Hi Sascha,
On Nov 4, 2013, at 4:53 PM, Sascha Hauer wrote:
> Hi Pantelis,
>
> Thank you for working on this again. I would really appreciate seeing
> this upstream.
>
Don't mention it. Let's try to make it happen then.
> On Mon, Nov 04, 2013 at 04:36:13PM +0200, Pantelis Antoniou wrote:
>> +Notice that all the nodes that had a label have been recorded, and that
>> +phandles have been generated for them.
>> +
>> +This blob can be used to boot the board normally, the __symbols__ node will
>> +be safely ignored both by the bootloader and the kernel (the only loss will
>> +be a few bytes of memory and disk space).
>> +
>> +3.b) The Device Tree fragments must be compiled with the same option but they
>> +must also have a tag (/plugin/) that allows undefined references to labels
>> +that are not present at compilation time to be recorded so that the runtime
>> +loader can fix them.
>> +
>> +So the bar peripheral's DTS format would be of the form:
>> +
>> +/plugin/; /* allow undefined label references and record them */
>> +/ {
>> + .... /* various properties for loader use; i.e. part id etc. */
>> + fragment@0 {
>> + target = <&ocp>;
>> + __overlay__ {
>> + /* bar peripheral */
>> + bar {
>> + compatible = "corp,bar";
>> + ... /* various properties and child nodes */
>> + }
>> + };
>> + };
>> +};
>
> When last looking at this patch I created the attached follow up. What
> I didn't like about this patch is that we currently have to write dts
> files explicitely as overlays. With the attached patch the above could
> be written as:
>
> &ocp: {
> compatible = "corp,bar";
> };
>
> This is easier to write and more important a dts snippet could be either
> compiled into a dtb or used as an overlay.
>
I see your point.
In my use case I always needed some out-of-band properties for the loader/manager
to track. Let me test your and see if it doesn't break my use-cases.
If it's fine, then I have no objections in including it.
> Sascha
>
Regards
-- Pantelis
> 8<-------------------------------------------------------------------
>
> From bf78934e2bfe5c220d97d52e4effdd95164e071f Mon Sep 17 00:00:00 2001
> From: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Date: Thu, 8 Aug 2013 23:08:31 +0200
> Subject: [PATCH] dtc: convert unresolved labels into overlay nodes
>
> Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> ---
> dtc-parser.y | 10 +++++++---
> dtc.h | 3 ++-
> livetree.c | 23 +++++++++++++++++++++++
> 3 files changed, 32 insertions(+), 4 deletions(-)
>
> diff --git a/dtc-parser.y b/dtc-parser.y
> index e444acf..db1e9f8 100644
> --- a/dtc-parser.y
> +++ b/dtc-parser.y
> @@ -166,10 +166,14 @@ devicetree:
> {
> struct node *target = get_node_by_ref($1, $2);
>
> - if (target)
> + if (target) {
> merge_nodes(target, $3);
> - else
> - print_error("label or path, '%s', not found", $2);
> + } else {
> + if (symbol_fixup_support)
> + add_orphan_node($1, $3, $2);
> + else
> + print_error("label or path, '%s', not found", $2);
> + }
> $$ = $1;
> }
> | devicetree DT_DEL_NODE DT_REF ';'
> diff --git a/dtc.h b/dtc.h
> index 8c9059b..147ab35 100644
> --- a/dtc.h
> +++ b/dtc.h
> @@ -20,7 +20,7 @@
> * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
> * USA
> */
> -
> +#define _GNU_SOURCE
> #include <stdio.h>
> #include <string.h>
> #include <stdlib.h>
> @@ -232,6 +232,7 @@ struct node *build_node_delete(void);
> struct node *name_node(struct node *node, char *name);
> struct node *chain_node(struct node *first, struct node *list);
> struct node *merge_nodes(struct node *old_node, struct node *new_node);
> +void add_orphan_node(struct node *old_node, struct node *new_node, char *ref);
>
> void add_property(struct node *node, struct property *prop);
> void delete_property_by_name(struct node *node, char *name);
> diff --git a/livetree.c b/livetree.c
> index b61465f..cc26fe1 100644
> --- a/livetree.c
> +++ b/livetree.c
> @@ -216,6 +216,29 @@ struct node *merge_nodes(struct node *old_node, struct node *new_node)
> return old_node;
> }
>
> +void add_orphan_node(struct node *dt, struct node *new_node, char *ref)
> +{
> + struct node *ovl = xmalloc(sizeof(*ovl));
> + struct property *p;
> + struct data d = empty_data;
> + char *name;
> +
> + memset(ovl, 0, sizeof(*ovl));
> +
> + d = data_add_marker(d, REF_PHANDLE, ref);
> + d = data_append_integer(d, 0xdeadbeef, 32);
> +
> + p = build_property("target", d);
> + add_property(ovl, p);
> +
> + asprintf(&name, "fragment@%s", ref);
> + name_node(ovl, name);
> + name_node(new_node, "__overlay__");
> +
> + add_child(dt, ovl);
> + add_child(ovl, new_node);
> +}
> +
> struct node *chain_node(struct node *first, struct node *list)
> {
> assert(first->next_sibling == NULL);
> --
> 1.8.4.rc3
>
> --
> Pengutronix e.K. | |
> Industrial Linux Solutions | http://www.pengutronix.de/ |
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