2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2013 David Chisnall
7 * This software was developed by SRI International and the University of
8 * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
9 * ("CTSRD"), as part of the DARPA CRASH research programme.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 #include <unordered_map>
39 #include <unordered_set>
45 #include "input_buffer.hh"
62 * Type for device tree write functions.
64 typedef void (device_tree::* tree_write_fn_ptr)(int);
66 * Type for device tree read functions.
68 typedef void (device_tree::* tree_read_fn_ptr)(const std::string &, FILE *);
70 * Type for (owned) pointers to properties.
72 typedef std::shared_ptr<property> property_ptr;
74 * Owning pointer to a node.
76 typedef std::unique_ptr<node> node_ptr;
78 * Map from macros to property pointers.
80 typedef std::unordered_map<std::string, property_ptr> define_map;
82 * Set of strings used for label names.
84 typedef std::unordered_set<std::string> string_set;
86 * Properties may contain a number of different value, each with a different
87 * label. This class encapsulates a single value.
92 * The label for this data. This is usually empty.
96 * If this value is a string, or something resolved from a string (a
97 * reference) then this contains the source string.
99 std::string string_data;
101 * The data that should be written to the final output.
103 byte_buffer byte_data;
105 * Enumeration describing the possible types of a value. Note that
106 * property-coded arrays will appear simply as binary (or possibly
107 * string, if they happen to be nul-terminated and printable), and must
108 * be checked separately.
113 * This is a list of strings. When read from source, string
114 * lists become one property value for each string, however
115 * when read from binary we have a single property value
116 * incorporating the entire text, with nul bytes separating the
121 * This property contains a single string.
125 * This is a binary value. Check the size of byte_data to
126 * determine how many bytes this contains.
129 /** This contains a short-form address that should be replaced
130 * by a fully-qualified version. This will only appear when
131 * the input is a device tree source. When parsed from a
132 * device tree blob, the cross reference will have already been
133 * resolved and the property value will be a string containing
134 * the full path of the target node. */
137 * This is a phandle reference. When parsed from source, the
138 * string_data will contain the node label for the target and,
139 * after cross references have been resolved, the binary data
140 * will contain a 32-bit integer that should match the phandle
141 * property of the target node.
145 * An empty property value. This will never appear on a real
146 * property value, it is used by checkers to indicate that no
147 * property values should exist for a property.
151 * The type of this property has not yet been determined.
156 * The type of this property.
160 * Returns true if this value is a cross reference, false otherwise.
162 inline bool is_cross_reference()
164 return is_type(CROSS_REFERENCE);
167 * Returns true if this value is a phandle reference, false otherwise.
169 inline bool is_phandle()
171 return is_type(PHANDLE);
174 * Returns true if this value is a string, false otherwise.
176 inline bool is_string()
178 return is_type(STRING);
181 * Returns true if this value is a string list (a nul-separated
182 * sequence of strings), false otherwise.
184 inline bool is_string_list()
186 return is_type(STRING_LIST);
189 * Returns true if this value is binary, false otherwise.
191 inline bool is_binary()
193 return is_type(BINARY);
196 * Returns this property value as a 32-bit integer. Returns 0 if this
197 * property value is not 32 bits long. The bytes in the property value
198 * are assumed to be in big-endian format, but the return value is in
199 * the host native endian.
201 uint32_t get_as_uint32();
203 * Default constructor, specifying the label of the value.
205 property_value(std::string l=std::string()) : label(l), type(UNKNOWN) {}
207 * Writes the data for this value into an output buffer.
209 void push_to_buffer(byte_buffer &buffer);
212 * Writes the property value to the standard output. This uses the
213 * following heuristics for deciding how to print the output:
215 * - If the value is nul-terminated and only contains printable
216 * characters, it is written as a string.
217 * - If it is a multiple of 4 bytes long, then it is printed as cells.
218 * - Otherwise, it is printed as a byte buffer.
220 void write_dts(FILE *file);
222 * Tries to merge adjacent property values, returns true if it succeeds and
225 bool try_to_merge(property_value &other);
227 * Returns the size (in bytes) of this property value.
232 * Returns whether the value is of the specified type. If the type of
233 * the value has not yet been determined, then this calculates it.
235 inline bool is_type(value_type v)
244 * Determines the type of the value based on its contents.
248 * Writes the property value to the specified file as a quoted string.
249 * This is used when generating DTS.
251 void write_as_string(FILE *file);
253 * Writes the property value to the specified file as a sequence of
254 * 32-bit big-endian cells. This is used when generating DTS.
256 void write_as_cells(FILE *file);
258 * Writes the property value to the specified file as a sequence of
259 * bytes. This is used when generating DTS.
261 void write_as_bytes(FILE *file);
265 * A value encapsulating a single property. This contains a key, optionally a
266 * label, and optionally one or more values.
271 * The name of this property.
275 * Zero or more labels.
279 * The values in this property.
281 std::vector<property_value> values;
283 * Value indicating that this is a valid property. If a parse error
284 * occurs, then this value is false.
288 * Parses a string property value, i.e. a value enclosed in double quotes.
290 void parse_string(text_input_buffer &input);
292 * Parses one or more 32-bit values enclosed in angle brackets.
294 void parse_cells(text_input_buffer &input, int cell_size);
296 * Parses an array of bytes, contained within square brackets.
298 void parse_bytes(text_input_buffer &input);
300 * Parses a reference. This is a node label preceded by an ampersand
301 * symbol, which should expand to the full path to that node.
303 * Note: The specification says that the target of such a reference is
304 * a node name, however dtc assumes that it is a label, and so we
305 * follow their interpretation for compatibility.
307 void parse_reference(text_input_buffer &input);
309 * Parse a predefined macro definition for a property.
311 void parse_define(text_input_buffer &input, define_map *defines);
313 * Constructs a new property from two input buffers, pointing to the
314 * struct and strings tables in the device tree blob, respectively.
315 * The structs input buffer is assumed to have just consumed the
318 property(input_buffer &structs, input_buffer &strings);
320 * Parses a new property from the input buffer.
322 property(text_input_buffer &input,
326 define_map *defines);
329 * Creates an empty property.
331 property(std::string &&k, string_set &&l=string_set())
332 : key(k), labels(l), valid(true) {}
336 property(property &p) : key(p.key), labels(p.labels), values(p.values),
339 * Factory method for constructing a new property. Attempts to parse a
340 * property from the input, and returns it on success. On any parse
341 * error, this will return 0.
343 static property_ptr parse_dtb(input_buffer &structs,
344 input_buffer &strings);
346 * Factory method for constructing a new property. Attempts to parse a
347 * property from the input, and returns it on success. On any parse
348 * error, this will return 0.
350 static property_ptr parse(text_input_buffer &input,
352 string_set &&labels=string_set(),
353 bool semicolonTerminated=true,
354 define_map *defines=0);
356 * Iterator type used for accessing the values of a property.
358 typedef std::vector<property_value>::iterator value_iterator;
360 * Returns an iterator referring to the first value in this property.
362 inline value_iterator begin()
364 return values.begin();
367 * Returns an iterator referring to the last value in this property.
369 inline value_iterator end()
374 * Adds a new value to an existing property.
376 inline void add_value(property_value v)
381 * Returns the key for this property.
383 inline const std::string &get_key()
388 * Writes the property to the specified writer. The property name is a
389 * reference into the strings table.
391 void write(dtb::output_writer &writer, dtb::string_table &strings);
393 * Writes in DTS format to the specified file, at the given indent
394 * level. This will begin the line with the number of tabs specified
395 * as the indent level and then write the property in the most
396 * applicable way that it can determine.
398 void write_dts(FILE *file, int indent);
400 * Returns the byte offset of the specified property value.
402 size_t offset_of_value(property_value &val);
406 * Class encapsulating a device tree node. Nodes may contain properties and
413 * The labels for this node, if any. Node labels are used as the
414 * targets for cross references.
416 std::unordered_set<std::string> labels;
418 * The name of the node.
422 * The name of the node is a path reference.
424 bool name_is_path_reference = false;
426 * The unit address of the node, which is optionally written after the
427 * name followed by an at symbol.
429 std::string unit_address;
431 * A flag indicating that this node has been marked /omit-if-no-ref/ and
432 * will be omitted if it is not referenced, either directly or indirectly,
433 * by a node that is not similarly denoted.
435 bool omit_if_no_ref = false;
437 * A flag indicating that this node has been referenced, either directly
438 * or indirectly, by a node that is not marked /omit-if-no-ref/.
442 * The type for the property vector.
444 typedef std::vector<property_ptr> property_vector;
446 * Iterator type for child nodes.
448 typedef std::vector<node_ptr>::iterator child_iterator;
450 * Recursion behavior to be observed for visiting
455 * Recurse as normal through the rest of the tree.
459 * Continue recursing through the device tree, but do not
460 * recurse through this branch of the tree any further.
464 * Immediately halt the visit. No further nodes will be visited.
470 * Adaptor to use children in range-based for loops.
474 child_range(node &nd) : n(nd) {}
475 child_iterator begin() { return n.child_begin(); }
476 child_iterator end() { return n.child_end(); }
481 * Adaptor to use properties in range-based for loops.
483 struct property_range
485 property_range(node &nd) : n(nd) {}
486 property_vector::iterator begin() { return n.property_begin(); }
487 property_vector::iterator end() { return n.property_end(); }
492 * The properties contained within this node.
494 property_vector props;
496 * The children of this node.
498 std::vector<node_ptr> children;
500 * Children that should be deleted from this node when merging.
502 std::unordered_set<std::string> deleted_children;
504 * Properties that should be deleted from this node when merging.
506 std::unordered_set<std::string> deleted_props;
508 * A flag indicating whether this node is valid. This is set to false
509 * if an error occurs during parsing.
513 * Parses a name inside a node, writing the string passed as the last
514 * argument as an error if it fails.
516 std::string parse_name(text_input_buffer &input,
520 * Constructs a new node from two input buffers, pointing to the struct
521 * and strings tables in the device tree blob, respectively.
523 node(input_buffer &structs, input_buffer &strings);
525 * Parses a new node from the specified input buffer. This is called
526 * when the input cursor is on the open brace for the start of the
527 * node. The name, and optionally label and unit address, should have
528 * already been parsed.
530 node(text_input_buffer &input,
533 std::unordered_set<std::string> &&l,
537 * Creates a special node with the specified name and properties.
539 node(const std::string &n, const std::vector<property_ptr> &p);
541 * Comparison function for properties, used when sorting the properties
542 * vector. Orders the properties based on their names.
544 static inline bool cmp_properties(property_ptr &p1, property_ptr &p2);
547 return p1->get_key() < p2->get_key();
551 * Comparison function for nodes, used when sorting the children
552 * vector. Orders the nodes based on their names or, if the names are
553 * the same, by the unit addresses.
555 static inline bool cmp_children(node_ptr &c1, node_ptr &c2);
558 * Sorts the node's properties and children into alphabetical order and
559 * recursively sorts the children.
563 * Returns an iterator for the first child of this node.
565 inline child_iterator child_begin()
567 return children.begin();
570 * Returns an iterator after the last child of this node.
572 inline child_iterator child_end()
574 return children.end();
577 * Returns a range suitable for use in a range-based for loop describing
578 * the children of this node.
580 inline child_range child_nodes()
582 return child_range(*this);
585 * Accessor for the deleted children.
587 inline const std::unordered_set<std::string> &deleted_child_nodes()
589 return deleted_children;
592 * Accessor for the deleted properties
594 inline const std::unordered_set<std::string> &deleted_properties()
596 return deleted_props;
599 * Returns a range suitable for use in a range-based for loop describing
600 * the properties of this node.
602 inline property_range properties()
604 return property_range(*this);
607 * Returns an iterator after the last property of this node.
609 inline property_vector::iterator property_begin()
611 return props.begin();
614 * Returns an iterator for the first property of this node.
616 inline property_vector::iterator property_end()
621 * Factory method for constructing a new node. Attempts to parse a
622 * node in DTS format from the input, and returns it on success. On
623 * any parse error, this will return 0. This should be called with the
624 * cursor on the open brace of the property, after the name and so on
627 static node_ptr parse(text_input_buffer &input,
630 std::unordered_set<std::string> &&label=std::unordered_set<std::string>(),
631 std::string &&address=std::string(),
632 define_map *defines=0);
634 * Factory method for constructing a new node. Attempts to parse a
635 * node in DTB format from the input, and returns it on success. On
636 * any parse error, this will return 0. This should be called with the
637 * cursor on the open brace of the property, after the name and so on
640 static node_ptr parse_dtb(input_buffer &structs, input_buffer &strings);
642 * Construct a new special node from a name and set of properties.
644 static node_ptr create_special_node(const std::string &name,
645 const std::vector<property_ptr> &props);
647 * Returns a property corresponding to the specified key, or 0 if this
648 * node does not contain a property of that name.
650 property_ptr get_property(const std::string &key);
652 * Adds a new property to this node.
654 inline void add_property(property_ptr &p)
659 * Adds a new child to this node.
661 inline void add_child(node_ptr &&n)
663 children.push_back(std::move(n));
666 * Deletes any children from this node.
668 inline void delete_children_if(bool (*predicate)(node_ptr &))
670 children.erase(std::remove_if(children.begin(), children.end(), predicate), children.end());
673 * Merges a node into this one. Any properties present in both are
674 * overridden, any properties present in only one are preserved.
676 void merge_node(node_ptr &other);
678 * Write this node to the specified output. Although nodes do not
679 * refer to a string table directly, their properties do. The string
680 * table passed as the second argument is used for the names of
681 * properties within this node and its children.
683 void write(dtb::output_writer &writer, dtb::string_table &strings);
685 * Writes the current node as DTS to the specified file. The second
686 * parameter is the indent level. This function will start every line
687 * with this number of tabs.
689 void write_dts(FILE *file, int indent);
691 * Recursively visit this node and then its children based on the
692 * callable's return value. The callable may return VISIT_BREAK
693 * immediately halt all recursion and end the visit, VISIT_CONTINUE to
694 * not recurse into the current node's children, or VISIT_RECURSE to recurse
695 * through children as expected. parent will be passed to the callable.
697 visit_behavior visit(std::function<visit_behavior(node&, node*)>, node *parent);
701 * Class encapsulating the entire parsed FDT. This is the top-level class,
702 * which parses the entire DTS representation and write out the finished
709 * Type used for node paths. A node path is sequence of names and unit
712 class node_path : public std::vector<std::pair<std::string,std::string>>
716 * Converts this to a string representation.
718 std::string to_string() const;
721 * Name that we should use for phandle nodes.
729 /** Create both nodes. */
734 * The format that we should use for writing phandles.
736 phandle_format phandle_node_name = EPAPR;
738 * Flag indicating that this tree is valid. This will be set to false
743 * Flag indicating that this tree requires garbage collection. This will be
744 * set to true if a node marked /omit-if-no-ref/ is encountered.
746 bool garbage_collect = false;
748 * Type used for memory reservations. A reservation is two 64-bit
749 * values indicating a base address and length in memory that the
750 * kernel should not use. The high 32 bits are ignored on 32-bit
753 typedef std::pair<uint64_t, uint64_t> reservation;
755 * The memory reserves table.
757 std::vector<reservation> reservations;
759 * Root node. All other nodes are children of this node.
763 * Mapping from names to nodes. Only unambiguous names are recorded,
764 * duplicate names are stored as (node*)-1.
766 std::unordered_map<std::string, node*> node_names;
768 * A map from labels to node paths. When resolving cross references,
769 * we look up referenced nodes in this and replace the cross reference
770 * with the full path to its target.
772 std::unordered_map<std::string, node_path> node_paths;
774 * All of the elements in `node_paths` in the order that they were
775 * created. This is used for emitting the `__symbols__` section, where
776 * we want to guarantee stable ordering.
778 std::vector<std::pair<std::string, node_path>> ordered_node_paths;
780 * A collection of property values that are references to other nodes.
781 * These should be expanded to the full path of their targets.
783 std::vector<property_value*> cross_references;
785 * The location of something requiring a fixup entry.
790 * The path to the node.
794 * The property containing the reference.
798 * The property value that contains the reference.
803 * A collection of property values that refer to phandles. These will
804 * be replaced by the value of the phandle property in their
807 std::vector<fixup> fixups;
809 * The locations of all of the values that are supposed to become phandle
810 * references, but refer to things outside of this file.
812 std::vector<std::reference_wrapper<fixup>> unresolved_fixups;
814 * The names of nodes that target phandles.
816 std::unordered_set<std::string> phandle_targets;
818 * A collection of input buffers that we are using. These input
819 * buffers are the ones that own their memory, and so we must preserve
820 * them for the lifetime of the device tree.
822 std::vector<std::unique_ptr<input_buffer>> buffers;
824 * A map of used phandle values to nodes. All phandles must be unique,
825 * so we keep a set of ones that the user explicitly provides in the
826 * input to ensure that we don't reuse them.
828 * This is a map, rather than a set, because we also want to be able to
829 * find phandles that were provided by the user explicitly when we are
832 std::unordered_map<uint32_t, node*> used_phandles;
834 * Paths to search for include files. This contains a set of
835 * nul-terminated strings, which are not owned by this class and so
836 * must be freed separately.
838 std::vector<std::string> include_paths;
840 * Dictionary of predefined macros provided on the command line.
844 * The default boot CPU, specified in the device tree header.
846 uint32_t boot_cpu = 0;
848 * The number of empty reserve map entries to generate in the blob.
850 uint32_t spare_reserve_map_entries = 0;
852 * The minimum size in bytes of the blob.
854 uint32_t minimum_blob_size = 0;
856 * The number of bytes of padding to add to the end of the blob.
858 uint32_t blob_padding = 0;
860 * Is this tree a plugin?
862 bool is_plugin = false;
864 * Visit all of the nodes recursively, and if they have labels then add
865 * them to the node_paths and node_names vectors so that they can be
866 * used in resolving cross references. Also collects phandle
867 * properties that have been explicitly added.
869 void collect_names_recursive(node_ptr &n, node_path &path);
871 * Assign a phandle property to a single node. The next parameter
872 * holds the phandle to be assigned, and will be incremented upon
875 property_ptr assign_phandle(node *n, uint32_t &next);
877 * Assign phandle properties to all nodes that have been referenced and
878 * require one. This method will recursively visit the tree starting at
879 * the node that it is passed.
881 void assign_phandles(node_ptr &n, uint32_t &next);
883 * Calls the recursive version of this method on every root node.
885 void collect_names();
887 * Resolves all cross references. Any properties that refer to another
888 * node must have their values replaced by either the node path or
889 * phandle value. The phandle parameter holds the next phandle to be
890 * assigned, should the need arise. It will be incremented upon each
891 * assignment of a phandle. Garbage collection of unreferenced nodes
892 * marked for "delete if unreferenced" will also occur here.
894 void resolve_cross_references(uint32_t &phandle);
896 * Garbage collects nodes that have been marked /omit-if-no-ref/ and do not
897 * have any references to them from nodes that are similarly marked. This
898 * is a fairly expensive operation. The return value indicates whether the
899 * tree has been dirtied as a result of this operation, so that the caller
900 * may take appropriate measures to bring the device tree into a consistent
903 bool garbage_collect_marked_nodes();
905 * Parses a dts file in the given buffer and adds the roots to the parsed
906 * set. The `read_header` argument indicates whether the header has
907 * already been read. Some dts files place the header in an include,
908 * rather than in the top-level file.
910 void parse_file(text_input_buffer &input,
911 std::vector<node_ptr> &roots,
914 * Template function that writes a dtb blob using the specified writer.
915 * The writer defines the output format (assembly, blob).
917 template<class writer>
921 * Should we write the __symbols__ node (to allow overlays to be linked
922 * against this blob)?
924 bool write_symbols = false;
926 * Returns the node referenced by the property. If this is a tree that
927 * is in source form, then we have a string that we can use to index
928 * the cross_references array and so we can just look that up.
930 node *referenced_node(property_value &v);
932 * Writes this FDT as a DTB to the specified output.
934 void write_binary(int fd);
936 * Writes this FDT as an assembly representation of the DTB to the
937 * specified output. The result can then be assembled and linked into
940 void write_asm(int fd);
942 * Writes the tree in DTS (source) format.
944 void write_dts(int fd);
946 * Default constructor. Creates a valid, but empty FDT.
950 * Constructs a device tree from the specified file name, referring to
951 * a file that contains a device tree blob.
953 void parse_dtb(const std::string &fn, FILE *depfile);
955 * Construct a fragment wrapper around node. This will assume that node's
956 * name may be used as the target of the fragment, and the contents are to
957 * be wrapped in an __overlay__ node. The fragment wrapper will be assigned
958 * fragnumas its fragment number, and fragment number will be incremented.
960 node_ptr create_fragment_wrapper(node_ptr &node, int &fragnum);
962 * Generate a root node from the node passed in. This is sensitive to
963 * whether we're in a plugin context or not, so that if we're in a plugin we
964 * can circumvent any errors that might normally arise from a non-/ root.
965 * fragnum will be assigned to any fragment wrapper generated as a result
966 * of the call, and fragnum will be incremented.
968 node_ptr generate_root(node_ptr &node, int &fragnum);
970 * Reassign any fragment numbers from this new node, based on the given
973 void reassign_fragment_numbers(node_ptr &node, int &delta);
975 * Constructs a device tree from the specified file name, referring to
976 * a file that contains device tree source.
978 void parse_dts(const std::string &fn, FILE *depfile);
980 * Returns whether this tree is valid.
982 inline bool is_valid()
987 * Mark this tree as needing garbage collection, because an /omit-if-no-ref/
988 * node has been encountered.
990 void set_needs_garbage_collection()
992 garbage_collect = true;
995 * Sets the format for writing phandle properties.
997 inline void set_phandle_format(phandle_format f)
999 phandle_node_name = f;
1002 * Returns a pointer to the root node of this tree. No ownership
1005 inline const node_ptr &get_root() const
1010 * Sets the physical boot CPU.
1012 void set_boot_cpu(uint32_t cpu)
1017 * Sorts the tree. Useful for debugging device trees.
1027 * Adds a path to search for include files. The argument must be a
1028 * nul-terminated string representing the path. The device tree keeps
1029 * a pointer to this string, but does not own it: the caller is
1030 * responsible for freeing it if required.
1032 void add_include_path(const char *path)
1034 std::string p(path);
1035 include_paths.push_back(std::move(p));
1038 * Sets the number of empty reserve map entries to add.
1040 void set_empty_reserve_map_entries(uint32_t e)
1042 spare_reserve_map_entries = e;
1045 * Sets the minimum size, in bytes, of the blob.
1047 void set_blob_minimum_size(uint32_t s)
1049 minimum_blob_size = s;
1052 * Sets the amount of padding to add to the blob.
1054 void set_blob_padding(uint32_t p)
1059 * Parses a predefined macro value.
1061 bool parse_define(const char *def);