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Re: [Xen-devel] [PATCH V1 16/29] xen/arm: Build DOM0 FDT by browsing the device tree structure

On 09/09/2013 01:39 PM, Ian Campbell wrote:
On Mon, 2013-09-09 at 13:26 +0100, Julien Grall wrote:
On 09/09/2013 12:33 PM, Ian Campbell wrote:
On Wed, 2013-08-28 at 15:47 +0100, Julien Grall wrote:
       if ( early_info.modules.nr_mods >= MOD_KERNEL &&
            early_info.modules.module[MOD_KERNEL].cmdline[0] )
           bootargs = &early_info.modules.module[MOD_KERNEL].cmdline[0];

-    for ( prop = fdt_first_property_offset(fdt, node);
-          prop >= 0;
-          prop = fdt_next_property_offset(fdt, prop) )
+    for_each_property_of_node (np, pp)

Is "of" here as in "the property of the node" or is it a stray Open
Firmware from the Linux naming of these functions?

Perhaps a dt_ prefix to match all the others?

Right. I will send a patch to rename for_each_property_of_node to

Might dt_for_each_node_property fit better with the other functions?

Sounds good.

This comment is saying that the name of the name property used to be
something else? What was it? Which version of FDT was that -- do we need
to care?

Right, on older FDT version (< 0x10) each node has 2 different name:
    - the name just after FDT_BEGIN_NODE in the fdt which correspond to
the "filename".
    - the name in property "name" which is a convenient name.

So we can't use the name field in device tree to retrieve the name to
create the node.

For the FDT version, I don't know if we need to care. Linux pays
attention to it in the device tree code.

I'm not sure we need to care either, I expect we will never see <0x10 in
our uses (they are probbaly burnt into the ROMs of PPC machines) but of
it is easy enough to so we might as well I guess?

I forgot that there is another issue, the ePAR describes the name has node-name@unit-address. The name field will contains node-name and not the full node name.

Lets say Xen only uses the field name (ie node-name) to create the FDT node name. We Linux will create the procfs for the device tree (/proc/devicetree), it's possible to have numerous warning because there is 2 nodes with the same name.

The alternative would be an explicit check for versions we know we

Julien Grall

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