1 // SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
3  * libfdt - Flat Device Tree manipulation
15  * overlay_get_target_phandle - retrieves the target phandle of a fragment
16  * @fdto: pointer to the device tree overlay blob
17  * @fragment: node offset of the fragment in the overlay
21  * property) instead of a path (target-path property).
26  *	-1, if the phandle was malformed
37 	if ((len != sizeof(*val)) || (fdt32_to_cpu(*val) == (uint32_t)-1))  in overlay_get_target_phandle()
38 		return (uint32_t)-1;  in overlay_get_target_phandle()
44  * overlay_get_target - retrieves the offset of a fragment's target
45  * @fdt: Base device tree blob
46  * @fdto: Device tree overlay blob
47  * @fragment: node offset of the fragment in the overlay
50  * overlay_get_target() retrieves the target offset in the base
51  * device tree of a fragment, no matter how the actual targeting is
55  *      the targeted node offset in the base device tree
67 	if (phandle == (uint32_t)-1)  in overlay_get_target()
68 		return -FDT_ERR_BADPHANDLE;  in overlay_get_target()
73 		path = fdt_getprop(fdto, fragment, "target-path", &path_len);  in overlay_get_target()
83 	* target-path property in a node that contains a  in overlay_get_target()
88 	if (ret < 0 && path_len == -FDT_ERR_NOTFOUND)  in overlay_get_target()
89 		ret = -FDT_ERR_BADOVERLAY;  in overlay_get_target()
103  * overlay_phandle_add_offset - Increases a phandle by an offset
104  * @fdt: Base device tree blob
105  * @node: Device tree overlay blob
128 		return -FDT_ERR_BADPHANDLE;  in overlay_phandle_add_offset()
132 		return -FDT_ERR_NOPHANDLES;  in overlay_phandle_add_offset()
135 	if (adj_val == (uint32_t)-1)  in overlay_phandle_add_offset()
136 		return -FDT_ERR_NOPHANDLES;  in overlay_phandle_add_offset()
142  * overlay_adjust_node_phandles - Offsets the phandles of a node
143  * @fdto: Device tree overlay blob
150  * phandles to not conflict with the overlays of the base device tree.
163 	if (ret && ret != -FDT_ERR_NOTFOUND)  in overlay_adjust_node_phandles()
167 	if (ret && ret != -FDT_ERR_NOTFOUND)  in overlay_adjust_node_phandles()
180  * overlay_adjust_local_phandles - Adjust the phandles of a whole overlay
181  * @fdto: Device tree overlay blob
187  * phandles to not conflict with the overlays of the base device tree.
202  * overlay_update_local_node_references - Adjust the overlay references
203  * @fdto: Device tree overlay blob
209  * pointing to a node within the device tree overlay by adding a
212  * This is mainly used as part of a device tree application process,
213  * where you want the device tree overlays phandles to not conflict
214  * with the ones from the base device tree before merging them.
243 			return -FDT_ERR_BADOVERLAY;  in overlay_update_local_node_references()
248 			if (tree_len == -FDT_ERR_NOTFOUND)  in overlay_update_local_node_references()
249 				return -FDT_ERR_BADOVERLAY;  in overlay_update_local_node_references()
277 			if (ret == -FDT_ERR_NOSPACE)  in overlay_update_local_node_references()
278 				return -FDT_ERR_BADOVERLAY;  in overlay_update_local_node_references()
292 		if (tree_child == -FDT_ERR_NOTFOUND)  in overlay_update_local_node_references()
293 			return -FDT_ERR_BADOVERLAY;  in overlay_update_local_node_references()
309  * overlay_update_local_references - Adjust the overlay references
310  * @fdto: Device tree overlay blob
314  * to a node within the device tree overlay by adding a constant
317  * This is mainly used as part of a device tree application process,
318  * where you want the device tree overlays phandles to not conflict
319  * with the ones from the base device tree before merging them.
332 		if (fixups == -FDT_ERR_NOTFOUND)  in overlay_update_local_references()
339 	 * Update our local references from the root of the tree  in overlay_update_local_references()
346  * overlay_fixup_one_phandle - Set an overlay phandle to the base one
347  * @fdt: Base Device Tree blob
348  * @fdto: Device tree overlay blob
349  * @symbols_off: Node offset of the symbols node in the base device tree
350  * @path: Path to a node holding a phandle in the overlay
352  * @name: Name of the property holding the phandle reference in the overlay
358  * a node in the base device tree.
360  * This is part of the device tree overlay application process, when
361  * you want all the phandles in the overlay to point to the actual
394 		return -FDT_ERR_NOTFOUND;  in overlay_fixup_one_phandle()
397 	if (fixup_off == -FDT_ERR_NOTFOUND)  in overlay_fixup_one_phandle()
398 		return -FDT_ERR_BADOVERLAY;  in overlay_fixup_one_phandle()
410  * overlay_fixup_phandle - Set an overlay phandle to the base one
411  * @fdt: Base Device Tree blob
412  * @fdto: Device tree overlay blob
413  * @symbols_off: Node offset of the symbols node in the base device tree
414  * @property: Property offset in the overlay holding the list of fixups
417  * to in a __fixups__ property, and updates them to match the phandles
418  * in use in the base device tree.
420  * This is part of the device tree overlay application process, when
421  * you want all the phandles in the overlay to point to the actual
438 		if (len == -FDT_ERR_NOTFOUND)  in overlay_fixup_phandle()
439 			return -FDT_ERR_INTERNAL;  in overlay_fixup_phandle()
454 			return -FDT_ERR_BADOVERLAY;  in overlay_fixup_phandle()
455 		fixup_len = fixup_end - fixup_str;  in overlay_fixup_phandle()
457 		len -= fixup_len + 1;  in overlay_fixup_phandle()
463 			return -FDT_ERR_BADOVERLAY;  in overlay_fixup_phandle()
465 		path_len = sep - path;  in overlay_fixup_phandle()
466 		if (path_len == (fixup_len - 1))  in overlay_fixup_phandle()
467 			return -FDT_ERR_BADOVERLAY;  in overlay_fixup_phandle()
469 		fixup_len -= path_len + 1;  in overlay_fixup_phandle()
473 			return -FDT_ERR_BADOVERLAY;  in overlay_fixup_phandle()
475 		name_len = sep - name;  in overlay_fixup_phandle()
477 			return -FDT_ERR_BADOVERLAY;  in overlay_fixup_phandle()
481 			return -FDT_ERR_BADOVERLAY;  in overlay_fixup_phandle()
494  * overlay_fixup_phandles - Resolve the overlay phandles to the base
495  *                          device tree
496  * @fdt: Base Device Tree blob
497  * @fdto: Device tree overlay blob
500  * to nodes in the base device tree.
502  * This is one of the steps of the device tree overlay application
503  * process, when you want all the phandles in the overlay to point to
517 	if (fixups_off == -FDT_ERR_NOTFOUND)  in overlay_fixup_phandles()
524 	if ((symbols_off < 0 && (symbols_off != -FDT_ERR_NOTFOUND)))  in overlay_fixup_phandles()
539  * overlay_apply_node - Merges a node into the base device tree
540  * @fdt: Base Device Tree blob
541  * @target: Node offset in the base device tree to apply the fragment to
542  * @fdto: Device tree overlay blob
543  * @node: Node offset in the overlay holding the changes to merge
545  * overlay_apply_node() merges a node into a target base device tree
548  * This is part of the final step in the device tree overlay
551  * tree.
571 		if (prop_len == -FDT_ERR_NOTFOUND)  in overlay_apply_node()
572 			return -FDT_ERR_INTERNAL;  in overlay_apply_node()
587 		if (nnode == -FDT_ERR_EXISTS) {  in overlay_apply_node()
589 			if (nnode == -FDT_ERR_NOTFOUND)  in overlay_apply_node()
590 				return -FDT_ERR_INTERNAL;  in overlay_apply_node()
605  * overlay_merge - Merge an overlay into its base device tree
606  * @fdt: Base Device Tree blob
607  * @fdto: Device tree overlay blob
609  * overlay_merge() merges an overlay into its base device tree.
611  * This is the next to last step in the device tree overlay application
613  * you just have to merge overlay into the base device tree.
633 		if (overlay == -FDT_ERR_NOTFOUND)  in overlay_merge()
673 	/* in case of root pretend it's "/" */  in get_path_len()
680  * overlay_symbol_update - Update the symbols of base tree after a merge
681  * @fdt: Base Device Tree blob
682  * @fdto: Device tree overlay blob
684  * overlay_symbol_update() updates the symbols of the base tree with the
687  * This is the last step in the device tree overlay application
717 	if (root_sym == -FDT_ERR_NOTFOUND)  in overlay_symbol_update()
731 		if (path_len < 1 || memchr(path, '\0', path_len) != &path[path_len - 1])  in overlay_symbol_update()
732 			return -FDT_ERR_BADVALUE;  in overlay_symbol_update()
738 			return -FDT_ERR_BADVALUE;  in overlay_symbol_update()
744 			 * up in the target tree */  in overlay_symbol_update()
749 		frag_name_len = s - path - 1;  in overlay_symbol_update()
751 		/* verify format; safe since "s" lies in \0 terminated prop */  in overlay_symbol_update()
752 		len = sizeof("/__overlay__/") - 1;  in overlay_symbol_update()
753 		if ((e - s) > len && (memcmp(s, "/__overlay__/", len) == 0)) {  in overlay_symbol_update()
754 			/* /<fragment-name>/__overlay__/<relative-subnode-path> */  in overlay_symbol_update()
756 			rel_path_len = e - rel_path - 1;  in overlay_symbol_update()
757 		} else if ((e - s) == len  in overlay_symbol_update()
758 			   && (memcmp(s, "/__overlay__", len - 1) == 0)) {  in overlay_symbol_update()
759 			/* /<fragment-name>/__overlay__ */  in overlay_symbol_update()
764 			 * up in the target tree */  in overlay_symbol_update()
768 		/* find the fragment index in which the symbol lies */  in overlay_symbol_update()
773 			return -FDT_ERR_BADOVERLAY;  in overlay_symbol_update()
779 			return -FDT_ERR_BADOVERLAY;  in overlay_symbol_update()
803 			/* again in case setprop_placeholder changed it */  in overlay_symbol_update()
820 			len--;  in overlay_symbol_update()
876 	 * The base device tree might have been damaged, erase its  in fdt_overlay_apply()