[U-Boot] [PATCH 1/3] dtc: libfdt: import fdt_addresses.c and fdt_overlay.c
Masahiro Yamada
yamada.masahiro at socionext.com
Tue Oct 17 01:11:41 UTC 2017
I will move the pylibfdt build script under the scripts/dtc/ in the
next commit. We need two more files to build the pylibfdt.
We have almost same copies in lib/libfdt, but we are collecting all
DTC-derived files into scripts/dtc.
Import fdt_addresses.c and fdt_overlay.c from DTC v1.4.5.
Signed-off-by: Masahiro Yamada <yamada.masahiro at socionext.com>
---
scripts/dtc/libfdt/fdt_addresses.c | 96 +++++
scripts/dtc/libfdt/fdt_overlay.c | 861 +++++++++++++++++++++++++++++++++++++
2 files changed, 957 insertions(+)
create mode 100644 scripts/dtc/libfdt/fdt_addresses.c
create mode 100644 scripts/dtc/libfdt/fdt_overlay.c
diff --git a/scripts/dtc/libfdt/fdt_addresses.c b/scripts/dtc/libfdt/fdt_addresses.c
new file mode 100644
index 0000000..eff4dbc
--- /dev/null
+++ b/scripts/dtc/libfdt/fdt_addresses.c
@@ -0,0 +1,96 @@
+/*
+ * libfdt - Flat Device Tree manipulation
+ * Copyright (C) 2014 David Gibson <david at gibson.dropbear.id.au>
+ *
+ * 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"
+
+int fdt_address_cells(const void *fdt, int nodeoffset)
+{
+ const fdt32_t *ac;
+ int val;
+ int len;
+
+ ac = fdt_getprop(fdt, nodeoffset, "#address-cells", &len);
+ if (!ac)
+ return 2;
+
+ if (len != sizeof(*ac))
+ return -FDT_ERR_BADNCELLS;
+
+ val = fdt32_to_cpu(*ac);
+ if ((val <= 0) || (val > FDT_MAX_NCELLS))
+ return -FDT_ERR_BADNCELLS;
+
+ return val;
+}
+
+int fdt_size_cells(const void *fdt, int nodeoffset)
+{
+ const fdt32_t *sc;
+ int val;
+ int len;
+
+ sc = fdt_getprop(fdt, nodeoffset, "#size-cells", &len);
+ if (!sc)
+ return 2;
+
+ if (len != sizeof(*sc))
+ return -FDT_ERR_BADNCELLS;
+
+ val = fdt32_to_cpu(*sc);
+ if ((val < 0) || (val > FDT_MAX_NCELLS))
+ return -FDT_ERR_BADNCELLS;
+
+ return val;
+}
diff --git a/scripts/dtc/libfdt/fdt_overlay.c b/scripts/dtc/libfdt/fdt_overlay.c
new file mode 100644
index 0000000..bd81241
--- /dev/null
+++ b/scripts/dtc/libfdt/fdt_overlay.c
@@ -0,0 +1,861 @@
+#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));
+};
+
+/**
+ * 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;
+}
--
2.7.4
More information about the U-Boot
mailing list