| # Copyright (c) 2019, Nordic Semiconductor |
| # SPDX-License-Identifier: BSD-3-Clause |
| |
| # Tip: You can view just the documentation with 'pydoc3 dtlib' |
| |
| # _init_tokens() builds names dynamically. |
| # |
| # pylint: disable=undefined-variable |
| |
| """ |
| A library for extracting information from .dts (Device Tree) files. See the |
| documentation for the DT and Node classes for more information. |
| |
| The top-level entry point of the library is the DT class. DT.__init__() takes a |
| .dts file to parse and a list of directories to search for any /include/d |
| files. |
| """ |
| |
| import collections |
| import errno |
| import os |
| import re |
| import sys |
| import textwrap |
| |
| # NOTE: testdtlib.py is the test suite for this library. It can be run directly. |
| |
| |
| class DT: |
| """ |
| Represents a device tree parsed from a .dts file (or from many files, if |
| the .dts file /include/s other files). Creating many instances of this |
| class is fine. The library has no global state. |
| |
| These attributes are available on DT instances: |
| |
| root: |
| A Node instance representing the root (/) node. |
| |
| alias2node: |
| A dictionary that maps maps alias strings (from /aliases) to Node |
| instances |
| |
| label2node: |
| A dictionary that maps each node label (a string) to the Node instance |
| for the node. |
| |
| label2prop: |
| A dictionary that maps each property label (a string) to a Property |
| instance. |
| |
| label2prop_offset: |
| A dictionary that maps each label (a string) within a property value |
| (e.g., 'x = label_1: < 1 label2: 2 >;') to a (prop, offset) tuple, where |
| 'prop' is a Property instance and 'offset' the byte offset (0 for label_1 |
| and 4 for label_2 in the example). |
| |
| phandle2node: |
| A dictionary that maps each phandle (a number) to a Node instance. |
| |
| memreserves: |
| A list of (labels, address, length) tuples for the /memreserve/s in the |
| .dts file, in the same order as they appear in the file. |
| |
| 'labels' is a possibly empty set with all labels preceding the memreserve |
| (e.g., 'label1: label2: /memreserve/ ...'). 'address' and 'length' are |
| numbers. |
| |
| filename: |
| The filename passed to the DT constructor. |
| """ |
| |
| # |
| # Public interface |
| # |
| |
| def __init__(self, filename, include_path=()): |
| """ |
| Parses a DTS file to create a DT instance. Raises OSError if 'filename' |
| can't be opened, and DTError for any parse errors. |
| |
| filename: |
| Path to the .dts file to parse. |
| |
| include_path: |
| An iterable (e.g. list or tuple) containing paths to search for |
| /include/d and /incbin/'d files. By default, files are only looked up |
| relative to the .dts file that contains the /include/ or /incbin/. |
| """ |
| self.filename = filename |
| self._include_path = include_path |
| |
| with open(filename, encoding="utf-8") as f: |
| self._file_contents = f.read() |
| |
| self._tok_i = self._tok_end_i = 0 |
| self._filestack = [] |
| |
| self.alias2node = {} |
| |
| self._lexer_state = _DEFAULT |
| self._saved_token = None |
| |
| self._lineno = 1 |
| |
| self._parse_dt() |
| |
| self._register_phandles() |
| self._fixup_props() |
| self._register_aliases() |
| self._remove_unreferenced() |
| self._register_labels() |
| |
| def get_node(self, path): |
| """ |
| Returns the Node instance for the node with path or alias 'path' (a |
| string). Raises DTError if the path or alias doesn't exist. |
| |
| For example, both dt.get_node("/foo/bar") and dt.get_node("bar-alias") |
| will return the 'bar' node below: |
| |
| /dts-v1/; |
| |
| / { |
| foo { |
| bar_label: bar { |
| baz { |
| }; |
| }; |
| }; |
| |
| aliases { |
| bar-alias = &bar-label; |
| }; |
| }; |
| |
| Fetching subnodes via aliases is supported: |
| dt.get_node("bar-alias/baz") returns the 'baz' node. |
| """ |
| if path.startswith("/"): |
| return _root_and_path_to_node(self.root, path, path) |
| |
| # Path does not start with '/'. First component must be an alias. |
| alias, _, rest = path.partition("/") |
| if alias not in self.alias2node: |
| _err("no alias '{}' found -- did you forget the leading '/' in " |
| "the node path?".format(alias)) |
| |
| return _root_and_path_to_node(self.alias2node[alias], rest, path) |
| |
| def has_node(self, path): |
| """ |
| Returns True if the path or alias 'path' exists. See Node.get_node(). |
| """ |
| try: |
| self.get_node(path) |
| return True |
| except DTError: |
| return False |
| |
| def node_iter(self): |
| """ |
| Returns a generator for iterating over all nodes in the device tree. |
| |
| For example, this will print the name of each node that has a property |
| called 'foo': |
| |
| for node in dt.node_iter(): |
| if "foo" in node.props: |
| print(node.name) |
| """ |
| yield from self.root.node_iter() |
| |
| def __str__(self): |
| """ |
| Returns a DTS representation of the device tree. Called automatically |
| if the DT instance is print()ed. |
| """ |
| s = "/dts-v1/;\n\n" |
| |
| if self.memreserves: |
| for labels, address, offset in self.memreserves: |
| # List the labels in a consistent order to help with testing |
| for label in labels: |
| s += label + ": " |
| s += "/memreserve/ {:#018x} {:#018x};\n" \ |
| .format(address, offset) |
| s += "\n" |
| |
| return s + str(self.root) |
| |
| def __repr__(self): |
| """ |
| Returns some information about the DT instance. Called automatically if |
| the DT instance is evaluated. |
| """ |
| return "DT(filename='{}', include_path={})" \ |
| .format(self.filename, self._include_path) |
| |
| # |
| # Parsing |
| # |
| |
| def _parse_dt(self): |
| # Top-level parsing loop |
| |
| self._parse_header() |
| self._parse_memreserves() |
| |
| self.root = None |
| |
| while True: |
| tok = self._next_token() |
| |
| if tok.val == "/": |
| # '/ { ... };', the root node |
| if not self.root: |
| self.root = Node(name="/", parent=None, dt=self) |
| self._parse_node(self.root) |
| |
| elif tok.id in (_T_LABEL, _T_REF): |
| # '&foo { ... };' or 'label: &foo { ... };'. The C tools only |
| # support a single label here too. |
| |
| if tok.id is _T_LABEL: |
| label = tok.val |
| tok = self._next_token() |
| if tok.id is not _T_REF: |
| self._parse_error("expected label reference (&foo)") |
| else: |
| label = None |
| |
| try: |
| node = self._ref2node(tok.val) |
| except DTError as e: |
| self._parse_error(e) |
| node = self._parse_node(node) |
| |
| if label: |
| _append_no_dup(node.labels, label) |
| |
| elif tok.id is _T_DEL_NODE: |
| self._next_ref2node()._del() |
| self._expect_token(";") |
| |
| elif tok.id is _T_OMIT_IF_NO_REF: |
| self._next_ref2node()._omit_if_no_ref = True |
| self._expect_token(";") |
| |
| elif tok.id is _T_EOF: |
| if not self.root: |
| self._parse_error("no root node defined") |
| return |
| |
| else: |
| self._parse_error("expected '/' or label reference (&foo)") |
| |
| def _parse_header(self): |
| # Parses /dts-v1/ (expected) and /plugin/ (unsupported) at the start of |
| # files. There may be multiple /dts-v1/ at the start of a file. |
| |
| has_dts_v1 = False |
| |
| while self._peek_token().id is _T_DTS_V1: |
| has_dts_v1 = True |
| self._next_token() |
| self._expect_token(";") |
| # /plugin/ always comes after /dts-v1/ |
| if self._peek_token().id is _T_PLUGIN: |
| self._parse_error("/plugin/ is not supported") |
| |
| if not has_dts_v1: |
| self._parse_error("expected '/dts-v1/;' at start of file") |
| |
| def _parse_memreserves(self): |
| # Parses /memreserve/, which appears after /dts-v1/ |
| |
| self.memreserves = [] |
| while True: |
| # Labels before /memreserve/ |
| labels = [] |
| while self._peek_token().id is _T_LABEL: |
| _append_no_dup(labels, self._next_token().val) |
| |
| if self._peek_token().id is _T_MEMRESERVE: |
| self._next_token() |
| self.memreserves.append( |
| (labels, self._eval_prim(), self._eval_prim())) |
| self._expect_token(";") |
| elif labels: |
| self._parse_error("expected /memreserve/ after labels at " |
| "beginning of file") |
| else: |
| return |
| |
| def _parse_node(self, node): |
| # Parses the '{ ... };' part of 'node-name { ... };'. Returns the new |
| # Node. |
| |
| self._expect_token("{") |
| while True: |
| labels, omit_if_no_ref = self._parse_propnode_labels() |
| tok = self._next_token() |
| |
| if tok.id is _T_PROPNODENAME: |
| if self._peek_token().val == "{": |
| # '<tok> { ...', expect node |
| |
| if tok.val.count("@") > 1: |
| self._parse_error("multiple '@' in node name") |
| |
| # Fetch the existing node if it already exists. This |
| # happens when overriding nodes. |
| child = node.nodes.get(tok.val) or \ |
| Node(name=tok.val, parent=node, dt=self) |
| |
| for label in labels: |
| _append_no_dup(child.labels, label) |
| |
| if omit_if_no_ref: |
| child._omit_if_no_ref = True |
| |
| node.nodes[child.name] = child |
| self._parse_node(child) |
| |
| else: |
| # Not '<tok> { ...', expect property assignment |
| |
| if omit_if_no_ref: |
| self._parse_error( |
| "/omit-if-no-ref/ can only be used on nodes") |
| |
| prop = node._get_prop(tok.val) |
| |
| if self._check_token("="): |
| self._parse_assignment(prop) |
| elif not self._check_token(";"): |
| # ';' is for an empty property, like 'foo;' |
| self._parse_error("expected '{', '=', or ';'") |
| |
| for label in labels: |
| _append_no_dup(prop.labels, label) |
| |
| elif tok.id is _T_DEL_NODE: |
| tok2 = self._next_token() |
| if tok2.id is not _T_PROPNODENAME: |
| self._parse_error("expected node name") |
| if tok2.val in node.nodes: |
| node.nodes[tok2.val]._del() |
| self._expect_token(";") |
| |
| elif tok.id is _T_DEL_PROP: |
| tok2 = self._next_token() |
| if tok2.id is not _T_PROPNODENAME: |
| self._parse_error("expected property name") |
| node.props.pop(tok2.val, None) |
| self._expect_token(";") |
| |
| elif tok.val == "}": |
| self._expect_token(";") |
| return node |
| |
| else: |
| self._parse_error("expected node name, property name, or '}'") |
| |
| def _parse_propnode_labels(self): |
| # _parse_node() helpers for parsing labels and /omit-if-no-ref/s before |
| # nodes and properties. Returns a (<label list>, <omit-if-no-ref bool>) |
| # tuple. |
| |
| labels = [] |
| omit_if_no_ref = False |
| while True: |
| tok = self._peek_token() |
| if tok.id is _T_LABEL: |
| _append_no_dup(labels, tok.val) |
| elif tok.id is _T_OMIT_IF_NO_REF: |
| omit_if_no_ref = True |
| elif (labels or omit_if_no_ref) and tok.id is not _T_PROPNODENAME: |
| # Got something like 'foo: bar: }' |
| self._parse_error("expected node or property name") |
| else: |
| return labels, omit_if_no_ref |
| |
| self._next_token() |
| |
| def _parse_assignment(self, prop): |
| # Parses the right-hand side of property assignment |
| # |
| # prop: |
| # 'Property' instance being assigned |
| |
| # Remove any old value, path/phandle references, and in-value labels, |
| # in case the property value is being overridden |
| prop.value = b"" |
| prop._markers = [] |
| |
| while True: |
| # Parse labels before the value (e.g., '..., label: < 0 >') |
| self._parse_value_labels(prop) |
| |
| tok = self._next_token() |
| |
| if tok.val == "<": |
| self._parse_cells(prop, 4) |
| |
| elif tok.id is _T_BITS: |
| n_bits = self._expect_num() |
| if n_bits not in {8, 16, 32, 64}: |
| self._parse_error("expected 8, 16, 32, or 64") |
| self._expect_token("<") |
| self._parse_cells(prop, n_bits//8) |
| |
| elif tok.val == "[": |
| self._parse_bytes(prop) |
| |
| elif tok.id is _T_STRING: |
| prop._add_marker(_TYPE_STRING) |
| prop.value += self._unescape(tok.val.encode("utf-8")) + b"\0" |
| |
| elif tok.id is _T_REF: |
| prop._add_marker(_REF_PATH, tok.val) |
| |
| elif tok.id is _T_INCBIN: |
| self._parse_incbin(prop) |
| |
| else: |
| self._parse_error("malformed value") |
| |
| # Parse labels after the value (e.g., '< 0 > label:, ...') |
| self._parse_value_labels(prop) |
| |
| tok = self._next_token() |
| if tok.val == ";": |
| return |
| if tok.val == ",": |
| continue |
| self._parse_error("expected ';' or ','") |
| |
| def _parse_cells(self, prop, n_bytes): |
| # Parses '<...>' |
| |
| prop._add_marker(_N_BYTES_TO_TYPE[n_bytes]) |
| |
| while True: |
| tok = self._peek_token() |
| if tok.id is _T_REF: |
| self._next_token() |
| if n_bytes != 4: |
| self._parse_error("phandle references are only allowed in " |
| "arrays with 32-bit elements") |
| prop._add_marker(_REF_PHANDLE, tok.val) |
| |
| elif tok.id is _T_LABEL: |
| prop._add_marker(_REF_LABEL, tok.val) |
| self._next_token() |
| |
| elif self._check_token(">"): |
| return |
| |
| else: |
| # Literal value |
| num = self._eval_prim() |
| try: |
| prop.value += num.to_bytes(n_bytes, "big") |
| except OverflowError: |
| try: |
| # Try again as a signed number, in case it's negative |
| prop.value += num.to_bytes(n_bytes, "big", signed=True) |
| except OverflowError: |
| self._parse_error("{} does not fit in {} bits" |
| .format(num, 8*n_bytes)) |
| |
| def _parse_bytes(self, prop): |
| # Parses '[ ... ]' |
| |
| prop._add_marker(_TYPE_UINT8) |
| |
| while True: |
| tok = self._next_token() |
| if tok.id is _T_BYTE: |
| prop.value += tok.val.to_bytes(1, "big") |
| |
| elif tok.id is _T_LABEL: |
| prop._add_marker(_REF_LABEL, tok.val) |
| |
| elif tok.val == "]": |
| return |
| |
| else: |
| self._parse_error("expected two-digit byte or ']'") |
| |
| def _parse_incbin(self, prop): |
| # Parses |
| # |
| # /incbin/ ("filename") |
| # |
| # and |
| # |
| # /incbin/ ("filename", <offset>, <size>) |
| |
| prop._add_marker(_TYPE_UINT8) |
| |
| self._expect_token("(") |
| |
| tok = self._next_token() |
| if tok.id is not _T_STRING: |
| self._parse_error("expected quoted filename") |
| filename = tok.val |
| |
| tok = self._next_token() |
| if tok.val == ",": |
| offset = self._eval_prim() |
| self._expect_token(",") |
| size = self._eval_prim() |
| self._expect_token(")") |
| else: |
| if tok.val != ")": |
| self._parse_error("expected ',' or ')'") |
| offset = None |
| |
| try: |
| with self._open(filename, "rb") as f: |
| if offset is None: |
| prop.value += f.read() |
| else: |
| f.seek(offset) |
| prop.value += f.read(size) |
| except OSError as e: |
| self._parse_error("could not read '{}': {}" |
| .format(filename, e)) |
| |
| def _parse_value_labels(self, prop): |
| # _parse_assignment() helper for parsing labels before/after each |
| # comma-separated value |
| |
| while True: |
| tok = self._peek_token() |
| if tok.id is not _T_LABEL: |
| return |
| prop._add_marker(_REF_LABEL, tok.val) |
| self._next_token() |
| |
| def _node_phandle(self, node): |
| # Returns the phandle for Node 'node', creating a new phandle if the |
| # node has no phandle, and fixing up the value for existing |
| # self-referential phandles (which get set to b'\0\0\0\0' initially). |
| # Self-referential phandles must be rewritten instead of recreated, so |
| # that labels are preserved. |
| |
| if "phandle" in node.props: |
| phandle_prop = node.props["phandle"] |
| else: |
| phandle_prop = Property(node, "phandle") |
| phandle_prop._add_marker(_TYPE_UINT32) # For displaying |
| phandle_prop.value = b'\0\0\0\0' |
| |
| if phandle_prop.value == b'\0\0\0\0': |
| phandle_i = 1 |
| while phandle_i in self.phandle2node: |
| phandle_i += 1 |
| self.phandle2node[phandle_i] = node |
| |
| phandle_prop.value = phandle_i.to_bytes(4, "big") |
| node.props["phandle"] = phandle_prop |
| |
| return phandle_prop.value |
| |
| # Expression evaluation |
| |
| def _eval_prim(self): |
| tok = self._peek_token() |
| if tok.id in (_T_NUM, _T_CHAR_LITERAL): |
| return self._next_token().val |
| |
| tok = self._next_token() |
| if tok.val != "(": |
| self._parse_error("expected number or parenthesized expression") |
| val = self._eval_ternary() |
| self._expect_token(")") |
| return val |
| |
| def _eval_ternary(self): |
| val = self._eval_or() |
| if self._check_token("?"): |
| if_val = self._eval_ternary() |
| self._expect_token(":") |
| else_val = self._eval_ternary() |
| return if_val if val else else_val |
| return val |
| |
| def _eval_or(self): |
| val = self._eval_and() |
| while self._check_token("||"): |
| val = 1 if self._eval_and() or val else 0 |
| return val |
| |
| def _eval_and(self): |
| val = self._eval_bitor() |
| while self._check_token("&&"): |
| val = 1 if self._eval_bitor() and val else 0 |
| return val |
| |
| def _eval_bitor(self): |
| val = self._eval_bitxor() |
| while self._check_token("|"): |
| val |= self._eval_bitxor() |
| return val |
| |
| def _eval_bitxor(self): |
| val = self._eval_bitand() |
| while self._check_token("^"): |
| val ^= self._eval_bitand() |
| return val |
| |
| def _eval_bitand(self): |
| val = self._eval_eq() |
| while self._check_token("&"): |
| val &= self._eval_eq() |
| return val |
| |
| def _eval_eq(self): |
| val = self._eval_rela() |
| while True: |
| if self._check_token("=="): |
| val = 1 if val == self._eval_rela() else 0 |
| elif self._check_token("!="): |
| val = 1 if val != self._eval_rela() else 0 |
| else: |
| return val |
| |
| def _eval_rela(self): |
| val = self._eval_shift() |
| while True: |
| if self._check_token("<"): |
| val = 1 if val < self._eval_shift() else 0 |
| elif self._check_token(">"): |
| val = 1 if val > self._eval_shift() else 0 |
| elif self._check_token("<="): |
| val = 1 if val <= self._eval_shift() else 0 |
| elif self._check_token(">="): |
| val = 1 if val >= self._eval_shift() else 0 |
| else: |
| return val |
| |
| def _eval_shift(self): |
| val = self._eval_add() |
| while True: |
| if self._check_token("<<"): |
| val <<= self._eval_add() |
| elif self._check_token(">>"): |
| val >>= self._eval_add() |
| else: |
| return val |
| |
| def _eval_add(self): |
| val = self._eval_mul() |
| while True: |
| if self._check_token("+"): |
| val += self._eval_mul() |
| elif self._check_token("-"): |
| val -= self._eval_mul() |
| else: |
| return val |
| |
| def _eval_mul(self): |
| val = self._eval_unary() |
| while True: |
| if self._check_token("*"): |
| val *= self._eval_unary() |
| elif self._check_token("/"): |
| denom = self._eval_unary() |
| if not denom: |
| self._parse_error("division by zero") |
| val //= denom |
| elif self._check_token("%"): |
| denom = self._eval_unary() |
| if not denom: |
| self._parse_error("division by zero") |
| val %= denom |
| else: |
| return val |
| |
| def _eval_unary(self): |
| if self._check_token("-"): |
| return -self._eval_unary() |
| if self._check_token("~"): |
| return ~self._eval_unary() |
| if self._check_token("!"): |
| return 0 if self._eval_unary() else 1 |
| return self._eval_prim() |
| |
| # |
| # Lexing |
| # |
| |
| def _check_token(self, val): |
| if self._peek_token().val == val: |
| self._next_token() |
| return True |
| return False |
| |
| def _peek_token(self): |
| if not self._saved_token: |
| self._saved_token = self._next_token() |
| return self._saved_token |
| |
| def _next_token(self): |
| if self._saved_token: |
| tmp = self._saved_token |
| self._saved_token = None |
| return tmp |
| |
| while True: |
| tok_id = None |
| |
| match = _token_re.match(self._file_contents, self._tok_end_i) |
| if match: |
| tok_id = match.lastindex |
| if tok_id is _T_CHAR_LITERAL: |
| val = self._unescape(match.group(tok_id).encode("utf-8")) |
| if len(val) != 1: |
| self._parse_error("character literals must be length 1") |
| tok_val = ord(val) |
| else: |
| tok_val = match.group(tok_id) |
| |
| elif self._lexer_state is _DEFAULT: |
| match = _num_re.match(self._file_contents, self._tok_end_i) |
| if match: |
| tok_id = _T_NUM |
| num_s = match.group(1) |
| tok_val = int(num_s, |
| 16 if num_s.startswith(("0x", "0X")) else |
| 8 if num_s[0] == "0" else |
| 10) |
| |
| elif self._lexer_state is _EXPECT_PROPNODENAME: |
| match = _propnodename_re.match(self._file_contents, |
| self._tok_end_i) |
| if match: |
| tok_id = _T_PROPNODENAME |
| tok_val = match.group(1) |
| self._lexer_state = _DEFAULT |
| |
| else: # self._lexer_state is _EXPECT_BYTE |
| match = _byte_re.match(self._file_contents, self._tok_end_i) |
| if match: |
| tok_id = _T_BYTE |
| tok_val = int(match.group(), 16) |
| |
| |
| if not tok_id: |
| match = _misc_re.match(self._file_contents, self._tok_end_i) |
| if match: |
| tok_id = _T_MISC |
| tok_val = match.group() |
| else: |
| self._tok_i = self._tok_end_i |
| # Could get here due to a node/property naming appearing in |
| # an unexpected context as well as for bad characters in |
| # files. Generate a token for it so that the error can |
| # trickle up to some context where we can give a more |
| # helpful error message. |
| return _Token(_T_BAD, "<unknown token>") |
| |
| self._tok_i = match.start() |
| self._tok_end_i = match.end() |
| |
| if tok_id is _T_SKIP: |
| self._lineno += tok_val.count("\n") |
| continue |
| |
| # /include/ is handled in the lexer in the C tools as well, and can |
| # appear anywhere |
| if tok_id is _T_INCLUDE: |
| # Can have newlines between /include/ and the filename |
| self._lineno += tok_val.count("\n") |
| # Do this manual extraction instead of doing it in the regex so |
| # that we can properly count newlines |
| filename = tok_val[tok_val.find('"') + 1:-1] |
| self._enter_file(filename) |
| continue |
| |
| if tok_id is _T_LINE: |
| # #line directive |
| self._lineno = int(tok_val.split()[0]) - 1 |
| self.filename = tok_val[tok_val.find('"') + 1:-1] |
| continue |
| |
| if tok_id is _T_EOF: |
| if self._filestack: |
| self._leave_file() |
| continue |
| return _Token(_T_EOF, "<EOF>") |
| |
| # State handling |
| |
| if tok_id in (_T_DEL_PROP, _T_DEL_NODE, _T_OMIT_IF_NO_REF) or \ |
| tok_val in ("{", ";"): |
| |
| self._lexer_state = _EXPECT_PROPNODENAME |
| |
| elif tok_val == "[": |
| self._lexer_state = _EXPECT_BYTE |
| |
| elif tok_id in (_T_MEMRESERVE, _T_BITS) or tok_val == "]": |
| self._lexer_state = _DEFAULT |
| |
| return _Token(tok_id, tok_val) |
| |
| def _expect_token(self, tok_val): |
| # Raises an error if the next token does not have the string value |
| # 'tok_val'. Returns the token. |
| |
| tok = self._next_token() |
| if tok.val != tok_val: |
| self._parse_error("expected '{}', not '{}'" |
| .format(tok_val, tok.val)) |
| |
| return tok |
| |
| def _expect_num(self): |
| # Raises an error if the next token is not a number. Returns the token. |
| |
| tok = self._next_token() |
| if tok.id is not _T_NUM: |
| self._parse_error("expected number") |
| return tok.val |
| |
| def _parse_error(self, s): |
| _err("{}:{} (column {}): parse error: {}".format( |
| self.filename, self._lineno, |
| # This works out for the first line of the file too, where rfind() |
| # returns -1 |
| self._tok_i - self._file_contents.rfind("\n", 0, self._tok_i + 1), |
| s)) |
| |
| def _enter_file(self, filename): |
| # Enters the /include/d file 'filename', remembering the position in |
| # the /include/ing file for later |
| |
| self._filestack.append((self.filename, self._lineno, |
| self._file_contents, self._tok_end_i)) |
| |
| # Handle escapes in filenames, just for completeness |
| filename = self._unescape(filename.encode("utf-8")) |
| try: |
| filename = filename.decode("utf-8") |
| except UnicodeDecodeError: |
| self._parse_error("filename is not valid UTF-8") |
| |
| with self._open(filename, encoding="utf-8") as f: |
| try: |
| self._file_contents = f.read() |
| except OSError as e: |
| self._parse_error(e) |
| |
| # Check for recursive /include/ |
| for i, parent in enumerate(self._filestack): |
| if filename == parent[0]: |
| self._parse_error("recursive /include/:\n" + " ->\n".join( |
| ["{}:{}".format(parent[0], parent[1]) |
| for parent in self._filestack[i:]] + |
| [filename])) |
| |
| self.filename = f.name |
| self._lineno = 1 |
| self._tok_end_i = 0 |
| |
| def _leave_file(self): |
| # Leaves an /include/d file, returning to the file that /include/d it |
| |
| self.filename, self._lineno, self._file_contents, self._tok_end_i = \ |
| self._filestack.pop() |
| |
| def _next_ref2node(self): |
| # Checks that the next token is a label/path reference and returns the |
| # Node it points to. Only used during parsing, so uses _parse_error() |
| # on errors to save some code in callers. |
| |
| label = self._next_token() |
| if label.id is not _T_REF: |
| self._parse_error( |
| "expected label (&foo) or path (&{/foo/bar}) reference") |
| try: |
| return self._ref2node(label.val) |
| except DTError as e: |
| self._parse_error(e) |
| |
| def _ref2node(self, s): |
| # Returns the Node the label/path reference 's' points to |
| |
| if s[0] == "{": |
| # Path reference (&{/foo/bar}) |
| path = s[1:-1] |
| if not path.startswith("/"): |
| _err("node path '{}' does not start with '/'".format(path)) |
| # Will raise DTError if the path doesn't exist |
| return _root_and_path_to_node(self.root, path, path) |
| |
| # Label reference (&foo). |
| |
| # label2node hasn't been filled in yet, and using it would get messy |
| # when nodes are deleted |
| for node in self.node_iter(): |
| if s in node.labels: |
| return node |
| |
| _err("undefined node label '{}'".format(s)) |
| |
| # |
| # Post-processing |
| # |
| |
| def _register_phandles(self): |
| # Registers any manually-inserted phandle properties in |
| # self.phandle2node, so that we can avoid allocating any phandles from |
| # that set. Also checks the format of the phandles and does misc. |
| # sanity checking. |
| |
| self.phandle2node = {} |
| for node in self.node_iter(): |
| phandle = node.props.get("phandle") |
| if phandle: |
| if len(phandle.value) != 4: |
| _err("{}: bad phandle length ({}), expected 4 bytes" |
| .format(node.path, len(phandle.value))) |
| |
| is_self_referential = False |
| for marker in phandle._markers: |
| _, marker_type, ref = marker |
| if marker_type is _REF_PHANDLE: |
| # The phandle's value is itself a phandle reference |
| if self._ref2node(ref) is node: |
| # Alright to set a node's phandle equal to its own |
| # phandle. It'll force a new phandle to be |
| # allocated even if the node is otherwise |
| # unreferenced. |
| is_self_referential = True |
| break |
| |
| _err("{}: {} refers to another node" |
| .format(node.path, phandle.name)) |
| |
| # Could put on else on the 'for' above too, but keep it |
| # somewhat readable |
| if not is_self_referential: |
| phandle_val = int.from_bytes(phandle.value, "big") |
| |
| if phandle_val in {0, 0xFFFFFFFF}: |
| _err("{}: bad value {:#010x} for {}" |
| .format(node.path, phandle_val, phandle.name)) |
| |
| if phandle_val in self.phandle2node: |
| _err("{}: duplicated phandle {:#x} (seen before at {})" |
| .format(node.path, phandle_val, |
| self.phandle2node[phandle_val].path)) |
| |
| self.phandle2node[phandle_val] = node |
| |
| def _fixup_props(self): |
| # Fills in node path and phandle references in property values, and |
| # registers labels within values. This must be done after parsing, |
| # since forwards references are allowed and nodes and properties might |
| # be deleted. |
| |
| for node in self.node_iter(): |
| # The tuple() avoids a 'dictionary changed size during iteration' |
| # error |
| for prop in tuple(node.props.values()): |
| # 'prev_pos' and 'pos' are indices in the unpatched |
| # property value. The result is built up in 'res'. |
| prev_pos = 0 |
| res = b"" |
| |
| for marker in prop._markers: |
| pos, marker_type, ref = marker |
| |
| # Add data before the marker, reading from the unpatched |
| # property value |
| res += prop.value[prev_pos:pos] |
| |
| # Fix the marker offset so that it's correct for the |
| # patched property value, for later (not used in this |
| # function). The offset might change due to path |
| # references, which expand to something like "/foo/bar". |
| marker[0] = len(res) |
| |
| if marker_type is _REF_LABEL: |
| # This is a temporary format so that we can catch |
| # duplicate references. prop.offset_labels is changed |
| # to a dictionary that maps labels to offsets in |
| # _register_labels(). |
| _append_no_dup(prop.offset_labels, (ref, len(res))) |
| elif marker_type in (_REF_PATH, _REF_PHANDLE): |
| # Path or phandle reference |
| try: |
| ref_node = self._ref2node(ref) |
| except DTError as e: |
| _err("{}: {}".format(prop.node.path, e)) |
| |
| # For /omit-if-no-ref/ |
| ref_node._is_referenced = True |
| |
| if marker_type is _REF_PATH: |
| res += ref_node.path.encode("utf-8") + b'\0' |
| else: # marker_type is PHANDLE |
| res += self._node_phandle(ref_node) |
| # Skip over the dummy phandle placeholder |
| pos += 4 |
| |
| prev_pos = pos |
| |
| # Store the final fixed-up value. Add the data after the last |
| # marker. |
| prop.value = res + prop.value[prev_pos:] |
| |
| def _register_aliases(self): |
| # Registers aliases from the /aliases node in self.alias2node. Also |
| # checks the format of the alias properties. |
| |
| # We copy this to self.alias2node at the end to avoid get_node() |
| # looking up paths via other aliases while verifying aliases |
| alias2node = {} |
| |
| alias_re = re.compile("[0-9a-z-]+$") |
| |
| aliases = self.root.nodes.get("aliases") |
| if aliases: |
| for prop in aliases.props.values(): |
| if not alias_re.match(prop.name): |
| _err("/aliases: alias property name '{}' should include " |
| "only characters from [0-9a-z-]".format(prop.name)) |
| |
| # Property.to_path() already checks that the node exists |
| alias2node[prop.name] = prop.to_path() |
| |
| self.alias2node = alias2node |
| |
| def _remove_unreferenced(self): |
| # Removes any unreferenced nodes marked with /omit-if-no-ref/ from the |
| # tree |
| |
| # tuple() is to avoid 'RuntimeError: dictionary changed size during |
| # iteration' errors |
| for node in tuple(self.node_iter()): |
| if node._omit_if_no_ref and not node._is_referenced: |
| node._del() |
| |
| def _register_labels(self): |
| # Checks for duplicate labels and registers labels in label2node, |
| # label2prop, and label2prop_offset |
| |
| label2things = collections.defaultdict(set) |
| |
| self.label2node = {} |
| self.label2prop = {} |
| self.label2prop_offset = {} |
| |
| # Register all labels and the nodes/props they point to in label2things |
| for node in self.node_iter(): |
| for label in node.labels: |
| label2things[label].add(node) |
| self.label2node[label] = node |
| |
| for prop in node.props.values(): |
| for label in prop.labels: |
| label2things[label].add(prop) |
| self.label2prop[label] = prop |
| |
| for label, offset in prop.offset_labels: |
| label2things[label].add((prop, offset)) |
| self.label2prop_offset[label] = (prop, offset) |
| |
| # See _fixup_props() |
| prop.offset_labels = {label: offset for label, offset in |
| prop.offset_labels} |
| |
| for label, things in label2things.items(): |
| if len(things) > 1: |
| strings = [] |
| for thing in things: |
| if isinstance(thing, Node): |
| strings.append("on " + thing.path) |
| elif isinstance(thing, Property): |
| strings.append("on property '{}' of node {}" |
| .format(thing.name, thing.node.path)) |
| else: |
| # Label within property value |
| strings.append("in the value of property '{}' of node {}" |
| .format(thing[0].name, |
| thing[0].node.path)) |
| |
| # Give consistent error messages to help with testing |
| strings.sort() |
| |
| _err("Label '{}' appears ".format(label) + |
| " and ".join(strings)) |
| |
| |
| # |
| # Misc. |
| # |
| |
| def _unescape(self, b): |
| # Replaces backslash escapes in the 'bytes' array 'b'. We can't do this at |
| # the string level, because the result might not be valid UTF-8 when |
| # octal/hex escapes are involved. |
| |
| def sub(match): |
| esc = match.group(1) |
| if esc == b"a": return b"\a" |
| if esc == b"b": return b"\b" |
| if esc == b"t": return b"\t" |
| if esc == b"n": return b"\n" |
| if esc == b"v": return b"\v" |
| if esc == b"f": return b"\f" |
| if esc == b"r": return b"\r" |
| |
| if esc[0] in b"01234567": |
| # Octal escape |
| try: |
| return int(esc, 8).to_bytes(1, "big") |
| except OverflowError: |
| self._parse_error("octal escape out of range (> 255)") |
| |
| if esc[0] == ord("x") and len(esc) > 1: |
| # Hex escape |
| return int(esc[1:], 16).to_bytes(1, "big") |
| |
| # Return <char> as-is for other \<char> |
| return esc[0].to_bytes(1, "big") |
| |
| return _unescape_re.sub(sub, b) |
| |
| def _open(self, filename, mode="r", **kwargs): |
| # Wrapper around standard Python open(), accepting the same params. |
| # But searches for a 'filename' file in the directory of the current |
| # file and the include path. |
| |
| # The C tools support specifying stdin with '-' too |
| if filename == "-": |
| return sys.stdin.buffer if "b" in mode else sys.stdin |
| |
| # Try the directory of the current file first |
| dirname = os.path.dirname(self.filename) |
| try: |
| return open(os.path.join(dirname, filename), mode, **kwargs) |
| except OSError as e: |
| if e.errno != errno.ENOENT: |
| self._parse_error(e) |
| |
| # Try each directory from the include path |
| for path in self._include_path: |
| try: |
| return open(os.path.join(path, filename), mode, **kwargs) |
| except OSError as e: |
| if e.errno != errno.ENOENT: |
| self._parse_error(e) |
| continue |
| |
| self._parse_error("'{}' could not be found".format(filename)) |
| |
| |
| class Node: |
| r""" |
| Represents a node in the device tree ('node-name { ... };'). |
| |
| These attributes are available on Node instances: |
| |
| name: |
| The name of the node (a string). |
| |
| unit_addr: |
| The portion after the '@' in the node's name, or the empty string if the |
| name has no '@' in it. |
| |
| Note that this is a string. Run int(node.unit_addr, 16) to get an |
| integer. |
| |
| props: |
| A dictionary that maps the properties defined on the node to their |
| values. 'props' is indexed by property name (a string), and values are |
| represented as 'bytes' arrays. |
| |
| To convert property values to Python numbers or strings, use |
| dtlib.to_num(), dtlib.to_nums(), or dtlib.to_string(). |
| |
| Property values are represented as 'bytes' arrays to support the full |
| generality of DTS, which allows assignments like |
| |
| x = "foo", < 0x12345678 >, [ 9A ]; |
| |
| This gives x the value b"foo\0\x12\x34\x56\x78\x9A". Numbers in DTS are |
| stored in big-endian format. |
| |
| nodes: |
| A dictionary containing the subnodes of the node, indexed by name. |
| |
| labels: |
| A list with all labels pointing to the node, in the same order as the |
| labels appear, but with duplicates removed. |
| |
| 'label_1: label_2: node { ... };' gives 'labels' the value |
| ["label_1", "label_2"]. |
| |
| parent: |
| The parent Node of the node. 'None' for the root node. |
| |
| path: |
| The path to the node as a string, e.g. "/foo/bar". |
| |
| dt: |
| The DT instance this node belongs to. |
| """ |
| |
| # |
| # Public interface |
| # |
| |
| def __init__(self, name, parent, dt): |
| """ |
| Node constructor. Not meant to be called directly by clients. |
| """ |
| self.name = name |
| self.parent = parent |
| self.dt = dt |
| |
| self.props = {} |
| self.nodes = {} |
| self.labels = [] |
| self._omit_if_no_ref = False |
| self._is_referenced = False |
| |
| @property |
| def unit_addr(self): |
| """ |
| See the class documentation. |
| """ |
| return self.name.partition("@")[2] |
| |
| @property |
| def path(self): |
| """ |
| See the class documentation. |
| """ |
| node_names = [] |
| |
| cur = self |
| while cur.parent: |
| node_names.append(cur.name) |
| cur = cur.parent |
| |
| return "/" + "/".join(reversed(node_names)) |
| |
| def node_iter(self): |
| """ |
| Returns a generator for iterating over the node and its children, |
| recursively. |
| |
| For example, this will iterate over all nodes in the tree (like |
| dt.node_iter()). |
| |
| for node in dt.root.node_iter(): |
| ... |
| """ |
| yield self |
| for node in self.nodes.values(): |
| yield from node.node_iter() |
| |
| def _get_prop(self, name): |
| # Returns the property named 'name' on the node, creating it if it |
| # doesn't already exist |
| |
| prop = self.props.get(name) |
| if not prop: |
| prop = Property(self, name) |
| self.props[name] = prop |
| return prop |
| |
| def _del(self): |
| # Removes the node from the tree |
| |
| self.parent.nodes.pop(self.name) |
| |
| def __str__(self): |
| """ |
| Returns a DTS representation of the node. Called automatically if the |
| node is print()ed. |
| """ |
| s = "".join(label + ": " for label in self.labels) |
| |
| s += "{} {{\n".format(self.name) |
| |
| for prop in self.props.values(): |
| s += "\t" + str(prop) + "\n" |
| |
| for child in self.nodes.values(): |
| s += textwrap.indent(child.__str__(), "\t") + "\n" |
| |
| s += "};" |
| |
| return s |
| |
| def __repr__(self): |
| """ |
| Returns some information about the Node instance. Called automatically |
| if the Node instance is evaluated. |
| """ |
| return "<Node {} in '{}'>" \ |
| .format(self.path, self.dt.filename) |
| |
| |
| class Property: |
| """ |
| Represents a property ('x = ...'). |
| |
| These attributes are available on Property instances: |
| |
| name: |
| The name of the property (a string). |
| |
| value: |
| The value of the property, as a 'bytes' string. Numbers are stored in |
| big-endian format, and strings are null-terminated. Putting multiple |
| comma-separated values in an assignment (e.g., 'x = < 1 >, "foo"') will |
| concatenate the values. |
| |
| See the to_*() methods for converting the value to other types. |
| |
| type: |
| The type of the property, inferred from the syntax used in the |
| assignment. This is one of the following constants (with example |
| assignments): |
| |
| Assignment | Property.type |
| ----------------------------+------------------------ |
| foo; | dtlib.TYPE_EMPTY |
| foo = []; | dtlib.TYPE_BYTES |
| foo = [01 02]; | dtlib.TYPE_BYTES |
| foo = /bits/ 8 <1>; | dtlib.TYPE_BYTES |
| foo = <1>; | dtlib.TYPE_NUM |
| foo = <>; | dtlib.TYPE_NUMS |
| foo = <1 2 3>; | dtlib.TYPE_NUMS |
| foo = <1 2>, <3>; | dtlib.TYPE_NUMS |
| foo = "foo"; | dtlib.TYPE_STRING |
| foo = "foo", "bar"; | dtlib.TYPE_STRINGS |
| foo = <&l>; | dtlib.TYPE_PHANDLE |
| foo = <&l1 &l2 &l3>; | dtlib.TYPE_PHANDLES |
| foo = <&l1 &l2>, <&l3>; | dtlib.TYPE_PHANDLES |
| foo = <&l1 1 2 &l2 3 4>; | dtlib.TYPE_PHANDLES_AND_NUMS |
| foo = <&l1 1 2>, <&l2 3 4>; | dtlib.TYPE_PHANDLES_AND_NUMS |
| foo = &l; | dtlib.TYPE_PATH |
| *Anything else* | dtlib.TYPE_COMPOUND |
| |
| *Anything else* includes properties mixing phandle (<&label>) and node |
| path (&label) references with other data. |
| |
| Data labels in the property value do not influence the type. |
| |
| labels: |
| A list with all labels pointing to the property, in the same order as the |
| labels appear, but with duplicates removed. |
| |
| 'label_1: label2: x = ...' gives 'labels' the value |
| {"label_1", "label_2"}. |
| |
| offset_labels: |
| A dictionary that maps any labels within the property's value to their |
| offset, in bytes. For example, 'x = < 0 label_1: 1 label_2: >' gives |
| 'offset_labels' the value {"label_1": 4, "label_2": 8}. |
| |
| Iteration order will match the order of the labels on Python versions |
| that preserve dict insertion order. |
| |
| node: |
| The Node the property is on. |
| """ |
| |
| # |
| # Public interface |
| # |
| |
| def __init__(self, node, name): |
| if "@" in name: |
| node.dt._parse_error("'@' is only allowed in node names") |
| |
| self.name = name |
| self.node = node |
| self.value = b"" |
| self.labels = [] |
| self.offset_labels = [] |
| |
| # A list of (offset, label, type) tuples (sorted by offset), giving the |
| # locations of references within the value. 'type' is either _REF_PATH, |
| # for a node path reference, _REF_PHANDLE, for a phandle reference, or |
| # _REF_LABEL, for a label on/within data. Node paths and phandles need |
| # to be patched in after parsing. |
| self._markers = [] |
| |
| def to_num(self, signed=False): |
| """ |
| Returns the value of the property as a number. |
| |
| Raises DTError if the property was not assigned with this syntax (has |
| Property.type TYPE_NUM): |
| |
| foo = < 1 >; |
| |
| signed (default: False): |
| If True, the value will be interpreted as signed rather than |
| unsigned. |
| """ |
| if self.type is not TYPE_NUM: |
| _err("expected property '{0}' on {1} in {2} to be assigned with " |
| "'{0} = < (number) >;', not '{3}'" |
| .format(self.name, self.node.path, self.node.dt.filename, |
| self)) |
| |
| return int.from_bytes(self.value, "big", signed=signed) |
| |
| def to_nums(self, signed=False): |
| """ |
| Returns the value of the property as a list of numbers. |
| |
| Raises DTError if the property was not assigned with this syntax (has |
| Property.type TYPE_NUM or TYPE_NUMS): |
| |
| foo = < 1 2 ... >; |
| |
| signed (default: False): |
| If True, the values will be interpreted as signed rather than |
| unsigned. |
| """ |
| if self.type not in (TYPE_NUM, TYPE_NUMS): |
| _err("expected property '{0}' on {1} in {2} to be assigned with " |
| "'{0} = < (number) (number) ... >;', not '{3}'" |
| .format(self.name, self.node.path, self.node.dt.filename, |
| self)) |
| |
| return [int.from_bytes(self.value[i:i + 4], "big", signed=signed) |
| for i in range(0, len(self.value), 4)] |
| |
| def to_bytes(self): |
| """ |
| Returns the value of the property as a raw 'bytes', like |
| Property.value, except with added type checking. |
| |
| Raises DTError if the property was not assigned with this syntax (has |
| Property.type TYPE_BYTES): |
| |
| foo = [ 01 ... ]; |
| """ |
| if self.type is not TYPE_BYTES: |
| _err("expected property '{0}' on {1} in {2} to be assigned with " |
| "'{0} = [ (byte) (byte) ... ];', not '{3}'" |
| .format(self.name, self.node.path, self.node.dt.filename, |
| self)) |
| |
| return self.value |
| |
| def to_string(self): |
| """ |
| Returns the value of the property as a string. |
| |
| Raises DTError if the property was not assigned with this syntax (has |
| Property.type TYPE_STRING): |
| |
| foo = "string"; |
| |
| This function might also raise UnicodeDecodeError if the string is |
| not valid UTF-8. |
| """ |
| if self.type is not TYPE_STRING: |
| _err("expected property '{0}' on {1} in {2} to be assigned with " |
| "'{0} = \"string\";', not '{3}'" |
| .format(self.name, self.node.path, self.node.dt.filename, |
| self)) |
| |
| try: |
| return self.value.decode("utf-8")[:-1] # Strip null |
| except UnicodeDecodeError: |
| _err("value of property '{}' ({}) on {} in {} is not valid UTF-8" |
| .format(self.name, self.value, self.node.path, |
| self.node.dt.filename)) |
| |
| def to_strings(self): |
| """ |
| Returns the value of the property as a list of strings. |
| |
| Raises DTError if the property was not assigned with this syntax (has |
| Property.type TYPE_STRING or TYPE_STRINGS): |
| |
| foo = "string", "string", ... ; |
| |
| Also raises DTError if any of the strings are not valid UTF-8. |
| """ |
| if self.type not in (TYPE_STRING, TYPE_STRINGS): |
| _err("expected property '{0}' on {1} in {2} to be assigned with " |
| "'{0} = \"string\", \"string\", ... ;', not '{3}'" |
| .format(self.name, self.node.path, self.node.dt.filename, |
| self)) |
| |
| try: |
| return self.value.decode("utf-8").split("\0")[:-1] |
| except UnicodeDecodeError: |
| _err("value of property '{}' ({}) on {} in {} is not valid UTF-8" |
| .format(self.name, self.value, self.node.path, |
| self.node.dt.filename)) |
| |
| def to_node(self): |
| """ |
| Returns the Node the phandle in the property points to. |
| |
| Raises DTError if the property was not assigned with this syntax (has |
| Property.type TYPE_PHANDLE). |
| |
| foo = < &bar >; |
| """ |
| if self.type is not TYPE_PHANDLE: |
| _err("expected property '{0}' on {1} in {2} to be assigned with " |
| "'{0} = < &foo >;', not '{3}'" |
| .format(self.name, self.node.path, self.node.dt.filename, |
| self)) |
| |
| return self.node.dt.phandle2node[int.from_bytes(self.value, "big")] |
| |
| def to_nodes(self): |
| """ |
| Returns a list with the Nodes the phandles in the property point to. |
| |
| Raises DTError if the property value contains anything other than |
| phandles. All of the following are accepted: |
| |
| foo = < > |
| foo = < &bar >; |
| foo = < &bar &baz ... >; |
| foo = < &bar ... >, < &baz ... >; |
| """ |
| def type_ok(): |
| if self.type in (TYPE_PHANDLE, TYPE_PHANDLES): |
| return True |
| # Also accept 'foo = < >;' |
| return self.type is TYPE_NUMS and not self.value |
| |
| if not type_ok(): |
| _err("expected property '{0}' on {1} in {2} to be assigned with " |
| "'{0} = < &foo &bar ... >;', not '{3}'" |
| .format(self.name, self.node.path, |
| self.node.dt.filename, self)) |
| |
| return [self.node.dt.phandle2node[int.from_bytes(self.value[i:i + 4], |
| "big")] |
| for i in range(0, len(self.value), 4)] |
| |
| def to_path(self): |
| """ |
| Returns the Node referenced by the path stored in the property. |
| |
| Raises DTError if the property was not assigned with either of these |
| syntaxes (has Property.type TYPE_PATH or TYPE_STRING): |
| |
| foo = &bar; |
| foo = "/bar"; |
| |
| For the second case, DTError is raised if the path does not exist. |
| """ |
| if self.type not in (TYPE_PATH, TYPE_STRING): |
| _err("expected property '{0}' on {1} in {2} to be assigned with " |
| "either '{0} = &foo' or '{0} = \"/path/to/node\"', not '{3}'" |
| .format(self.name, self.node.path, self.node.dt.filename, |
| self)) |
| |
| try: |
| path = self.value.decode("utf-8")[:-1] |
| except UnicodeDecodeError: |
| _err("value of property '{}' ({}) on {} in {} is not valid UTF-8" |
| .format(self.name, self.value, self.node.path, |
| self.node.dt.filename)) |
| |
| try: |
| return self.node.dt.get_node(path) |
| except DTError: |
| _err("property '{}' on {} in {} points to the non-existent node " |
| "\"{}\"".format(self.name, self.node.path, |
| self.node.dt.filename, path)) |
| |
| @property |
| def type(self): |
| """ |
| See the class docstring. |
| """ |
| # Data labels (e.g. 'foo = label: <3>') are irrelevant, so filter them |
| # out |
| types = [marker[1] for marker in self._markers |
| if marker[1] != _REF_LABEL] |
| |
| if not types: |
| return TYPE_EMPTY |
| |
| if types == [_TYPE_UINT8]: |
| return TYPE_BYTES |
| |
| if types == [_TYPE_UINT32]: |
| return TYPE_NUM if len(self.value) == 4 else TYPE_NUMS |
| |
| # Treat 'foo = <1 2 3>, <4 5>, ...' as TYPE_NUMS too |
| if set(types) == {_TYPE_UINT32}: |
| return TYPE_NUMS |
| |
| if set(types) == {_TYPE_STRING}: |
| return TYPE_STRING if len(types) == 1 else TYPE_STRINGS |
| |
| if types == [_REF_PATH]: |
| return TYPE_PATH |
| |
| if types == [_TYPE_UINT32, _REF_PHANDLE] and len(self.value) == 4: |
| return TYPE_PHANDLE |
| |
| if set(types) == {_TYPE_UINT32, _REF_PHANDLE}: |
| if len(self.value) == 4*types.count(_REF_PHANDLE): |
| # Array with just phandles in it |
| return TYPE_PHANDLES |
| # Array with both phandles and numbers |
| return TYPE_PHANDLES_AND_NUMS |
| |
| return TYPE_COMPOUND |
| |
| def __str__(self): |
| s = "".join(label + ": " for label in self.labels) + self.name |
| if not self.value: |
| return s + ";" |
| |
| s += " =" |
| |
| for i, (pos, marker_type, ref) in enumerate(self._markers): |
| if i < len(self._markers) - 1: |
| next_marker = self._markers[i + 1] |
| else: |
| next_marker = None |
| |
| # End of current marker |
| end = next_marker[0] if next_marker else len(self.value) |
| |
| if marker_type is _TYPE_STRING: |
| # end - 1 to strip off the null terminator |
| s += ' "{}"'.format(_decode_and_escape( |
| self.value[pos:end - 1])) |
| if end != len(self.value): |
| s += "," |
| elif marker_type is _REF_PATH: |
| s += " &" + ref |
| if end != len(self.value): |
| s += "," |
| else: |
| # <> or [] |
| |
| if marker_type is _REF_LABEL: |
| s += " {}:".format(ref) |
| elif marker_type is _REF_PHANDLE: |
| s += " &" + ref |
| pos += 4 |
| # Subtle: There might be more data between the phandle and |
| # the next marker, so we can't 'continue' here |
| else: # marker_type is _TYPE_UINT* |
| elm_size = _TYPE_TO_N_BYTES[marker_type] |
| s += _N_BYTES_TO_START_STR[elm_size] |
| |
| while pos != end: |
| num = int.from_bytes(self.value[pos:pos + elm_size], |
| "big") |
| if elm_size == 1: |
| s += " {:02X}".format(num) |
| else: |
| s += " " + hex(num) |
| |
| pos += elm_size |
| |
| if pos != 0 and \ |
| (not next_marker or |
| next_marker[1] not in (_REF_PHANDLE, _REF_LABEL)): |
| |
| s += _N_BYTES_TO_END_STR[elm_size] |
| if pos != len(self.value): |
| s += "," |
| |
| return s + ";" |
| |
| |
| def __repr__(self): |
| return "<Property '{}' at '{}' in '{}'>" \ |
| .format(self.name, self.node.path, self.node.dt.filename) |
| |
| # |
| # Internal functions |
| # |
| |
| def _add_marker(self, marker_type, data=None): |
| # Helper for registering markers in the value that are processed after |
| # parsing. See _fixup_props(). 'marker_type' identifies the type of |
| # marker, and 'data' has any optional data associated with the marker. |
| |
| # len(self.value) gives the current offset. This function is called |
| # while the value is built. We use a list instead of a tuple to be able |
| # to fix up offsets later (they might increase if the value includes |
| # path references, e.g. 'foo = &bar, <3>;', which are expanded later). |
| self._markers.append([len(self.value), marker_type, data]) |
| |
| # For phandle references, add a dummy value with the same length as a |
| # phandle. This is handy for the length check in _register_phandles(). |
| if marker_type is _REF_PHANDLE: |
| self.value += b"\0\0\0\0" |
| |
| |
| # |
| # Public functions |
| # |
| |
| |
| def to_num(data, length=None, signed=False): |
| """ |
| Converts the 'bytes' array 'data' to a number. The value is expected to be |
| in big-endian format, which is standard in Device Tree. |
| |
| length (default: None): |
| The expected length of the value in bytes, as a simple type check. If |
| None, the length check is skipped. |
| |
| signed (default: False): |
| If True, the value will be interpreted as signed rather than unsigned. |
| """ |
| _check_is_bytes(data) |
| if length is not None: |
| _check_length_positive(length) |
| if len(data) != length: |
| _err("{} is {} bytes long, expected {}" |
| .format(data, len(data), length)) |
| |
| return int.from_bytes(data, "big", signed=signed) |
| |
| |
| def to_nums(data, length=4, signed=False): |
| """ |
| Like Property.to_nums(), but takes an arbitrary 'bytes' array. The values |
| are assumed to be in big-endian format, which is standard in Device Tree. |
| """ |
| _check_is_bytes(data) |
| _check_length_positive(length) |
| |
| if len(data) % length: |
| _err("{} is {} bytes long, expected a length that's a a multiple of {}" |
| .format(data, len(data), length)) |
| |
| return [int.from_bytes(data[i:i + length], "big", signed=signed) |
| for i in range(0, len(data), length)] |
| |
| |
| # |
| # Public constants |
| # |
| |
| # See Property.type |
| TYPE_EMPTY = 0 |
| TYPE_BYTES = 1 |
| TYPE_NUM = 2 |
| TYPE_NUMS = 3 |
| TYPE_STRING = 4 |
| TYPE_STRINGS = 5 |
| TYPE_PATH = 6 |
| TYPE_PHANDLE = 7 |
| TYPE_PHANDLES = 8 |
| TYPE_PHANDLES_AND_NUMS = 9 |
| TYPE_COMPOUND = 10 |
| |
| |
| def _check_is_bytes(data): |
| if not isinstance(data, bytes): |
| _err("'{}' has type '{}', expected 'bytes'" |
| .format(data, type(data).__name__)) |
| |
| |
| def _check_length_positive(length): |
| if length < 1: |
| _err("'length' must be greater than zero, was " + str(length)) |
| |
| |
| def _append_no_dup(lst, elm): |
| # Appends 'elm' to 'lst', but only if it isn't already in 'lst'. Lets us |
| # preserve order, which a set() doesn't. |
| |
| if elm not in lst: |
| lst.append(elm) |
| |
| |
| def _decode_and_escape(b): |
| # Decodes the 'bytes' array 'b' as UTF-8 and backslash-escapes special |
| # characters |
| |
| # Hacky but robust way to avoid double-escaping any '\' spit out by |
| # 'backslashreplace' bytes.translate() can't map to more than a single |
| # byte, but str.translate() can map to more than one character, so it's |
| # nice here. There's probably a nicer way to do this. |
| return b.decode("utf-8", "surrogateescape") \ |
| .translate(_escape_table) \ |
| .encode("utf-8", "surrogateescape") \ |
| .decode("utf-8", "backslashreplace") |
| |
| |
| def _root_and_path_to_node(cur, path, fullpath): |
| # Returns the node pointed at by 'path', relative to the Node 'cur'. For |
| # example, if 'cur' has path /foo/bar, and 'path' is "baz/qaz", then the |
| # node with path /foo/bar/baz/qaz is returned. 'fullpath' is the path as |
| # given in the .dts file, for error messages. |
| |
| for component in path.split("/"): |
| # Collapse multiple / in a row, and allow a / at the end |
| if not component: |
| continue |
| |
| if component not in cur.nodes: |
| _err("component '{}' in path '{}' does not exist" |
| .format(component, fullpath)) |
| |
| cur = cur.nodes[component] |
| |
| return cur |
| |
| |
| def _err(msg): |
| raise DTError(msg) |
| |
| |
| _escape_table = str.maketrans({ |
| "\\": "\\\\", |
| '"': '\\"', |
| "\a": "\\a", |
| "\b": "\\b", |
| "\t": "\\t", |
| "\n": "\\n", |
| "\v": "\\v", |
| "\f": "\\f", |
| "\r": "\\r"}) |
| |
| |
| class DTError(Exception): |
| "Exception raised for Device Tree-related errors" |
| |
| |
| _Token = collections.namedtuple("Token", "id val") |
| |
| # Lexer states |
| _DEFAULT = 0 |
| _EXPECT_PROPNODENAME = 1 |
| _EXPECT_BYTE = 2 |
| |
| _num_re = re.compile(r"(0[xX][0-9a-fA-F]+|[0-9]+)(?:ULL|UL|LL|U|L)?") |
| |
| # A leading \ is allowed property and node names, probably to allow weird node |
| # names that would clash with other stuff |
| _propnodename_re = re.compile(r"\\?([a-zA-Z0-9,._+*#?@-]+)") |
| |
| # Misc. tokens that are tried after a property/node name. This is important, as |
| # there's overlap with the allowed characters in names. |
| _misc_re = re.compile( |
| "|".join(re.escape(pat) for pat in ( |
| "==", "!=", "!", "=", ",", ";", "+", "-", "*", "/", "%", "~", "?", ":", |
| "^", "(", ")", "{", "}", "[", "]", "<<", "<=", "<", ">>", ">=", ">", |
| "||", "|", "&&", "&"))) |
| |
| _byte_re = re.compile(r"[0-9a-fA-F]{2}") |
| |
| # Matches a backslash escape within a 'bytes' array. Captures the 'c' part of |
| # '\c', where c might be a single character or an octal/hex escape. |
| _unescape_re = re.compile(br'\\([0-7]{1,3}|x[0-9A-Fa-f]{1,2}|.)') |
| |
| # #line directive (this is the regex the C tools use) |
| _line_re = re.compile( |
| r'^#(?:line)?[ \t]+([0-9]+)[ \t]+"((?:[^\\"]|\\.)*)"(?:[ \t]+[0-9]+)?', |
| re.MULTILINE) |
| |
| |
| def _init_tokens(): |
| # Builds a (<token 1>)|(<token 2>)|... regex and assigns the index of each |
| # capturing group to a corresponding _T_<TOKEN> variable. This makes the |
| # token type appear in match.lastindex after a match. |
| |
| global _token_re |
| global _T_NUM |
| global _T_PROPNODENAME |
| global _T_MISC |
| global _T_BYTE |
| global _T_BAD |
| |
| # Each pattern must have exactly one capturing group, which can capture any |
| # part of the pattern. This makes match.lastindex match the token type. |
| # _Token.val is based on the captured string. |
| token_spec = (("_T_INCLUDE", r'(/include/\s*"(?:[^\\"]|\\.)*")'), |
| ("_T_LINE", # #line directive |
| r'^#(?:line)?[ \t]+([0-9]+[ \t]+"(?:[^\\"]|\\.)*")(?:[ \t]+[0-9]+)?'), |
| ("_T_STRING", r'"((?:[^\\"]|\\.)*)"'), |
| ("_T_DTS_V1", r"(/dts-v1/)"), |
| ("_T_PLUGIN", r"(/plugin/)"), |
| ("_T_MEMRESERVE", r"(/memreserve/)"), |
| ("_T_BITS", r"(/bits/)"), |
| ("_T_DEL_PROP", r"(/delete-property/)"), |
| ("_T_DEL_NODE", r"(/delete-node/)"), |
| ("_T_OMIT_IF_NO_REF", r"(/omit-if-no-ref/)"), |
| ("_T_LABEL", r"([a-zA-Z_][a-zA-Z0-9_]*):"), |
| ("_T_CHAR_LITERAL", r"'((?:[^\\']|\\.)*)'"), |
| ("_T_REF", |
| r"&([a-zA-Z_][a-zA-Z0-9_]*|{[a-zA-Z0-9,._+*#?@/-]*})"), |
| ("_T_INCBIN", r"(/incbin/)"), |
| # Whitespace, C comments, and C++ comments |
| ("_T_SKIP", r"(\s+|(?:/\*(?:.|\n)*?\*/)|//.*$)"), |
| # Return a token for end-of-file so that the parsing code can |
| # always assume that there are more tokens when looking |
| # ahead. This simplifies things. |
| ("_T_EOF", r"(\Z)")) |
| |
| # MULTILINE is needed for C++ comments and #line directives |
| _token_re = re.compile("|".join(spec[1] for spec in token_spec), |
| re.MULTILINE | re.ASCII) |
| |
| for i, spec in enumerate(token_spec, 1): |
| globals()[spec[0]] = i |
| |
| # pylint: disable=undefined-loop-variable |
| _T_NUM = i + 1 |
| _T_PROPNODENAME = i + 2 |
| _T_MISC = i + 3 |
| _T_BYTE = i + 4 |
| _T_BAD = i + 5 |
| |
| |
| _init_tokens() |
| |
| # Markers in property values |
| |
| # References |
| _REF_PATH = 0 # &foo |
| _REF_PHANDLE = 1 # <&foo> |
| _REF_LABEL = 2 # foo: <1 2 3> |
| # Start of data blocks of specific type |
| _TYPE_UINT8 = 3 # [00 01 02] (and also used for /incbin/) |
| _TYPE_UINT16 = 4 # /bits/ 16 <1 2 3> |
| _TYPE_UINT32 = 5 # <1 2 3> |
| _TYPE_UINT64 = 6 # /bits/ 64 <1 2 3> |
| _TYPE_STRING = 7 # "foo" |
| |
| _TYPE_TO_N_BYTES = { |
| _TYPE_UINT8: 1, |
| _TYPE_UINT16: 2, |
| _TYPE_UINT32: 4, |
| _TYPE_UINT64: 8, |
| } |
| |
| _N_BYTES_TO_TYPE = { |
| 1: _TYPE_UINT8, |
| 2: _TYPE_UINT16, |
| 4: _TYPE_UINT32, |
| 8: _TYPE_UINT64, |
| } |
| |
| _N_BYTES_TO_START_STR = { |
| 1: " [", |
| 2: " /bits/ 16 <", |
| 4: " <", |
| 8: " /bits/ 64 <", |
| } |
| |
| _N_BYTES_TO_END_STR = { |
| 1: " ]", |
| 2: " >", |
| 4: " >", |
| 8: " >", |
| } |
