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()
52 	if (phandle == (uint32_t)-1)  in fdt_overlay_target_offset()
53 		return -FDT_ERR_BADPHANDLE;  in fdt_overlay_target_offset()
58 		path = fdt_getprop(fdto, fragment_offset, "target-path", &path_len);  in fdt_overlay_target_offset()
68 	* target-path property in a node that contains a  in fdt_overlay_target_offset()
73 	if (ret < 0 && path_len == -FDT_ERR_NOTFOUND)  in fdt_overlay_target_offset()
74 		ret = -FDT_ERR_BADOVERLAY;  in fdt_overlay_target_offset()
88  * overlay_phandle_add_offset - Increases a phandle by an offset
89  * @fdt: Base device tree blob
90  * @node: Device tree overlay blob
112 		return -FDT_ERR_BADPHANDLE;  in overlay_phandle_add_offset()
115 	if (val + delta < val || val + delta == (uint32_t)-1)  in overlay_phandle_add_offset()
116 		return -FDT_ERR_NOPHANDLES;  in overlay_phandle_add_offset()
123  * overlay_adjust_node_phandles - Offsets the phandles of a node
124  * @fdto: Device tree overlay blob
131  * phandles to not conflict with the overlays of the base device tree.
144 	if (ret && ret != -FDT_ERR_NOTFOUND)  in overlay_adjust_node_phandles()
148 	if (ret && ret != -FDT_ERR_NOTFOUND)  in overlay_adjust_node_phandles()
161  * overlay_adjust_local_phandles - Adjust the phandles of a whole overlay
162  * @fdto: Device tree overlay blob
168  * phandles to not conflict with the overlays of the base device tree.
183  * overlay_update_local_node_references - Adjust the overlay references
184  * @fdto: Device tree overlay blob
190  * pointing to a node within the device tree overlay by adding a
193  * This is mainly used as part of a device tree application process,
194  * where you want the device tree overlays phandles to not conflict
195  * with the ones from the base device tree before merging them.
224 			return -FDT_ERR_BADOVERLAY;  in overlay_update_local_node_references()
229 			if (tree_len == -FDT_ERR_NOTFOUND)  in overlay_update_local_node_references()
230 				return -FDT_ERR_BADOVERLAY;  in overlay_update_local_node_references()
255 		if (tree_child == -FDT_ERR_NOTFOUND)  in overlay_update_local_node_references()
256 			return -FDT_ERR_BADOVERLAY;  in overlay_update_local_node_references()
272  * overlay_update_local_references - Adjust the overlay references
273  * @fdto: Device tree overlay blob
277  * to a node within the device tree overlay by adding a constant
280  * This is mainly used as part of a device tree application process,
281  * where you want the device tree overlays phandles to not conflict
282  * with the ones from the base device tree before merging them.
295 		if (fixups == -FDT_ERR_NOTFOUND)  in overlay_update_local_references()
302 	 * Update our local references from the root of the tree  in overlay_update_local_references()
309  * overlay_fixup_one_phandle - Set an overlay phandle to the base one
310  * @fdt: Base Device Tree blob
311  * @fdto: Device tree overlay blob
312  * @symbols_off: Node offset of the symbols node in the base device tree
313  * @path: Path to a node holding a phandle in the overlay
315  * @name: Name of the property holding the phandle reference in the overlay
321  * a node in the base device tree.
323  * This is part of the device tree overlay application process, when
324  * you want all the phandles in the overlay to point to the actual
344 	if (fixup_off == -FDT_ERR_NOTFOUND)  in overlay_fixup_one_phandle()
345 		return -FDT_ERR_BADOVERLAY;  in overlay_fixup_one_phandle()
357  * overlay_fixup_phandle - Set an overlay phandle to the base one
358  * @fdt: Base Device Tree blob
359  * @fdto: Device tree overlay blob
360  * @symbols_off: Node offset of the symbols node in the base device tree
361  * @property: Property offset in the overlay holding the list of fixups
364  * to in a __fixups__ property, and updates them to match the phandles
365  * in use in the base device tree.
367  * This is part of the device tree overlay application process, when
368  * you want all the phandles in the overlay to point to the actual
389 		if (len == -FDT_ERR_NOTFOUND)  in overlay_fixup_phandle()
390 			return -FDT_ERR_INTERNAL;  in overlay_fixup_phandle()
405 		return -FDT_ERR_NOTFOUND;  in overlay_fixup_phandle()
417 			return -FDT_ERR_BADOVERLAY;  in overlay_fixup_phandle()
418 		fixup_len = fixup_end - fixup_str;  in overlay_fixup_phandle()
420 		len -= fixup_len + 1;  in overlay_fixup_phandle()
426 			return -FDT_ERR_BADOVERLAY;  in overlay_fixup_phandle()
428 		path_len = sep - path;  in overlay_fixup_phandle()
429 		if (path_len == (fixup_len - 1))  in overlay_fixup_phandle()
430 			return -FDT_ERR_BADOVERLAY;  in overlay_fixup_phandle()
432 		fixup_len -= path_len + 1;  in overlay_fixup_phandle()
436 			return -FDT_ERR_BADOVERLAY;  in overlay_fixup_phandle()
438 		name_len = sep - name;  in overlay_fixup_phandle()
440 			return -FDT_ERR_BADOVERLAY;  in overlay_fixup_phandle()
444 			return -FDT_ERR_BADOVERLAY;  in overlay_fixup_phandle()
457  * overlay_fixup_phandles - Resolve the overlay phandles to the base
458  *                          device tree
459  * @fdt: Base Device Tree blob
460  * @fdto: Device tree overlay blob
463  * to nodes in the base device tree.
465  * This is one of the steps of the device tree overlay application
466  * process, when you want all the phandles in the overlay to point to
480 	if (fixups_off == -FDT_ERR_NOTFOUND)  in overlay_fixup_phandles()
487 	if ((symbols_off < 0 && (symbols_off != -FDT_ERR_NOTFOUND)))  in overlay_fixup_phandles()
503  * @fdto: Device tree overlay
535  * overlay_update_node_conflicting_references - Recursively replace phandle values
536  * @fdto: Device tree overlay blob
571 			return -FDT_ERR_BADOVERLAY;  in overlay_update_node_conflicting_references()
576 			if (tree_len == -FDT_ERR_NOTFOUND)  in overlay_update_node_conflicting_references()
577 				return -FDT_ERR_BADOVERLAY;  in overlay_update_node_conflicting_references()
600 		if (tree_child == -FDT_ERR_NOTFOUND)  in overlay_update_node_conflicting_references()
601 			return -FDT_ERR_BADOVERLAY;  in overlay_update_node_conflicting_references()
617  * overlay_update_local_conflicting_references - Recursively replace phandle values
618  * @fdto: Device tree overlay blob
635 	if (fixups == -FDT_ERR_NOTFOUND)  in overlay_update_local_conflicting_references()
646  * overlay_prevent_phandle_overwrite_node - Helper function for overlay_prevent_phandle_overwrite
647  * @fdt: Base Device tree blob
648  * @fdtnode: Node in fdt that is checked for an overwrite
649  * @fdto: Device tree overlay blob
650  * @fdtonode: Node in fdto matching @fdtnode
686 		if (fdtchild == -FDT_ERR_NOTFOUND)  in overlay_prevent_phandle_overwrite_node()
703  * overlay_prevent_phandle_overwrite - Fixes overlay phandles to not overwrite base phandles
704  * @fdt: Base Device Tree blob
705  * @fdto: Device tree overlay blob
707  * Checks recursively if applying fdto overwrites phandle values in the base
709  * phandle value to not break references in the base.
725 		if (overlay == -FDT_ERR_NOTFOUND)  in overlay_prevent_phandle_overwrite()
732 		if (target == -FDT_ERR_NOTFOUND)  in overlay_prevent_phandle_overwrite()
734 			 * The subtree doesn't exist in the base, so nothing  in overlay_prevent_phandle_overwrite()
751  * overlay_apply_node - Merges a node into the base device tree
752  * @fdt: Base Device Tree blob
753  * @target: Node offset in the base device tree to apply the fragment to
754  * @fdto: Device tree overlay blob
755  * @node: Node offset in the overlay holding the changes to merge
757  * overlay_apply_node() merges a node into a target base device tree
760  * This is part of the final step in the device tree overlay
763  * tree.
783 		if (prop_len == -FDT_ERR_NOTFOUND)  in overlay_apply_node()
784 			return -FDT_ERR_INTERNAL;  in overlay_apply_node()
799 		if (nnode == -FDT_ERR_EXISTS) {  in overlay_apply_node()
801 			if (nnode == -FDT_ERR_NOTFOUND)  in overlay_apply_node()
802 				return -FDT_ERR_INTERNAL;  in overlay_apply_node()
817  * overlay_merge - Merge an overlay into its base device tree
818  * @fdt: Base Device Tree blob
819  * @fdto: Device tree overlay blob
821  * overlay_merge() merges an overlay into its base device tree.
823  * This is the next to last step in the device tree overlay application
825  * you just have to merge overlay into the base device tree.
845 		if (overlay == -FDT_ERR_NOTFOUND)  in overlay_merge()
885 	/* in case of root pretend it's "/" */  in get_path_len()
892  * overlay_symbol_update - Update the symbols of base tree after a merge
893  * @fdt: Base Device Tree blob
894  * @fdto: Device tree overlay blob
896  * overlay_symbol_update() updates the symbols of the base tree with the
899  * This is the last step in the device tree overlay application
929 	if (root_sym == -FDT_ERR_NOTFOUND)  in overlay_symbol_update()
943 		if (path_len < 1 || memchr(path, '\0', path_len) != &path[path_len - 1])  in overlay_symbol_update()
944 			return -FDT_ERR_BADVALUE;  in overlay_symbol_update()
950 			return -FDT_ERR_BADVALUE;  in overlay_symbol_update()
956 			 * up in the target tree */  in overlay_symbol_update()
961 		frag_name_len = s - path - 1;  in overlay_symbol_update()
963 		/* verify format; safe since "s" lies in \0 terminated prop */  in overlay_symbol_update()
964 		len = sizeof("/__overlay__/") - 1;  in overlay_symbol_update()
965 		if ((e - s) > len && (memcmp(s, "/__overlay__/", len) == 0)) {  in overlay_symbol_update()
966 			/* /<fragment-name>/__overlay__/<relative-subnode-path> */  in overlay_symbol_update()
968 			rel_path_len = e - rel_path - 1;  in overlay_symbol_update()
969 		} else if ((e - s) == len  in overlay_symbol_update()
970 			   && (memcmp(s, "/__overlay__", len - 1) == 0)) {  in overlay_symbol_update()
971 			/* /<fragment-name>/__overlay__ */  in overlay_symbol_update()
976 			 * up in the target tree */  in overlay_symbol_update()
980 		/* find the fragment index in which the symbol lies */  in overlay_symbol_update()
985 			return -FDT_ERR_BADOVERLAY;  in overlay_symbol_update()
991 			return -FDT_ERR_BADOVERLAY;  in overlay_symbol_update()
1015 			/* again in case setprop_placeholder changed it */  in overlay_symbol_update()
1032 			len--;  in overlay_symbol_update()
1054 	/* Increase all phandles in the fdto by delta */  in fdt_overlay_apply()
1059 	/* Adapt the phandle values in fdto to the above increase */  in fdt_overlay_apply()
1069 	/* Don't overwrite phandles in fdt */  in fdt_overlay_apply()
1096 	 * The base device tree might have been damaged, erase its  in fdt_overlay_apply()