Subject: Re: Porting NetBSD to Sega Dreamcast / 200MHz SH4
To: None <email@example.com>
From: None <firstname.lastname@example.org>
Date: 06/30/2000 11:08:16
I just joined the email@example.com list yesterday, and what's the first
message that I see but yours asking "How possible is it that NetBSD *could*
be compiled for the Dreamcast?"
Well, I'm (slowly) working on it. So far I have the start of a cross-
development environment done. I have gcc and the gnu binutils compiled
to produce SH binaries. There were a couple of minor problems which I
had to solve before I got them to work under OpenBSD 2.6. My next step
is to grab the crt0.a from the NetBSD/sh3 port and try using it.
It's not a matter of "could", because there is no doubt that it _can_
be done. It's a matter of deciding exactly _how_ to do it.
Thank you very much for the URL's in your post. They contain invaluable
information, and confirm many suspicions that I had, such as the DC's
ability to boot from a normal ISO-9660 session, rather than only from a
GDROM. I surmised this last year, but had no way of testing it.
> it *should* be possible and perhaps not even VERY dificult, as I believe
> the SH4 is backwards compatible with the SH3 to a certain degree.
Yes, the SH-4 is a superset of the SH-3, so code should run unmodifed on
the SH-4 unless it uses SH-3 features that are necessarily changed on the
SH-4, such as MMU control registers. gcc and gas support both sh3 and sh4
Now that we have (1) a means to boot the Dreamcast to our own code, from
CD-R, and (2) a means to load code from the PC via the serial port for
testing, and (3) a cross-development system, work should proceed more
quickly towards getting BSD/DC going. While I'm initally concentrating
on OpenBSD as a target, NetBSD should be a simple matter of using the
NetBSD source tree instead of the OpenBSD source.
> 56k Hardware Modem (US model LAN/DSL/etc adaptors available soon)
Yes, I'm looking forward to the 10BaseT adaptor for the DC.
It will turn the DC into a diskless workstation. And when
the DC ZIP Disk unit comes out, the system will be complete.
> 4 Controller Inputs (of use to this port, a Keyboard is available and a
> mouse will be shortly)
The controller inputs are each a dual serial bus. Each bus runs at
1.0 megabit per second, and uses a packetized protocol with Manchester
encoding. They are versatile, much like a USB port. Besides keyboards,
game controllers, and smart memory cards (VMU), there are microphones and
cameras for them.
> Certainly seem's it could handle it, from a hardware point of view. Any
A sun 3/60 can run SunOS 4.1 or NetBSD with X11 just fine, in 16 MB of
memory and diskless, so the DC won't have any problem handling it either.
- William - (spuug)