[POWERPC] In booting-without-of.txt, clarify that properties must precede subnodes

A strict reading of the flattened device tree format defined in
booting-without-of.txt does in fact require that all the tags defining
properties for a node go before any definitions of subnodes, however
it's not particularly emphasised.  Although allowing intermingled
properties and subnodes would not be ambiguous in meaning, the kernel
parser does currently require that properties precede subnodes.
Furthermore, keeping this constraint makes life easier for various
device tree scanning tools.

Therefore, re-emphasise in booting-without-of.txt that this is a
strict requirement of the flattened device tree format.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
David Gibson 2007-06-28 15:56:26 +10:00 committed by Paul Mackerras
parent ea1a734ad7
commit eff2ebd207

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@ -626,6 +626,14 @@ So the node content can be summarized as a start token, a full path,
a list of properties, a list of child nodes, and an end token. Every
child node is a full node structure itself as defined above.
NOTE: The above definition requires that all property definitions for
a particular node MUST precede any subnode definitions for that node.
Although the structure would not be ambiguous if properties and
subnodes were intermingled, the kernel parser requires that the
properties come first (up until at least 2.6.22). Any tools
manipulating a flattened tree must take care to preserve this
constraint.
4) Device tree "strings" block
In order to save space, property names, which are generally redundant,