[syslinux] memdisk as A: and B:?

[Michael E Brown]

On Tue, 2005-08-16 at 16:39 +0200, Velu Erwan wrote:
> > 	For background on what we are trying to do, the windows installer can
> > load driver updates from a memdisk image. The problem is that it then
> > switches to protected mode and tries to copy the driver from the disk.
> > This, of course, fails because at that point windows is using its own
> > protected mode floppy handler and not int13. But, there is a workaround.
> > If the floppy is B:, windows will treat the floppy specially, as a
> > "virtual" floppy, loading the entire image into memory before switching
> > to protected mode. This means that driver updates would be possible
> > using memdisk.
> Memdisk seems to have two options for this issue : raw or bigraw.
> This options seems to address this problem, does it solves yours ?
> (cf memdisk/memdisk.doc)

Not really. I did see the docs for this, but it doesn't do what we need.

memdisk works by hooking int13. So, any program that read the disk using
int13 will work with memdisk. The problem is that the windows installer
switches halfway through textmode from a mode where it uses int13 to a
mode where it uses its own protected mode driver, bypassing int13
altogether.

Once windows starts directly accessing the physical hardware using its
own driver, we can no longer virtualize it with memdisk.

--
Michael