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-rw-r--r--libfdt/libfdt.h378
1 files changed, 348 insertions, 30 deletions
diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
index c4d5a9134bfcb..ac42e0459524b 100644
--- a/libfdt/libfdt.h
+++ b/libfdt/libfdt.h
@@ -61,7 +61,7 @@
#define FDT_ERR_NOTFOUND 1
/* FDT_ERR_NOTFOUND: The requested node or property does not exist */
#define FDT_ERR_EXISTS 2
- /* FDT_ERR_EXISTS: Attemped to create a node or property which
+ /* FDT_ERR_EXISTS: Attempted to create a node or property which
* already exists */
#define FDT_ERR_NOSPACE 3
/* FDT_ERR_NOSPACE: Operation needed to expand the device
@@ -79,8 +79,10 @@
* (e.g. missing a leading / for a function which requires an
* absolute path) */
#define FDT_ERR_BADPHANDLE 6
- /* FDT_ERR_BADPHANDLE: Function was passed an invalid phandle
- * value. phandle values of 0 and -1 are not permitted. */
+ /* FDT_ERR_BADPHANDLE: Function was passed an invalid phandle.
+ * This can be caused either by an invalid phandle property
+ * length, or the phandle value was either 0 or -1, which are
+ * not permitted. */
#define FDT_ERR_BADSTATE 7
/* FDT_ERR_BADSTATE: Function was passed an incomplete device
* tree created by the sequential-write functions, which is
@@ -116,7 +118,26 @@
* Should never be returned, if it is, it indicates a bug in
* libfdt itself. */
-#define FDT_ERR_MAX 13
+/* Errors in device tree content */
+#define FDT_ERR_BADNCELLS 14
+ /* FDT_ERR_BADNCELLS: Device tree has a #address-cells, #size-cells
+ * or similar property with a bad format or value */
+
+#define FDT_ERR_BADVALUE 15
+ /* FDT_ERR_BADVALUE: Device tree has a property with an unexpected
+ * value. For example: a property expected to contain a string list
+ * is not NUL-terminated within the length of its value. */
+
+#define FDT_ERR_BADOVERLAY 16
+ /* FDT_ERR_BADOVERLAY: The device tree overlay, while
+ * correctly structured, cannot be applied due to some
+ * unexpected or missing value, property or node. */
+
+#define FDT_ERR_NOPHANDLES 17
+ /* FDT_ERR_NOPHANDLES: The device tree doesn't have any
+ * phandle available anymore without causing an overflow */
+
+#define FDT_ERR_MAX 17
/**********************************************************************/
/* Low-level functions (you probably don't need these) */
@@ -158,27 +179,55 @@ int fdt_first_subnode(const void *fdt, int offset);
*/
int fdt_next_subnode(const void *fdt, int offset);
+/**
+ * fdt_for_each_subnode - iterate over all subnodes of a parent
+ *
+ * @node: child node (int, lvalue)
+ * @fdt: FDT blob (const void *)
+ * @parent: parent node (int)
+ *
+ * This is actually a wrapper around a for loop and would be used like so:
+ *
+ * fdt_for_each_subnode(node, fdt, parent) {
+ * Use node
+ * ...
+ * }
+ *
+ * if ((node < 0) && (node != -FDT_ERR_NOT_FOUND)) {
+ * Error handling
+ * }
+ *
+ * Note that this is implemented as a macro and @node is used as
+ * iterator in the loop. The parent variable be constant or even a
+ * literal.
+ *
+ */
+#define fdt_for_each_subnode(node, fdt, parent) \
+ for (node = fdt_first_subnode(fdt, parent); \
+ node >= 0; \
+ node = fdt_next_subnode(fdt, node))
+
/**********************************************************************/
/* General functions */
/**********************************************************************/
#define fdt_get_header(fdt, field) \
(fdt32_to_cpu(((const struct fdt_header *)(fdt))->field))
-#define fdt_magic(fdt) (fdt_get_header(fdt, magic))
+#define fdt_magic(fdt) (fdt_get_header(fdt, magic))
#define fdt_totalsize(fdt) (fdt_get_header(fdt, totalsize))
#define fdt_off_dt_struct(fdt) (fdt_get_header(fdt, off_dt_struct))
#define fdt_off_dt_strings(fdt) (fdt_get_header(fdt, off_dt_strings))
#define fdt_off_mem_rsvmap(fdt) (fdt_get_header(fdt, off_mem_rsvmap))
#define fdt_version(fdt) (fdt_get_header(fdt, version))
-#define fdt_last_comp_version(fdt) (fdt_get_header(fdt, last_comp_version))
-#define fdt_boot_cpuid_phys(fdt) (fdt_get_header(fdt, boot_cpuid_phys))
-#define fdt_size_dt_strings(fdt) (fdt_get_header(fdt, size_dt_strings))
+#define fdt_last_comp_version(fdt) (fdt_get_header(fdt, last_comp_version))
+#define fdt_boot_cpuid_phys(fdt) (fdt_get_header(fdt, boot_cpuid_phys))
+#define fdt_size_dt_strings(fdt) (fdt_get_header(fdt, size_dt_strings))
#define fdt_size_dt_struct(fdt) (fdt_get_header(fdt, size_dt_struct))
#define __fdt_set_hdr(name) \
static inline void fdt_set_##name(void *fdt, uint32_t val) \
{ \
- struct fdt_header *fdth = (struct fdt_header*)fdt; \
+ struct fdt_header *fdth = (struct fdt_header *)fdt; \
fdth->name = cpu_to_fdt32(val); \
}
__fdt_set_hdr(magic);
@@ -249,6 +298,21 @@ int fdt_move(const void *fdt, void *buf, int bufsize);
const char *fdt_string(const void *fdt, int stroffset);
/**
+ * fdt_get_max_phandle - retrieves the highest phandle in a tree
+ * @fdt: pointer to the device tree blob
+ *
+ * fdt_get_max_phandle retrieves the highest phandle in the given
+ * device tree. This will ignore badly formatted phandles, or phandles
+ * with a value of 0 or -1.
+ *
+ * returns:
+ * the highest phandle on success
+ * 0, if no phandle was found in the device tree
+ * -1, if an error occurred
+ */
+uint32_t fdt_get_max_phandle(const void *fdt);
+
+/**
* fdt_num_mem_rsv - retrieve the number of memory reserve map entries
* @fdt: pointer to the device tree blob
*
@@ -308,8 +372,9 @@ int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
* returns:
* structure block offset of the requested subnode (>=0), on success
* -FDT_ERR_NOTFOUND, if the requested subnode does not exist
- * -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
- * -FDT_ERR_BADMAGIC,
+ * -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE
+ * tag
+ * -FDT_ERR_BADMAGIC,
* -FDT_ERR_BADVERSION,
* -FDT_ERR_BADSTATE,
* -FDT_ERR_BADSTRUCTURE,
@@ -318,6 +383,17 @@ int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
/**
+ * fdt_path_offset_namelen - find a tree node by its full path
+ * @fdt: pointer to the device tree blob
+ * @path: full path of the node to locate
+ * @namelen: number of characters of path to consider
+ *
+ * Identical to fdt_path_offset(), but only consider the first namelen
+ * characters of path as the path name.
+ */
+int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen);
+
+/**
* fdt_path_offset - find a tree node by its full path
* @fdt: pointer to the device tree blob
* @path: full path of the node to locate
@@ -330,7 +406,8 @@ int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
* address).
*
* returns:
- * structure block offset of the node with the requested path (>=0), on success
+ * structure block offset of the node with the requested path (>=0), on
+ * success
* -FDT_ERR_BADPATH, given path does not begin with '/' or is invalid
* -FDT_ERR_NOTFOUND, if the requested node does not exist
* -FDT_ERR_BADMAGIC,
@@ -354,10 +431,12 @@ int fdt_path_offset(const void *fdt, const char *path);
*
* returns:
* pointer to the node's name, on success
- * If lenp is non-NULL, *lenp contains the length of that name (>=0)
+ * If lenp is non-NULL, *lenp contains the length of that name
+ * (>=0)
* NULL, on error
* if lenp is non-NULL *lenp contains an error code (<0):
- * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
+ * tag
* -FDT_ERR_BADMAGIC,
* -FDT_ERR_BADVERSION,
* -FDT_ERR_BADSTATE, standard meanings
@@ -406,6 +485,33 @@ int fdt_first_property_offset(const void *fdt, int nodeoffset);
int fdt_next_property_offset(const void *fdt, int offset);
/**
+ * fdt_for_each_property_offset - iterate over all properties of a node
+ *
+ * @property_offset: property offset (int, lvalue)
+ * @fdt: FDT blob (const void *)
+ * @node: node offset (int)
+ *
+ * This is actually a wrapper around a for loop and would be used like so:
+ *
+ * fdt_for_each_property_offset(property, fdt, node) {
+ * Use property
+ * ...
+ * }
+ *
+ * if ((property < 0) && (property != -FDT_ERR_NOT_FOUND)) {
+ * Error handling
+ * }
+ *
+ * Note that this is implemented as a macro and property is used as
+ * iterator in the loop. The node variable can be constant or even a
+ * literal.
+ */
+#define fdt_for_each_property_offset(property, fdt, node) \
+ for (property = fdt_first_property_offset(fdt, node); \
+ property >= 0; \
+ property = fdt_next_property_offset(fdt, property))
+
+/**
* fdt_get_property_by_offset - retrieve the property at a given offset
* @fdt: pointer to the device tree blob
* @offset: offset of the property to retrieve
@@ -441,8 +547,8 @@ const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
* @namelen: number of characters of name to consider
* @lenp: pointer to an integer variable (will be overwritten) or NULL
*
- * Identical to fdt_get_property_namelen(), but only examine the first
- * namelen characters of name for matching the property name.
+ * Identical to fdt_get_property(), but only examine the first namelen
+ * characters of name for matching the property name.
*/
const struct fdt_property *fdt_get_property_namelen(const void *fdt,
int nodeoffset,
@@ -469,7 +575,8 @@ const struct fdt_property *fdt_get_property_namelen(const void *fdt,
* NULL, on error
* if lenp is non-NULL, *lenp contains an error code (<0):
* -FDT_ERR_NOTFOUND, node does not have named property
- * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
+ * tag
* -FDT_ERR_BADMAGIC,
* -FDT_ERR_BADVERSION,
* -FDT_ERR_BADSTATE,
@@ -533,6 +640,13 @@ const void *fdt_getprop_by_offset(const void *fdt, int offset,
*/
const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
const char *name, int namelen, int *lenp);
+static inline void *fdt_getprop_namelen_w(void *fdt, int nodeoffset,
+ const char *name, int namelen,
+ int *lenp)
+{
+ return (void *)(uintptr_t)fdt_getprop_namelen(fdt, nodeoffset, name,
+ namelen, lenp);
+}
/**
* fdt_getprop - retrieve the value of a given property
@@ -554,7 +668,8 @@ const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
* NULL, on error
* if lenp is non-NULL, *lenp contains an error code (<0):
* -FDT_ERR_NOTFOUND, node does not have named property
- * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
+ * tag
* -FDT_ERR_BADMAGIC,
* -FDT_ERR_BADVERSION,
* -FDT_ERR_BADSTATE,
@@ -596,7 +711,7 @@ const char *fdt_get_alias_namelen(const void *fdt,
const char *name, int namelen);
/**
- * fdt_get_alias - retreive the path referenced by a given alias
+ * fdt_get_alias - retrieve the path referenced by a given alias
* @fdt: pointer to the device tree blob
* @name: name of the alias th look up
*
@@ -626,7 +741,7 @@ const char *fdt_get_alias(const void *fdt, const char *name);
* 0, on success
* buf contains the absolute path of the node at
* nodeoffset, as a NUL-terminated string.
- * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
+ * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
* -FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
* characters and will not fit in the given buffer.
* -FDT_ERR_BADMAGIC,
@@ -656,11 +771,11 @@ int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);
* structure from the start to nodeoffset.
*
* returns:
-
* structure block offset of the node at node offset's ancestor
* of depth supernodedepth (>=0), on success
- * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
-* -FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of nodeoffset
+ * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
+ * -FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of
+ * nodeoffset
* -FDT_ERR_BADMAGIC,
* -FDT_ERR_BADVERSION,
* -FDT_ERR_BADSTATE,
@@ -682,7 +797,7 @@ int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
*
* returns:
* depth of the node at nodeoffset (>=0), on success
- * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
+ * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
* -FDT_ERR_BADMAGIC,
* -FDT_ERR_BADVERSION,
* -FDT_ERR_BADSTATE,
@@ -705,7 +820,7 @@ int fdt_node_depth(const void *fdt, int nodeoffset);
* returns:
* structure block offset of the parent of the node at nodeoffset
* (>=0), on success
- * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
+ * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
* -FDT_ERR_BADMAGIC,
* -FDT_ERR_BADVERSION,
* -FDT_ERR_BADSTATE,
@@ -745,7 +860,7 @@ int fdt_parent_offset(const void *fdt, int nodeoffset);
* on success
* -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
* tree after startoffset
- * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
+ * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
* -FDT_ERR_BADMAGIC,
* -FDT_ERR_BADVERSION,
* -FDT_ERR_BADSTATE,
@@ -792,7 +907,7 @@ int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);
* 1, if the node has a 'compatible' property, but it does not list
* the given string
* -FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
- * -FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
+ * -FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
* -FDT_ERR_BADMAGIC,
* -FDT_ERR_BADVERSION,
* -FDT_ERR_BADSTATE,
@@ -829,7 +944,7 @@ int fdt_node_check_compatible(const void *fdt, int nodeoffset,
* on success
* -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
* tree after startoffset
- * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
+ * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
* -FDT_ERR_BADMAGIC,
* -FDT_ERR_BADVERSION,
* -FDT_ERR_BADSTATE,
@@ -852,11 +967,151 @@ int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
*/
int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
+/**
+ * fdt_stringlist_count - count the number of strings in a string list
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of a tree node
+ * @property: name of the property containing the string list
+ * @return:
+ * the number of strings in the given property
+ * -FDT_ERR_BADVALUE if the property value is not NUL-terminated
+ * -FDT_ERR_NOTFOUND if the property does not exist
+ */
+int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property);
+
+/**
+ * fdt_stringlist_search - find a string in a string list and return its index
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of a tree node
+ * @property: name of the property containing the string list
+ * @string: string to look up in the string list
+ *
+ * Note that it is possible for this function to succeed on property values
+ * that are not NUL-terminated. That's because the function will stop after
+ * finding the first occurrence of @string. This can for example happen with
+ * small-valued cell properties, such as #address-cells, when searching for
+ * the empty string.
+ *
+ * @return:
+ * the index of the string in the list of strings
+ * -FDT_ERR_BADVALUE if the property value is not NUL-terminated
+ * -FDT_ERR_NOTFOUND if the property does not exist or does not contain
+ * the given string
+ */
+int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
+ const char *string);
+
+/**
+ * fdt_stringlist_get() - obtain the string at a given index in a string list
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of a tree node
+ * @property: name of the property containing the string list
+ * @index: index of the string to return
+ * @lenp: return location for the string length or an error code on failure
+ *
+ * Note that this will successfully extract strings from properties with
+ * non-NUL-terminated values. For example on small-valued cell properties
+ * this function will return the empty string.
+ *
+ * If non-NULL, the length of the string (on success) or a negative error-code
+ * (on failure) will be stored in the integer pointer to by lenp.
+ *
+ * @return:
+ * A pointer to the string at the given index in the string list or NULL on
+ * failure. On success the length of the string will be stored in the memory
+ * location pointed to by the lenp parameter, if non-NULL. On failure one of
+ * the following negative error codes will be returned in the lenp parameter
+ * (if non-NULL):
+ * -FDT_ERR_BADVALUE if the property value is not NUL-terminated
+ * -FDT_ERR_NOTFOUND if the property does not exist
+ */
+const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
+ const char *property, int index,
+ int *lenp);
+
+/**********************************************************************/
+/* Read-only functions (addressing related) */
+/**********************************************************************/
+
+/**
+ * FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells
+ *
+ * This is the maximum value for #address-cells, #size-cells and
+ * similar properties that will be processed by libfdt. IEE1275
+ * requires that OF implementations handle values up to 4.
+ * Implementations may support larger values, but in practice higher
+ * values aren't used.
+ */
+#define FDT_MAX_NCELLS 4
+
+/**
+ * fdt_address_cells - retrieve address size for a bus represented in the tree
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node to find the address size for
+ *
+ * When the node has a valid #address-cells property, returns its value.
+ *
+ * returns:
+ * 0 <= n < FDT_MAX_NCELLS, on success
+ * 2, if the node has no #address-cells property
+ * -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
+ * #address-cells property
+ * -FDT_ERR_BADMAGIC,
+ * -FDT_ERR_BADVERSION,
+ * -FDT_ERR_BADSTATE,
+ * -FDT_ERR_BADSTRUCTURE,
+ * -FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_address_cells(const void *fdt, int nodeoffset);
+
+/**
+ * fdt_size_cells - retrieve address range size for a bus represented in the
+ * tree
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node to find the address range size for
+ *
+ * When the node has a valid #size-cells property, returns its value.
+ *
+ * returns:
+ * 0 <= n < FDT_MAX_NCELLS, on success
+ * 2, if the node has no #address-cells property
+ * -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
+ * #size-cells property
+ * -FDT_ERR_BADMAGIC,
+ * -FDT_ERR_BADVERSION,
+ * -FDT_ERR_BADSTATE,
+ * -FDT_ERR_BADSTRUCTURE,
+ * -FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_size_cells(const void *fdt, int nodeoffset);
+
+
/**********************************************************************/
/* Write-in-place functions */
/**********************************************************************/
/**
+ * fdt_setprop_inplace_namelen_partial - change a property's value,
+ * but not its size
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to change
+ * @name: name of the property to change
+ * @namelen: number of characters of name to consider
+ * @idx: index of the property to change in the array
+ * @val: pointer to data to replace the property value with
+ * @len: length of the property value
+ *
+ * Identical to fdt_setprop_inplace(), but modifies the given property
+ * starting from the given index, and using only the first characters
+ * of the name. It is useful when you want to manipulate only one value of
+ * an array and you have a string that doesn't end with \0.
+ */
+int fdt_setprop_inplace_namelen_partial(void *fdt, int nodeoffset,
+ const char *name, int namelen,
+ uint32_t idx, const void *val,
+ int len);
+
+/**
* fdt_setprop_inplace - change a property's value, but not its size
* @fdt: pointer to the device tree blob
* @nodeoffset: offset of the node whose property to change
@@ -1272,6 +1527,36 @@ static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
#define fdt_setprop_string(fdt, nodeoffset, name, str) \
fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
+
+/**
+ * fdt_setprop_empty - set a property to an empty value
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to change
+ * @name: name of the property to change
+ *
+ * fdt_setprop_empty() sets the value of the named property in the
+ * given node to an empty (zero length) value, or creates a new empty
+ * property if it does not already exist.
+ *
+ * This function may insert or delete data from the blob, and will
+ * therefore change the offsets of some existing nodes.
+ *
+ * returns:
+ * 0, on success
+ * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
+ * contain the new property value
+ * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ * -FDT_ERR_BADLAYOUT,
+ * -FDT_ERR_BADMAGIC,
+ * -FDT_ERR_BADVERSION,
+ * -FDT_ERR_BADSTATE,
+ * -FDT_ERR_BADSTRUCTURE,
+ * -FDT_ERR_BADLAYOUT,
+ * -FDT_ERR_TRUNCATED, standard meanings
+ */
+#define fdt_setprop_empty(fdt, nodeoffset, name) \
+ fdt_setprop((fdt), (nodeoffset), (name), NULL, 0)
+
/**
* fdt_appendprop - append to or create a property
* @fdt: pointer to the device tree blob
@@ -1466,9 +1751,11 @@ int fdt_add_subnode_namelen(void *fdt, int parentoffset,
* change the offsets of some existing nodes.
* returns:
- * structure block offset of the created nodeequested subnode (>=0), on success
+ * structure block offset of the created nodeequested subnode (>=0), on
+ * success
* -FDT_ERR_NOTFOUND, if the requested subnode does not exist
- * -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
+ * -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE
+ * tag
* -FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
* the given name
* -FDT_ERR_NOSPACE, if there is insufficient free space in the
@@ -1506,6 +1793,37 @@ 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 */
/**********************************************************************/