On Mon, Feb 26, 2018 at 08:33:06AM +0100, Julia Lawall wrote:
>
>
> On Sun, 25 Feb 2018, frowand.list@xxxxxxxxx wrote:
>
> > From: Frank Rowand <frowand.list@xxxxxxxxx>
> >
> > Hi All,
> >
> > I am once again out of my depth with bison and flex.
> >
> > The Devicetree Specification and ePAPR both tell me that I can
> > put a label on a node, as in:
> >
> > [label:] node-name[@unit-address] {
> > [properties definitions]
> > [child nodes]
> > }
> >
> > and do not make any mention of the root node as being different
> > that any other node in this respect.
> >
> > However, the dtc implementation does not allow a label on the
> > root node. I tried modifying the dtc parser to allow a label
> > on the root node. The result is patch 1/2 in this series.
> >
> > After applying patch 1/2, I get a syntax error when I try to
> > compile a devicetree source with a label on the root node:
> >
> > $ dtc -O dts junk_lab.dts >junk
> > Error: junk_lab.dts:3.9-10 syntax error
> > FATAL ERROR: Unable to parse input tree
> >
> > Here are the first few lines of the source file:
> >
> > $ nl -ba junk_lab.dts | head
> > 1 /dts-v1/;
> > 2
> > 3 myroot: / {
> > 4 #address-cells = <0x1>;
> > 5 #size-cells = <0x1>;
> > 6 compatible = "qcom,apq8074-dragonboard", "qcom,apq8074";
> > 7 interrupt-parent = <0x1>;
> > 8 model = "Qualcomm APQ8074 Dragonboard";
> > 9
> > 10 adsp-pil {
> >
> > I did my best to debug the cause of the symptom, and at one point
> > tried removing the parse code that allows /memreserve/ to have
> > a label, which is patch 2/2. This was just trying to better
> > understand what was going on, not actually with the intent of
> > submitting patch 2/2 for real. However, I can successfully
> > compile a devicetree with a label on the root node when I
> > have both patch 1/2 and patch 2/2 applied.
> >
> > Am I missing something that will let me add labels to the root
> > node _without_ having to remove the capability of having
> > labels on /memreserve/?
>
> OK, I read the mails out of order, so I see that you found the memreserve
> problem. Is there a way that you expect the grammar to know whether the
> label is part of the memreserve declaration or the devicetree declaration?
> It needs to know immediately so it can choose between the rules
> (memreserves and devicetree).
>
> Is it intentional that memreserve is recursive? Ie that lots of labels
> should be allowed before a given DT_MEMRESERVE? If it were not recursive,
> it might be smart enough to realize that the two kinds of DT_LABEL are
> followed by different things.
Yes, that's intentional. In general if something allows one label it
should allow an arbitrary number.
--
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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