[RFC PATCH 00/12] Merge common OpenFirmware device tree code
wmb at firmworks.com
Thu Oct 8 06:30:47 EST 2009
> Sun3 doesn't have OF
When I was first developing Open Boot for the SPARCstation-1, I was also
simultaneously trying to do it for a Sun-3 system that was being built
at the same time.
It proved to be too much to do both jobs at the same time, especially in
light of all the hardware debugging that is part of a new system
bringup. So I gave up on Sun 3 and just focused on SS-1.
That particular Sun-3 machine never sold very well, while the SS-1 was
very popular. That was Sun's last 680x0 machine.
Personally, I think that continuing to support Sun-3 in Linux is not
useful in a practical sense. To the extent that supporting
long-obsolete platforms and devices makes the job harder for current
systems, it is actually harmful. Portability and generality is good in
some theoretical "rightness" sense, but there are practical limits.
Code can become so heavily layered that approaching it requires a huge
commitment of effort to learn all the artificial layers. Sometimes you
have to prune the dead branches so the living ones can get light and air.
Taking this one step further, I don't see any real good reason to
continue supporting Sun4 going forward. I got rid of my Sun4 systems
long ago because it was just too hard to keep them working - after
having used them long after most people had moved on. Dropping Sun3 and
Sun4 eliminates all vestiges of the sunmon interface and also allows
dropping support for OBP version 1, which only shipped on SS1-class
machines - the first machines in the Sun4c subclass.
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