Hi David, On 5 June 2014 at 08:12, David Gibson <david@xxxxxxxxxxxxxxxxxxxxx> wrote: > > On Mon, Jun 02, 2014 at 09:12:55PM -0600, Simon Glass wrote: > > Hi David, > > > > On 1 May 2014 23:40, David Gibson <david@xxxxxxxxxxxxxxxxxxxxx> wrote: > > > On Thu, May 01, 2014 at 09:13:51AM -0700, Simon Glass wrote: > > >> Hi, > > >> > > >> On 22 March 2014 08:07, Simon Glass <sjg@xxxxxxxxxxxx> wrote: > > >> > Given a set of nodes and properties, find the regions of the device tree > > >> > which describe those parts. > > >> > > > >> > A test is provided which builds a tree while tracking where the regions > > >> > should be, then calls fdt_first/next_region() to make sure that it agrees. > > >> > > > >> > Further tests will come as part of fdtgrep. > > >> > > > >> > Signed-off-by: Simon Glass <sjg@xxxxxxxxxxxx> > > >> > > >> Have I sent this to the right place? Any comments? > > > > > > Sorry. I know you've resent this several times, and I've been > > > procrastinating about it since forever. > > > > > > Basically, I'm just not convinced. For all your efforts to explain > > > the rationale, it just seems like a really ad-hoc set of flags and > > > conditions that doesn't seem to form a coherent whole. > > > > Are you referring to fdtgrep or the new library function? I'd be happy > > enough getting the library function to start with in if there isn't > > much need for the grep utility. > > The library function primarily. > > > > From the lack of other responses, I'm assuming there's not really > > > anyone else who sees it as a compelling feature either. > > > > Is there normally a lot of mailing list traffic for new libfdt > > features? This is used for verified boot in U-Boot for example. > > Hm, that's true I guess. I'd like to dredge this up again. I'm currently working on adding device tree support in U-Boot SPL (the tiny loader that loads U-Boot). U-Boot currently uses device tree for normal operation, but since SPL can run in very small RAM sizes there is often not enough space for a full (~40KB) device tree. In fact often all that is needed is the UART and perhaps SPI/I2C. This is <1KB. There seem to be a several options here: 1. Create a separate device tree file for each board, just for SPL, with just what is needed to boot SPL 2. Use #ifdef and the preprocessor to remove what is not needed, and run dtc twice with different #defines 3. Use fdtgrep to chop down the device tree file by removing unwanted nodes I think that option 3 is the best. It avoids copying source code, or littering it with #ifdef. If necessary I suppose this tool could just live in U-Boot but that seems a shame. I understand that fdtgrep perhaps has too many options for your liking. Is there some subset that you think would be worthy of including as a new device-tree-compiler tool? If so, then I would rather create fdtgrep (or fdtprune or whatever) there than add a special tool to U-Boot. Please let me know what you think. Regards, Simon -- To unsubscribe from this list: send the line "unsubscribe devicetree-compiler" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
