| /* Taken from depthcharge: src/base/device_tree.c */ |
| /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| |
| #include <assert.h> |
| #include <commonlib/stdlib.h> |
| #include <console/console.h> |
| #include <ctype.h> |
| #include <device_tree.h> |
| #include <endian.h> |
| #include <stdint.h> |
| #include <string.h> |
| #include <stddef.h> |
| #include <stdlib.h> |
| |
| /* |
| * Functions for picking apart flattened trees. |
| */ |
| |
| 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); |
| |
| 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); |
| } |
| |
| int fdt_node_name(const void *blob, uint32_t offset, const char **name) |
| { |
| uint8_t *ptr = ((uint8_t *)blob) + offset; |
| if (be32dec(ptr) != FDT_TOKEN_BEGIN_NODE) |
| return 0; |
| |
| ptr += 4; |
| if (name) |
| *name = (char *)ptr; |
| return ALIGN_UP(strlen((char *)ptr) + 1, sizeof(uint32_t)) + 4; |
| } |
| |
| static int dt_prop_is_phandle(struct device_tree_property *prop) |
| { |
| return !(strcmp("phandle", prop->prop.name) && |
| strcmp("linux,phandle", prop->prop.name)); |
| } |
| |
| |
| |
| /* |
| * 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 (const char *c = prop->data; *c != '\0'; c++) |
| if (!isprint(*c)) |
| is_string = 0; |
| |
| 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_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); |
| } |
| |
| |
| |
| /* |
| * A utility function to skip past nodes in flattened trees. |
| */ |
| |
| int fdt_skip_node(const void *blob, uint32_t start_offset) |
| { |
| int offset = start_offset; |
| int size; |
| |
| const char *name; |
| size = fdt_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; |
| |
| return offset - start_offset + sizeof(uint32_t); |
| } |
| |
| |
| |
| /* |
| * Functions to turn a flattened tree into an unflattened one. |
| */ |
| |
| 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_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; |
| } |
| |
| 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; |
| |
| 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_DEBUG, "Invalid device tree magic %#.8x!\n", magic); |
| free(tree); |
| return NULL; |
| } |
| if (last_comp_version > FDT_SUPPORTED_VERSION) { |
| printk(BIOS_DEBUG, "Unsupported device tree version %u(>=%u)\n", |
| version, last_comp_version); |
| free(tree); |
| return NULL; |
| } |
| if (version > FDT_SUPPORTED_VERSION) |
| printk(BIOS_DEBUG, |
| "NOTE: FDT version %u too new, should add support!\n", |
| version); |
| |
| 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 = malloc(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 addrs 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_DEBUG, "ERROR: 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_DEBUG, "ERROR: 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_DEBUG, |
| "ERROR: 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_DEBUG, "ERROR: 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; |
| } |