dtc: Assume properties preced subnodes in the flattened tree

With kernel commit eff2ebd207af9f501af0ef667a7d14befcb36c1b, we
clarified that in the flattened tree format, a particular nodes
properties are required to precede its subdnodes.

At present however, both dtc and libfdt will process trees which don't
meet this condition.  This patch simplifies the code for
fdt_get_property() based on assuming that constraint.  dtc continues
to be able to handle such an invalid tree - on the grounds that it's
useful for dtc to be able to correct such a broken tree - but this
patch adds a warning when this condition is not met while reading a
flattened tree.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 3 insertions, 0 deletions

diff --git a/flattree.c b/flattree.c
index e857b08..d7dc6b0 100644
--- a/flattree.c
+++ b/flattree.c
@@ -779,6 +779,9 @@ static struct node *unflatten_tree(struct inbuf *dtbuf,
 		val = flat_read_word(dtbuf);
 		switch (val) {
 		case OF_DT_PROP:
+			if (node->children)
+				fprintf(stderr, "Warning: Flat tree input has "
+					"subnodes preceding a property.\n");
 			prop = flat_read_property(dtbuf, strbuf, flags);
 			add_property(node, prop);
 			break;