treewide: Move device_tree to commonlib
Signed-off-by: Maximilian Brune <maximilian.brune@9elements.com>
Change-Id: I990d74d9fff06b17ec8a6ee962955e4b0df8b907
Reviewed-on: https://review.coreboot.org/c/coreboot/+/77970
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/commonlib/device_tree.c b/src/commonlib/device_tree.c
new file mode 100644
index 0000000..f70aaf7
--- /dev/null
+++ b/src/commonlib/device_tree.c
@@ -0,0 +1,2018 @@
+/* Taken from depthcharge: src/base/device_tree.c */
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <assert.h>
+#include <commonlib/device_tree.h>
+#include <ctype.h>
+#include <endian.h>
+#include <stdbool.h>
+#include <stdint.h>
+#ifdef __COREBOOT__
+#include <console/console.h>
+#else
+#include <stdio.h>
+#define printk(level, ...) printf(__VA_ARGS__)
+#endif
+#include <stdio.h>
+#include <string.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <limits.h>
+
+#define FDT_PATH_MAX_DEPTH 10 // should be a good enough upper bound
+#define FDT_PATH_MAX_LEN 128 // should be a good enough upper bound
+#define FDT_MAX_MEMORY_NODES 4 // should be a good enough upper bound
+#define FDT_MAX_MEMORY_REGIONS 16 // should be a good enough upper bound
+
+/*
+ * Functions for picking apart flattened trees.
+ */
+
+static int fdt_skip_nops(const void *blob, uint32_t offset)
+{
+ uint32_t *ptr = (uint32_t *)(((uint8_t *)blob) + offset);
+
+ int index = 0;
+ while (be32toh(ptr[index]) == FDT_TOKEN_NOP)
+ index++;
+
+ return index * sizeof(uint32_t);
+}
+
+int fdt_next_property(const void *blob, uint32_t offset,
+ struct fdt_property *prop)
+{
+ struct fdt_header *header = (struct fdt_header *)blob;
+ uint32_t *ptr = (uint32_t *)(((uint8_t *)blob) + offset);
+
+ // skip NOP tokens
+ offset += fdt_skip_nops(blob, offset);
+
+ int index = 0;
+ if (be32toh(ptr[index++]) != FDT_TOKEN_PROPERTY)
+ return 0;
+
+ uint32_t size = be32toh(ptr[index++]);
+ uint32_t name_offset = be32toh(ptr[index++]);
+ name_offset += be32toh(header->strings_offset);
+
+ if (prop) {
+ prop->name = (char *)((uint8_t *)blob + name_offset);
+ prop->data = &ptr[index];
+ prop->size = size;
+ }
+
+ index += DIV_ROUND_UP(size, sizeof(uint32_t));
+
+ return index * sizeof(uint32_t);
+}
+
+/*
+ * fdt_next_node_name reads a node name
+ *
+ * @params blob address of FDT
+ * @params offset offset to the node to read the name from
+ * @params name parameter to hold the name that has been read or NULL
+ *
+ * @returns Either 0 on error or offset to the properties that come after the node name
+ */
+int fdt_next_node_name(const void *blob, uint32_t offset, const char **name)
+{
+ // skip NOP tokens
+ offset += fdt_skip_nops(blob, offset);
+
+ char *ptr = ((char *)blob) + offset;
+ if (be32dec(ptr) != FDT_TOKEN_BEGIN_NODE)
+ return 0;
+
+ ptr += 4;
+ if (name)
+ *name = ptr;
+
+ return ALIGN_UP(strlen(ptr) + 1, 4) + 4;
+}
+
+/*
+ * A utility function to skip past nodes in flattened trees.
+ */
+int fdt_skip_node(const void *blob, uint32_t start_offset)
+{
+ uint32_t offset = start_offset;
+
+ const char *name;
+ int size = fdt_next_node_name(blob, offset, &name);
+ if (!size)
+ return 0;
+ offset += size;
+
+ while ((size = fdt_next_property(blob, offset, NULL)))
+ offset += size;
+
+ while ((size = fdt_skip_node(blob, offset)))
+ offset += size;
+
+ // skip NOP tokens
+ offset += fdt_skip_nops(blob, offset);
+
+ return offset - start_offset + sizeof(uint32_t);
+}
+
+/*
+ * fdt_read_prop reads a property inside a node
+ *
+ * @params blob address of FDT
+ * @params node_offset offset to the node to read the property from
+ * @params prop_name name of the property to read
+ * @params fdt_prop property is saved inside this parameter
+ *
+ * @returns Either 0 if no property has been found or an offset that points to the location
+ * of the property
+ */
+u32 fdt_read_prop(const void *blob, u32 node_offset, const char *prop_name,
+ struct fdt_property *fdt_prop)
+{
+ u32 offset = node_offset;
+
+ offset += fdt_next_node_name(blob, offset, NULL); // skip node name
+
+ size_t size;
+ while ((size = fdt_next_property(blob, offset, fdt_prop))) {
+ if (strcmp(fdt_prop->name, prop_name) == 0)
+ return offset;
+ offset += size;
+ }
+ return 0; // property not found
+}
+
+/*
+ * fdt_read_reg_prop reads the reg property inside a node
+ *
+ * @params blob address of FDT
+ * @params node_offset offset to the node to read the reg property from
+ * @params addr_cells number of cells used for one address
+ * @params size_cells number of cells used for one size
+ * @params regions all regions that are read inside the reg property are saved inside
+ * this array
+ * @params regions_count maximum number of entries that can be saved inside the regions array.
+ *
+ * Returns: Either 0 on error or returns the number of regions put into the regions array.
+ */
+u32 fdt_read_reg_prop(const void *blob, u32 node_offset, u32 addr_cells, u32 size_cells,
+ struct device_tree_region regions[], size_t regions_count)
+{
+ struct fdt_property prop;
+ u32 offset = fdt_read_prop(blob, node_offset, "reg", &prop);
+
+ if (!offset) {
+ printk(BIOS_DEBUG, "no reg property found in node_offset: %x\n", node_offset);
+ return 0;
+ }
+
+ // we found the reg property, now need to parse all regions in 'reg'
+ size_t count = prop.size / (4 * addr_cells + 4 * size_cells);
+ if (count > regions_count) {
+ printk(BIOS_ERR, "reg property at node_offset: %x has more entries (%zd) than regions array can hold (%zd)\n", node_offset, count, regions_count);
+ count = regions_count;
+ }
+ if (addr_cells > 2 || size_cells > 2) {
+ printk(BIOS_ERR, "addr_cells (%d) or size_cells (%d) bigger than 2\n",
+ addr_cells, size_cells);
+ return 0;
+ }
+ uint32_t *ptr = prop.data;
+ for (int i = 0; i < count; i++) {
+ if (addr_cells == 1)
+ regions[i].addr = be32dec(ptr);
+ else if (addr_cells == 2)
+ regions[i].addr = be64dec(ptr);
+ ptr += addr_cells;
+ if (size_cells == 1)
+ regions[i].size = be32dec(ptr);
+ else if (size_cells == 2)
+ regions[i].size = be64dec(ptr);
+ ptr += size_cells;
+ }
+
+ return count; // return the number of regions found in the reg property
+}
+
+static u32 fdt_read_cell_props(const void *blob, u32 node_offset, u32 *addrcp, u32 *sizecp)
+{
+ struct fdt_property prop;
+ u32 offset = node_offset;
+ size_t size;
+ while ((size = fdt_next_property(blob, offset, &prop))) {
+ if (addrcp && !strcmp(prop.name, "#address-cells"))
+ *addrcp = be32dec(prop.data);
+ if (sizecp && !strcmp(prop.name, "#size-cells"))
+ *sizecp = be32dec(prop.data);
+ offset += size;
+ }
+ return offset;
+}
+
+/*
+ * fdt_find_node searches for a node relative to another node
+ *
+ * @params blob address of FDT
+ *
+ * @params parent_node_offset offset to node from which to traverse the tree
+ *
+ * @params path null terminated array of node names specifying a
+ * relative path (e.g: { "cpus", "cpu0", NULL })
+ *
+ * @params addrcp/sizecp If any address-cells and size-cells properties are found that are
+ * part of the parent node of the node we are looking, addrcp and sizecp
+ * are set to these respectively.
+ *
+ * @returns: Either 0 if no node has been found or the offset to the node found
+ */
+static u32 fdt_find_node(const void *blob, u32 parent_node_offset, char **path,
+ u32 *addrcp, u32 *sizecp)
+{
+ if (*path == NULL)
+ return parent_node_offset; // node found
+
+ size_t size = fdt_next_node_name(blob, parent_node_offset, NULL); // skip node name
+
+ /*
+ * get address-cells and size-cells properties while skipping the others.
+ * According to spec address-cells and size-cells are not inherited, but we
+ * intentionally follow the Linux implementation here and treat them as inheritable.
+ */
+ u32 node_offset = fdt_read_cell_props(blob, parent_node_offset + size, addrcp, sizecp);
+
+ const char *node_name;
+ // walk all children nodes
+ while ((size = fdt_next_node_name(blob, node_offset, &node_name))) {
+ if (!strcmp(*path, node_name)) {
+ // traverse one level deeper into the path
+ return fdt_find_node(blob, node_offset, path + 1, addrcp, sizecp);
+ }
+ // node is not the correct one. skip current node
+ node_offset += fdt_skip_node(blob, node_offset);
+ }
+
+ // we have searched everything and could not find a fitting node
+ return 0;
+}
+
+/*
+ * fdt_find_node_by_path finds a node behind a given node path
+ *
+ * @params blob address of FDT
+ * @params path absolute path to the node that should be searched for
+ *
+ * @params addrcp/sizecp Pointer that will be updated with any #address-cells and #size-cells
+ * value found in the node of the node specified by node_offset. Either
+ * may be NULL to ignore. If no #address-cells and #size-cells is found
+ * default values of #address-cells=2 and #size-cells=1 are returned.
+ *
+ * @returns Either 0 on error or the offset to the node found behind the path
+ */
+u32 fdt_find_node_by_path(const void *blob, const char *path, u32 *addrcp, u32 *sizecp)
+{
+ // sanity check
+ if (path[0] != '/') {
+ printk(BIOS_ERR, "devicetree path must start with a /\n");
+ return 0;
+ }
+ if (!blob) {
+ printk(BIOS_ERR, "devicetree blob is NULL\n");
+ return 0;
+ }
+
+ if (addrcp)
+ *addrcp = 2;
+ if (sizecp)
+ *sizecp = 1;
+
+ struct fdt_header *fdt_hdr = (struct fdt_header *)blob;
+
+ /*
+ * split path into separate nodes
+ * e.g: "/cpus/cpu0" -> { "cpus", "cpu0" }
+ */
+ char *path_array[FDT_PATH_MAX_DEPTH];
+ size_t path_size = strlen(path);
+ assert(path_size < FDT_PATH_MAX_LEN);
+ char path_copy[FDT_PATH_MAX_LEN];
+ memcpy(path_copy, path, path_size + 1);
+ char *cur = path_copy;
+ int i;
+ for (i = 0; i < FDT_PATH_MAX_DEPTH; i++) {
+ path_array[i] = strtok_r(NULL, "/", &cur);
+ if (!path_array[i])
+ break;
+ }
+ assert(i < FDT_PATH_MAX_DEPTH);
+
+ return fdt_find_node(blob, be32toh(fdt_hdr->structure_offset), path_array, addrcp, sizecp);
+}
+
+/*
+ * fdt_find_subnodes_by_prefix finds a node with a given prefix relative to a parent node
+ *
+ * @params blob The FDT to search.
+ *
+ * @params node_offset offset to the node of which the children should be searched
+ *
+ * @params prefix A string to search for a node with a given prefix. This can for example
+ * be 'cpu' to look for all nodes matching this prefix. Only children of
+ * node_offset are searched. Therefore in order to search all nodes matching
+ * the 'cpu' prefix, node_offset should probably point to the 'cpus' node.
+ * An empty prefix ("") searches for all children nodes of node_offset.
+ *
+ * @params addrcp/sizecp Pointer that will be updated with any #address-cells and #size-cells
+ * value found in the node of the node specified by node_offset. Either
+ * may be NULL to ignore. If no #address-cells and #size-cells is found
+ * addrcp and sizecp are left untouched.
+ *
+ * @params results Array of offsets pointing to each node matching the given prefix.
+ * @params results_len Number of entries allocated for the 'results' array
+ *
+ * @returns offset to last node found behind path or 0 if no node has been found
+ */
+size_t fdt_find_subnodes_by_prefix(const void *blob, u32 node_offset, const char *prefix,
+ u32 *addrcp, u32 *sizecp, u32 *results, size_t results_len)
+{
+ // sanity checks
+ if (!blob || !results || !prefix) {
+ printk(BIOS_ERR, "%s: input parameter cannot be null/\n", __func__);
+ return 0;
+ }
+
+ u32 offset = node_offset;
+
+ // we don't care about the name of the current node
+ u32 size = fdt_next_node_name(blob, offset, NULL);
+ if (!size) {
+ printk(BIOS_ERR, "%s: node_offset: %x does not point to a node\n",
+ __func__, node_offset);
+ return 0;
+ }
+ offset += size;
+
+ /*
+ * update addrcp and sizecp if the node contains an address-cells and size-cells
+ * property. Otherwise use addrcp and sizecp provided by caller.
+ */
+ offset = fdt_read_cell_props(blob, offset, addrcp, sizecp);
+
+ size_t count_results = 0;
+ int prefix_len = strlen(prefix);
+ const char *node_name;
+ // walk all children nodes of offset
+ while ((size = fdt_next_node_name(blob, offset, &node_name))) {
+
+ if (count_results >= results_len) {
+ printk(BIOS_WARNING,
+ "%s: results_len (%zd) smaller than count_results (%zd)\n",
+ __func__, results_len, count_results);
+ break;
+ }
+
+ if (!strncmp(prefix, node_name, prefix_len)) {
+ // we found a node that matches the prefix
+ results[count_results++] = offset;
+ }
+
+ // node does not match the prefix. skip current node
+ offset += fdt_skip_node(blob, offset);
+ }
+
+ // return last occurrence
+ return count_results;
+}
+
+static const char *fdt_read_alias_prop(const void *blob, const char *alias_name)
+{
+ u32 node_offset = fdt_find_node_by_path(blob, "/aliases", NULL, NULL);
+ if (!node_offset) {
+ printk(BIOS_DEBUG, "no /aliases node found\n");
+ return NULL;
+ }
+ struct fdt_property alias_prop;
+ if (!fdt_read_prop(blob, node_offset, alias_name, &alias_prop)) {
+ printk(BIOS_DEBUG, "property %s in /aliases node not found\n", alias_name);
+ return NULL;
+ }
+ return (const char *)alias_prop.data;
+}
+
+/*
+ * Find a node in the tree from a string device tree path.
+ *
+ * @params blob Address to the FDT
+ * @params alias_name node name alias that should be searched for.
+ * @params addrcp/sizecp Pointer that will be updated with any #address-cells and #size-cells
+ * value found in the node of the node specified by node_offset. Either
+ * may be NULL to ignore. If no #address-cells and #size-cells is found
+ * default values of #address-cells=2 and #size-cells=1 are returned.
+ *
+ * @returns offset to last node found behind path or 0 if no node has been found
+ */
+u32 fdt_find_node_by_alias(const void *blob, const char *alias_name, u32 *addrcp, u32 *sizecp)
+{
+ const char *node_name = fdt_read_alias_prop(blob, alias_name);
+ if (!node_name) {
+ printk(BIOS_DEBUG, "alias %s not found\n", alias_name);
+ return 0;
+ }
+
+ u32 node_offset = fdt_find_node_by_path(blob, node_name, addrcp, sizecp);
+ if (!node_offset) {
+ // This should not happen (invalid devicetree)
+ printk(BIOS_WARNING,
+ "Could not find node '%s', which alias was referring to '%s'\n",
+ node_name, alias_name);
+ return 0;
+ }
+ return node_offset;
+}
+
+
+/*
+ * Functions for printing flattened trees.
+ */
+
+static void print_indent(int depth)
+{
+ printk(BIOS_DEBUG, "%*s", depth * 8, "");
+}
+
+static void print_property(const struct fdt_property *prop, int depth)
+{
+ int is_string = prop->size > 0 &&
+ ((char *)prop->data)[prop->size - 1] == '\0';
+
+ if (is_string) {
+ for (int i = 0; i < prop->size - 1; i++) {
+ if (!isprint(((char *)prop->data)[i])) {
+ is_string = 0;
+ break;
+ }
+ }
+ }
+
+ print_indent(depth);
+ if (is_string) {
+ printk(BIOS_DEBUG, "%s = \"%s\";\n",
+ prop->name, (const char *)prop->data);
+ } else {
+ printk(BIOS_DEBUG, "%s = < ", prop->name);
+ for (int i = 0; i < MIN(128, prop->size); i += 4) {
+ uint32_t val = 0;
+ for (int j = 0; j < MIN(4, prop->size - i); j++)
+ val |= ((uint8_t *)prop->data)[i + j] <<
+ (24 - j * 8);
+ printk(BIOS_DEBUG, "%#.2x ", val);
+ }
+ if (prop->size > 128)
+ printk(BIOS_DEBUG, "...");
+ printk(BIOS_DEBUG, ">;\n");
+ }
+}
+
+static int print_flat_node(const void *blob, uint32_t start_offset, int depth)
+{
+ int offset = start_offset;
+ const char *name;
+ int size;
+
+ size = fdt_next_node_name(blob, offset, &name);
+ if (!size)
+ return 0;
+ offset += size;
+
+ print_indent(depth);
+ printk(BIOS_DEBUG, "%s {\n", name);
+
+ struct fdt_property prop;
+ while ((size = fdt_next_property(blob, offset, &prop))) {
+ print_property(&prop, depth + 1);
+
+ offset += size;
+ }
+
+ printk(BIOS_DEBUG, "\n"); /* empty line between props and nodes */
+
+ while ((size = print_flat_node(blob, offset, depth + 1)))
+ offset += size;
+
+ print_indent(depth);
+ printk(BIOS_DEBUG, "}\n");
+
+ return offset - start_offset + sizeof(uint32_t);
+}
+
+void fdt_print_node(const void *blob, uint32_t offset)
+{
+ print_flat_node(blob, offset, 0);
+}
+
+/*
+ * fdt_read_memory_regions finds memory ranges from a flat device-tree
+ *
+ * @params blob address of FDT
+ * @params regions all regions that are read inside the reg property of
+ * memory nodes are saved inside this array
+ * @params regions_count maximum number of entries that can be saved inside
+ * the regions array.
+ *
+ * Returns: Either 0 on error or returns the number of regions put into the regions array.
+ */
+size_t fdt_read_memory_regions(const void *blob,
+ struct device_tree_region regions[],
+ size_t regions_count)
+{
+ u32 node, root, addrcp, sizecp;
+ u32 nodes[FDT_MAX_MEMORY_NODES] = {0};
+ size_t region_idx = 0;
+ size_t node_count = 0;
+
+ if (!fdt_is_valid(blob))
+ return 0;
+
+ node = fdt_find_node_by_path(blob, "/memory", &addrcp, &sizecp);
+ if (node) {
+ region_idx += fdt_read_reg_prop(blob, node, addrcp, sizecp,
+ regions, regions_count);
+ if (region_idx >= regions_count) {
+ printk(BIOS_WARNING, "FDT: Too many memory regions\n");
+ goto out;
+ }
+ }
+
+ root = fdt_find_node_by_path(blob, "/", &addrcp, &sizecp);
+ node_count = fdt_find_subnodes_by_prefix(blob, root, "memory@",
+ &addrcp, &sizecp, nodes,
+ FDT_MAX_MEMORY_NODES);
+ if (node_count >= FDT_MAX_MEMORY_NODES) {
+ printk(BIOS_WARNING, "FDT: Too many memory nodes\n");
+ /* Can still reading the regions for those we got */
+ }
+
+ for (size_t i = 0; i < MIN(node_count, FDT_MAX_MEMORY_NODES); i++) {
+ region_idx += fdt_read_reg_prop(blob, nodes[i], addrcp, sizecp,
+ ®ions[region_idx],
+ regions_count - region_idx);
+ if (region_idx >= regions_count) {
+ printk(BIOS_WARNING, "FDT: Too many memory regions\n");
+ goto out;
+ }
+ }
+
+out:
+ for (size_t i = 0; i < MIN(region_idx, regions_count); i++) {
+ printk(BIOS_DEBUG, "FDT: Memory region [%#llx - %#llx]\n",
+ regions[i].addr, regions[i].addr + regions[i].size);
+ }
+
+ return region_idx;
+}
+
+/*
+ * fdt_get_memory_top finds top of memory from a flat device-tree
+ *
+ * @params blob address of FDT
+ *
+ * Returns: Either 0 on error or returns the maximum memory address
+ */
+uint64_t fdt_get_memory_top(const void *blob)
+{
+ struct device_tree_region regions[FDT_MAX_MEMORY_REGIONS] = {0};
+ uint64_t top = 0;
+ uint64_t total = 0;
+ size_t count;
+
+ if (!fdt_is_valid(blob))
+ return 0;
+
+ count = fdt_read_memory_regions(blob, regions, FDT_MAX_MEMORY_REGIONS);
+ for (size_t i = 0; i < MIN(count, FDT_MAX_MEMORY_REGIONS); i++) {
+ top = MAX(top, regions[i].addr + regions[i].size);
+ total += regions[i].size;
+ }
+
+ printk(BIOS_DEBUG, "FDT: Found %u MiB of RAM\n",
+ (uint32_t)(total / MiB));
+
+ return top;
+}
+
+/*
+ * Functions to turn a flattened tree into an unflattened one.
+ */
+
+static int dt_prop_is_phandle(struct device_tree_property *prop)
+{
+ return !(strcmp("phandle", prop->prop.name) &&
+ strcmp("linux,phandle", prop->prop.name));
+}
+
+static int fdt_unflatten_node(const void *blob, uint32_t start_offset,
+ struct device_tree *tree,
+ struct device_tree_node **new_node)
+{
+ struct list_node *last;
+ int offset = start_offset;
+ const char *name;
+ int size;
+
+ size = fdt_next_node_name(blob, offset, &name);
+ if (!size)
+ return 0;
+ offset += size;
+
+ struct device_tree_node *node = xzalloc(sizeof(*node));
+ *new_node = node;
+ node->name = name;
+
+ struct fdt_property fprop;
+ last = &node->properties;
+ while ((size = fdt_next_property(blob, offset, &fprop))) {
+ struct device_tree_property *prop = xzalloc(sizeof(*prop));
+ prop->prop = fprop;
+
+ if (dt_prop_is_phandle(prop)) {
+ node->phandle = be32dec(prop->prop.data);
+ if (node->phandle > tree->max_phandle)
+ tree->max_phandle = node->phandle;
+ }
+
+ list_insert_after(&prop->list_node, last);
+ last = &prop->list_node;
+
+ offset += size;
+ }
+
+ struct device_tree_node *child;
+ last = &node->children;
+ while ((size = fdt_unflatten_node(blob, offset, tree, &child))) {
+ list_insert_after(&child->list_node, last);
+ last = &child->list_node;
+
+ offset += size;
+ }
+
+ return offset - start_offset + sizeof(uint32_t);
+}
+
+static int fdt_unflatten_map_entry(const void *blob, uint32_t offset,
+ struct device_tree_reserve_map_entry **new)
+{
+ const uint64_t *ptr = (const uint64_t *)(((uint8_t *)blob) + offset);
+ const uint64_t start = be64toh(ptr[0]);
+ const uint64_t size = be64toh(ptr[1]);
+
+ if (!size)
+ return 0;
+
+ struct device_tree_reserve_map_entry *entry = xzalloc(sizeof(*entry));
+ *new = entry;
+ entry->start = start;
+ entry->size = size;
+
+ return sizeof(uint64_t) * 2;
+}
+
+bool fdt_is_valid(const void *blob)
+{
+ const struct fdt_header *header = (const struct fdt_header *)blob;
+
+ uint32_t magic = be32toh(header->magic);
+ uint32_t version = be32toh(header->version);
+ uint32_t last_comp_version = be32toh(header->last_comp_version);
+
+ if (magic != FDT_HEADER_MAGIC) {
+ printk(BIOS_ERR, "Invalid device tree magic %#.8x!\n", magic);
+ return false;
+ }
+ if (last_comp_version > FDT_SUPPORTED_VERSION) {
+ printk(BIOS_ERR, "Unsupported device tree version %u(>=%u)\n",
+ version, last_comp_version);
+ return false;
+ }
+ if (version > FDT_SUPPORTED_VERSION)
+ printk(BIOS_NOTICE, "FDT version %u too new, should add support!\n",
+ version);
+ return true;
+}
+
+struct device_tree *fdt_unflatten(const void *blob)
+{
+ struct device_tree *tree = xzalloc(sizeof(*tree));
+ const struct fdt_header *header = (const struct fdt_header *)blob;
+ tree->header = header;
+
+ if (!fdt_is_valid(blob))
+ return NULL;
+
+ uint32_t struct_offset = be32toh(header->structure_offset);
+ uint32_t strings_offset = be32toh(header->strings_offset);
+ uint32_t reserve_offset = be32toh(header->reserve_map_offset);
+ uint32_t min_offset = 0;
+ min_offset = MIN(struct_offset, strings_offset);
+ min_offset = MIN(min_offset, reserve_offset);
+ /* Assume everything up to the first non-header component is part of
+ the header and needs to be preserved. This will protect us against
+ new elements being added in the future. */
+ tree->header_size = min_offset;
+
+ struct device_tree_reserve_map_entry *entry;
+ uint32_t offset = reserve_offset;
+ int size;
+ struct list_node *last = &tree->reserve_map;
+ while ((size = fdt_unflatten_map_entry(blob, offset, &entry))) {
+ list_insert_after(&entry->list_node, last);
+ last = &entry->list_node;
+
+ offset += size;
+ }
+
+ fdt_unflatten_node(blob, struct_offset, tree, &tree->root);
+
+ return tree;
+}
+
+
+
+/*
+ * Functions to find the size of the device tree if it was flattened.
+ */
+
+static void dt_flat_prop_size(struct device_tree_property *prop,
+ uint32_t *struct_size, uint32_t *strings_size)
+{
+ /* Starting token. */
+ *struct_size += sizeof(uint32_t);
+ /* Size. */
+ *struct_size += sizeof(uint32_t);
+ /* Name offset. */
+ *struct_size += sizeof(uint32_t);
+ /* Property value. */
+ *struct_size += ALIGN_UP(prop->prop.size, sizeof(uint32_t));
+
+ /* Property name. */
+ *strings_size += strlen(prop->prop.name) + 1;
+}
+
+static void dt_flat_node_size(struct device_tree_node *node,
+ uint32_t *struct_size, uint32_t *strings_size)
+{
+ /* Starting token. */
+ *struct_size += sizeof(uint32_t);
+ /* Node name. */
+ *struct_size += ALIGN_UP(strlen(node->name) + 1, sizeof(uint32_t));
+
+ struct device_tree_property *prop;
+ list_for_each(prop, node->properties, list_node)
+ dt_flat_prop_size(prop, struct_size, strings_size);
+
+ struct device_tree_node *child;
+ list_for_each(child, node->children, list_node)
+ dt_flat_node_size(child, struct_size, strings_size);
+
+ /* End token. */
+ *struct_size += sizeof(uint32_t);
+}
+
+uint32_t dt_flat_size(const struct device_tree *tree)
+{
+ uint32_t size = tree->header_size;
+ struct device_tree_reserve_map_entry *entry;
+ list_for_each(entry, tree->reserve_map, list_node)
+ size += sizeof(uint64_t) * 2;
+ size += sizeof(uint64_t) * 2;
+
+ uint32_t struct_size = 0;
+ uint32_t strings_size = 0;
+ dt_flat_node_size(tree->root, &struct_size, &strings_size);
+
+ size += struct_size;
+ /* End token. */
+ size += sizeof(uint32_t);
+
+ size += strings_size;
+
+ return size;
+}
+
+
+
+/*
+ * Functions to flatten a device tree.
+ */
+
+static void dt_flatten_map_entry(struct device_tree_reserve_map_entry *entry,
+ void **map_start)
+{
+ ((uint64_t *)*map_start)[0] = htobe64(entry->start);
+ ((uint64_t *)*map_start)[1] = htobe64(entry->size);
+ *map_start = ((uint8_t *)*map_start) + sizeof(uint64_t) * 2;
+}
+
+static void dt_flatten_prop(struct device_tree_property *prop,
+ void **struct_start, void *strings_base,
+ void **strings_start)
+{
+ uint8_t *dstruct = (uint8_t *)*struct_start;
+ uint8_t *dstrings = (uint8_t *)*strings_start;
+
+ be32enc(dstruct, FDT_TOKEN_PROPERTY);
+ dstruct += sizeof(uint32_t);
+
+ be32enc(dstruct, prop->prop.size);
+ dstruct += sizeof(uint32_t);
+
+ uint32_t name_offset = (uintptr_t)dstrings - (uintptr_t)strings_base;
+ be32enc(dstruct, name_offset);
+ dstruct += sizeof(uint32_t);
+
+ strcpy((char *)dstrings, prop->prop.name);
+ dstrings += strlen(prop->prop.name) + 1;
+
+ memcpy(dstruct, prop->prop.data, prop->prop.size);
+ dstruct += ALIGN_UP(prop->prop.size, sizeof(uint32_t));
+
+ *struct_start = dstruct;
+ *strings_start = dstrings;
+}
+
+static void dt_flatten_node(const struct device_tree_node *node,
+ void **struct_start, void *strings_base,
+ void **strings_start)
+{
+ uint8_t *dstruct = (uint8_t *)*struct_start;
+ uint8_t *dstrings = (uint8_t *)*strings_start;
+
+ be32enc(dstruct, FDT_TOKEN_BEGIN_NODE);
+ dstruct += sizeof(uint32_t);
+
+ strcpy((char *)dstruct, node->name);
+ dstruct += ALIGN_UP(strlen(node->name) + 1, sizeof(uint32_t));
+
+ struct device_tree_property *prop;
+ list_for_each(prop, node->properties, list_node)
+ dt_flatten_prop(prop, (void **)&dstruct, strings_base,
+ (void **)&dstrings);
+
+ struct device_tree_node *child;
+ list_for_each(child, node->children, list_node)
+ dt_flatten_node(child, (void **)&dstruct, strings_base,
+ (void **)&dstrings);
+
+ be32enc(dstruct, FDT_TOKEN_END_NODE);
+ dstruct += sizeof(uint32_t);
+
+ *struct_start = dstruct;
+ *strings_start = dstrings;
+}
+
+void dt_flatten(const struct device_tree *tree, void *start_dest)
+{
+ uint8_t *dest = (uint8_t *)start_dest;
+
+ memcpy(dest, tree->header, tree->header_size);
+ struct fdt_header *header = (struct fdt_header *)dest;
+ dest += tree->header_size;
+
+ struct device_tree_reserve_map_entry *entry;
+ list_for_each(entry, tree->reserve_map, list_node)
+ dt_flatten_map_entry(entry, (void **)&dest);
+ ((uint64_t *)dest)[0] = ((uint64_t *)dest)[1] = 0;
+ dest += sizeof(uint64_t) * 2;
+
+ uint32_t struct_size = 0;
+ uint32_t strings_size = 0;
+ dt_flat_node_size(tree->root, &struct_size, &strings_size);
+
+ uint8_t *struct_start = dest;
+ header->structure_offset = htobe32(dest - (uint8_t *)start_dest);
+ header->structure_size = htobe32(struct_size);
+ dest += struct_size;
+
+ *((uint32_t *)dest) = htobe32(FDT_TOKEN_END);
+ dest += sizeof(uint32_t);
+
+ uint8_t *strings_start = dest;
+ header->strings_offset = htobe32(dest - (uint8_t *)start_dest);
+ header->strings_size = htobe32(strings_size);
+ dest += strings_size;
+
+ dt_flatten_node(tree->root, (void **)&struct_start, strings_start,
+ (void **)&strings_start);
+
+ header->totalsize = htobe32(dest - (uint8_t *)start_dest);
+}
+
+
+
+/*
+ * Functions for printing a non-flattened device tree.
+ */
+
+static void print_node(const struct device_tree_node *node, int depth)
+{
+ print_indent(depth);
+ if (depth == 0) /* root node has no name, print a starting slash */
+ printk(BIOS_DEBUG, "/");
+ printk(BIOS_DEBUG, "%s {\n", node->name);
+
+ struct device_tree_property *prop;
+ list_for_each(prop, node->properties, list_node)
+ print_property(&prop->prop, depth + 1);
+
+ printk(BIOS_DEBUG, "\n"); /* empty line between props and nodes */
+
+ struct device_tree_node *child;
+ list_for_each(child, node->children, list_node)
+ print_node(child, depth + 1);
+
+ print_indent(depth);
+ printk(BIOS_DEBUG, "};\n");
+}
+
+void dt_print_node(const struct device_tree_node *node)
+{
+ print_node(node, 0);
+}
+
+
+
+/*
+ * Functions for reading and manipulating an unflattened device tree.
+ */
+
+/*
+ * Read #address-cells and #size-cells properties from a node.
+ *
+ * @param node The device tree node to read from.
+ * @param addrcp Pointer to store #address-cells in, skipped if NULL.
+ * @param sizecp Pointer to store #size-cells in, skipped if NULL.
+ */
+void dt_read_cell_props(const struct device_tree_node *node, u32 *addrcp,
+ u32 *sizecp)
+{
+ struct device_tree_property *prop;
+ list_for_each(prop, node->properties, list_node) {
+ if (addrcp && !strcmp("#address-cells", prop->prop.name))
+ *addrcp = be32dec(prop->prop.data);
+ if (sizecp && !strcmp("#size-cells", prop->prop.name))
+ *sizecp = be32dec(prop->prop.data);
+ }
+}
+
+/*
+ * Find a node from a device tree path, relative to a parent node.
+ *
+ * @param parent The node from which to start the relative path lookup.
+ * @param path An array of path component strings that will be looked
+ * up in order to find the node. Must be terminated with
+ * a NULL pointer. Example: {'firmware', 'coreboot', NULL}
+ * @param addrcp Pointer that will be updated with any #address-cells
+ * value found in the path. May be NULL to ignore.
+ * @param sizecp Pointer that will be updated with any #size-cells
+ * value found in the path. May be NULL to ignore.
+ * @param create 1: Create node(s) if not found. 0: Return NULL instead.
+ * @return The found/created node, or NULL.
+ */
+struct device_tree_node *dt_find_node(struct device_tree_node *parent,
+ const char **path, u32 *addrcp,
+ u32 *sizecp, int create)
+{
+ struct device_tree_node *node, *found = NULL;
+
+ /* Update #address-cells and #size-cells for this level. */
+ dt_read_cell_props(parent, addrcp, sizecp);
+
+ if (!*path)
+ return parent;
+
+ /* Find the next node in the path, if it exists. */
+ list_for_each(node, parent->children, list_node) {
+ if (!strcmp(node->name, *path)) {
+ found = node;
+ break;
+ }
+ }
+
+ /* Otherwise create it or return NULL. */
+ if (!found) {
+ if (!create)
+ return NULL;
+
+ found = calloc(1, sizeof(*found));
+ if (!found)
+ return NULL;
+ found->name = strdup(*path);
+ if (!found->name)
+ return NULL;
+
+ list_insert_after(&found->list_node, &parent->children);
+ }
+
+ return dt_find_node(found, path + 1, addrcp, sizecp, create);
+}
+
+/*
+ * Find a node in the tree from a string device tree path.
+ *
+ * @param tree The device tree to search.
+ * @param path A string representing a path in the device tree, with
+ * nodes separated by '/'. Example: "/firmware/coreboot"
+ * @param addrcp Pointer that will be updated with any #address-cells
+ * value found in the path. May be NULL to ignore.
+ * @param sizecp Pointer that will be updated with any #size-cells
+ * value found in the path. May be NULL to ignore.
+ * @param create 1: Create node(s) if not found. 0: Return NULL instead.
+ * @return The found/created node, or NULL.
+ *
+ * It is the caller responsibility to provide a path string that doesn't end
+ * with a '/' and doesn't contain any "//". If the path does not start with a
+ * '/', the first segment is interpreted as an alias. */
+struct device_tree_node *dt_find_node_by_path(struct device_tree *tree,
+ const char *path, u32 *addrcp,
+ u32 *sizecp, int create)
+{
+ char *sub_path;
+ char *duped_str;
+ struct device_tree_node *parent;
+ char *next_slash;
+ /* Hopefully enough depth for any node. */
+ const char *path_array[15];
+ int i;
+ struct device_tree_node *node = NULL;
+
+ if (path[0] == '/') { /* regular path */
+ if (path[1] == '\0') { /* special case: "/" is root node */
+ dt_read_cell_props(tree->root, addrcp, sizecp);
+ return tree->root;
+ }
+
+ sub_path = duped_str = strdup(&path[1]);
+ if (!sub_path)
+ return NULL;
+
+ parent = tree->root;
+ } else { /* alias */
+ char *alias;
+
+ alias = duped_str = strdup(path);
+ if (!alias)
+ return NULL;
+
+ sub_path = strchr(alias, '/');
+ if (sub_path)
+ *sub_path = '\0';
+
+ parent = dt_find_node_by_alias(tree, alias);
+ if (!parent) {
+ printk(BIOS_DEBUG,
+ "Could not find node '%s', alias '%s' does not exist\n",
+ path, alias);
+ free(duped_str);
+ return NULL;
+ }
+
+ if (!sub_path) {
+ /* it's just the alias, no sub-path */
+ free(duped_str);
+ return parent;
+ }
+
+ sub_path++;
+ }
+
+ next_slash = sub_path;
+ path_array[0] = sub_path;
+ for (i = 1; i < (ARRAY_SIZE(path_array) - 1); i++) {
+ next_slash = strchr(next_slash, '/');
+ if (!next_slash)
+ break;
+
+ *next_slash++ = '\0';
+ path_array[i] = next_slash;
+ }
+
+ if (!next_slash) {
+ path_array[i] = NULL;
+ node = dt_find_node(parent, path_array,
+ addrcp, sizecp, create);
+ }
+
+ free(duped_str);
+ return node;
+}
+
+/*
+ * Find a node from an alias
+ *
+ * @param tree The device tree.
+ * @param alias The alias name.
+ * @return The found node, or NULL.
+ */
+struct device_tree_node *dt_find_node_by_alias(struct device_tree *tree,
+ const char *alias)
+{
+ struct device_tree_node *node;
+ const char *alias_path;
+
+ node = dt_find_node_by_path(tree, "/aliases", NULL, NULL, 0);
+ if (!node)
+ return NULL;
+
+ alias_path = dt_find_string_prop(node, alias);
+ if (!alias_path)
+ return NULL;
+
+ return dt_find_node_by_path(tree, alias_path, NULL, NULL, 0);
+}
+
+struct device_tree_node *dt_find_node_by_phandle(struct device_tree_node *root,
+ uint32_t phandle)
+{
+ if (!root)
+ return NULL;
+
+ if (root->phandle == phandle)
+ return root;
+
+ struct device_tree_node *node;
+ struct device_tree_node *result;
+ list_for_each(node, root->children, list_node) {
+ result = dt_find_node_by_phandle(node, phandle);
+ if (result)
+ return result;
+ }
+
+ return NULL;
+}
+
+/*
+ * Check if given node is compatible.
+ *
+ * @param node The node which is to be checked for compatible property.
+ * @param compat The compatible string to match.
+ * @return 1 = compatible, 0 = not compatible.
+ */
+static int dt_check_compat_match(struct device_tree_node *node,
+ const char *compat)
+{
+ struct device_tree_property *prop;
+
+ list_for_each(prop, node->properties, list_node) {
+ if (!strcmp("compatible", prop->prop.name)) {
+ size_t bytes = prop->prop.size;
+ const char *str = prop->prop.data;
+ while (bytes > 0) {
+ if (!strncmp(compat, str, bytes))
+ return 1;
+ size_t len = strnlen(str, bytes) + 1;
+ if (bytes <= len)
+ break;
+ str += len;
+ bytes -= len;
+ }
+ break;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Find a node from a compatible string, in the subtree of a parent node.
+ *
+ * @param parent The parent node under which to look.
+ * @param compat The compatible string to find.
+ * @return The found node, or NULL.
+ */
+struct device_tree_node *dt_find_compat(struct device_tree_node *parent,
+ const char *compat)
+{
+ /* Check if the parent node itself is compatible. */
+ if (dt_check_compat_match(parent, compat))
+ return parent;
+
+ struct device_tree_node *child;
+ list_for_each(child, parent->children, list_node) {
+ struct device_tree_node *found = dt_find_compat(child, compat);
+ if (found)
+ return found;
+ }
+
+ return NULL;
+}
+
+/*
+ * Find the next compatible child of a given parent. All children up to the
+ * child passed in by caller are ignored. If child is NULL, it considers all the
+ * children to find the first child which is compatible.
+ *
+ * @param parent The parent node under which to look.
+ * @param child The child node to start search from (exclusive). If NULL
+ * consider all children.
+ * @param compat The compatible string to find.
+ * @return The found node, or NULL.
+ */
+struct device_tree_node *
+dt_find_next_compat_child(struct device_tree_node *parent,
+ struct device_tree_node *child,
+ const char *compat)
+{
+ struct device_tree_node *next;
+ int ignore = 0;
+
+ if (child)
+ ignore = 1;
+
+ list_for_each(next, parent->children, list_node) {
+ if (ignore) {
+ if (child == next)
+ ignore = 0;
+ continue;
+ }
+
+ if (dt_check_compat_match(next, compat))
+ return next;
+ }
+
+ return NULL;
+}
+
+/*
+ * Find a node with matching property value, in the subtree of a parent node.
+ *
+ * @param parent The parent node under which to look.
+ * @param name The property name to look for.
+ * @param data The property value to look for.
+ * @param size The property size.
+ */
+struct device_tree_node *dt_find_prop_value(struct device_tree_node *parent,
+ const char *name, void *data,
+ size_t size)
+{
+ struct device_tree_property *prop;
+
+ /* Check if parent itself has the required property value. */
+ list_for_each(prop, parent->properties, list_node) {
+ if (!strcmp(name, prop->prop.name)) {
+ size_t bytes = prop->prop.size;
+ const void *prop_data = prop->prop.data;
+ if (size != bytes)
+ break;
+ if (!memcmp(data, prop_data, size))
+ return parent;
+ break;
+ }
+ }
+
+ struct device_tree_node *child;
+ list_for_each(child, parent->children, list_node) {
+ struct device_tree_node *found = dt_find_prop_value(child, name,
+ data, size);
+ if (found)
+ return found;
+ }
+ return NULL;
+}
+
+/*
+ * Write an arbitrary sized big-endian integer into a pointer.
+ *
+ * @param dest Pointer to the DT property data buffer to write.
+ * @param src The integer to write (in CPU endianness).
+ * @param length the length of the destination integer in bytes.
+ */
+void dt_write_int(u8 *dest, u64 src, size_t length)
+{
+ while (length--) {
+ dest[length] = (u8)src;
+ src >>= 8;
+ }
+}
+
+/*
+ * Delete a property by name in a given node if it exists.
+ *
+ * @param node The device tree node to operate on.
+ * @param name The name of the property to delete.
+ */
+void dt_delete_prop(struct device_tree_node *node, const char *name)
+{
+ struct device_tree_property *prop;
+
+ list_for_each(prop, node->properties, list_node) {
+ if (!strcmp(prop->prop.name, name)) {
+ list_remove(&prop->list_node);
+ return;
+ }
+ }
+}
+
+/*
+ * Add an arbitrary property to a node, or update it if it already exists.
+ *
+ * @param node The device tree node to add to.
+ * @param name The name of the new property.
+ * @param data The raw data blob to be stored in the property.
+ * @param size The size of data in bytes.
+ */
+void dt_add_bin_prop(struct device_tree_node *node, const char *name,
+ void *data, size_t size)
+{
+ struct device_tree_property *prop;
+
+ list_for_each(prop, node->properties, list_node) {
+ if (!strcmp(prop->prop.name, name)) {
+ prop->prop.data = data;
+ prop->prop.size = size;
+ return;
+ }
+ }
+
+ prop = xzalloc(sizeof(*prop));
+ list_insert_after(&prop->list_node, &node->properties);
+ prop->prop.name = name;
+ prop->prop.data = data;
+ prop->prop.size = size;
+}
+
+/*
+ * Find given string property in a node and return its content.
+ *
+ * @param node The device tree node to search.
+ * @param name The name of the property.
+ * @return The found string, or NULL.
+ */
+const char *dt_find_string_prop(const struct device_tree_node *node,
+ const char *name)
+{
+ const void *content;
+ size_t size;
+
+ dt_find_bin_prop(node, name, &content, &size);
+
+ return content;
+}
+
+/*
+ * Find given property in a node.
+ *
+ * @param node The device tree node to search.
+ * @param name The name of the property.
+ * @param data Pointer to return raw data blob in the property.
+ * @param size Pointer to return the size of data in bytes.
+ */
+void dt_find_bin_prop(const struct device_tree_node *node, const char *name,
+ const void **data, size_t *size)
+{
+ struct device_tree_property *prop;
+
+ *data = NULL;
+ *size = 0;
+
+ list_for_each(prop, node->properties, list_node) {
+ if (!strcmp(prop->prop.name, name)) {
+ *data = prop->prop.data;
+ *size = prop->prop.size;
+ return;
+ }
+ }
+}
+
+/*
+ * Add a string property to a node, or update it if it already exists.
+ *
+ * @param node The device tree node to add to.
+ * @param name The name of the new property.
+ * @param str The zero-terminated string to be stored in the property.
+ */
+void dt_add_string_prop(struct device_tree_node *node, const char *name,
+ const char *str)
+{
+ dt_add_bin_prop(node, name, (char *)str, strlen(str) + 1);
+}
+
+/*
+ * Add a 32-bit integer property to a node, or update it if it already exists.
+ *
+ * @param node The device tree node to add to.
+ * @param name The name of the new property.
+ * @param val The integer to be stored in the property.
+ */
+void dt_add_u32_prop(struct device_tree_node *node, const char *name, u32 val)
+{
+ u32 *val_ptr = xmalloc(sizeof(val));
+ *val_ptr = htobe32(val);
+ dt_add_bin_prop(node, name, val_ptr, sizeof(*val_ptr));
+}
+
+/*
+ * Add a 64-bit integer property to a node, or update it if it already exists.
+ *
+ * @param node The device tree node to add to.
+ * @param name The name of the new property.
+ * @param val The integer to be stored in the property.
+ */
+void dt_add_u64_prop(struct device_tree_node *node, const char *name, u64 val)
+{
+ u64 *val_ptr = xmalloc(sizeof(val));
+ *val_ptr = htobe64(val);
+ dt_add_bin_prop(node, name, val_ptr, sizeof(*val_ptr));
+}
+
+/*
+ * Add a 'reg' address list property to a node, or update it if it exists.
+ *
+ * @param node The device tree node to add to.
+ * @param regions Array of address values to be stored in the property.
+ * @param sizes Array of corresponding size values to 'addrs'.
+ * @param count Number of values in 'addrs' and 'sizes' (must be equal).
+ * @param addr_cells Value of #address-cells property valid for this node.
+ * @param size_cells Value of #size-cells property valid for this node.
+ */
+void dt_add_reg_prop(struct device_tree_node *node, u64 *addrs, u64 *sizes,
+ int count, u32 addr_cells, u32 size_cells)
+{
+ int i;
+ size_t length = (addr_cells + size_cells) * sizeof(u32) * count;
+ u8 *data = xmalloc(length);
+ u8 *cur = data;
+
+ for (i = 0; i < count; i++) {
+ dt_write_int(cur, addrs[i], addr_cells * sizeof(u32));
+ cur += addr_cells * sizeof(u32);
+ dt_write_int(cur, sizes[i], size_cells * sizeof(u32));
+ cur += size_cells * sizeof(u32);
+ }
+
+ dt_add_bin_prop(node, "reg", data, length);
+}
+
+/*
+ * Fixups to apply to a kernel's device tree before booting it.
+ */
+
+struct list_node device_tree_fixups;
+
+int dt_apply_fixups(struct device_tree *tree)
+{
+ struct device_tree_fixup *fixup;
+ list_for_each(fixup, device_tree_fixups, list_node) {
+ assert(fixup->fixup);
+ if (fixup->fixup(fixup, tree))
+ return 1;
+ }
+ return 0;
+}
+
+int dt_set_bin_prop_by_path(struct device_tree *tree, const char *path,
+ void *data, size_t data_size, int create)
+{
+ char *path_copy, *prop_name;
+ struct device_tree_node *dt_node;
+
+ path_copy = strdup(path);
+
+ if (!path_copy) {
+ printk(BIOS_ERR, "Failed to allocate a copy of path %s\n",
+ path);
+ return 1;
+ }
+
+ prop_name = strrchr(path_copy, '/');
+ if (!prop_name) {
+ free(path_copy);
+ printk(BIOS_ERR, "Path %s does not include '/'\n", path);
+ return 1;
+ }
+
+ *prop_name++ = '\0'; /* Separate path from the property name. */
+
+ dt_node = dt_find_node_by_path(tree, path_copy, NULL,
+ NULL, create);
+
+ if (!dt_node) {
+ printk(BIOS_ERR, "Failed to %s %s in the device tree\n",
+ create ? "create" : "find", path_copy);
+ free(path_copy);
+ return 1;
+ }
+
+ dt_add_bin_prop(dt_node, prop_name, data, data_size);
+ free(path_copy);
+
+ return 0;
+}
+
+/*
+ * Prepare the /reserved-memory/ node.
+ *
+ * Technically, this can be called more than one time, to init and/or retrieve
+ * the node. But dt_add_u32_prop() may leak a bit of memory if you do.
+ *
+ * @tree: Device tree to add/retrieve from.
+ * @return: The /reserved-memory/ node (or NULL, if error).
+ */
+struct device_tree_node *dt_init_reserved_memory_node(struct device_tree *tree)
+{
+ struct device_tree_node *reserved;
+ u32 addr = 0, size = 0;
+
+ reserved = dt_find_node_by_path(tree, "/reserved-memory", &addr,
+ &size, 1);
+ if (!reserved)
+ return NULL;
+
+ /* Binding doc says this should have the same #{address,size}-cells as
+ the root. */
+ dt_add_u32_prop(reserved, "#address-cells", addr);
+ dt_add_u32_prop(reserved, "#size-cells", size);
+ /* Binding doc says this should be empty (1:1 mapping from root). */
+ dt_add_bin_prop(reserved, "ranges", NULL, 0);
+
+ return reserved;
+}
+
+/*
+ * Increment a single phandle in prop at a given offset by a given adjustment.
+ *
+ * @param prop Property whose phandle should be adjusted.
+ * @param adjustment Value that should be added to the existing phandle.
+ * @param offset Byte offset of the phandle in the property data.
+ *
+ * @return New phandle value, or 0 on error.
+ */
+static uint32_t dt_adjust_phandle(struct device_tree_property *prop,
+ uint32_t adjustment, uint32_t offset)
+{
+ if (offset + 4 > prop->prop.size)
+ return 0;
+
+ uint32_t phandle = be32dec(prop->prop.data + offset);
+ if (phandle == 0 ||
+ phandle == FDT_PHANDLE_ILLEGAL ||
+ phandle == 0xffffffff)
+ return 0;
+
+ phandle += adjustment;
+ if (phandle >= FDT_PHANDLE_ILLEGAL)
+ return 0;
+
+ be32enc(prop->prop.data + offset, phandle);
+ return phandle;
+}
+
+/*
+ * Adjust all phandles in subtree by adding a new base offset.
+ *
+ * @param node Root node of the subtree to work on.
+ * @param base New phandle base to be added to all phandles.
+ *
+ * @return New highest phandle in the subtree, or 0 on error.
+ */
+static uint32_t dt_adjust_all_phandles(struct device_tree_node *node,
+ uint32_t base)
+{
+ uint32_t new_max = MAX(base, 1); /* make sure we don't return 0 */
+ struct device_tree_property *prop;
+ struct device_tree_node *child;
+
+ if (!node)
+ return new_max;
+
+ list_for_each(prop, node->properties, list_node)
+ if (dt_prop_is_phandle(prop)) {
+ node->phandle = dt_adjust_phandle(prop, base, 0);
+ if (!node->phandle)
+ return 0;
+ new_max = MAX(new_max, node->phandle);
+ } /* no break -- can have more than one phandle prop */
+
+ list_for_each(child, node->children, list_node)
+ new_max = MAX(new_max, dt_adjust_all_phandles(child, base));
+
+ return new_max;
+}
+
+/*
+ * Apply a /__local_fixup__ subtree to the corresponding overlay subtree.
+ *
+ * @param node Root node of the overlay subtree to fix up.
+ * @param node Root node of the /__local_fixup__ subtree.
+ * @param base Adjustment that was added to phandles in the overlay.
+ *
+ * @return 0 on success, -1 on error.
+ */
+static int dt_fixup_locals(struct device_tree_node *node,
+ struct device_tree_node *fixup, uint32_t base)
+{
+ struct device_tree_property *prop;
+ struct device_tree_property *fixup_prop;
+ struct device_tree_node *child;
+ struct device_tree_node *fixup_child;
+ int i;
+
+ /*
+ * For local fixups the /__local_fixup__ subtree contains the same node
+ * hierarchy as the main tree we're fixing up. Each property contains
+ * the fixup offsets for the respective property in the main tree. For
+ * each property in the fixup node, find the corresponding property in
+ * the base node and apply fixups to all offsets it specifies.
+ */
+ list_for_each(fixup_prop, fixup->properties, list_node) {
+ struct device_tree_property *base_prop = NULL;
+ list_for_each(prop, node->properties, list_node)
+ if (!strcmp(prop->prop.name, fixup_prop->prop.name)) {
+ base_prop = prop;
+ break;
+ }
+
+ /* We should always find a corresponding base prop for a fixup,
+ and fixup props contain a list of 32-bit fixup offsets. */
+ if (!base_prop || fixup_prop->prop.size % sizeof(uint32_t))
+ return -1;
+
+ for (i = 0; i < fixup_prop->prop.size; i += sizeof(uint32_t))
+ if (!dt_adjust_phandle(base_prop, base, be32dec(
+ fixup_prop->prop.data + i)))
+ return -1;
+ }
+
+ /* Now recursively descend both the base tree and the /__local_fixups__
+ subtree in sync to apply all fixups. */
+ list_for_each(fixup_child, fixup->children, list_node) {
+ struct device_tree_node *base_child = NULL;
+ list_for_each(child, node->children, list_node)
+ if (!strcmp(child->name, fixup_child->name)) {
+ base_child = child;
+ break;
+ }
+
+ /* All fixup nodes should have a corresponding base node. */
+ if (!base_child)
+ return -1;
+
+ if (dt_fixup_locals(base_child, fixup_child, base) < 0)
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * Update all /__symbols__ properties in an overlay that start with
+ * "/fragment@X/__overlay__" with corresponding path prefix in the base tree.
+ *
+ * @param symbols /__symbols__ done to update.
+ * @param fragment /fragment@X node that references to should be updated.
+ * @param base_path Path of base tree node that the fragment overlaid.
+ */
+static void dt_fix_symbols(struct device_tree_node *symbols,
+ struct device_tree_node *fragment,
+ const char *base_path)
+{
+ struct device_tree_property *prop;
+ char buf[512]; /* Should be enough for maximum DT path length? */
+ char node_path[64]; /* easily enough for /fragment@XXXX/__overlay__ */
+
+ if (!symbols) /* If the overlay has no /__symbols__ node, we're done! */
+ return;
+
+ int len = snprintf(node_path, sizeof(node_path), "/%s/__overlay__",
+ fragment->name);
+
+ list_for_each(prop, symbols->properties, list_node)
+ if (!strncmp(prop->prop.data, node_path, len)) {
+ prop->prop.size = snprintf(buf, sizeof(buf), "%s%s",
+ base_path, (char *)prop->prop.data + len) + 1;
+ free(prop->prop.data);
+ prop->prop.data = strdup(buf);
+ }
+}
+
+/*
+ * Fix up overlay according to a property in /__fixup__. If the fixed property
+ * is a /fragment@X:target, also update /__symbols__ references to fragment.
+ *
+ * @params overlay Overlay to fix up.
+ * @params fixup /__fixup__ property.
+ * @params phandle phandle value to insert where the fixup points to.
+ * @params base_path Path to the base DT node that the fixup points to.
+ * @params overlay_symbols /__symbols__ node of the overlay.
+ *
+ * @return 0 on success, -1 on error.
+ */
+static int dt_fixup_external(struct device_tree *overlay,
+ struct device_tree_property *fixup,
+ uint32_t phandle, const char *base_path,
+ struct device_tree_node *overlay_symbols)
+{
+ struct device_tree_property *prop;
+
+ /* External fixup properties are encoded as "<path>:<prop>:<offset>". */
+ char *entry = fixup->prop.data;
+ while ((void *)entry < fixup->prop.data + fixup->prop.size) {
+ /* okay to destroy fixup property value, won't need it again */
+ char *node_path = entry;
+ entry = strchr(node_path, ':');
+ if (!entry)
+ return -1;
+ *entry++ = '\0';
+
+ char *prop_name = entry;
+ entry = strchr(prop_name, ':');
+ if (!entry)
+ return -1;
+ *entry++ = '\0';
+
+ struct device_tree_node *ovl_node = dt_find_node_by_path(
+ overlay, node_path, NULL, NULL, 0);
+ if (!ovl_node || !isdigit(*entry))
+ return -1;
+
+ struct device_tree_property *ovl_prop = NULL;
+ list_for_each(prop, ovl_node->properties, list_node)
+ if (!strcmp(prop->prop.name, prop_name)) {
+ ovl_prop = prop;
+ break;
+ }
+
+ /* Move entry to first char after number, must be a '\0'. */
+ uint32_t offset = skip_atoi(&entry);
+ if (!ovl_prop || offset + 4 > ovl_prop->prop.size || entry[0])
+ return -1;
+ entry++; /* jump over '\0' to potential next fixup */
+
+ be32enc(ovl_prop->prop.data + offset, phandle);
+
+ /* If this is a /fragment@X:target property, update references
+ to this fragment in the overlay __symbols__ now. */
+ if (offset == 0 && !strcmp(prop_name, "target") &&
+ !strchr(node_path + 1, '/')) /* only toplevel nodes */
+ dt_fix_symbols(overlay_symbols, ovl_node, base_path);
+ }
+
+ return 0;
+}
+
+/*
+ * Apply all /__fixup__ properties in the overlay. This will destroy the
+ * property data in /__fixup__ and it should not be accessed again.
+ *
+ * @params tree Base device tree that the overlay updates.
+ * @params symbols /__symbols__ node of the base device tree.
+ * @params overlay Overlay to fix up.
+ * @params fixups /__fixup__ node in the overlay.
+ * @params overlay_symbols /__symbols__ node of the overlay.
+ *
+ * @return 0 on success, -1 on error.
+ */
+static int dt_fixup_all_externals(struct device_tree *tree,
+ struct device_tree_node *symbols,
+ struct device_tree *overlay,
+ struct device_tree_node *fixups,
+ struct device_tree_node *overlay_symbols)
+{
+ struct device_tree_property *fix;
+
+ /* If we have any external fixups, base tree must have /__symbols__. */
+ if (!symbols)
+ return -1;
+
+ /*
+ * Unlike /__local_fixups__, /__fixups__ is not a whole subtree that
+ * mirrors the node hierarchy. It's just a directory of fixup properties
+ * that each directly contain all information necessary to apply them.
+ */
+ list_for_each(fix, fixups->properties, list_node) {
+ /* The name of a fixup property is the label of the node we want
+ a property to phandle-reference. Look up in /__symbols__. */
+ const char *path = dt_find_string_prop(symbols, fix->prop.name);
+ if (!path)
+ return -1;
+
+ /* Find node the label pointed to figure out its phandle. */
+ struct device_tree_node *node = dt_find_node_by_path(tree, path,
+ NULL, NULL, 0);
+ if (!node)
+ return -1;
+
+ /* Write into the overlay property(s) pointing to that node. */
+ if (dt_fixup_external(overlay, fix, node->phandle,
+ path, overlay_symbols) < 0)
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * Copy all nodes and properties from one DT subtree into another. This is a
+ * shallow copy so both trees will point to the same property data afterwards.
+ *
+ * @params dst Destination subtree to copy into.
+ * @params src Source subtree to copy from.
+ * @params upd 1 to overwrite same-name properties, 0 to discard them.
+ */
+static void dt_copy_subtree(struct device_tree_node *dst,
+ struct device_tree_node *src, int upd)
+{
+ struct device_tree_property *prop;
+ struct device_tree_property *src_prop;
+ list_for_each(src_prop, src->properties, list_node) {
+ if (dt_prop_is_phandle(src_prop) ||
+ !strcmp(src_prop->prop.name, "name")) {
+ printk(BIOS_DEBUG,
+ "WARNING: ignoring illegal overlay prop '%s'\n",
+ src_prop->prop.name);
+ continue;
+ }
+
+ struct device_tree_property *dst_prop = NULL;
+ list_for_each(prop, dst->properties, list_node)
+ if (!strcmp(prop->prop.name, src_prop->prop.name)) {
+ dst_prop = prop;
+ break;
+ }
+
+ if (dst_prop) {
+ if (!upd) {
+ printk(BIOS_DEBUG,
+ "WARNING: ignoring prop update '%s'\n",
+ src_prop->prop.name);
+ continue;
+ }
+ } else {
+ dst_prop = xzalloc(sizeof(*dst_prop));
+ list_insert_after(&dst_prop->list_node,
+ &dst->properties);
+ }
+
+ dst_prop->prop = src_prop->prop;
+ }
+
+ struct device_tree_node *node;
+ struct device_tree_node *src_node;
+ list_for_each(src_node, src->children, list_node) {
+ struct device_tree_node *dst_node = NULL;
+ list_for_each(node, dst->children, list_node)
+ if (!strcmp(node->name, src_node->name)) {
+ dst_node = node;
+ break;
+ }
+
+ if (!dst_node) {
+ dst_node = xzalloc(sizeof(*dst_node));
+ *dst_node = *src_node;
+ list_insert_after(&dst_node->list_node, &dst->children);
+ } else {
+ dt_copy_subtree(dst_node, src_node, upd);
+ }
+ }
+}
+
+/*
+ * Apply an overlay /fragment@X node to a base device tree.
+ *
+ * @param tree Base device tree.
+ * @param fragment /fragment@X node.
+ * @params overlay_symbols /__symbols__ node of the overlay.
+ *
+ * @return 0 on success, -1 on error.
+ */
+static int dt_import_fragment(struct device_tree *tree,
+ struct device_tree_node *fragment,
+ struct device_tree_node *overlay_symbols)
+{
+ /* The actual overlaid nodes/props are in an __overlay__ child node. */
+ static const char *overlay_path[] = { "__overlay__", NULL };
+ struct device_tree_node *overlay = dt_find_node(fragment, overlay_path,
+ NULL, NULL, 0);
+
+ /* If it doesn't have an __overlay__ child, it's not a fragment. */
+ if (!overlay)
+ return 0;
+
+ /* Target node of the fragment can be given by path or by phandle. */
+ struct device_tree_property *prop;
+ struct device_tree_property *phandle = NULL;
+ struct device_tree_property *path = NULL;
+ list_for_each(prop, fragment->properties, list_node) {
+ if (!strcmp(prop->prop.name, "target")) {
+ phandle = prop;
+ break; /* phandle target has priority, stop looking */
+ }
+ if (!strcmp(prop->prop.name, "target-path"))
+ path = prop;
+ }
+
+ struct device_tree_node *target = NULL;
+ if (phandle) {
+ if (phandle->prop.size != sizeof(uint32_t))
+ return -1;
+ target = dt_find_node_by_phandle(tree->root,
+ be32dec(phandle->prop.data));
+ /* Symbols already updated as part of dt_fixup_external(). */
+ } else if (path) {
+ target = dt_find_node_by_path(tree, path->prop.data,
+ NULL, NULL, 0);
+ dt_fix_symbols(overlay_symbols, fragment, path->prop.data);
+ }
+ if (!target)
+ return -1;
+
+ dt_copy_subtree(target, overlay, 1);
+ return 0;
+}
+
+/*
+ * Apply a device tree overlay to a base device tree. This will
+ * destroy/incorporate the overlay data, so it should not be freed or reused.
+ * See dtc.git/Documentation/dt-object-internal.txt for overlay format details.
+ *
+ * @param tree Unflattened base device tree to add the overlay into.
+ * @param overlay Unflattened overlay device tree to apply to the base.
+ *
+ * @return 0 on success, -1 on error.
+ */
+int dt_apply_overlay(struct device_tree *tree, struct device_tree *overlay)
+{
+ /*
+ * First, we need to make sure phandles inside the overlay don't clash
+ * with those in the base tree. We just define the highest phandle value
+ * in the base tree as the "phandle offset" for this overlay and
+ * increment all phandles in it by that value.
+ */
+ uint32_t phandle_base = tree->max_phandle;
+ uint32_t new_max = dt_adjust_all_phandles(overlay->root, phandle_base);
+ if (!new_max) {
+ printk(BIOS_ERR, "invalid phandles in overlay\n");
+ return -1;
+ }
+ tree->max_phandle = new_max;
+
+ /* Now that we changed phandles in the overlay, we need to update any
+ nodes referring to them. Those are listed in /__local_fixups__. */
+ struct device_tree_node *local_fixups = dt_find_node_by_path(overlay,
+ "/__local_fixups__", NULL, NULL, 0);
+ if (local_fixups && dt_fixup_locals(overlay->root, local_fixups,
+ phandle_base) < 0) {
+ printk(BIOS_ERR, "invalid local fixups in overlay\n");
+ return -1;
+ }
+
+ /*
+ * Besides local phandle references (from nodes within the overlay to
+ * other nodes within the overlay), the overlay may also contain phandle
+ * references to the base tree. These are stored with invalid values and
+ * must be updated now. /__symbols__ contains a list of all labels in
+ * the base tree, and /__fixups__ describes all nodes in the overlay
+ * that contain external phandle references.
+ * We also take this opportunity to update all /fragment@X/__overlay__/
+ * prefixes in the overlay's /__symbols__ node to the correct path that
+ * the fragment will be placed in later, since this is the only step
+ * where we have all necessary information for that easily available.
+ */
+ struct device_tree_node *symbols = dt_find_node_by_path(tree,
+ "/__symbols__", NULL, NULL, 0);
+ struct device_tree_node *fixups = dt_find_node_by_path(overlay,
+ "/__fixups__", NULL, NULL, 0);
+ struct device_tree_node *overlay_symbols = dt_find_node_by_path(overlay,
+ "/__symbols__", NULL, NULL, 0);
+ if (fixups && dt_fixup_all_externals(tree, symbols, overlay,
+ fixups, overlay_symbols) < 0) {
+ printk(BIOS_ERR, "cannot match external fixups from overlay\n");
+ return -1;
+ }
+
+ /* After all this fixing up, we can finally merge overlay into the tree
+ (one fragment at a time, because for some reason it's split up). */
+ struct device_tree_node *fragment;
+ list_for_each(fragment, overlay->root->children, list_node)
+ if (dt_import_fragment(tree, fragment, overlay_symbols) < 0) {
+ printk(BIOS_ERR, "bad DT fragment '%s'\n",
+ fragment->name);
+ return -1;
+ }
+
+ /*
+ * We need to also update /__symbols__ to include labels from this
+ * overlay, in case we want to load further overlays with external
+ * phandle references to it. If the base tree already has a /__symbols__
+ * we merge them together, otherwise we just insert the overlay's
+ * /__symbols__ node into the base tree root.
+ */
+ if (overlay_symbols) {
+ if (symbols)
+ dt_copy_subtree(symbols, overlay_symbols, 0);
+ else
+ list_insert_after(&overlay_symbols->list_node,
+ &tree->root->children);
+ }
+
+ return 0;
+}