Re: Floppy Support

Tim Kientzle wrote:
> Terry Lambert wrote:
> > Tim Kientzle wrote:
> >>I suppose it's time to modify the boot loader to
> >>load a single kernel image from multiple floppies.
> >
> > It can load drivers from a seperate location ...as long as the
> > separate location has a driver that allows you to access it.
> 
> Yes, but....
>    a) This requires user expertise; they have to
>       know what driver to load.

Three possible answers to that:

i)	Warner was talking about autoloading by PCI ID found
	at one point.

ii)	Load them all.

iii)	Make BIOS-based disk drivers, and switch over to the
	higher performance protected mode drivers later.

I still like the last one, which I first suggested in 1993.  8-).


>    b) That still leaves a lengthy list of items that
>       must be in the single kernel image; how long will
>       it be before even the most minimal kernel no longer
>       fits on a floppy?

Yes, this will be a problem, eventually, if people insist on
bunches of vendors for their hardware.  Fortunately, Silicon
Valley tanked in 2001, and it seems that there is not quite
so many vendors of hardware as there used to be...

The way this was handled in the past was by seperating the
kernel boot floppy from the root floppy, so there were two
floppies.  This is how 386BSD worked.  The reason it was
deprecated was because people wanted more than one floppy.


> Most users will find it simpler to just follow
> the prompts:  "Insert Floppy #4 and press [ENTER]"
> 
> >>That, at least, would end the continual release
> >>breakage: the release builder could just create
> >>as many floppy images as necessary.
> >
> > You can't do this and do the non-El Torito floppy-on-CDROM
> > boot hack, since the BIOS will only fake up a single floppy.
> 
> This is true, although I thought BTX could read
> BIOS-supported CD-ROMs.  That might provide a way out.

Most of the CDROMs where you care about this approach are
*not* supported by disk BIOS; those that are, well, you
don't care about the approach.  Catch-22.


> If BTX could read and concatenate several sources into
> a single kernel image in memory, then the floppy-emulated
> CD boot could pull the remaining pieces from CD; the floppy
> installer could pull the remaining pieces from subsequent
> floppies.

You might as well say that you have to have the CDROM code
path supported in the kernel by default (which is a subset of
a full boot path for all possible "floppy disk" cases).

-- Terry