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- /*
- * libfdt - Flat Device Tree manipulation
- * Copyright (C) 2016 Free Electrons
- * Copyright (C) 2016 NextThing Co.
- *
- * libfdt is dual licensed: you can use it either under the terms of
- * the GPL, or the BSD license, at your option.
- *
- * a) This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this library; if not, write to the Free
- * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
- * MA 02110-1301 USA
- *
- * Alternatively,
- *
- * b) Redistribution and use in source and binary forms, with or
- * without modification, are permitted provided that the following
- * conditions are met:
- *
- * 1. Redistributions of source code must retain the above
- * copyright notice, this list of conditions and the following
- * disclaimer.
- * 2. Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following
- * disclaimer in the documentation and/or other materials
- * provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
- * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
- * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
- * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
- * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
- #include "libfdt_env.h"
- #include <fdt.h>
- #include <libfdt.h>
- #include "libfdt_internal.h"
- /**
- * overlay_get_target_phandle - retrieves the target phandle of a fragment
- * @fdto: pointer to the device tree overlay blob
- * @fragment: node offset of the fragment in the overlay
- *
- * overlay_get_target_phandle() retrieves the target phandle of an
- * overlay fragment when that fragment uses a phandle (target
- * property) instead of a path (target-path property).
- *
- * returns:
- * the phandle pointed by the target property
- * 0, if the phandle was not found
- * -1, if the phandle was malformed
- */
- static uint32_t
- overlay_get_target_phandle (
- const void *fdto,
- int fragment
- )
- {
- const fdt32_t *val;
- int len;
- val = fdt_getprop (fdto, fragment, "target", &len);
- if (!val) {
- return 0;
- }
- if ((len != sizeof (*val)) || (fdt32_to_cpu (*val) == (uint32_t)-1)) {
- return (uint32_t)-1;
- }
- return fdt32_to_cpu (*val);
- }
- /**
- * overlay_get_target - retrieves the offset of a fragment's target
- * @fdt: Base device tree blob
- * @fdto: Device tree overlay blob
- * @fragment: node offset of the fragment in the overlay
- * @pathp: pointer which receives the path of the target (or NULL)
- *
- * overlay_get_target() retrieves the target offset in the base
- * device tree of a fragment, no matter how the actual targetting is
- * done (through a phandle or a path)
- *
- * returns:
- * the targetted node offset in the base device tree
- * Negative error code on error
- */
- static int
- overlay_get_target (
- const void *fdt,
- const void *fdto,
- int fragment,
- char const **pathp
- )
- {
- uint32_t phandle;
- const char *path = NULL;
- int path_len = 0, ret;
- /* Try first to do a phandle based lookup */
- phandle = overlay_get_target_phandle (fdto, fragment);
- if (phandle == (uint32_t)-1) {
- return -FDT_ERR_BADPHANDLE;
- }
- /* no phandle, try path */
- if (!phandle) {
- /* And then a path based lookup */
- path = fdt_getprop (fdto, fragment, "target-path", &path_len);
- if (path) {
- ret = fdt_path_offset (fdt, path);
- } else {
- ret = path_len;
- }
- } else {
- ret = fdt_node_offset_by_phandle (fdt, phandle);
- }
- /*
- * If we haven't found either a target or a
- * target-path property in a node that contains a
- * __overlay__ subnode (we wouldn't be called
- * otherwise), consider it a improperly written
- * overlay
- */
- if ((ret < 0) && (path_len == -FDT_ERR_NOTFOUND)) {
- ret = -FDT_ERR_BADOVERLAY;
- }
- /* return on error */
- if (ret < 0) {
- return ret;
- }
- /* return pointer to path (if available) */
- if (pathp) {
- *pathp = path ? path : NULL;
- }
- return ret;
- }
- /**
- * overlay_phandle_add_offset - Increases a phandle by an offset
- * @fdt: Base device tree blob
- * @node: Device tree overlay blob
- * @name: Name of the property to modify (phandle or linux,phandle)
- * @delta: offset to apply
- *
- * overlay_phandle_add_offset() increments a node phandle by a given
- * offset.
- *
- * returns:
- * 0 on success.
- * Negative error code on error
- */
- static int
- overlay_phandle_add_offset (
- void *fdt,
- int node,
- const char *name,
- uint32_t delta
- )
- {
- const fdt32_t *val;
- uint32_t adj_val;
- int len;
- val = fdt_getprop (fdt, node, name, &len);
- if (!val) {
- return len;
- }
- if (len != sizeof (*val)) {
- return -FDT_ERR_BADPHANDLE;
- }
- adj_val = fdt32_to_cpu (*val);
- if ((adj_val + delta) < adj_val) {
- return -FDT_ERR_NOPHANDLES;
- }
- adj_val += delta;
- if (adj_val == (uint32_t)-1) {
- return -FDT_ERR_NOPHANDLES;
- }
- return fdt_setprop_inplace_u32 (fdt, node, name, adj_val);
- }
- /**
- * overlay_adjust_node_phandles - Offsets the phandles of a node
- * @fdto: Device tree overlay blob
- * @node: Offset of the node we want to adjust
- * @delta: Offset to shift the phandles of
- *
- * overlay_adjust_node_phandles() adds a constant to all the phandles
- * of a given node. This is mainly use as part of the overlay
- * application process, when we want to update all the overlay
- * phandles to not conflict with the overlays of the base device tree.
- *
- * returns:
- * 0 on success
- * Negative error code on failure
- */
- static int
- overlay_adjust_node_phandles (
- void *fdto,
- int node,
- uint32_t delta
- )
- {
- int child;
- int ret;
- ret = overlay_phandle_add_offset (fdto, node, "phandle", delta);
- if (ret && (ret != -FDT_ERR_NOTFOUND)) {
- return ret;
- }
- ret = overlay_phandle_add_offset (fdto, node, "linux,phandle", delta);
- if (ret && (ret != -FDT_ERR_NOTFOUND)) {
- return ret;
- }
- fdt_for_each_subnode (child, fdto, node) {
- ret = overlay_adjust_node_phandles (fdto, child, delta);
- if (ret) {
- return ret;
- }
- }
- return 0;
- }
- /**
- * overlay_adjust_local_phandles - Adjust the phandles of a whole overlay
- * @fdto: Device tree overlay blob
- * @delta: Offset to shift the phandles of
- *
- * overlay_adjust_local_phandles() adds a constant to all the
- * phandles of an overlay. This is mainly use as part of the overlay
- * application process, when we want to update all the overlay
- * phandles to not conflict with the overlays of the base device tree.
- *
- * returns:
- * 0 on success
- * Negative error code on failure
- */
- static int
- overlay_adjust_local_phandles (
- void *fdto,
- uint32_t delta
- )
- {
- /*
- * Start adjusting the phandles from the overlay root
- */
- return overlay_adjust_node_phandles (fdto, 0, delta);
- }
- /**
- * overlay_update_local_node_references - Adjust the overlay references
- * @fdto: Device tree overlay blob
- * @tree_node: Node offset of the node to operate on
- * @fixup_node: Node offset of the matching local fixups node
- * @delta: Offset to shift the phandles of
- *
- * overlay_update_local_nodes_references() update the phandles
- * pointing to a node within the device tree overlay by adding a
- * constant delta.
- *
- * This is mainly used as part of a device tree application process,
- * where you want the device tree overlays phandles to not conflict
- * with the ones from the base device tree before merging them.
- *
- * returns:
- * 0 on success
- * Negative error code on failure
- */
- static int
- overlay_update_local_node_references (
- void *fdto,
- int tree_node,
- int fixup_node,
- uint32_t delta
- )
- {
- int fixup_prop;
- int fixup_child;
- int ret;
- fdt_for_each_property_offset (fixup_prop, fdto, fixup_node) {
- const fdt32_t *fixup_val;
- const char *tree_val;
- const char *name;
- int fixup_len;
- int tree_len;
- int i;
- fixup_val = fdt_getprop_by_offset (
- fdto,
- fixup_prop,
- &name,
- &fixup_len
- );
- if (!fixup_val) {
- return fixup_len;
- }
- if (fixup_len % sizeof (uint32_t)) {
- return -FDT_ERR_BADOVERLAY;
- }
- tree_val = fdt_getprop (fdto, tree_node, name, &tree_len);
- if (!tree_val) {
- if (tree_len == -FDT_ERR_NOTFOUND) {
- return -FDT_ERR_BADOVERLAY;
- }
- return tree_len;
- }
- for (i = 0; i < (fixup_len / sizeof (uint32_t)); i++) {
- fdt32_t adj_val;
- uint32_t poffset;
- poffset = fdt32_to_cpu (fixup_val[i]);
- /*
- * phandles to fixup can be unaligned.
- *
- * Use a memcpy for the architectures that do
- * not support unaligned accesses.
- */
- memcpy (&adj_val, tree_val + poffset, sizeof (adj_val));
- adj_val = cpu_to_fdt32 (fdt32_to_cpu (adj_val) + delta);
- ret = fdt_setprop_inplace_namelen_partial (
- fdto,
- tree_node,
- name,
- strlen (name),
- poffset,
- &adj_val,
- sizeof (adj_val)
- );
- if (ret == -FDT_ERR_NOSPACE) {
- return -FDT_ERR_BADOVERLAY;
- }
- if (ret) {
- return ret;
- }
- }
- }
- fdt_for_each_subnode (fixup_child, fdto, fixup_node) {
- const char *fixup_child_name = fdt_get_name (
- fdto,
- fixup_child,
- NULL
- );
- int tree_child;
- tree_child = fdt_subnode_offset (
- fdto,
- tree_node,
- fixup_child_name
- );
- if (tree_child == -FDT_ERR_NOTFOUND) {
- return -FDT_ERR_BADOVERLAY;
- }
- if (tree_child < 0) {
- return tree_child;
- }
- ret = overlay_update_local_node_references (
- fdto,
- tree_child,
- fixup_child,
- delta
- );
- if (ret) {
- return ret;
- }
- }
- return 0;
- }
- /**
- * overlay_update_local_references - Adjust the overlay references
- * @fdto: Device tree overlay blob
- * @delta: Offset to shift the phandles of
- *
- * overlay_update_local_references() update all the phandles pointing
- * to a node within the device tree overlay by adding a constant
- * delta to not conflict with the base overlay.
- *
- * This is mainly used as part of a device tree application process,
- * where you want the device tree overlays phandles to not conflict
- * with the ones from the base device tree before merging them.
- *
- * returns:
- * 0 on success
- * Negative error code on failure
- */
- static int
- overlay_update_local_references (
- void *fdto,
- uint32_t delta
- )
- {
- int fixups;
- fixups = fdt_path_offset (fdto, "/__local_fixups__");
- if (fixups < 0) {
- /* There's no local phandles to adjust, bail out */
- if (fixups == -FDT_ERR_NOTFOUND) {
- return 0;
- }
- return fixups;
- }
- /*
- * Update our local references from the root of the tree
- */
- return overlay_update_local_node_references (
- fdto,
- 0,
- fixups,
- delta
- );
- }
- /**
- * overlay_fixup_one_phandle - Set an overlay phandle to the base one
- * @fdt: Base Device Tree blob
- * @fdto: Device tree overlay blob
- * @symbols_off: Node offset of the symbols node in the base device tree
- * @path: Path to a node holding a phandle in the overlay
- * @path_len: number of path characters to consider
- * @name: Name of the property holding the phandle reference in the overlay
- * @name_len: number of name characters to consider
- * @poffset: Offset within the overlay property where the phandle is stored
- * @label: Label of the node referenced by the phandle
- *
- * overlay_fixup_one_phandle() resolves an overlay phandle pointing to
- * a node in the base device tree.
- *
- * This is part of the device tree overlay application process, when
- * you want all the phandles in the overlay to point to the actual
- * base dt nodes.
- *
- * returns:
- * 0 on success
- * Negative error code on failure
- */
- static int
- overlay_fixup_one_phandle (
- void *fdt,
- void *fdto,
- int symbols_off,
- const char *path,
- uint32_t path_len,
- const char *name,
- uint32_t name_len,
- int poffset,
- const char *label
- )
- {
- const char *symbol_path;
- uint32_t phandle;
- fdt32_t phandle_prop;
- int symbol_off, fixup_off;
- int prop_len;
- if (symbols_off < 0) {
- return symbols_off;
- }
- symbol_path = fdt_getprop (
- fdt,
- symbols_off,
- label,
- &prop_len
- );
- if (!symbol_path) {
- return prop_len;
- }
- symbol_off = fdt_path_offset (fdt, symbol_path);
- if (symbol_off < 0) {
- return symbol_off;
- }
- phandle = fdt_get_phandle (fdt, symbol_off);
- if (!phandle) {
- return -FDT_ERR_NOTFOUND;
- }
- fixup_off = fdt_path_offset_namelen (fdto, path, path_len);
- if (fixup_off == -FDT_ERR_NOTFOUND) {
- return -FDT_ERR_BADOVERLAY;
- }
- if (fixup_off < 0) {
- return fixup_off;
- }
- phandle_prop = cpu_to_fdt32 (phandle);
- return fdt_setprop_inplace_namelen_partial (
- fdto,
- fixup_off,
- name,
- name_len,
- poffset,
- &phandle_prop,
- sizeof (phandle_prop)
- );
- }
- unsigned long
- strtoul (
- const char *nptr,
- char **endptr,
- int base
- );
- /**
- * overlay_fixup_phandle - Set an overlay phandle to the base one
- * @fdt: Base Device Tree blob
- * @fdto: Device tree overlay blob
- * @symbols_off: Node offset of the symbols node in the base device tree
- * @property: Property offset in the overlay holding the list of fixups
- *
- * overlay_fixup_phandle() resolves all the overlay phandles pointed
- * to in a __fixups__ property, and updates them to match the phandles
- * in use in the base device tree.
- *
- * This is part of the device tree overlay application process, when
- * you want all the phandles in the overlay to point to the actual
- * base dt nodes.
- *
- * returns:
- * 0 on success
- * Negative error code on failure
- */
- static int
- overlay_fixup_phandle (
- void *fdt,
- void *fdto,
- int symbols_off,
- int property
- )
- {
- const char *value;
- const char *label;
- int len;
- value = fdt_getprop_by_offset (
- fdto,
- property,
- &label,
- &len
- );
- if (!value) {
- if (len == -FDT_ERR_NOTFOUND) {
- return -FDT_ERR_INTERNAL;
- }
- return len;
- }
- do {
- const char *path, *name, *fixup_end;
- const char *fixup_str = value;
- uint32_t path_len, name_len;
- uint32_t fixup_len;
- char *sep, *endptr;
- int poffset, ret;
- fixup_end = memchr (value, '\0', len);
- if (!fixup_end) {
- return -FDT_ERR_BADOVERLAY;
- }
- fixup_len = fixup_end - fixup_str;
- len -= fixup_len + 1;
- value += fixup_len + 1;
- path = fixup_str;
- sep = memchr (fixup_str, ':', fixup_len);
- if (!sep || (*sep != ':')) {
- return -FDT_ERR_BADOVERLAY;
- }
- path_len = sep - path;
- if (path_len == (fixup_len - 1)) {
- return -FDT_ERR_BADOVERLAY;
- }
- fixup_len -= path_len + 1;
- name = sep + 1;
- sep = memchr (name, ':', fixup_len);
- if (!sep || (*sep != ':')) {
- return -FDT_ERR_BADOVERLAY;
- }
- name_len = sep - name;
- if (!name_len) {
- return -FDT_ERR_BADOVERLAY;
- }
- poffset = strtoul (sep + 1, &endptr, 10);
- if ((*endptr != '\0') || (endptr <= (sep + 1))) {
- return -FDT_ERR_BADOVERLAY;
- }
- ret = overlay_fixup_one_phandle (
- fdt,
- fdto,
- symbols_off,
- path,
- path_len,
- name,
- name_len,
- poffset,
- label
- );
- if (ret) {
- return ret;
- }
- } while (len > 0);
- return 0;
- }
- /**
- * overlay_fixup_phandles - Resolve the overlay phandles to the base
- * device tree
- * @fdt: Base Device Tree blob
- * @fdto: Device tree overlay blob
- *
- * overlay_fixup_phandles() resolves all the overlay phandles pointing
- * to nodes in the base device tree.
- *
- * This is one of the steps of the device tree overlay application
- * process, when you want all the phandles in the overlay to point to
- * the actual base dt nodes.
- *
- * returns:
- * 0 on success
- * Negative error code on failure
- */
- static int
- overlay_fixup_phandles (
- void *fdt,
- void *fdto
- )
- {
- int fixups_off, symbols_off;
- int property;
- /* We can have overlays without any fixups */
- fixups_off = fdt_path_offset (fdto, "/__fixups__");
- if (fixups_off == -FDT_ERR_NOTFOUND) {
- return 0; /* nothing to do */
- }
- if (fixups_off < 0) {
- return fixups_off;
- }
- /* And base DTs without symbols */
- symbols_off = fdt_path_offset (fdt, "/__symbols__");
- if (((symbols_off < 0) && (symbols_off != -FDT_ERR_NOTFOUND))) {
- return symbols_off;
- }
- fdt_for_each_property_offset (property, fdto, fixups_off) {
- int ret;
- ret = overlay_fixup_phandle (fdt, fdto, symbols_off, property);
- if (ret) {
- return ret;
- }
- }
- return 0;
- }
- /**
- * overlay_apply_node - Merges a node into the base device tree
- * @fdt: Base Device Tree blob
- * @target: Node offset in the base device tree to apply the fragment to
- * @fdto: Device tree overlay blob
- * @node: Node offset in the overlay holding the changes to merge
- *
- * overlay_apply_node() merges a node into a target base device tree
- * node pointed.
- *
- * This is part of the final step in the device tree overlay
- * application process, when all the phandles have been adjusted and
- * resolved and you just have to merge overlay into the base device
- * tree.
- *
- * returns:
- * 0 on success
- * Negative error code on failure
- */
- static int
- overlay_apply_node (
- void *fdt,
- int target,
- void *fdto,
- int node
- )
- {
- int property;
- int subnode;
- fdt_for_each_property_offset (property, fdto, node) {
- const char *name;
- const void *prop;
- int prop_len;
- int ret;
- prop = fdt_getprop_by_offset (
- fdto,
- property,
- &name,
- &prop_len
- );
- if (prop_len == -FDT_ERR_NOTFOUND) {
- return -FDT_ERR_INTERNAL;
- }
- if (prop_len < 0) {
- return prop_len;
- }
- ret = fdt_setprop (fdt, target, name, prop, prop_len);
- if (ret) {
- return ret;
- }
- }
- fdt_for_each_subnode (subnode, fdto, node) {
- const char *name = fdt_get_name (fdto, subnode, NULL);
- int nnode;
- int ret;
- nnode = fdt_add_subnode (fdt, target, name);
- if (nnode == -FDT_ERR_EXISTS) {
- nnode = fdt_subnode_offset (fdt, target, name);
- if (nnode == -FDT_ERR_NOTFOUND) {
- return -FDT_ERR_INTERNAL;
- }
- }
- if (nnode < 0) {
- return nnode;
- }
- ret = overlay_apply_node (fdt, nnode, fdto, subnode);
- if (ret) {
- return ret;
- }
- }
- return 0;
- }
- /**
- * overlay_merge - Merge an overlay into its base device tree
- * @fdt: Base Device Tree blob
- * @fdto: Device tree overlay blob
- *
- * overlay_merge() merges an overlay into its base device tree.
- *
- * This is the next to last step in the device tree overlay application
- * process, when all the phandles have been adjusted and resolved and
- * you just have to merge overlay into the base device tree.
- *
- * returns:
- * 0 on success
- * Negative error code on failure
- */
- static int
- overlay_merge (
- void *fdt,
- void *fdto
- )
- {
- int fragment;
- fdt_for_each_subnode (fragment, fdto, 0) {
- int overlay;
- int target;
- int ret;
- /*
- * Each fragments will have an __overlay__ node. If
- * they don't, it's not supposed to be merged
- */
- overlay = fdt_subnode_offset (fdto, fragment, "__overlay__");
- if (overlay == -FDT_ERR_NOTFOUND) {
- continue;
- }
- if (overlay < 0) {
- return overlay;
- }
- target = overlay_get_target (fdt, fdto, fragment, NULL);
- if (target < 0) {
- return target;
- }
- ret = overlay_apply_node (fdt, target, fdto, overlay);
- if (ret) {
- return ret;
- }
- }
- return 0;
- }
- static int
- get_path_len (
- const void *fdt,
- int nodeoffset
- )
- {
- int len = 0, namelen;
- const char *name;
- FDT_CHECK_HEADER (fdt);
- for ( ; ;) {
- name = fdt_get_name (fdt, nodeoffset, &namelen);
- if (!name) {
- return namelen;
- }
- /* root? we're done */
- if (namelen == 0) {
- break;
- }
- nodeoffset = fdt_parent_offset (fdt, nodeoffset);
- if (nodeoffset < 0) {
- return nodeoffset;
- }
- len += namelen + 1;
- }
- /* in case of root pretend it's "/" */
- if (len == 0) {
- len++;
- }
- return len;
- }
- /**
- * overlay_symbol_update - Update the symbols of base tree after a merge
- * @fdt: Base Device Tree blob
- * @fdto: Device tree overlay blob
- *
- * overlay_symbol_update() updates the symbols of the base tree with the
- * symbols of the applied overlay
- *
- * This is the last step in the device tree overlay application
- * process, allowing the reference of overlay symbols by subsequent
- * overlay operations.
- *
- * returns:
- * 0 on success
- * Negative error code on failure
- */
- static int
- overlay_symbol_update (
- void *fdt,
- void *fdto
- )
- {
- int root_sym, ov_sym, prop, path_len, fragment, target;
- int len, frag_name_len, ret, rel_path_len;
- const char *s, *e;
- const char *path;
- const char *name;
- const char *frag_name;
- const char *rel_path;
- const char *target_path;
- char *buf;
- void *p;
- ov_sym = fdt_subnode_offset (fdto, 0, "__symbols__");
- /* if no overlay symbols exist no problem */
- if (ov_sym < 0) {
- return 0;
- }
- root_sym = fdt_subnode_offset (fdt, 0, "__symbols__");
- /* it no root symbols exist we should create them */
- if (root_sym == -FDT_ERR_NOTFOUND) {
- root_sym = fdt_add_subnode (fdt, 0, "__symbols__");
- }
- /* any error is fatal now */
- if (root_sym < 0) {
- return root_sym;
- }
- /* iterate over each overlay symbol */
- fdt_for_each_property_offset (prop, fdto, ov_sym) {
- path = fdt_getprop_by_offset (fdto, prop, &name, &path_len);
- if (!path) {
- return path_len;
- }
- /* verify it's a string property (terminated by a single \0) */
- if ((path_len < 1) || (memchr (path, '\0', path_len) != &path[path_len - 1])) {
- return -FDT_ERR_BADVALUE;
- }
- /* keep end marker to avoid strlen() */
- e = path + path_len;
- /* format: /<fragment-name>/__overlay__/<relative-subnode-path> */
- if (*path != '/') {
- return -FDT_ERR_BADVALUE;
- }
- /* get fragment name first */
- s = strchr (path + 1, '/');
- if (!s) {
- return -FDT_ERR_BADOVERLAY;
- }
- frag_name = path + 1;
- frag_name_len = s - path - 1;
- /* verify format; safe since "s" lies in \0 terminated prop */
- len = sizeof ("/__overlay__/") - 1;
- if (((e - s) < len) || memcmp (s, "/__overlay__/", len)) {
- return -FDT_ERR_BADOVERLAY;
- }
- rel_path = s + len;
- rel_path_len = e - rel_path;
- /* find the fragment index in which the symbol lies */
- ret = fdt_subnode_offset_namelen (
- fdto,
- 0,
- frag_name,
- frag_name_len
- );
- /* not found? */
- if (ret < 0) {
- return -FDT_ERR_BADOVERLAY;
- }
- fragment = ret;
- /* an __overlay__ subnode must exist */
- ret = fdt_subnode_offset (fdto, fragment, "__overlay__");
- if (ret < 0) {
- return -FDT_ERR_BADOVERLAY;
- }
- /* get the target of the fragment */
- ret = overlay_get_target (fdt, fdto, fragment, &target_path);
- if (ret < 0) {
- return ret;
- }
- target = ret;
- /* if we have a target path use */
- if (!target_path) {
- ret = get_path_len (fdt, target);
- if (ret < 0) {
- return ret;
- }
- len = ret;
- } else {
- len = strlen (target_path);
- }
- ret = fdt_setprop_placeholder (
- fdt,
- root_sym,
- name,
- len + (len > 1) + rel_path_len + 1,
- &p
- );
- if (ret < 0) {
- return ret;
- }
- if (!target_path) {
- /* again in case setprop_placeholder changed it */
- ret = overlay_get_target (fdt, fdto, fragment, &target_path);
- if (ret < 0) {
- return ret;
- }
- target = ret;
- }
- buf = p;
- if (len > 1) {
- /* target is not root */
- if (!target_path) {
- ret = fdt_get_path (fdt, target, buf, len + 1);
- if (ret < 0) {
- return ret;
- }
- } else {
- memcpy (buf, target_path, len + 1);
- }
- } else {
- len--;
- }
- buf[len] = '/';
- memcpy (buf + len + 1, rel_path, rel_path_len);
- buf[len + 1 + rel_path_len] = '\0';
- }
- return 0;
- }
- int
- fdt_overlay_apply (
- void *fdt,
- void *fdto
- )
- {
- uint32_t delta = fdt_get_max_phandle (fdt);
- int ret;
- FDT_CHECK_HEADER (fdt);
- FDT_CHECK_HEADER (fdto);
- ret = overlay_adjust_local_phandles (fdto, delta);
- if (ret) {
- goto err;
- }
- ret = overlay_update_local_references (fdto, delta);
- if (ret) {
- goto err;
- }
- ret = overlay_fixup_phandles (fdt, fdto);
- if (ret) {
- goto err;
- }
- ret = overlay_merge (fdt, fdto);
- if (ret) {
- goto err;
- }
- ret = overlay_symbol_update (fdt, fdto);
- if (ret) {
- goto err;
- }
- /*
- * The overlay has been damaged, erase its magic.
- */
- fdt_set_magic (fdto, ~0);
- return 0;
- err:
- /*
- * The overlay might have been damaged, erase its magic.
- */
- fdt_set_magic (fdto, ~0);
- /*
- * The base device tree might have been damaged, erase its
- * magic.
- */
- fdt_set_magic (fdt, ~0);
- return ret;
- }
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