/* | |
* 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; | |
} |