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
37 #include <unordered_map>
38 #include <unordered_set>
44 #include "input_buffer.hh"
61 * Type for (owned) pointers to properties.
63 typedef std::shared_ptr<property> property_ptr;
65 * Owning pointer to a node.
67 typedef std::unique_ptr<node> node_ptr;
69 * Map from macros to property pointers.
71 typedef std::unordered_map<std::string, property_ptr> define_map;
73 * Set of strings used for label names.
75 typedef std::unordered_set<std::string> string_set;
77 * Properties may contain a number of different value, each with a different
78 * label. This class encapsulates a single value.
83 * The label for this data. This is usually empty.
87 * If this value is a string, or something resolved from a string (a
88 * reference) then this contains the source string.
90 std::string string_data;
92 * The data that should be written to the final output.
94 byte_buffer byte_data;
96 * Enumeration describing the possible types of a value. Note that
97 * property-coded arrays will appear simply as binary (or possibly
98 * string, if they happen to be nul-terminated and printable), and must
99 * be checked separately.
104 * This is a list of strings. When read from source, string
105 * lists become one property value for each string, however
106 * when read from binary we have a single property value
107 * incorporating the entire text, with nul bytes separating the
112 * This property contains a single string.
116 * This is a binary value. Check the size of byte_data to
117 * determine how many bytes this contains.
120 /** This contains a short-form address that should be replaced
121 * by a fully-qualified version. This will only appear when
122 * the input is a device tree source. When parsed from a
123 * device tree blob, the cross reference will have already been
124 * resolved and the property value will be a string containing
125 * the full path of the target node. */
128 * This is a phandle reference. When parsed from source, the
129 * string_data will contain the node label for the target and,
130 * after cross references have been resolved, the binary data
131 * will contain a 32-bit integer that should match the phandle
132 * property of the target node.
136 * An empty property value. This will never appear on a real
137 * property value, it is used by checkers to indicate that no
138 * property values should exist for a property.
142 * The type of this property has not yet been determined.
147 * The type of this property.
151 * Returns true if this value is a cross reference, false otherwise.
153 inline bool is_cross_reference()
155 return is_type(CROSS_REFERENCE);
158 * Returns true if this value is a phandle reference, false otherwise.
160 inline bool is_phandle()
162 return is_type(PHANDLE);
165 * Returns true if this value is a string, false otherwise.
167 inline bool is_string()
169 return is_type(STRING);
172 * Returns true if this value is a string list (a nul-separated
173 * sequence of strings), false otherwise.
175 inline bool is_string_list()
177 return is_type(STRING_LIST);
180 * Returns true if this value is binary, false otherwise.
182 inline bool is_binary()
184 return is_type(BINARY);
187 * Returns this property value as a 32-bit integer. Returns 0 if this
188 * property value is not 32 bits long. The bytes in the property value
189 * are assumed to be in big-endian format, but the return value is in
190 * the host native endian.
192 uint32_t get_as_uint32();
194 * Default constructor, specifying the label of the value.
196 property_value(std::string l=std::string()) : label(l), type(UNKNOWN) {}
198 * Writes the data for this value into an output buffer.
200 void push_to_buffer(byte_buffer &buffer);
203 * Writes the property value to the standard output. This uses the
204 * following heuristics for deciding how to print the output:
206 * - If the value is nul-terminated and only contains printable
207 * characters, it is written as a string.
208 * - If it is a multiple of 4 bytes long, then it is printed as cells.
209 * - Otherwise, it is printed as a byte buffer.
211 void write_dts(FILE *file);
213 * Tries to merge adjacent property values, returns true if it succeeds and
216 bool try_to_merge(property_value &other);
218 * Returns the size (in bytes) of this property value.
223 * Returns whether the value is of the specified type. If the type of
224 * the value has not yet been determined, then this calculates it.
226 inline bool is_type(value_type v)
235 * Determines the type of the value based on its contents.
239 * Writes the property value to the specified file as a quoted string.
240 * This is used when generating DTS.
242 void write_as_string(FILE *file);
244 * Writes the property value to the specified file as a sequence of
245 * 32-bit big-endian cells. This is used when generating DTS.
247 void write_as_cells(FILE *file);
249 * Writes the property value to the specified file as a sequence of
250 * bytes. This is used when generating DTS.
252 void write_as_bytes(FILE *file);
256 * A value encapsulating a single property. This contains a key, optionally a
257 * label, and optionally one or more values.
262 * The name of this property.
266 * Zero or more labels.
270 * The values in this property.
272 std::vector<property_value> values;
274 * Value indicating that this is a valid property. If a parse error
275 * occurs, then this value is false.
279 * Parses a string property value, i.e. a value enclosed in double quotes.
281 void parse_string(text_input_buffer &input);
283 * Parses one or more 32-bit values enclosed in angle brackets.
285 void parse_cells(text_input_buffer &input, int cell_size);
287 * Parses an array of bytes, contained within square brackets.
289 void parse_bytes(text_input_buffer &input);
291 * Parses a reference. This is a node label preceded by an ampersand
292 * symbol, which should expand to the full path to that node.
294 * Note: The specification says that the target of such a reference is
295 * a node name, however dtc assumes that it is a label, and so we
296 * follow their interpretation for compatibility.
298 void parse_reference(text_input_buffer &input);
300 * Parse a predefined macro definition for a property.
302 void parse_define(text_input_buffer &input, define_map *defines);
304 * Constructs a new property from two input buffers, pointing to the
305 * struct and strings tables in the device tree blob, respectively.
306 * The structs input buffer is assumed to have just consumed the
309 property(input_buffer &structs, input_buffer &strings);
311 * Parses a new property from the input buffer.
313 property(text_input_buffer &input,
317 define_map *defines);
320 * Creates an empty property.
322 property(std::string &&k, string_set &&l=string_set())
323 : key(k), labels(l), valid(true) {}
327 property(property &p) : key(p.key), labels(p.labels), values(p.values),
330 * Factory method for constructing a new property. Attempts to parse a
331 * property from the input, and returns it on success. On any parse
332 * error, this will return 0.
334 static property_ptr parse_dtb(input_buffer &structs,
335 input_buffer &strings);
337 * Factory method for constructing a new property. Attempts to parse a
338 * property from the input, and returns it on success. On any parse
339 * error, this will return 0.
341 static property_ptr parse(text_input_buffer &input,
343 string_set &&labels=string_set(),
344 bool semicolonTerminated=true,
345 define_map *defines=0);
347 * Iterator type used for accessing the values of a property.
349 typedef std::vector<property_value>::iterator value_iterator;
351 * Returns an iterator referring to the first value in this property.
353 inline value_iterator begin()
355 return values.begin();
358 * Returns an iterator referring to the last value in this property.
360 inline value_iterator end()
365 * Adds a new value to an existing property.
367 inline void add_value(property_value v)
372 * Returns the key for this property.
374 inline const std::string &get_key()
379 * Writes the property to the specified writer. The property name is a
380 * reference into the strings table.
382 void write(dtb::output_writer &writer, dtb::string_table &strings);
384 * Writes in DTS format to the specified file, at the given indent
385 * level. This will begin the line with the number of tabs specified
386 * as the indent level and then write the property in the most
387 * applicable way that it can determine.
389 void write_dts(FILE *file, int indent);
391 * Returns the byte offset of the specified property value.
393 size_t offset_of_value(property_value &val);
397 * Class encapsulating a device tree node. Nodes may contain properties and
404 * The labels for this node, if any. Node labels are used as the
405 * targets for cross references.
407 std::unordered_set<std::string> labels;
409 * The name of the node.
413 * The name of the node is a path reference.
415 bool name_is_path_reference = false;
417 * The unit address of the node, which is optionally written after the
418 * name followed by an at symbol.
420 std::string unit_address;
422 * A flag indicating that this node has been marked /omit-if-no-ref/ and
423 * will be omitted if it is not referenced, either directly or indirectly,
424 * by a node that is not similarly denoted.
426 bool omit_if_no_ref = false;
428 * A flag indicating that this node has been referenced, either directly
429 * or indirectly, by a node that is not marked /omit-if-no-ref/.
433 * The type for the property vector.
435 typedef std::vector<property_ptr> property_vector;
437 * Iterator type for child nodes.
439 typedef std::vector<node_ptr>::iterator child_iterator;
441 * Recursion behavior to be observed for visiting
446 * Recurse as normal through the rest of the tree.
450 * Continue recursing through the device tree, but do not
451 * recurse through this branch of the tree any further.
455 * Immediately halt the visit. No further nodes will be visited.
461 * Adaptor to use children in range-based for loops.
465 child_range(node &nd) : n(nd) {}
466 child_iterator begin() { return n.child_begin(); }
467 child_iterator end() { return n.child_end(); }
472 * Adaptor to use properties in range-based for loops.
474 struct property_range
476 property_range(node &nd) : n(nd) {}
477 property_vector::iterator begin() { return n.property_begin(); }
478 property_vector::iterator end() { return n.property_end(); }
483 * The properties contained within this node.
485 property_vector props;
487 * The children of this node.
489 std::vector<node_ptr> children;
491 * Children that should be deleted from this node when merging.
493 std::unordered_set<std::string> deleted_children;
495 * Properties that should be deleted from this node when merging.
497 std::unordered_set<std::string> deleted_props;
499 * A flag indicating whether this node is valid. This is set to false
500 * if an error occurs during parsing.
504 * Parses a name inside a node, writing the string passed as the last
505 * argument as an error if it fails.
507 std::string parse_name(text_input_buffer &input,
511 * Constructs a new node from two input buffers, pointing to the struct
512 * and strings tables in the device tree blob, respectively.
514 node(input_buffer &structs, input_buffer &strings);
516 * Parses a new node from the specified input buffer. This is called
517 * when the input cursor is on the open brace for the start of the
518 * node. The name, and optionally label and unit address, should have
519 * already been parsed.
521 node(text_input_buffer &input,
524 std::unordered_set<std::string> &&l,
528 * Creates a special node with the specified name and properties.
530 node(const std::string &n, const std::vector<property_ptr> &p);
532 * Comparison function for properties, used when sorting the properties
533 * vector. Orders the properties based on their names.
535 static inline bool cmp_properties(property_ptr &p1, property_ptr &p2);
538 return p1->get_key() < p2->get_key();
542 * Comparison function for nodes, used when sorting the children
543 * vector. Orders the nodes based on their names or, if the names are
544 * the same, by the unit addresses.
546 static inline bool cmp_children(node_ptr &c1, node_ptr &c2);
549 * Sorts the node's properties and children into alphabetical order and
550 * recursively sorts the children.
554 * Returns an iterator for the first child of this node.
556 inline child_iterator child_begin()
558 return children.begin();
561 * Returns an iterator after the last child of this node.
563 inline child_iterator child_end()
565 return children.end();
568 * Returns a range suitable for use in a range-based for loop describing
569 * the children of this node.
571 inline child_range child_nodes()
573 return child_range(*this);
576 * Accessor for the deleted children.
578 inline const std::unordered_set<std::string> &deleted_child_nodes()
580 return deleted_children;
583 * Accessor for the deleted properties
585 inline const std::unordered_set<std::string> &deleted_properties()
587 return deleted_props;
590 * Returns a range suitable for use in a range-based for loop describing
591 * the properties of this node.
593 inline property_range properties()
595 return property_range(*this);
598 * Returns an iterator after the last property of this node.
600 inline property_vector::iterator property_begin()
602 return props.begin();
605 * Returns an iterator for the first property of this node.
607 inline property_vector::iterator property_end()
612 * Factory method for constructing a new node. Attempts to parse a
613 * node in DTS format from the input, and returns it on success. On
614 * any parse error, this will return 0. This should be called with the
615 * cursor on the open brace of the property, after the name and so on
618 static node_ptr parse(text_input_buffer &input,
621 std::unordered_set<std::string> &&label=std::unordered_set<std::string>(),
622 std::string &&address=std::string(),
623 define_map *defines=0);
625 * Factory method for constructing a new node. Attempts to parse a
626 * node in DTB format from the input, and returns it on success. On
627 * any parse error, this will return 0. This should be called with the
628 * cursor on the open brace of the property, after the name and so on
631 static node_ptr parse_dtb(input_buffer &structs, input_buffer &strings);
633 * Construct a new special node from a name and set of properties.
635 static node_ptr create_special_node(const std::string &name,
636 const std::vector<property_ptr> &props);
638 * Returns a property corresponding to the specified key, or 0 if this
639 * node does not contain a property of that name.
641 property_ptr get_property(const std::string &key);
643 * Adds a new property to this node.
645 inline void add_property(property_ptr &p)
650 * Adds a new child to this node.
652 inline void add_child(node_ptr &&n)
654 children.push_back(std::move(n));
657 * Deletes any children from this node.
659 inline void delete_children_if(bool (*predicate)(node_ptr &))
661 children.erase(std::remove_if(children.begin(), children.end(), predicate), children.end());
664 * Merges a node into this one. Any properties present in both are
665 * overridden, any properties present in only one are preserved.
667 void merge_node(node_ptr &other);
669 * Write this node to the specified output. Although nodes do not
670 * refer to a string table directly, their properties do. The string
671 * table passed as the second argument is used for the names of
672 * properties within this node and its children.
674 void write(dtb::output_writer &writer, dtb::string_table &strings);
676 * Writes the current node as DTS to the specified file. The second
677 * parameter is the indent level. This function will start every line
678 * with this number of tabs.
680 void write_dts(FILE *file, int indent);
682 * Recursively visit this node and then its children based on the
683 * callable's return value. The callable may return VISIT_BREAK
684 * immediately halt all recursion and end the visit, VISIT_CONTINUE to
685 * not recurse into the current node's children, or VISIT_RECURSE to recurse
686 * through children as expected. parent will be passed to the callable.
688 visit_behavior visit(std::function<visit_behavior(node&, node*)>, node *parent);
692 * Class encapsulating the entire parsed FDT. This is the top-level class,
693 * which parses the entire DTS representation and write out the finished
700 * Type used for node paths. A node path is sequence of names and unit
703 class node_path : public std::vector<std::pair<std::string,std::string>>
707 * Converts this to a string representation.
709 std::string to_string() const;
712 * Name that we should use for phandle nodes.
720 /** Create both nodes. */
725 * The format that we should use for writing phandles.
727 phandle_format phandle_node_name = EPAPR;
729 * Flag indicating that this tree is valid. This will be set to false
734 * Flag indicating that this tree requires garbage collection. This will be
735 * set to true if a node marked /omit-if-no-ref/ is encountered.
737 bool garbage_collect = false;
739 * Type used for memory reservations. A reservation is two 64-bit
740 * values indicating a base address and length in memory that the
741 * kernel should not use. The high 32 bits are ignored on 32-bit
744 typedef std::pair<uint64_t, uint64_t> reservation;
746 * The memory reserves table.
748 std::vector<reservation> reservations;
750 * Root node. All other nodes are children of this node.
754 * Mapping from names to nodes. Only unambiguous names are recorded,
755 * duplicate names are stored as (node*)-1.
757 std::unordered_map<std::string, node*> node_names;
759 * A map from labels to node paths. When resolving cross references,
760 * we look up referenced nodes in this and replace the cross reference
761 * with the full path to its target.
763 std::unordered_map<std::string, node_path> node_paths;
765 * All of the elements in `node_paths` in the order that they were
766 * created. This is used for emitting the `__symbols__` section, where
767 * we want to guarantee stable ordering.
769 std::vector<std::pair<std::string, node_path>> ordered_node_paths;
771 * A collection of property values that are references to other nodes.
772 * These should be expanded to the full path of their targets.
774 std::vector<property_value*> cross_references;
776 * The location of something requiring a fixup entry.
781 * The path to the node.
785 * The property containing the reference.
789 * The property value that contains the reference.
794 * A collection of property values that refer to phandles. These will
795 * be replaced by the value of the phandle property in their
798 std::vector<fixup> fixups;
800 * The locations of all of the values that are supposed to become phandle
801 * references, but refer to things outside of this file.
803 std::vector<std::reference_wrapper<fixup>> unresolved_fixups;
805 * The names of nodes that target phandles.
807 std::unordered_set<std::string> phandle_targets;
809 * A collection of input buffers that we are using. These input
810 * buffers are the ones that own their memory, and so we must preserve
811 * them for the lifetime of the device tree.
813 std::vector<std::unique_ptr<input_buffer>> buffers;
815 * A map of used phandle values to nodes. All phandles must be unique,
816 * so we keep a set of ones that the user explicitly provides in the
817 * input to ensure that we don't reuse them.
819 * This is a map, rather than a set, because we also want to be able to
820 * find phandles that were provided by the user explicitly when we are
823 std::unordered_map<uint32_t, node*> used_phandles;
825 * Paths to search for include files. This contains a set of
826 * nul-terminated strings, which are not owned by this class and so
827 * must be freed separately.
829 std::vector<std::string> include_paths;
831 * Dictionary of predefined macros provided on the command line.
835 * The default boot CPU, specified in the device tree header.
837 uint32_t boot_cpu = 0;
839 * The number of empty reserve map entries to generate in the blob.
841 uint32_t spare_reserve_map_entries = 0;
843 * The minimum size in bytes of the blob.
845 uint32_t minimum_blob_size = 0;
847 * The number of bytes of padding to add to the end of the blob.
849 uint32_t blob_padding = 0;
851 * Is this tree a plugin?
853 bool is_plugin = false;
855 * Visit all of the nodes recursively, and if they have labels then add
856 * them to the node_paths and node_names vectors so that they can be
857 * used in resolving cross references. Also collects phandle
858 * properties that have been explicitly added.
860 void collect_names_recursive(node_ptr &n, node_path &path);
862 * Assign a phandle property to a single node. The next parameter
863 * holds the phandle to be assigned, and will be incremented upon
866 property_ptr assign_phandle(node *n, uint32_t &next);
868 * Assign phandle properties to all nodes that have been referenced and
869 * require one. This method will recursively visit the tree starting at
870 * the node that it is passed.
872 void assign_phandles(node_ptr &n, uint32_t &next);
874 * Calls the recursive version of this method on every root node.
876 void collect_names();
878 * Resolves all cross references. Any properties that refer to another
879 * node must have their values replaced by either the node path or
880 * phandle value. The phandle parameter holds the next phandle to be
881 * assigned, should the need arise. It will be incremented upon each
882 * assignment of a phandle. Garbage collection of unreferenced nodes
883 * marked for "delete if unreferenced" will also occur here.
885 void resolve_cross_references(uint32_t &phandle);
887 * Garbage collects nodes that have been marked /omit-if-no-ref/ and do not
888 * have any references to them from nodes that are similarly marked. This
889 * is a fairly expensive operation. The return value indicates whether the
890 * tree has been dirtied as a result of this operation, so that the caller
891 * may take appropriate measures to bring the device tree into a consistent
894 bool garbage_collect_marked_nodes();
896 * Parses a dts file in the given buffer and adds the roots to the parsed
897 * set. The `read_header` argument indicates whether the header has
898 * already been read. Some dts files place the header in an include,
899 * rather than in the top-level file.
901 void parse_file(text_input_buffer &input,
902 std::vector<node_ptr> &roots,
905 * Template function that writes a dtb blob using the specified writer.
906 * The writer defines the output format (assembly, blob).
908 template<class writer>
912 * Should we write the __symbols__ node (to allow overlays to be linked
913 * against this blob)?
915 bool write_symbols = false;
917 * Returns the node referenced by the property. If this is a tree that
918 * is in source form, then we have a string that we can use to index
919 * the cross_references array and so we can just look that up.
921 node *referenced_node(property_value &v);
923 * Writes this FDT as a DTB to the specified output.
925 void write_binary(int fd);
927 * Writes this FDT as an assembly representation of the DTB to the
928 * specified output. The result can then be assembled and linked into
931 void write_asm(int fd);
933 * Writes the tree in DTS (source) format.
935 void write_dts(int fd);
937 * Default constructor. Creates a valid, but empty FDT.
941 * Constructs a device tree from the specified file name, referring to
942 * a file that contains a device tree blob.
944 void parse_dtb(const std::string &fn, FILE *depfile);
946 * Construct a fragment wrapper around node. This will assume that node's
947 * name may be used as the target of the fragment, and the contents are to
948 * be wrapped in an __overlay__ node. The fragment wrapper will be assigned
949 * fragnumas its fragment number, and fragment number will be incremented.
951 node_ptr create_fragment_wrapper(node_ptr &node, int &fragnum);
953 * Generate a root node from the node passed in. This is sensitive to
954 * whether we're in a plugin context or not, so that if we're in a plugin we
955 * can circumvent any errors that might normally arise from a non-/ root.
956 * fragnum will be assigned to any fragment wrapper generated as a result
957 * of the call, and fragnum will be incremented.
959 node_ptr generate_root(node_ptr &node, int &fragnum);
961 * Reassign any fragment numbers from this new node, based on the given
964 void reassign_fragment_numbers(node_ptr &node, int &delta);
966 * Constructs a device tree from the specified file name, referring to
967 * a file that contains device tree source.
969 void parse_dts(const std::string &fn, FILE *depfile);
971 * Returns whether this tree is valid.
973 inline bool is_valid()
978 * Mark this tree as needing garbage collection, because an /omit-if-no-ref/
979 * node has been encountered.
981 void set_needs_garbage_collection()
983 garbage_collect = true;
986 * Sets the format for writing phandle properties.
988 inline void set_phandle_format(phandle_format f)
990 phandle_node_name = f;
993 * Returns a pointer to the root node of this tree. No ownership
996 inline const node_ptr &get_root() const
1001 * Sets the physical boot CPU.
1003 void set_boot_cpu(uint32_t cpu)
1008 * Sorts the tree. Useful for debugging device trees.
1018 * Adds a path to search for include files. The argument must be a
1019 * nul-terminated string representing the path. The device tree keeps
1020 * a pointer to this string, but does not own it: the caller is
1021 * responsible for freeing it if required.
1023 void add_include_path(const char *path)
1025 std::string p(path);
1026 include_paths.push_back(std::move(p));
1029 * Sets the number of empty reserve map entries to add.
1031 void set_empty_reserve_map_entries(uint32_t e)
1033 spare_reserve_map_entries = e;
1036 * Sets the minimum size, in bytes, of the blob.
1038 void set_blob_minimum_size(uint32_t s)
1040 minimum_blob_size = s;
1043 * Sets the amount of padding to add to the blob.
1045 void set_blob_padding(uint32_t p)
1050 * Parses a predefined macro value.
1052 bool parse_define(const char *def);