Re: [U-Boot-Users] RFA & Update: Using libfdt in u-boot for fdt command

On Fri, Mar 02, 2007 at 01:35:35PM -0500, Jerry Van Baren wrote:

Jerry Van Baren wrote:

quoted

David Gibson wrote:

[snip]

OK, here is a reference on the OF device tree browsing commands:
<http://www.firmworks.com/QuickRef.html#Device%20Tree%20Browsing>

Where I'm coming from is that I've written the "fdt print" command to 
put out the same text (possibly with data formatting differences) as 
went into the dtc to create the blob.  This is very useful and intuitive 
to me.

The OF device tree browsing is modeled after filesys directory and file 
browsing (sorta).
   ".properties" ~ "ls" but only shows files (properties ~ files)
   "dev" == "cd"
   "ls" == "ls -d *" (only shows subdirectories)
   "pwd" == "pwd"
   "dend" - has no equiv
   "show-devs" - has no equiv, sounds like it may be my "print" command
   "words" - has no equiv, does not apply (dir *.exe in DOS :-)
   "sift-devs ccc" == find . -name "*ccc*"

Looks a lot more complex with no clear benefit for u-boot.

Sorry, I was unclear.  I wasn't trying to suggest you use the OF
client interface model for device tree commands in general.  Just that
you don't treat properties as having paths.

I have not found any character that could clearly and cleanly be used to 
separate the node path from the property name.
* Comma ',' - used to separate a device name from an argument - one
      could argue that the property name is an argument to the path.
      "/foo/bar,baz" is the property baz under the node "/foo/bar".
* Space ' ' - "/foo/bar/baz" is a node path, "/foo/bar baz" is the
     property baz under the node "/foo/bar".  Spaces complicate parsing.

Space only complicates parsing if you insist of thinking of these
things as paths-to-properties, which is not really a good idea in the
first place.  Just think of the node-path and the property name as
separate parameters to your commands.

So, getprop takes 2 parameters (node, property), setprop takes 3
(node, property, value).  print, or whatever you end up calling it
takes either 1 or 2 (node, plus optional property name)

Any strong opinions?  At this point I don't see any reason to change 
from my current technique and proposed command set for u-boot.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson