Re: [PATCH v3] sim: bfin: new port

Mike Frysinger
2011-02-15T21:56:46Z

On Tuesday, February 15, 2011 10:56:55 Pedro Alves wrote:
> On Tuesday 15 February 2011 22:10:54, Mike Frysinger wrote:
> > > What kind of rom, and what kind of hardware?
> >
> > it's the on-chip rom that exists on all Blackfin parts. usually it's
> > used for bootstrapping a part, but it also has helper functions which
> > are sometimes used at runtime by the boot loader (i.e. u-boot).
> >
> > > What tool does one use to extract this rom?
> >
> > it's memory mapped, so any code that runs on the processor can read it.
> > which is fairly trivial when the part can boot linux.
>
> So it sounds like these would qualify as device firmware, which are
> okay to have source trees in some circles, but I'm obviously not a lawyer,
> and certainly not an FSF representative in any way regarding
> licensing/copyright, so I may be totally wrong, and I don't know if
> FSF repositories belong in the circles that allow such blobs.

it depends how you qualify it. this is not microcode that is loaded at
runtime and/or can be modified in any way. it is completely burned into the
hardware. every Blackfin processor has a static ROM when it comes out of the
factory sitting at address 0xef000000. it's not like we're talking firmware
blobs that get loaded into a parallel processor at runtime (i.e. WiFi drivers)
which could in practice be tweaked by end users.

> Is there any other similar case in the sim/ for other
> architectures, perhaps?

i couldnt really find anything. but i get the feeling that people stopped
doing this level of development on the GNU sim some time ago.

> I think you'll need to find out about that redistributable license, and
> someone other than me will have to bless having such binaries in
> the tree. I suggest contacting FSF legal.
>
> Patch-wise, I expect you'll at least need to put your answers above
> in the sources in some form, and add mentions of the copyright and
> licensing that applies to these files and blobs.

sounds more like i'll just drop it for now since it is a minor part of the
bigger picture.
-mike