Thanks for the replies!

I think I have enough pointers to get testing and try to come up with 
something. And what I'm also seeing on my end seems to indicate that the 
BIOS or MBR alone cannot help "skip" a drive letter - it has to be done 
a bit further down the line.

On 2012.03.21 21:51, Robert Riebisch wrote:
>> 2). I'm not sure this was ever tested with FreeDOS proper, only other
>> DOSes, as it used "lots of undocumented, low-level stuff", but maybe
>> this will also be of interest??
>>
>> http://www.bttr-software.de/products/drvexch/
>
> On<http://www.bttr-software.de/forum/forum_entry.php?id=8499>  Michal said:
> "I admit I have not touched DRVEXCH since 2001, and I do not remember
> testing it with any version of FreeDOS. The method I used was an ugly
> hack (modifying low-level internal DOS structures) as nothing else I
> tried worked reliably enough with all tested DOS versions."

Quite interesting, though at first glance, DRVEXCH doesn't seem to be 
able to remap C:. Not entirely surprising, as that would be like 
removing the floor beneath one's feet.

It goes over the order of assignation in its documentation, which is 
also not much of a mystery for anyone who ever booted DOS on computers 
with a few FAT partitions spawning disks:

On a two-disk system with 1 primary partition and 2 logical drives in an
extended partition for each hard disk:
(*) primary DOS partition on the first hard disk becomes drive C:
(*) primary DOS partition on the second hard disk becomes drive D:
(*) next drive letters are assigned to logical drives in extended
     partitions on the first hard disk
(*) next drive letters are assigned to logical drives in extended
     partitions on the second hard disk

I guess if someone wants to fiddle with the primary drive assignation, 
they're going to have to do it before drivers and executable are being 
loaded from that partition, so probably through kernel/sys.com. But I'll 
also have a look at what grub4dos does, as it may provide some more data 
or an alternate way to do it.

Thanks again,

/Pete

------------------------------------------------------------------------------
This SF email is sponsosred by:
Try Windows Azure free for 90 days Click Here 
http://p.sf.net/sfu/sfd2d-msazure
_______________________________________________
Freedos-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/freedos-devel

Reply via email to