On Mon, Aug 26, 2013 at 10:40:27AM +0800, TigerLiu@viatech.com.cn wrote:
Hi, Rini:
CONFIG_FIT and CONFIG_OF_LIBFDT are indeed unrelated options. You can use DT files with legacy images and plain zImages as well.
Thanks for your reply!
I also have a question about CONFIG_OF_CONTROL. If CONFIG_OF_CONTROL is defined, then Uboot will use FDT to configure device. But based on README, it said: This option is experimental and only available on a few boards.
So, most currently released u-boot binary still didn't use FDT to configure device during uboot posting phase?
Correct. Only a few drivers have been converted at this time. Frankly, I would like to see things stabilize within the kernel a bit more, make sure people really are happy with the bindings they need for a particular thing, and then we can see about using them again in U-Boot.
Just use FDT as kernel parameter passed to linux kernel's entry point?
That is one use, yes. But that may or may not be a recommended way to store the FDT for a platform (based on some discussion on the devicetrees mailing list, while there's no formal recommendations yet, having the shipped with platform FDT be done in such a way that it can be updated is strongly encouraged, possibly without having to replace the rest of the firmware as that's seen as a possible way to brick the hardware).
If you're planning on shipping hardware soon, with a device tree embedded within it, I would strongly encourage talking with devicetrees@vger.kernel.org about how to best do it, for your platform.