[PATCH v2 3/4] common: oftree: Pass bootsource and bootsource instance to kernel

[Andrey Smirnov]

Pass barebox-detected bootsource to Linux to make it availible to
Linux userspace. That information is passed as full path to the node
corresponding to the bootsource and is placed under /chosen/bootsource
and it can be read under Linux in

/sys/firmware/devicetree/base/chosen/bootsource

Signed-off-by: Andrey Smirnov <andrew.smirnov at gmail.com>
---
 common/oftree.c | 46 +++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 45 insertions(+), 1 deletion(-)

diff --git a/common/oftree.c b/common/oftree.c
index 8a2ede4c6..5ab6bf089 100644
--- a/common/oftree.c
+++ b/common/oftree.c
@@ -11,6 +11,7 @@
 #include <getopt.h>
 #include <init.h>
 #include <boot.h>
+#include <bootsource.h>
 #include <i2c/i2c.h>
 
 #define MAX_LEVEL	32		/* how deeply nested we will go */
@@ -114,6 +115,47 @@ void of_print_cmdline(struct device_node *root)
 	printf("commandline: %s\n", cmdline);
 }
 
+static int of_fixup_bootargs_bootsource(struct device_node *root,
+					struct device_node *chosen)
+{
+	char *alias_name = bootsource_get_alias_name();
+	struct device_node *bootsource;
+	struct device_node *aliasnp;
+	struct property *p;
+	int ret;
+
+	if (!alias_name)
+		return 0;
+
+	bootsource = of_find_node_by_alias(root, alias_name);
+	/*
+	 * If kerenel DTB doesn't have the appropriate alias set up,
+	 * give up and exit early. No error is reported.
+	 */
+	if (!bootsource) {
+		ret = 0;
+		goto exit;
+	}
+
+	aliasnp = of_find_node_by_path_from(root, "/aliases");
+	if (!aliasnp) {
+		ret = -ENOENT;
+		goto exit;
+	}
+
+	p = of_find_property(aliasnp, alias_name, NULL);
+	if (!p) {
+		ret = -ENOENT;
+		goto exit;
+	}
+
+	ret = of_set_property(chosen, "bootsource", of_property_get_value(p),
+			      p->length, true);
+exit:
+	free(alias_name);
+	return ret;
+}
+
 static int of_fixup_bootargs(struct device_node *root, void *unused)
 {
 	struct device_node *node;
@@ -131,8 +173,10 @@ static int of_fixup_bootargs(struct device_node *root, void *unused)
 	of_property_write_string(node, "barebox-version", release_string);
 
 	err = of_property_write_string(node, "bootargs", str);
+	if (err)
+		return err;
 
-	return err;
+	return of_fixup_bootargs_bootsource(root, node);
 }
 
 static int of_register_bootargs_fixup(void)
-- 
2.17.0