Messages in this thread | | | Subject | Re: [PATCH 1/2] OLPC: Add support for calling into Open Firmware | From | David Woodhouse <> | Date | Mon, 21 Apr 2008 16:54:13 +0100 |
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On Mon, 2008-04-21 at 10:24 -0400, Andres Salomon wrote: > I'm not actually convinced that we *do* want to keep OFW resident in memory, > especially given the memory tricks we need to play. I also don't actually > like the OFW interface that we. The debugging aspect of it was a > compelling argument up until a week ago (when kernel debuggers started > finally finding their way into the kernel).
I don't actually think that the debugging aspect was _ever_ a compelling argument. It might have made it theoretically possible for _Mitch_ to debug kernel problems, should he be inclined to do so -- but for the rest of us mere mortals it's just a PITA trying to keep OpenFirmware live. A gdb stub is much more useful, in my experience.
> However, until we clean up the promfs stuff, there's no chance of getting > an OFW device tree upstream.
I see no reason why we shouldn't be able to create a 'flattened' device-tree during early boot, like the PowerPC kernel does. And use it thereafter, having quiesced OpenFirmware. Haven't we already been working on unifying this between SPARC and PowerPC kernels?
I definitely don't think we need to play these tricks to keep OpenFirmware resident while the kernel is running. Take a look at your second patch -- it's _all_ just lookups in the device-tree, and you're inventing a new way to do it instead of using the existing one.
-- dwmw2
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