sunxi: non-FEL SPL boot support for sun7i

[karo-tx-uboot.git] / include / libfdt.h

diff --git a/include/libfdt.h b/include/libfdt.h
index c5ec2acfd82927f070923e118766aad22986b3a9..9eefaaf5f87a7de869f78a05c67bed09d56202bd 100644 (file)
--- a/include/libfdt.h
+++ b/include/libfdt.h
@@ -596,9 +596,9 @@ 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
+ * @name: name of the alias to look up
  *
  * fdt_get_alias() retrieves the value of a given alias.  That is, the
  * value of the property named 'name' in the node /aliases.
@@ -1511,4 +1511,68 @@ int fdt_del_node(void *fdt, int nodeoffset);
 
 const char *fdt_strerror(int errval);
 
+struct fdt_region {
+       int offset;
+       int size;
+};
+
+/**
+ * fdt_find_regions() - find regions in device tree
+ *
+ * Given a list of nodes to include and properties to exclude, find
+ * the regions of the device tree which describe those included parts.
+ *
+ * The intent is to get a list of regions which will be invariant provided
+ * those parts are invariant. For example, if you request a list of regions
+ * for all nodes but exclude the property "data", then you will get the
+ * same region contents regardless of any change to "data" properties.
+ *
+ * This function can be used to produce a byte-stream to send to a hashing
+ * function to verify that critical parts of the FDT have not changed.
+ *
+ * Nodes which are given in 'inc' are included in the region list, as
+ * are the names of the immediate subnodes nodes (but not the properties
+ * or subnodes of those subnodes).
+ *
+ * For eaxample "/" means to include the root node, all root properties
+ * and the FDT_BEGIN_NODE and FDT_END_NODE of all subnodes of /. The latter
+ * ensures that we capture the names of the subnodes. In a hashing situation
+ * it prevents the root node from changing at all Any change to non-excluded
+ * properties, names of subnodes or number of subnodes would be detected.
+ *
+ * When used with FITs this provides the ability to hash and sign parts of
+ * the FIT based on different configurations in the FIT. Then it is
+ * impossible to change anything about that configuration (include images
+ * attached to the configuration), but it may be possible to add new
+ * configurations, new images or new signatures within the existing
+ * framework.
+ *
+ * Adding new properties to a device tree may result in the string table
+ * being extended (if the new property names are different from those
+ * already added). This function can optionally include a region for
+ * the string table so that this can be part of the hash too.
+ *
+ * The device tree header is not included in the list.
+ *
+ * @fdt:       Device tree to check
+ * @inc:       List of node paths to included
+ * @inc_count: Number of node paths in list
+ * @exc_prop:  List of properties names to exclude
+ * @exc_prop_count:    Number of properties in exclude list
+ * @region:    Returns list of regions
+ * @max_region:        Maximum length of region list
+ * @path:      Pointer to a temporary string for the function to use for
+ *             building path names
+ * @path_len:  Length of path, must be large enough to hold the longest
+ *             path in the tree
+ * @add_string_tab:    1 to add a region for the string table
+ * @return number of regions in list. If this is >max_regions then the
+ * region array was exhausted. You should increase max_regions and try
+ * the call again.
+ */
+int fdt_find_regions(const void *fdt, char * const inc[], int inc_count,
+                    char * const exc_prop[], int exc_prop_count,
+                    struct fdt_region region[], int max_regions,
+                    char *path, int path_len, int add_string_tab);
+
 #endif /* _LIBFDT_H */