On Tue, May 24, 2016 at 08:50:38PM +0300, Pantelis Antoniou wrote: > This patch enable the generation of symbols & local fixup information > for trees compiled with the -@ (--symbols) option. > > Using this patch labels in the tree and their users emit information > in __symbols__ and __local_fixups__ nodes. > > The __fixups__ node make possible the dynamic resolution of phandle > references which are present in the plugin tree but lie in the > tree that are applying the overlay against. > > Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx> > Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> > Signed-off-by: Jan Luebbe <jlu@xxxxxxxxxxxxxx> So, I think I've identified the underlying thing which was bothering me about these patches. With the new dynamic patching stuff, "overlays" (for want of a better term) now have a real existence both in the dts source format, and in the dtb object format. However, these patches don't give them a concrete, explicit representation within dtc itself - instead we just kind of mangle one representation to the other as we're parsing. I think this is a mistaken approach. I'm toying with some patches to give overlays a full representation in dtc which I think will handle these cases better - and allow for easier experimentation with different possible ways of encoding the overlays. One side point - writing plugins in dts format leads to an irritating little ambiguity in the grammar. Well, not an ambiguity technically, but a place where we need more lookahead than normal, meaning we get shift/reduce conflicts. It arises because both memreserves and overlays can have a label in front of them. So, if we see a label as our next token after the version tag, we don't know if a memreserve or overlay is coming next, so the parser doesn't know which path to go down (with a single token lookahead). We could handle it with %glr-parser, of course, but I have been trying to avoid that. I think this will apply both with your patches and with the approach I'm working on - not sure what to do about it yet. -- 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
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