Re: VSTa boot

Hi,

Bryan Ford wrote:
>
> However, supporting both approaches may not be as big of a problem as it
> may seem at first. The Mach server bootstrap program (the program that
> loads servers once the "microkernel" has already been started) in the new
> mach4 distribution already has a rudimentary VFS-like layer and supports
> MINIX, ext2fs, and BFFS file systems at the same time

Why does mach need the microkernel loaded and running first? Certainly we'd
have a problem under VSTa as we can't switch back to real mode at the moment
(and I'm not too sure I'd like to be able to). I know that mach used to
have it's device drivers running in kernel space - is this still true (and
thus why we need the microkernel running)?

> >BTW I seem to remember something about BSD partitions not being the same as
> >DOS partitions. If this is true (and I'm not sure) then this also
> >complicates matters.
>
> Maybe even create a "generic
> partition-interpretation library" or somesuch... :-)

Well we already have code for VSTa to handle dos partitions via a library
and I guess supporting BSD partitioning wouldn't be a bad idea as well
(someone's bound to suggest porting BFFS to VSTa sometime).

> >FWIW I believe these are the fs's we'd have to support to cover most of the
> >free OS set (there are more): minix, ext2fs, bffs, vstafs, dos fat, and
> >umsdos.
>
> This looks like a good list, although umsdos is not absolutely necessary
> since files written through umsdos can be accessed by the same names
> through a traditional msdos filesystem as long as they're not too long or
> have funny characters or anything. And as I said before, the first three
> are already covered. :-)

It's the long filenames I was thinking of really. It's not too bad though
as we can get most of the format from the dos code.

> No, the BSD/Mach boot loaders use the normal BIOS calls. They load
> large boot images into >1MB memory by switching in and out of protected
> mode, just like DOS extenders do. In fact, unlike LILO, much of the
> BSD/Mach boot loader code is written in normal 32-bit C, compiled with GCC.

Does NetBSD do this differently then? I have some of what I believe is the
standard NetBSD boot code and it talks to the hardware directly. Can you
point me at BIOS supporting code - thanks :-)

> Oops, I see you already had the basic idea - so I guess my news is that
> it's already done, and the code is available. :-)

I'd like to see what's been done before, but I'm beginning to suspect that
we need something new (just borrowing functions from elsewhere). I'd like
to see the BIOS extender code, but I have some I wrote a couple of years ago
that would do as well (just needs porting from TASM format to bin86 format,
but that's pretty easy).

Now if I can just find that magic 8th and 9th day next week ... :-)

                        Regards,
                        Dave
Received on Sun Nov 6 05:43:44 1994