On Tue, 12 Nov 2013 11:20:04 +0100, Pantelis Antoniou <panto@xxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hi Grant, > > On Nov 11, 2013, at 6:56 PM, Grant Likely wrote: > > > On Tue, 29 Oct 2013 21:01:06 +0200, Pantelis Antoniou <panto@xxxxxxxxxxxxxxxxxxxxxxx> wrote: > >> Enable the generation of symbol & fixup information for > >> usage with dynamic DT loading. > >> > >> Passing the -@ option generates a __symbols__ node at the > >> root node of the resulting blob for any node labels used. > >> > >> When using the /plugin/ tag all unresolved label references > >> be tracked in the __fixups__ node, while all local phandle > >> references will the tracked in the __local_fixups__ node. > >> > >> This is sufficient to implement a dynamic DT object loader. > >> > >> Changes since v1: > >> > >> * Forward ported to 1.4 version > >> * Added manual entries for the -@ option > >> > >> Signed-off-by: Pantelis Antoniou <panto@xxxxxxxxxxxxxxxxxxxxxxx> > > > > Hi Pantelis, > > > > This looks pretty good on first look. Comments below. > > > >> --- > >> Documentation/dt-object-internal.txt | 295 +++++++++++++++++++++++++++++++++++ > >> Documentation/manual.txt | 10 ++ > > [snip] > > >> +----------------------------------------- > >> + > >> +Since the device tree is used for booting a number of very different hardware > >> +platforms it is imperative that we tread very carefully. > >> + > >> +2.a) No changes to the Device Tree binary format. We cannot modify the tree > >> +format at all and all the information we require should be encoded using device > >> +tree itself. We can add nodes that can be safely ignored by both bootloaders and > >> +the kernel. > > > > Not /entirely/ true. It would be completely fine to bump up the binary > > format version for the overlays since they will never be loaded > > standalone. If there are specific things that you would like to have in > > the marshalled format then go ahead and propose them. Then the overlay > > would use the new protocol version, but the base tree would use the > > existing one. > > OK, I see. I am very hesitant to bump the format version, because both the > base DTS and the overlay need to be compiled with symbol support. > We can bump the version format for the overlay fragment, but bumping the > version for the base DTS will affect bootloaders badly. Hmmm, I missed that detail. Why does the base tree require symbol support? It looked to me like the overlay had all the resolution information needed. g. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
