Re: Debian-installer, older hardware, boot loaders, miboot & amiboot & ..

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

On Wed, Mar 31, 2004 at 03:15:21AM -0500, Branden Robinson wrote:
> On Tue, Mar 30, 2004 at 09:03:19AM +0200, Sven Luther wrote:
> > On Mon, Mar 29, 2004 at 01:10:36PM -0800, Jeff Bailey wrote:
> > > On Mon, Mar 29, 2004 at 04:05:48PM -0500, Branden Robinson wrote:
> > > 
> > > > Hacker #2 affirms that he has never looked at the existing boot
> > > > sector, and will not do so in the future.  He or she understands MacOS
> > > > well enough to know how to hand-code 1kB worth of assembly (or
> > > > possibly compilable C code) to create a functionally-identical boot
> > > > sector from the plain English description.
> > > 
> > > If I understand right from my GNU hacking, it's preferable to take a
> > > slightly different approach if possible.  Doing some of it in C instead
> > > of ASM (if at all possible, obviously) might result in that anyway.
> > 
> > Notice that there is 200bytes or so of m68k asm, most of them A-trap
> > calls to the Mac OS rom, concerned. I doubt you have much chance of
> > getting anything but a 100% identical code, whatever the way you go at
> > generating it.
> 
> If true, and you're confident enough in this that you think we'd have no
> trouble finding an expert witness (such as a professor of computer
> science) to testify to this effect, then in the United States, this
> would be a serious blow to such code being copyrightable in the first
> place.

Notice that it is very probable that Apple will probably in this case not
assert copyright on this bit of obsolet code. Do we know someone at
apple who may wish to comment on this stuff ? 

> Under U.S. copyright law, a work has to be "expressive" and "original"
> to enjoy copyright protection.  If there's only one way, or an extremely
> narrow range of ways to accomplish something, copyright does not attach.

Well, can you copyright the usage instructions of a care (like open the
door, sit, but your belt on, insert the key, push cloach and a bit of
accelerator and then turn the key, ...). I believe this to be comparable
to what is going on here. The old world machine have a rom, and in order
to boot them, a certain number of rom calls need to be made, and no
others. There may be a few variants, but i believe (even if copyright
doesn't in the US) that every owner of such hardware should have the
unalienable right to make use of it, and this include passing the ROM
the appropriate instruction to boot the box. Since there is no
encryption involved, not even the DMCA will help on this.

> For example, in the U.S., you cannot copyright your filled-out income
> tax return.
> 
> Of course, I speak of the U.S. only.  In other jurisdictions, it may be
> possible to assert a copyright on, for instance, the sequence of prime
> numbers smaller than 100, in increasing order.

Well, probably, but as i believe some over 2000 year old dead greek has
the copyright over this, ...

And in sensible legislations, you cannot copyright algorithms, not the
result thereof, so ...

> Whether we need to be worried about other jurisdictions is a question I
> will leave to others, as I'm only willing to play armchair lawyer with
> respect to U.S. law.

Well, the US are mostly the most restrictive (unreasonable) juridiction
on this kind of issues, so ...

> > Anything you may do, these calls are needed, you could add some noop
> > calls in between, or some random stuff, but i doubt that this will be
> > more than smoke and mirrors.
> 
> I don't think it's necessary to try to obfuscate anything at all.

Yeah. 

So, to go back on topic. If there is no way to express this same
sequence of calls in another form while achieving the same result, or if
apple gives its benediction ot using said boot block in a free way
(including DFGS-free modification of the source code, taking the
unassembly output as source), we would be go for a miboot in
debian/contrib ? 

Friendly,

Sven Luther