Re: "free" miboot on OldWorld Mac

[Sven Luther <sven.luther@wanadoo.fr>]

On Wed, Nov 10, 2004 at 05:21:04PM -0500, Rick Thomas wrote:
> 
> On Aug 11, 2004, at 3:44 PM, Sven Luther wrote:
> >On Wed, Aug 11, 2004 at 03:12:49PM -0400, Rick_Thomas wrote:
> >>Here are a few practical suggestions:
> >>
> >>Has anyone looked at "inside Macintosh" or some of the other early Mac
> >>technical docs?  I wonder if this code is, maybe, described there?
> >
> >The real problem is that i am not a mac user, since i came from the 
> >amiga
> >world, and am currently working for genesi, who produce the pegasos and
> >MorphOS, which is an amiga OS reimplementation. We have information 
> >about the
> >boot block, but not the code in question. I know that it is mostly trap
> >instructions, and do some basic mac rom calls. If we were able to know 
> >which
> >rom calls those are, and what they do, this would be enough for a 
> >clean room
> >reimplementation.
> 
> I've been doing some research into this.  In particular, I've been 
> looking at the "Monster drivers tech note" available on Apple's Tech 
> Support web site.
> 
> As I mentioned in another thread, calls to the OldWorld Mac ROM, for 
> anything other than a floppy, are actually calls to a patched/extended 
> image of the ROM -- patched and extended with whatever driver 
> information is needed to help the ROM code read from the device in 
> question on that particular type of Mac.  Those patches/drivers are 
> licensed IP of Apple (or a third-party vendor if Apple doesn't directly 
> support booting from the device in question.)
> 
> The patches/drivers get installed on your hard disk by the Apple disk 
> partitioning utility (or a similar third-party utility) which is only 
> available as part of MacOS (or from the third party vendor).
> 
> It appears that re-writing the boot code part of miboot is really just 
> the tip of a very large iceberg.  To be truly "free", you have to 
> provide a substitute for the patches and drivers.

Which is why miboot is only recomended for floppy things, and not CD/disk
based ones.

Friendly,

Sven Luther