David Gibson <[email protected]> writes: > On Mon, Feb 16, 2009 at 05:39:40PM +0100, Markus Armbruster wrote: >> David Gibson <[email protected]> writes: >> > On Fri, Feb 13, 2009 at 12:26:28PM +0100, Markus Armbruster wrote: > [snip] >> > I think the idea behind using IEEE1275-like trees is that there is >> > significant overlap between the device information that IEEE1275 >> > represents, and the device information which is configurable in qemu. >> > Ultimately whether it buys you enough depends on how large that >> > overlap is. >> >> I think that's fair. >> >> I believe we don't quite know yet whether the overlap will make it >> worthwhile. > > Yeah, true enough. > >> One way to approach this is to assume it will until proven wrong. You >> start with an IEEE 1275 description of the machine, and extend or adapt >> it as you go. My problem with that is that we don't have such >> descriptions for the machines that interest me. Developing them is a >> big step that pays no immediate benefits, but blocks the little steps >> that do pay. Moreover, without a *real* user of the description, I'd >> likely develop something that looks like IEEE 1275 to me, but isn't. If >> it turns out that IEEE 1275 is not worth it, tough, we already paid for >> it. >> >> Another way to approach this is to admit we don't know enough and punt >> the decision until we do. Start with the beneficial baby steps. Limit >> the machine description business to what is required for the baby steps, >> making a best effort to stay close to IEEE 1275 structurally. If it >> turns out that IEEE 1275 is worth it, we do whatever is left to make the >> descriptions conform to it. >> >> I'm much more comfortable with the second approach. > > That's reasonable. However, once you've taken enough baby steps you > do want to be careful that you don't end up long term with something > that's similar enough to 1275 to be confusing, but not similar enough > to be useful. So at some point we do want to take a look ahead and > see how much difference there will be between the qemu-required config > information and the 1275 dectree.
Agreed. I think it would help if 1275 experts reviewed the baby steps for gratuitous deviations from 1275. [Rest snipped, helpful comments, but I don't have anything interesting to add...] _______________________________________________ devicetree-discuss mailing list [email protected] https://ozlabs.org/mailman/listinfo/devicetree-discuss
