On Monday 16 of December 2013 11:08:33 Stephen Warren wrote:
> On 12/13/2013 09:49 AM, Tomasz Figa wrote:
> > Currently dtc loses information about data types when parsing DTS,
> > because it flattens all the parsed property data into a flat stream of
> > bytes. The only saved metadata is for references to other nodes inside
> > cell arrays. This makes it impossible to do any checks on data types on
> > livetree representation.
> >
> > This patch makes dtc store type information inside data struct by using
> > marker infrastructure. A new type of marker is introduced that holds
> > type enum as its ref member. Such markers are then inserted wherever
> > data of given type starts, so information about type of each property
> > data section is preserved.
>
> > diff --git a/dtc-parser.y b/dtc-parser.y
>
> > | propdataprefix DT_REF
> > {
> > - $$ = data_add_marker($1, REF_PATH, $2);
> > + struct data d;
> > + d = data_add_marker($1, TYPE, (char *)TYPE_STRING);
> > + $$ = data_add_marker(d, REF_PATH, $2);
> > }
>
> I guess here, the lexer does give us a string that's the target of the
> reference, so this is correct. However, I wonder if semantically we
> shouldn't call this a TYPE_REFERENCE, so we can distinguish between
> references and regular strings?
Hmm, a REF_PATH tag is already being added by this code, so you don't lose
this information. Still, maybe it would be better to unify REF_* and TYPE
tags and add TYPE_PATH and TYPE_PHANDLE types...
>
> > diff --git a/livetree.c b/livetree.c
>
> > @@ -530,16 +530,24 @@ cell_t get_node_phandle(struct node *root, struct
> > node *node)
> > node->phandle = phandle;
> >
> > if (!get_property(node, "linux,phandle")
> > - && (phandle_format & PHANDLE_LEGACY))
> > + && (phandle_format & PHANDLE_LEGACY)) {
> > + struct data d;
> > +
> > + d = data_add_marker(empty_data, TYPE, (char *)TYPE_ARRAY_INT32);
>
> Similarly here, can we encode as e.g. TYPE_PHANDLE or something like
> that, so we keep the semantic information?
"linux,phandle" property isn't really a phandle (as in reference by
phandle), but an integer assigning phandle number for given node, so
I'm not sure if TYPE_PHANDLE would be correct here.
Best regards,
Tomasz
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