 and memdisk to successfully boot dos on my PXE
capable
> workstation.
> But aber the DOS boot I need to get access to Drive A: again. My DOS
> bootimage is putting all necessary stuff into it's own RAMdisk.
> How can I disable memdisk, so that it releases drive A: (does not
> necessarily free the allocated memory for it's RAMdisk ..)
> 
This is currently not supported.  It wouldn't be too hard to add, 
though, so I might do that.

Note that you can access your floppy drive as B: when MEMDISK is loaded.

	-hpa

Bernd.von.Osten at bccomponents.com wrote:
> 
> BWLOADHI has a "bwloadhi /u" option, which uses an additional
int13h
> function to trigger the unload procedure. Maybe this can be implemented in
> Memdisk as well?
> 
Something like that would work.
> At the moment I'm thinking about a quick and dirty test program (IMDL -
> IsMemDiskLoaded), which detects the presense on Memdisk in the workstations
> memory but looking for magic strings in Memory
> (like:
> "MEMDISK " VERSION " " DATE;
> const char copyright[] > "Copyright " FIRSTYEAR "-"
COPYYEAR " H. Peter Anvin";
>  )
Unfortunately doesn't work -- that's in the setup code, which is not 
retained.
> Then I can react on that issue correctly in my batch file within dos and
> ignore the presence test of the bootmedia in the boot drive.
The easiest thing to do, if this is possible, is to put a well-known 
volume label on the MEMDISK image and look for that.  I don't know if 
that's what you want to do, though.

	-hpa