[syslinux] Problem with memdisk and Free FDISK

Patrick J. LoPresti patl at users.sourceforge.net
Fri Jul 4 09:26:15 PDT 2003

Sorry for the cross-post, but I do not know whether this is a bug in
Free FDISK, memdisk, or neither.

This problem is with Free FDISK 1.2.1 and memdisk 2.04.

I am using PXELINUX+memdisk to boot to a virtual hard drive containing
MS-DOS 6.22.  This works fine; DOS boots and the virtual drive appears
as C:.

Now I want to use Free FDISK to partition the *physical* drive.  But
when I run any of the following commands:

    fdisk /info
    fdisk /info 1
    fdisk /info 2

...it says:

    Invalid drive designation...Operation Terminated.

It then exits with status 5.

However, if I do:

    set FFD_VERSION=6
    fdisk /info

...it correctly displays the partition table for the virtual drive.

If I then do "fdisk /info 2", it displays the partition table for the
physical disk, but only the first 8 gigabytes (not surprisingly).  So
setting FFD_VERSION=6 is only a partial workaround, because sometimes
I need to partition the entire drive.

Browsing the fdisk source code, I suspect I could work around this
problem by setting "EMULATE_DISK=1", but since my copy of fdisk.exe
does not have debugging enabled, this option is not recognized.


  1) Where can I obtain a copy of fdisk.exe with DEBUG enabled?  (Do I
     have to purchase Borland C++ and build it myself?)

  2) This appears to be some sort of bug with INT13 extensions.  Is it
     most likely a bug in fdisk, memdisk, or my BIOS?  Just curious.

  3) What can I do to help fix this?


 - Pat

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