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Re: Status of miBoot in Debian?

On Mon, Mar 06, 2006 at 03:27:40AM -0800, Daniel Gimpelevich wrote:
> >Ok. But like said, thanks to Piotr, we have a reverse engineered spec 
> >of the
> >boot block, and can do a clean-room reimplementation.
> The spec of the boot-block structure has always been publicly 
> available. The boot-block code is quite another matter, and it does not 
> exist in a vacuum. It cannot be described outside of the context in 
> which the Mac OS ROM code calls (or doesn't call) it, which must also 
> be reverse-engineered.

Ok, let me rephrase this. The structure is documented, and cause no copyright
problems. We have a reverse engineered spec of the actual code blob, which we
can thus reimplement.

> >>>>>Second, Piotr has
> >>>>>actually reverse engineered said boot block, and we only need 
> >>>>>someone
> >>>>>knowledgeable with m68k assembly and mac-os roms to reimplement it,
> >>>>>you sound
> >>>>>like a likely candidate for that :)
> >>>>
> >>>>I would not be a candidate for a "clean room" approach because I 
> >>>>have
> >>>>been staring at disassemblies of Mac OS ROMs for more than 20 
> >>>>years. I
> >>>>do not know what his "reverse engineering" consisted of, but I have
> >>>>walked through the m68k machine code that's in it.
> >>>
> >>>Did you look at the boot block ?
> >>
> >>A code walk-through is rather impossible without the code in front of
> >>you...
> >
> >Ok, i meant, have you looked at the asm of the boot block, not the 
> >rest of it.
> >If you have not looked at it, but only at other mac os rom parts, you 
> >are a
> >good candidate for reimplementation.
> Yes, when I say "m68k machine code" I'm referring to asm, of course. 
> And by "in it" I mean in the boot block. I have seen it many times.

ok. Maybe you can compliment the info found in Piotr's work then.

> >>>We have no problem with rsrce.
> >>
> >>I have not looked at rsrce's source yet, but somehow I doubt it fully
> >>implements the data-moving algorithms that would be necessary to
> >>accomplish what it claims to do.
> >
> >As long as we can boot a linux kernel from a floppy, i am happyt.
> I still dream of a floppy-initiated netboot for OldWorld...

:) I guess if the kernel included the network driver and nfs-root support, it
should be ok.

> >>>>problems with the last binary I built from Etsushi Kato's sources
> >>>>could
> >>>>be catalogued...
> >>>
> >>>Could you provide me with this build, i will try to build some sample
> >>>floppies
> >>>with it and 2.6.15 kernel, and propose them for our users to test.
> >>
> >>wget http://homepage.mac.com/danielg4/System.bin
> >>hcopy -m System.bin :
> >>
> >>You will also need to create a configuration file, preferably named
> >>miboot.conf, with a layout similar to lilo.conf, but more restricted.
> >
> >mmm, i will add testing this on my TODO list. Not before a week or two 
> >though.
> >
> >As for the config file, we right now do :
> >
> >        dd if=/dev/zero of=$@ bs=1024 count=$(FLOPPY_SIZE)
> >        hformat -l $(DISK_LABEL) $@
> >        echo device $(TEMP_BOOT).new > $(TEMP)/miboot.conf
> >        echo kernel $(TEMP_KERNEL).gz $(KERNEL_CMDL) >> 
> >$(TEMP)/miboot.conf
> >        miboot -c $(TEMP)/miboot.conf
> >
> >with miboot doing the proper magic, and the miboot packages contains :
> >
> >/usr/share/miboot/System.rsrc
> >/usr/share/miboot/hfs-bootblock.b
> >
> >So, i should replace the System.rsrc by your System.bin in some way ?
> Your current "miboot" shell script bends over backwards to install the 
> file from a dump of its resource fork. I could supply the binary in 
> such a format, but this way, it could be installed with a simple "hcopy 
> -m" command as shown above. The "miboot" shell script would not be 
> used.

What about the configuration file, of which the kernel options are the most
important ones ? 


Sven Luther

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