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authorMaxime Ripard <maxime.ripard@free-electrons.com>2016-09-30 15:57:16 +0200
committerSebastian Huber <sebastian.huber@embedded-brains.de>2018-07-19 07:01:09 +0200
commite879a98ddeb5c738d598d6a91e4b4f2da6933cde (patch)
tree676c355973f31eb75bff720f2f7383ab0c73a640 /cpukit
parentb0ceda549821c6c2743cf2ce7d13cf921b7a4df0 (diff)
downloadrtems-e879a98ddeb5c738d598d6a91e4b4f2da6933cde.tar.bz2
libfdt: Add overlay application function
The device tree overlays are a good way to deal with user-modifyable boards or boards with some kind of an expansion mechanism where we can easily plug new board in (like the BBB, the Raspberry Pi or the CHIP). Add a new function to merge overlays with a base device tree. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Diffstat (limited to 'cpukit')
-rw-r--r--cpukit/include/libfdt.h31
-rw-r--r--cpukit/include/libfdt_env.h1
2 files changed, 32 insertions, 0 deletions
diff --git a/cpukit/include/libfdt.h b/cpukit/include/libfdt.h
index d2e5e031fb..c69e918899 100644
--- a/cpukit/include/libfdt.h
+++ b/cpukit/include/libfdt.h
@@ -1763,6 +1763,37 @@ int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
*/
int fdt_del_node(void *fdt, int nodeoffset);
+/**
+ * fdt_overlay_apply - Applies a DT overlay on a base DT
+ * @fdt: pointer to the base device tree blob
+ * @fdto: pointer to the device tree overlay blob
+ *
+ * fdt_overlay_apply() will apply the given device tree overlay on the
+ * given base device tree.
+ *
+ * Expect the base device tree to be modified, even if the function
+ * returns an error.
+ *
+ * returns:
+ * 0, on success
+ * -FDT_ERR_NOSPACE, there's not enough space in the base device tree
+ * -FDT_ERR_NOTFOUND, the overlay points to some inexistant nodes or
+ * properties in the base DT
+ * -FDT_ERR_BADPHANDLE,
+ * -FDT_ERR_BADOVERLAY,
+ * -FDT_ERR_NOPHANDLES,
+ * -FDT_ERR_INTERNAL,
+ * -FDT_ERR_BADLAYOUT,
+ * -FDT_ERR_BADMAGIC,
+ * -FDT_ERR_BADOFFSET,
+ * -FDT_ERR_BADPATH,
+ * -FDT_ERR_BADVERSION,
+ * -FDT_ERR_BADSTRUCTURE,
+ * -FDT_ERR_BADSTATE,
+ * -FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_overlay_apply(void *fdt, void *fdto);
+
/**********************************************************************/
/* Debugging / informational functions */
/**********************************************************************/
diff --git a/cpukit/include/libfdt_env.h b/cpukit/include/libfdt_env.h
index 9dea97dfff..99f936dacc 100644
--- a/cpukit/include/libfdt_env.h
+++ b/cpukit/include/libfdt_env.h
@@ -54,6 +54,7 @@
#include <stddef.h>
#include <stdint.h>
+#include <stdlib.h>
#include <string.h>
#ifdef __CHECKER__