Messages in this thread | | | Date | Mon, 21 Apr 2008 13:03:20 -0400 | From | Andres Salomon <> | Subject | Re: [PATCH 1/2] OLPC: Add support for calling into Open Firmware |
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On Mon, 21 Apr 2008 16:54:13 +0100 David Woodhouse <dwmw2@infradead.org> wrote:
> 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'b > 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?
Quite simply, it's a lot more work (*and* we have to play nice w/ sparc and ppc). I had intended to eventually do it, but first I wanted to get this stuff in for 2.6.26 so that we could at least boot upstream kernels on XOs.
I was also hoping to not get into this conversation, but alas.. too late. :)
> > 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. >
-- Need a kernel or Debian developer? Contact me, I'm looking for contracts.
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