[LinuxBIOS] [Fwd: Re: /proc/device-tree is working]

Richard Smith smithbone at gmail.com
Tue Dec 26 16:21:16 CET 2006

For those of you not on the OLPC devel list...

We have the unified device tree code for all arch's close to ready.  Its 
in /proc for now but I think it will be moved into /sys in the next week 
or 2.

Look for it in an olpc kernel in the near future.

I think this will help us out in linuxbios quite a bit.

Here's a snippit of the thread.

> On Mon, 2006-12-25 at 00:42 -1000, Mitch Bradley wrote:
>> -bash-3.1# cd /proc/device-tree/
>> -bash-3.1# ls
>> #address-cells  chosen          memory at 0            null-nvram  pci
>> aliases         cpus            mmu                 openprom
>> architecture    dma-ranges      model               options
>> banner-name     flash at fff20000  nandflash at 20000000  packages
> Neat!  What's left to do, and what's the schedule for integration?
> Dan
Left to do:

a) Audit the device tree and correct any errors and omissions.

b) Release an Open Firmware version that uses virtual addressing so that
Linux doesn't clobber it upon startup.  The coding is already done, so
this is just a release and test step.  This version is compatible with
existing kernels so its release doesn't require a simultaneous release
of a new kernel.

c) Decide whether or not we want to go ahead with the /proc/device-tree
version, or convert to /sys first.  If the latter, we have to develop
the sysfs version of the code.  I think I understand how to convert to
sysfs for the bulk of the code, but there is still an issue that I don't
grok, namely the kobjects tie-in.

d) Do the administrative mechanics of expressing the changes as a patch.

e) Start converting OLPC userland code to use the device tree info
instead of the various ad-hoc detections schemes currently in place.

f) Do whatever needs to be done to announce the patch, submit it
upstream, or whatever we want to do on that front.

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