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

Mark A. Greer wrote:

On Thu, Mar 01, 2007 at 09:01:24AM -0500, Jerry Van Baren wrote:

quoted

Hi all,

This is a Request for Advice.

Hi Jerry.

One minor thing.  I'd just want to remind you that we shouldn't stray
too far from the OF interface.  The bootwrapper code sits on top of
either the FDT access interface or the true OF DT access interface.  
The closer we keep the two, the cleaner & easier the we can keep
the bootwrapper code.

Mark

Hi Mark,

Understood, but that isn't really my battle.  David Gibson created the 
libfdt interface so any linux/bootwrapper changes are really his battle. 
  I'm working in u-boot land so linux/bootwrapper aren't in my problem 
domain - using libfdt in u-boot doesn't affect the bootwrapper code. 
Having said that, I'm hoping for shared code synergy, which would 
require the linux kernel to adopt libfdt as a replacement for 
flatdevtree.[ch].  David has also talked about using libfdt in the dtc 
suite, so there is potentially a three way synergy.

The flattened device tree which is passed from u-boot to linux is 
unchanged*, so the interface is the same at that level (to state the 
obvious).

David's libfdt is a potential replacement for flatdevtree.c.  I have 
pursued using libfdt rather than flatdevtree (in u-boot) because the 
interface is much cleaner (IMHO, and, I'm sure, IDHO).  Of course "much 
cleaner" is the fancy way of saying "not compatible." :-/  On the other 
hand, I looked at arch/powerpc/boot/of.c, ops.h, and flatdevtree_misc.c. 
  It looks like it would be relatively easy to redo flatdevtree_misc.c 
to glue to libfdt instead of flatdevtree.c (he says blithely).

* ...other than a backwards compatible version 16 -> 17 upgrade.

Best regards,
gvb