Diff: mbed-os/tools/config/__init__.py

Revision:

0:380207fcb5c1

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os/tools/config/__init__.py	Thu Mar 29 07:02:09 2018 +0000
@@ -0,0 +1,1083 @@
+"""
+mbed SDK
+Copyright (c) 2016 ARM Limited
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+"""
+from __future__ import print_function, division, absolute_import
+
+from copy import deepcopy
+from six import moves
+import json
+import six
+import os
+from os.path import dirname, abspath, exists, join, isabs
+import sys
+from collections import namedtuple
+from os.path import splitext, relpath
+from intelhex import IntelHex
+from jinja2 import FileSystemLoader, StrictUndefined
+from jinja2.environment import Environment
+from jsonschema import Draft4Validator, RefResolver
+
+from ..utils import json_file_to_dict, intelhex_offset, integer
+from ..arm_pack_manager import Cache
+from ..targets import (CUMULATIVE_ATTRIBUTES, TARGET_MAP, generate_py_target,
+                       get_resolution_order, Target)
+
+try:
+    unicode
+except NameError:
+    unicode = str
+PATH_OVERRIDES = set(["target.bootloader_img"])
+BOOTLOADER_OVERRIDES = set(["target.bootloader_img", "target.restrict_size",
+                            "target.header_format", "target.header_offset",
+                            "target.app_offset",
+                            "target.mbed_app_start", "target.mbed_app_size"])
+
+
+# Base class for all configuration exceptions
+class ConfigException(Exception):
+    """Config system only exception. Makes it easier to distinguish config
+    errors"""
+    pass
+
+class ConfigParameter(object):
+    """This class keeps information about a single configuration parameter"""
+
+    def __init__(self, name, data, unit_name, unit_kind):
+        """Construct a ConfigParameter
+
+        Positional arguments:
+        name - the name of the configuration parameter
+        data - the data associated with the configuration parameter
+        unit_name - the unit (target/library/application) that defines this
+                    parameter
+        unit_ kind - the kind of the unit ("target", "library" or "application")
+        """
+        self.name = self.get_full_name(name, unit_name, unit_kind,
+                                       allow_prefix=False)
+        self.defined_by = self.get_display_name(unit_name, unit_kind)
+        self.set_value(data.get("value", None), unit_name, unit_kind)
+        self.help_text = data.get("help", None)
+        self.required = data.get("required", False)
+        self.macro_name = data.get("macro_name", "MBED_CONF_%s" %
+                                   self.sanitize(self.name.upper()))
+        self.config_errors = []
+
+    @staticmethod
+    def get_full_name(name, unit_name, unit_kind, label=None,
+                      allow_prefix=True):
+        """Return the full (prefixed) name of a parameter. If the parameter
+        already has a prefix, check if it is valid
+
+        Positional arguments:
+        name - the simple (unqualified) name of the parameter
+        unit_name - the unit (target/library/application) that defines this
+                    parameter
+        unit_kind - the kind of the unit ("target", "library" or "application")
+
+        Keyword arguments:
+        label - the name of the label in the 'target_config_overrides' section
+        allow_prefix - True to allow the original name to have a prefix, False
+                       otherwise
+        """
+        if name.find('.') == -1: # the name is not prefixed
+            if unit_kind == "target":
+                prefix = "target."
+            elif unit_kind == "application":
+                prefix = "app."
+            else:
+                prefix = unit_name + '.'
+            return prefix + name
+        if name in BOOTLOADER_OVERRIDES:
+            return name
+        # The name has a prefix, so check if it is valid
+        if not allow_prefix:
+            raise ConfigException("Invalid parameter name '%s' in '%s'" %
+                                  (name, ConfigParameter.get_display_name(
+                                      unit_name, unit_kind, label)))
+        temp = name.split(".")
+        # Check if the parameter syntax is correct (must be
+        # unit_name.parameter_name)
+        if len(temp) != 2:
+            raise ConfigException("Invalid parameter name '%s' in '%s'" %
+                                  (name, ConfigParameter.get_display_name(
+                                      unit_name, unit_kind, label)))
+        prefix = temp[0]
+        # Check if the given parameter prefix matches the expected prefix
+        if (unit_kind == "library" and prefix != unit_name) or \
+           (unit_kind == "target" and prefix != "target"):
+            raise ConfigException(
+                "Invalid prefix '%s' for parameter name '%s' in '%s'" %
+                (prefix, name, ConfigParameter.get_display_name(
+                    unit_name, unit_kind, label)))
+        return name
+
+    @staticmethod
+    def get_display_name(unit_name, unit_kind, label=None):
+        """Return the name displayed for a unit when interrogating the origin
+        and the last set place of a parameter
+
+        Positional arguments:
+        unit_name - the unit (target/library/application) that defines this
+                    parameter
+        unit_kind - the kind of the unit ("target", "library" or "application")
+
+        Keyword arguments:
+        label - the name of the label in the 'target_config_overrides' section
+        """
+        if unit_kind == "target":
+            return "target:" + unit_name
+        elif unit_kind == "application":
+            return "application%s" % ("[%s]" % label if label else "")
+        else: # library
+            return "library:%s%s" % (unit_name, "[%s]" % label if label else "")
+
+    @staticmethod
+    def sanitize(name):
+        """ "Sanitize" a name so that it is a valid C macro name. Currently it
+        simply replaces '.' and '-' with '_'.
+
+        Positional arguments:
+        name - the name to make into a valid C macro
+        """
+        return name.replace('.', '_').replace('-', '_')
+
+    def set_value(self, value, unit_name, unit_kind, label=None):
+        """ Sets a value for this parameter, remember the place where it was
+        set.  If the value is a Boolean, it is converted to 1 (for True) or
+        to 0 (for False).
+
+        Positional arguments:
+        value - the value of the parameter
+        unit_name - the unit (target/library/application) that defines this
+                   parameter
+        unit_kind - the kind of the unit ("target", "library" or "application")
+
+        Keyword arguments:
+        label - the name of the label in the 'target_config_overrides' section
+               (optional)
+        """
+        self.value = int(value) if isinstance(value, bool) else value
+        self.set_by = self.get_display_name(unit_name, unit_kind, label)
+
+    def __str__(self):
+        """Return the string representation of this configuration parameter
+
+        Arguments: None
+        """
+        if self.value is not None:
+            return '%s = %s (macro name: "%s")' % \
+                (self.name, self.value, self.macro_name)
+        else:
+            return '%s has no value' % self.name
+
+    def get_verbose_description(self):
+        """Return a verbose description of this configuration parameter as a
+        string
+
+        Arguments: None
+        """
+        desc = "Name: %s%s\n" % \
+               (self.name, " (required parameter)" if self.required else "")
+        if self.help_text:
+            desc += "    Description: %s\n" % self.help_text
+        desc += "    Defined by: %s\n" % self.defined_by
+        if not self.value:
+            return desc + "    No value set"
+        desc += "    Macro name: %s\n" % self.macro_name
+        desc += "    Value: %s (set by %s)" % (self.value, self.set_by)
+        return desc
+
+class ConfigMacro(object):
+    """ A representation of a configuration macro. It handles both macros
+    without a value (MACRO) and with a value (MACRO=VALUE)
+    """
+    def __init__(self, name, unit_name, unit_kind):
+        """Construct a ConfigMacro object
+
+        Positional arguments:
+        name - the macro's name
+        unit_name - the location where the macro was defined
+        unit_kind - the type of macro this is
+        """
+        self.name = name
+        self.defined_by = ConfigParameter.get_display_name(unit_name, unit_kind)
+        if name.find("=") != -1:
+            tmp = name.split("=")
+            if len(tmp) != 2:
+                raise ValueError("Invalid macro definition '%s' in '%s'" %
+                                 (name, self.defined_by))
+            self.macro_name = tmp[0]
+            self.macro_value = tmp[1]
+        else:
+            self.macro_name = name
+            self.macro_value = None
+
+class ConfigCumulativeOverride(object):
+    """Representation of overrides for cumulative attributes"""
+    def __init__(self, name, additions=None, removals=None, strict=False):
+        """Construct a ConfigCumulativeOverride object
+
+        Positional arguments:
+        name - the name of the config file this came from ?
+
+        Keyword arguments:
+        additions - macros to add to the overrides
+        removals - macros to remove from the overrides
+        strict - Boolean indicating that attempting to remove from an override
+                 that does not exist should error
+        """
+        self.name = name
+        if additions:
+            self.additions = set(additions)
+        else:
+            self.additions = set()
+        if removals:
+            self.removals = set(removals)
+        else:
+            self.removals = set()
+        self.strict = strict
+
+    def remove_cumulative_overrides(self, overrides):
+        """Extend the list of override removals.
+
+        Positional arguments:
+        overrides - a list of names that, when the override is evaluated, will
+                    be removed
+        """
+        for override in overrides:
+            if override in self.additions:
+                raise ConfigException(
+                    "Configuration conflict. The %s %s both added and removed."
+                    % (self.name[:-1], override))
+
+        self.removals |= set(overrides)
+
+    def add_cumulative_overrides(self, overrides):
+        """Extend the list of override additions.
+
+        Positional arguments:
+        overrides - a list of a names that, when the override is evaluated, will
+                    be added to the list
+        """
+        for override in overrides:
+            if override in self.removals or \
+               (self.strict and override not in self.additions):
+                raise ConfigException(
+                    "Configuration conflict. The %s %s both added and removed."
+                    % (self.name[:-1], override))
+
+        self.additions |= set(overrides)
+
+    def strict_cumulative_overrides(self, overrides):
+        """Remove all overrides that are not the specified ones
+
+        Positional arguments:
+        overrides - a list of names that will replace the entire attribute when
+                    this override is evaluated.
+        """
+        self.remove_cumulative_overrides(self.additions - set(overrides))
+        self.add_cumulative_overrides(overrides)
+        self.strict = True
+
+    def update_target(self, target):
+        """Update the attributes of a target based on this override"""
+        setattr(target, self.name,
+                list((set(getattr(target, self.name, []))
+                      | self.additions) - self.removals))
+
+
+def _process_config_parameters(data, params, unit_name, unit_kind):
+    """Process a "config_parameters" section in either a target, a library,
+    or the application.
+
+    Positional arguments:
+    data - a dictionary with the configuration parameters
+    params - storage for the discovered configuration parameters
+    unit_name - the unit (target/library/application) that defines this
+                parameter
+    unit_kind - the kind of the unit ("target", "library" or "application")
+    """
+    for name, val in data.items():
+        full_name = ConfigParameter.get_full_name(name, unit_name, unit_kind)
+        # If the parameter was already defined, raise an error
+        if full_name in params:
+            raise ConfigException(
+                "Parameter name '%s' defined in both '%s' and '%s'" %
+                (name, ConfigParameter.get_display_name(unit_name, unit_kind),
+                 params[full_name].defined_by))
+        # Otherwise add it to the list of known parameters
+        # If "val" is not a dictionary, this is a shortcut definition,
+        # otherwise it is a full definition
+        params[full_name] = ConfigParameter(name, val if isinstance(val, dict)
+                                            else {"value": val}, unit_name,
+                                            unit_kind)
+    return params
+
+
+def _process_macros(mlist, macros, unit_name, unit_kind):
+    """Process a macro definition and check for incompatible duplicate
+    definitions.
+
+    Positional arguments:
+    mlist - list of macro names to process
+    macros - dictionary with currently discovered macros
+    unit_name - the unit (library/application) that defines this macro
+    unit_kind - the kind of the unit ("library" or "application")
+    """
+    for mname in mlist:
+        macro = ConfigMacro(mname, unit_name, unit_kind)
+        if (macro.macro_name in macros) and \
+           (macros[macro.macro_name].name != mname):
+            # Found an incompatible definition of the macro in another module,
+            # so raise an error
+            full_unit_name = ConfigParameter.get_display_name(unit_name,
+                                                              unit_kind)
+            raise ConfigException(
+                ("Macro '%s' defined in both '%s' and '%s'"
+                 % (macro.macro_name, macros[macro.macro_name].defined_by,
+                    full_unit_name)) +
+                " with incompatible values")
+        macros[macro.macro_name] = macro
+
+
+Region = namedtuple("Region", "name start size active filename")
+
+class Config(object):
+    """'Config' implements the mbed configuration mechanism"""
+
+    # Libraries and applications have different names for their configuration
+    # files
+    __mbed_app_config_name = "mbed_app.json"
+    __mbed_lib_config_name = "mbed_lib.json"
+
+    __unused_overrides = set(["target.bootloader_img", "target.restrict_size",
+                              "target.mbed_app_start", "target.mbed_app_size"])
+
+    # Allowed features in configurations
+    __allowed_features = [
+        "UVISOR", "BLE", "CLIENT", "IPV4", "LWIP", "COMMON_PAL", "STORAGE", "NANOSTACK",
+        # Nanostack configurations
+        "LOWPAN_BORDER_ROUTER", "LOWPAN_HOST", "LOWPAN_ROUTER", "NANOSTACK_FULL", "THREAD_BORDER_ROUTER", "THREAD_END_DEVICE", "THREAD_ROUTER", "ETHERNET_HOST"
+        ]
+
+    @classmethod
+    def find_app_config(cls, top_level_dirs):
+        app_config_location = None
+        for directory in top_level_dirs:
+            full_path = os.path.join(directory, cls.__mbed_app_config_name)
+            if os.path.isfile(full_path):
+                if app_config_location is not None:
+                    raise ConfigException("Duplicate '%s' file in '%s' and '%s'"
+                                            % (cls.__mbed_app_config_name,
+                                               cls.app_config_location, full_path))
+                else:
+                    app_config_location = full_path
+        return app_config_location
+
+    def format_validation_error(self, error, path):
+        if error.context:
+            return self.format_validation_error(error.context[0], path)
+        else:
+            return "in {} element {}: {}".format(
+                path, str(".".join(str(p) for p in error.absolute_path)), error.message)
+
+    def __init__(self, tgt, top_level_dirs=None, app_config=None):
+        """Construct a mbed configuration
+
+        Positional arguments:
+        target - the name of the mbed target used for this configuration
+                 instance
+
+        Keyword argumets:
+        top_level_dirs - a list of top level source directories (where
+                         mbed_app_config.json could be found)
+        app_config - location of a chosen mbed_app.json file
+
+        NOTE: Construction of a Config object will look for the application
+        configuration file in top_level_dirs. If found once, it'll parse it.
+        top_level_dirs may be None (in this case, the constructor will not
+        search for a configuration file).
+        """
+        config_errors = []
+        self.app_config_location = app_config
+        if self.app_config_location is None and top_level_dirs:
+            self.app_config_location = self.find_app_config(top_level_dirs)
+        try:
+            self.app_config_data = json_file_to_dict(self.app_config_location) \
+                                   if self.app_config_location else {}
+        except ValueError as exc:
+            self.app_config_data = {}
+            config_errors.append(
+                ConfigException("Could not parse mbed app configuration from %s"
+                                % self.app_config_location))
+
+
+        if self.app_config_location is not None:
+            # Validate the format of the JSON file based on schema_app.json
+            schema_root = os.path.dirname(os.path.abspath(__file__))
+            schema_path = os.path.join(schema_root, "schema_app.json")
+            schema      = json_file_to_dict(schema_path)
+
+            url = moves.urllib.request.pathname2url(schema_path)
+            uri = moves.urllib_parse.urljoin("file://", url)
+
+            resolver = RefResolver(uri, schema)
+            validator = Draft4Validator(schema, resolver=resolver)
+
+            errors = sorted(validator.iter_errors(self.app_config_data))
+
+            if errors:
+                raise ConfigException("; ".join(
+                    self.format_validation_error(x, self.app_config_location)
+                    for x in errors))
+
+        # Update the list of targets with the ones defined in the application
+        # config, if applicable
+        self.lib_config_data = {}
+        # Make sure that each config is processed only once
+        self.processed_configs = {}
+        if isinstance(tgt, Target):
+            self.target = tgt
+        else:
+            if tgt in TARGET_MAP:
+                self.target = TARGET_MAP[tgt]
+            else:
+                self.target = generate_py_target(
+                    self.app_config_data.get("custom_targets", {}), tgt)
+        self.target = deepcopy(self.target)
+        self.target_labels = self.target.labels
+        for override in BOOTLOADER_OVERRIDES:
+            _, attr = override.split(".")
+            setattr(self.target, attr, None)
+
+        self.cumulative_overrides = {key: ConfigCumulativeOverride(key)
+                                     for key in CUMULATIVE_ATTRIBUTES}
+
+        self._process_config_and_overrides(self.app_config_data, {}, "app",
+                                           "application")
+        self.config_errors = config_errors
+
+    def add_config_files(self, flist):
+        """Add configuration files
+
+        Positional arguments:
+        flist - a list of files to add to this configuration
+        """
+        for config_file in flist:
+            if not config_file.endswith(self.__mbed_lib_config_name):
+                continue
+            full_path = os.path.normpath(os.path.abspath(config_file))
+            # Check that we didn't already process this file
+            if full_path in self.processed_configs:
+                continue
+            self.processed_configs[full_path] = True
+            # Read the library configuration and add a "__full_config_path"
+            # attribute to it
+            try:
+                cfg = json_file_to_dict(config_file)
+            except ValueError as exc:
+                sys.stderr.write(str(exc) + "\n")
+                continue
+
+            # Validate the format of the JSON file based on the schema_lib.json
+            schema_root = os.path.dirname(os.path.abspath(__file__))
+            schema_path = os.path.join(schema_root, "schema_lib.json")
+            schema_file = json_file_to_dict(schema_path)
+
+            url = moves.urllib.request.pathname2url(schema_path)
+            uri = moves.urllib_parse.urljoin("file://", url)
+
+            resolver = RefResolver(uri, schema_file)
+            validator = Draft4Validator(schema_file, resolver=resolver)
+
+            errors = sorted(validator.iter_errors(cfg))
+
+            if errors:
+                raise ConfigException("; ".join(
+                    self.format_validation_error(x, config_file)
+                    for x in errors))
+
+            cfg["__config_path"] = full_path
+
+            # If there's already a configuration for a module with the same
+            # name, exit with error
+            if cfg["name"] in self.lib_config_data:
+                raise ConfigException(
+                    "Library name '%s' is not unique (defined in '%s' and '%s')"
+                    % (cfg["name"], full_path,
+                       self.lib_config_data[cfg["name"]]["__config_path"]))
+            self.lib_config_data[cfg["name"]] = cfg
+
+    @property
+    def has_regions(self):
+        """Does this config have regions defined?"""
+        for override in BOOTLOADER_OVERRIDES:
+            _, attr = override.split(".")
+            if getattr(self.target, attr, None):
+                return True
+        return False
+
+    @property
+    def sectors(self):
+        """Return a list of tuples of sector start,size"""
+        cache = Cache(False, False)
+        if self.target.device_name not in cache.index:
+            raise ConfigException("Bootloader not supported on this target: "
+                                  "targets.json `device_name` not found in "
+                                  "arm_pack_manager index.")
+        cmsis_part = cache.index[self.target.device_name]
+        sectors = cmsis_part['sectors']
+        if sectors:
+            return sectors
+        raise ConfigException("No sector info available")
+
+    @property
+    def regions(self):
+        """Generate a list of regions from the config"""
+        if not self.target.bootloader_supported:
+            raise ConfigException("Bootloader not supported on this target.")
+        if not hasattr(self.target, "device_name"):
+            raise ConfigException("Bootloader not supported on this target: "
+                                  "targets.json `device_name` not specified.")
+        cache = Cache(False, False)
+        if self.target.device_name not in cache.index:
+            raise ConfigException("Bootloader not supported on this target: "
+                                  "targets.json `device_name` not found in "
+                                  "arm_pack_manager index.")
+        cmsis_part = cache.index[self.target.device_name]
+        if  ((self.target.bootloader_img or self.target.restrict_size) and
+             (self.target.mbed_app_start or self.target.mbed_app_size)):
+            raise ConfigException(
+                "target.bootloader_img and target.restirct_size are "
+                "incompatible with target.mbed_app_start and "
+                "target.mbed_app_size")
+        try:
+            rom_size = int(cmsis_part['memory']['IROM1']['size'], 0)
+            rom_start = int(cmsis_part['memory']['IROM1']['start'], 0)
+        except KeyError:
+            try:
+                rom_size = int(cmsis_part['memory']['PROGRAM_FLASH']['size'], 0)
+                rom_start = int(cmsis_part['memory']['PROGRAM_FLASH']['start'], 0)
+            except KeyError:
+                raise ConfigException("Not enough information in CMSIS packs to "
+                                      "build a bootloader project")
+        if self.target.bootloader_img or self.target.restrict_size:
+            return self._generate_bootloader_build(rom_start, rom_size)
+        elif self.target.mbed_app_start or self.target.mbed_app_size:
+            return self._generate_linker_overrides(rom_start, rom_size)
+        else:
+            raise ConfigException(
+                "Bootloader build requested but no bootlader configuration")
+
+    @staticmethod
+    def header_member_size(member):
+        _, _, subtype, _ = member
+        try:
+            return int(subtype[:-2]) // 8
+        except:
+            if subtype.startswith("CRCITT32"):
+                return 32 // 8
+            elif subtype == "SHA256":
+                return 256 // 8
+            elif subtype == "SHA512":
+                return 512 // 8
+            else:
+                raise ValueError("target.header_format: subtype %s is not "
+                                 "understood" % subtype)
+
+    @staticmethod
+    def _header_size(format):
+        return sum(Config.header_member_size(m) for m in format)
+
+    def _make_header_region(self, start, header_format, offset=None):
+        size = self._header_size(header_format)
+        region = Region("header", start, size, False, None)
+        start += size
+        start = ((start + 7) // 8) * 8
+        return (start, region)
+
+    @staticmethod
+    def _assign_new_offset(rom_start, start, new_offset, region_name):
+        newstart = rom_start + integer(new_offset, 0)
+        if newstart < start:
+            raise ConfigException(
+                "Can not place % region inside previous region" % region_name)
+        return newstart
+
+    def _generate_bootloader_build(self, rom_start, rom_size):
+        start = rom_start
+        rom_end = rom_start + rom_size
+        if self.target.bootloader_img:
+            if isabs(self.target.bootloader_img):
+                filename = self.target.bootloader_img
+            else:
+                basedir = abspath(dirname(self.app_config_location))
+                filename = join(basedir, self.target.bootloader_img)
+            if not exists(filename):
+                raise ConfigException("Bootloader %s not found" % filename)
+            part = intelhex_offset(filename, offset=rom_start)
+            if part.minaddr() != rom_start:
+                raise ConfigException("bootloader executable does not "
+                                      "start at 0x%x" % rom_start)
+            part_size = (part.maxaddr() - part.minaddr()) + 1
+            part_size = Config._align_ceiling(rom_start + part_size, self.sectors) - rom_start
+            yield Region("bootloader", rom_start, part_size, False,
+                         filename)
+            start = rom_start + part_size
+            if self.target.header_format:
+                if self.target.header_offset:
+                    start = self._assign_new_offset(
+                        rom_start, start, self.target.header_offset, "header")
+                start, region = self._make_header_region(
+                    start, self.target.header_format)
+                yield region._replace(filename=self.target.header_format)
+        if self.target.restrict_size is not None:
+            new_size = int(self.target.restrict_size, 0)
+            new_size = Config._align_floor(start + new_size, self.sectors) - start
+            yield Region("application", start, new_size, True, None)
+            start += new_size
+            if self.target.header_format:
+                if self.target.header_offset:
+                    start = self._assign_new_offset(
+                        rom_start, start, self.target.header_offset, "header")
+                start, region = self._make_header_region(
+                    start, self.target.header_format)
+                yield region
+            if self.target.app_offset:
+                start = self._assign_new_offset(
+                    rom_start, start, self.target.app_offset, "application")
+            yield Region("post_application", start, rom_end - start,
+                         False, None)
+        else:
+            if self.target.app_offset:
+                start = self._assign_new_offset(
+                    rom_start, start, self.target.app_offset, "application")
+            yield Region("application", start, rom_end - start,
+                         True, None)
+        if start > rom_start + rom_size:
+            raise ConfigException("Not enough memory on device to fit all "
+                                  "application regions")
+    
+    @staticmethod
+    def _find_sector(address, sectors):
+        target_size = -1
+        target_start = -1
+        for (start, size) in sectors:
+            if address < start:
+                break
+            target_start = start
+            target_size = size
+        if (target_size < 0):
+            raise ConfigException("No valid sector found")
+        return target_start, target_size
+        
+    @staticmethod
+    def _align_floor(address, sectors):
+        target_start, target_size = Config._find_sector(address, sectors)
+        sector_num = (address - target_start) // target_size
+        return target_start + (sector_num * target_size)
+    
+    @staticmethod
+    def _align_ceiling(address, sectors):
+        target_start, target_size = Config._find_sector(address, sectors)
+        sector_num = ((address - target_start) + target_size - 1) // target_size
+        return target_start + (sector_num * target_size)
+
+    @property
+    def report(self):
+        return {'app_config': self.app_config_location,
+                'library_configs': map(relpath, self.processed_configs.keys())}
+
+    def _generate_linker_overrides(self, rom_start, rom_size):
+        if self.target.mbed_app_start is not None:
+            start = int(self.target.mbed_app_start, 0)
+        else:
+            start = rom_start
+        if self.target.mbed_app_size is not None:
+            size = int(self.target.mbed_app_size, 0)
+        else:
+            size = (rom_size + rom_start) - start
+        if start < rom_start:
+            raise ConfigException("Application starts before ROM")
+        if size + start > rom_size + rom_start:
+            raise ConfigException("Application ends after ROM")
+        yield Region("application", start, size, True, None)
+
+    def _process_config_and_overrides(self, data, params, unit_name, unit_kind):
+        """Process "config_parameters" and "target_config_overrides" into a
+        given dictionary
+
+        Positional arguments:
+        data - the configuration data of the library/appliation
+        params - storage for the discovered configuration parameters
+        unit_name - the unit (library/application) that defines this parameter
+        unit_kind - the kind of the unit ("library" or "application")
+        """
+        self.config_errors = []
+        _process_config_parameters(data.get("config", {}), params, unit_name,
+                                   unit_kind)
+        for label, overrides in data.get("target_overrides", {}).items():
+            # If the label is defined by the target or it has the special value
+            # "*", process the overrides
+            if (label == '*') or (label in self.target_labels):
+                # Check for invalid cumulative overrides in libraries
+                if (unit_kind == 'library' and
+                    any(attr.startswith('target.extra_labels') for attr
+                        in overrides.keys())):
+                    raise ConfigException(
+                        "Target override 'target.extra_labels' in " +
+                        ConfigParameter.get_display_name(unit_name, unit_kind,
+                                                         label) +
+                        " is only allowed at the application level")
+
+                # Parse out cumulative overrides
+                for attr, cumulatives in self.cumulative_overrides.items():
+                    if 'target.'+attr in overrides:
+                        key = 'target.' + attr
+                        if not isinstance(overrides[key], list):
+                            raise ConfigException(
+                                "The value of %s.%s is not of type %s" %
+                                (unit_name, "target_overrides." + key,
+                                 "list"))
+                        cumulatives.strict_cumulative_overrides(overrides[key])
+                        del overrides[key]
+
+                    if 'target.'+attr+'_add' in overrides:
+                        key = 'target.' + attr + "_add"
+                        if not isinstance(overrides[key], list):
+                            raise ConfigException(
+                                "The value of %s.%s is not of type %s" %
+                                (unit_name, "target_overrides." + key,
+                                 "list"))
+                        cumulatives.add_cumulative_overrides(overrides[key])
+                        del overrides[key]
+
+                    if 'target.'+attr+'_remove' in overrides:
+                        key = 'target.' + attr + "_remove"
+                        if not isinstance(overrides[key], list):
+                            raise ConfigException(
+                                "The value of %s.%s is not of type %s" %
+                                (unit_name, "target_overrides." + key,
+                                 "list"))
+                        cumulatives.remove_cumulative_overrides(overrides[key])
+                        del overrides[key]
+
+                # Consider the others as overrides
+                for name, val in overrides.items():
+                    if (name in PATH_OVERRIDES and "__config_path" in data):
+                        val = os.path.join(
+                            os.path.dirname(data["__config_path"]), val)
+
+                    # Get the full name of the parameter
+                    full_name = ConfigParameter.get_full_name(name, unit_name,
+                                                              unit_kind, label)
+                    if full_name in params:
+                        params[full_name].set_value(val, unit_name, unit_kind,
+                                                    label)
+                    elif (name.startswith("target.") and
+                        (unit_kind is "application" or
+                         name in BOOTLOADER_OVERRIDES)):
+                        _, attribute = name.split(".")
+                        setattr(self.target, attribute, val)
+                        continue
+                    else:
+                        self.config_errors.append(
+                            ConfigException(
+                                "Attempt to override undefined parameter" +
+                                (" '%s' in '%s'"
+                                 % (full_name,
+                                    ConfigParameter.get_display_name(unit_name,
+                                                                     unit_kind,
+                                                                     label)))))
+
+        for cumulatives in self.cumulative_overrides.values():
+            cumulatives.update_target(self.target)
+
+        return params
+
+    def get_target_config_data(self):
+        """Read and interpret configuration data defined by targets.
+
+        We consider the resolution order for our target and sort it by level
+        reversed, so that we first look at the top level target (the parent),
+        then its direct children, then the children of those children and so on,
+        until we reach self.target
+        TODO: this might not work so well in some multiple inheritance scenarios
+        At each step, look at two keys of the target data:
+          - config_parameters: used to define new configuration parameters
+          - config_overrides: used to override already defined configuration
+                              parameters
+
+        Arguments: None
+        """
+        params, json_data = {}, self.target.json_data
+        resolution_order = [e[0] for e
+                            in sorted(
+                                self.target.resolution_order,
+                                key=lambda e: e[1], reverse=True)]
+        for tname in resolution_order:
+            # Read the target data directly from its description
+            target_data = json_data[tname]
+            # Process definitions first
+            _process_config_parameters(target_data.get("config", {}), params,
+                                       tname, "target")
+            # Then process overrides
+            for name, val in target_data.get("overrides", {}).items():
+                full_name = ConfigParameter.get_full_name(name, tname, "target")
+                # If the parameter name is not defined or if there isn't a path
+                # from this target to the target where the parameter was defined
+                # in the target inheritance tree, raise an error We need to use
+                # 'defined_by[7:]' to remove the "target:" prefix from
+                # defined_by
+                rel_names = [tgt for tgt, _ in
+                             get_resolution_order(self.target.json_data, tname,
+                                                  [])]
+                if full_name in BOOTLOADER_OVERRIDES:
+                    continue
+                if (full_name not in params) or \
+                   (params[full_name].defined_by[7:] not in rel_names):
+                    raise ConfigException(
+                        "Attempt to override undefined parameter '%s' in '%s'"
+                        % (name,
+                           ConfigParameter.get_display_name(tname, "target")))
+                # Otherwise update the value of the parameter
+                params[full_name].set_value(val, tname, "target")
+        return params
+
+    def get_lib_config_data(self):
+        """ Read and interpret configuration data defined by libraries. It is
+        assumed that "add_config_files" above was already called and the library
+        configuration data exists in self.lib_config_data
+
+        Arguments: None
+        """
+        all_params, macros = {}, {}
+        for lib_name, lib_data in self.lib_config_data.items():
+            all_params.update(self._process_config_and_overrides(lib_data, {},
+                                                                 lib_name,
+                                                                 "library"))
+            _process_macros(lib_data.get("macros", []), macros, lib_name,
+                            "library")
+        return all_params, macros
+
+    def get_app_config_data(self, params, macros):
+        """ Read and interpret the configuration data defined by the target. The
+        target can override any configuration parameter, as well as define its
+        own configuration data.
+
+        Positional arguments.
+        params - the dictionary with configuration parameters found so far (in
+                 the target and in libraries)
+        macros - the list of macros defined in the configuration
+        """
+        app_cfg = self.app_config_data
+        # The application can have a "config_parameters" and a
+        # "target_config_overrides" section just like a library
+        self._process_config_and_overrides(app_cfg, params, "app",
+                                           "application")
+        # The application can also defined macros
+        _process_macros(app_cfg.get("macros", []), macros, "app",
+                        "application")
+
+    def get_config_data(self):
+        """ Return the configuration data in two parts: (params, macros)
+        params - a dictionary with mapping a name to a ConfigParam
+        macros - the list of macros defined with "macros" in libraries and in
+                 the application (as ConfigMacro instances)
+
+        Arguments: None
+        """
+        all_params = self.get_target_config_data()
+        lib_params, macros = self.get_lib_config_data()
+        all_params.update(lib_params)
+        self.get_app_config_data(all_params, macros)
+        return all_params, macros
+
+    @staticmethod
+    def _check_required_parameters(params):
+        """Check that there are no required parameters without a value
+
+        Positional arguments:
+        params - the list of parameters to check
+
+        NOTE: This function does not return. Instead, it throws a
+        ConfigException when any of the required parameters are missing values
+        """
+        for param in params.values():
+            if param.required and (param.value is None):
+                raise ConfigException("Required parameter '" + param.name +
+                                      "' defined by '" + param.defined_by +
+                                      "' doesn't have a value")
+
+    @staticmethod
+    def parameters_to_macros(params):
+        """ Encode the configuration parameters as C macro definitions.
+
+        Positional arguments:
+        params - a dictionary mapping a name to a ConfigParameter
+
+        Return: a list of strings that encode the configuration parameters as
+        C pre-processor macros
+        """
+        return ['%s=%s' % (m.macro_name, m.value) for m in params.values()
+                if m.value is not None]
+
+    @staticmethod
+    def config_macros_to_macros(macros):
+        """ Return the macro definitions generated for a dictionary of
+        ConfigMacros (as returned by get_config_data).
+
+        Positional arguments:
+        params - a dictionary mapping a name to a ConfigMacro instance
+
+        Return: a list of strings that are the C pre-processor macros
+        """
+        return [m.name for m in macros.values()]
+
+    @staticmethod
+    def config_to_macros(config):
+        """Convert the configuration data to a list of C macros
+
+        Positional arguments:
+        config - configuration data as (ConfigParam instances, ConfigMacro
+                 instances) tuple (as returned by get_config_data())
+        """
+        params, macros = config[0], config[1]
+        Config._check_required_parameters(params)
+        return Config.config_macros_to_macros(macros) + \
+            Config.parameters_to_macros(params)
+
+    def get_config_data_macros(self):
+        """ Convert a Config object to a list of C macros
+
+        Arguments: None
+        """
+        return self.config_to_macros(self.get_config_data())
+
+    def get_features(self):
+        """ Extract any features from the configuration data
+
+        Arguments: None
+        """
+        params, _ = self.get_config_data()
+        self._check_required_parameters(params)
+        self.cumulative_overrides['features']\
+            .update_target(self.target)
+
+        for feature in self.target.features:
+            if feature not in self.__allowed_features:
+                raise ConfigException(
+                    "Feature '%s' is not a supported features" % feature)
+
+        return self.target.features
+
+    def validate_config(self):
+        """ Validate configuration settings. This either returns True or
+        raises an exception
+
+        Arguments: None
+        """
+        if self.config_errors:
+            raise self.config_errors[0]
+        return True
+
+
+    @property
+    def name(self):
+        if "artifact_name" in self.app_config_data:
+            return self.app_config_data["artifact_name"]
+        else:
+            return None
+
+    def load_resources(self, resources):
+        """ Load configuration data from a Resources instance and expand it
+        based on defined features.
+
+        Positional arguments:
+        resources - the resources object to load from and expand
+        """
+        # Update configuration files until added features creates no changes
+        prev_features = set()
+        self.validate_config()
+        while True:
+            # Add/update the configuration with any .json files found while
+            # scanning
+            self.add_config_files(resources.json_files)
+
+            # Add features while we find new ones
+            features = set(self.get_features())
+            if features == prev_features:
+                break
+
+            for feature in features:
+                if feature in resources.features:
+                    resources.add(resources.features[feature])
+
+            prev_features = features
+        self.validate_config()
+
+        return resources
+
+    @staticmethod
+    def config_to_header(config, fname=None):
+        """ Convert the configuration data to the content of a C header file,
+        meant to be included to a C/C++ file. The content is returned as a
+        string.
+
+        Positional arguments:
+        config - configuration data as (ConfigParam instances, ConfigMacro
+                 instances) tuple (as returned by get_config_data())
+
+        Keyword arguments:
+        fname -  also write the content is to the file called "fname".
+                 WARNING: if 'fname' names an existing file, it will be
+                 overwritten!
+        """
+        params, macros = config[0] or {}, config[1] or {}
+        Config._check_required_parameters(params)
+        params_with_values = [p for p in params.values() if p.value is not None]
+        ctx = {
+            "cfg_params" : [(p.macro_name, str(p.value), p.set_by)
+                            for p in params_with_values],
+            "macros": [(m.macro_name, str(m.macro_value or ""), m.defined_by)
+                       for m in macros.values()],
+            "name_len":  max([len(m.macro_name) for m in macros.values()] +
+                             [len(m.macro_name) for m in params_with_values]
+                             + [0]),
+            "val_len" : max([len(str(m.value)) for m in params_with_values] +
+                            [len(m.macro_value or "") for m in macros.values()]
+                            + [0]),
+        }
+        jinja_loader = FileSystemLoader(dirname(abspath(__file__)))
+        jinja_environment = Environment(loader=jinja_loader,
+                                        undefined=StrictUndefined)
+        header_data = jinja_environment.get_template("header.tmpl").render(ctx)
+        # If fname is given, write "header_data" to it
+        if fname:
+            with open(fname, "w+") as file_desc:
+                file_desc.write(header_data)
+        return header_data
+
+    def get_config_data_header(self, fname=None):
+        """ Convert a Config instance to the content of a C header file, meant
+        to be included to a C/C++ file. The content is returned as a string.
+
+        Keyword arguments:
+        fname - also write the content to the file called "fname".
+                WARNING: if 'fname' names an existing file, it will be
+                overwritten!
+        """
+        return self.config_to_header(self.get_config_data(), fname)