Hardware-Accelerated Graphics On SGI O2 Under NetBSD

Zadok_Allan writes "It's a bit late, but since many readers will remember the SGI O2 fondly, this might interest a few. The gist of the story is this: NetBSD now supports hardware accelerated graphics on the O2 both in X and in the kernel. We didn't get any help from SGI, and the documentation available doesn't go beyond a general description and a little theory of operation, which is why it took so long to figure it out. The X driver still has a few rough edges (all the acceleration frameworks pretty much expect a mappable linear framebuffer, if you don't have one — like on most SGI hardware — you'll have to jump through a lot of hoops and make sure there's no falling back to cfb and friends) but it supports XRENDER well enough to run KDE 3.5. Yes, it's usable on a 200MHz R5k O2. Not quite as snappy as any modern hardware but nowhere near as sluggish as you'd expect, and since Xsgi doesn't support any kind of XRENDER support, let alone hardware acceleration, pretty much anything using anti-aliased fonts gets a huge performance boost out of this compared to IRIX."

Comments

IRIS != IRIX

[Hazelesque]

IRIS is not the same thing as IRIX.

IRIS[1] stands for "Integrated Raster Imaging System", and was the name of a series of SGI hardware.

1. See http://www.irisindigo.com/index.php/Main_Page

Re:What a waste of time

[howlingmadhowie]

well, it's about using a computer some of us grew up dreaming about in freedom with a modern software stack. i think the correct tag for this story would be 'insanely cool'.

Re:Octane / Onyx

[Zadok_Allan]

I seem to remember IRIX having an xrender library available, possibly from sgifreeware or nekochan, or does it just do software rendering? IRIX used to make a very fast X terminal, but modern apps always seemed very sluggish on it and perhaps that's why..

That's the client library, as far as I know there is no Xrender extension for Xsgi so all anti-aliased text is rendered client-side, by software, which burns lots of CPU cycles. On slow CPUs like the R5k that really, really hurts.

About Onyx and Octane - there's linux code available to make IMPACT-based boards do tricks but nothing for vPro, let alone Reality Engine or Infinite Reality. IIRC all these graphics options understand OpenGL opcodes more or less directly so once someone finds out how to feed them commands the rest should be easy.
( btw. the O2's rendering engine is nothing like that, you program it like most other graphics chips, by hammering data into registers or feeding register write commands into a ring buffer )