Syslinux - Aug 2005 - Usin ISO Linux & Memdisk to create a Viritual Floppydrive that Linux & Windows can load driver disk from.

With windows, if your "virtual" floppy is drive B:, then windows
will treat it specially. It will basically copy the contents into
memory from real mode using int13h, knowing that it will not be 
able to access the device after it switches to protected mode.

I asked a few days ago about support for making a memdisk image 
behave as drive B:, but got no answer. :-(  

We have our assembly language guy looking at it, but it is slow as 
he isn't very familiar with the syslinux codebase.
--
Michael
> -----Original Message-----
> From: syslinux-bounces at zytor.com 
> [mailto:syslinux-bounces at zytor.com] On Behalf Of H. Peter Anvin
> Sent: Monday, August 22, 2005 10:28 AM
> To: Jensas, Harald
> Cc: SYSLINUX at zytor.com
> Subject: Re: [syslinux] Usin ISO Linux & Memdisk to create a 
> Viritual Floppydrive that Linux & Windows can load driver disk from.
> 
> 
> Harald_Jensas at Dell.com wrote:
> > Hi,
> > 
> > It is becoming a bad habit for big OEM vendors to sell computers &
> > servers without floppy drives. Unfortunatly both Windows and Linux 
> > (RedHat) need a floppy drive to load storage drivers etc. during 
> > installation.
> > 
> > This is what I was thinking:
> > Use ISOLINUX and MEMDISK to load a floppy image of a driver 
> disk into 
> > memory as a viritual floppy drive "A:"/"/dev/fda"
And then
> "chainload" 
> > into Windows Installation and be able to F6 and load the 
> driver of the 
> > viritual floppy drive.
> > 
> > Would this be possilble?
> > 
> > I would like to create a CD with several driver disks, and possibly 
> > eaven some diagnostic tools and recovery console etc. Anyone done 
> > something like this before? Dockumented anywhere?
> > 
> 
> Someone would have to write a Windows driver for the virtual 
> disk, and 
> *I* won't do that.  It shouldn't be too hard, however, since 
> it's just a 
> chunk of memory which should be preserved from the OS.  The MEMDISK 
> detection API will tell you where in memory it is located, so 
> it can be 
> treated as a MTD (memory technology disk) at that appropriate 
> location.
> 
> As far as Linux is concerned, the easy way to do this is to use the 
> existing MTD driver, and either add detection code or somehow 
> configure 
> it manually.
> 
> 	-hpa
> 
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Michael_E_Brown at Dell.com wrote:
> With windows, if your "virtual" floppy is drive B:, then windows
> will treat it specially. It will basically copy the contents into
> memory from real mode using int13h, knowing that it will not be 
> able to access the device after it switches to protected mode.
> 
> I asked a few days ago about support for making a memdisk image 
> behave as drive B:, but got no answer. :-(  
It's not a super-easy thing to make happen; it certainly won't make
3.10.
> We have our assembly language guy looking at it, but it is slow as 
> he isn't very familiar with the syslinux codebase.
Try the attached path, then give the "floppyb" command-line argument
to
memdisk.

	-hpa
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Thanks, will test.
--
Michael
> -----Original Message-----
> From: H. Peter Anvin [mailto:hpa at zytor.com] 
> Sent: Monday, August 22, 2005 3:16 PM
> To: Brown, Michael E
> Cc: Jensas, Harald; SYSLINUX at zytor.com
> Subject: Re: [syslinux] Usin ISO Linux & Memdisk to create a 
> Viritual Floppydrive that Linux & Windows can load driver disk from.
> 
> 
> Michael_E_Brown at Dell.com wrote:
> > With windows, if your "virtual" floppy is drive B:, then 
> windows will 
> > treat it specially. It will basically copy the contents into memory 
> > from real mode using int13h, knowing that it will not be able to 
> > access the device after it switches to protected mode.
> > 
> > I asked a few days ago about support for making a memdisk image
> > behave as drive B:, but got no answer. :-(  
> 
> It's not a super-easy thing to make happen; it certainly 
> won't make 3.10.
> 
> > We have our assembly language guy looking at it, but it is slow as
> > he isn't very familiar with the syslinux codebase.
> 
> Try the attached path, then give the "floppyb" command-line 
> argument to 
> memdisk.
> 
> 	-hpa
>