diff options
Diffstat (limited to 'tools/dtoc/fdt.py')
| -rw-r--r-- | tools/dtoc/fdt.py | 197 |
1 files changed, 187 insertions, 10 deletions
diff --git a/tools/dtoc/fdt.py b/tools/dtoc/fdt.py index 55baa3857f..2df2d4b0cc 100644 --- a/tools/dtoc/fdt.py +++ b/tools/dtoc/fdt.py @@ -43,6 +43,7 @@ class Prop: self.name = name self.value = None self.bytes = str(bytes) + self.dirty = False if not bytes: self.type = TYPE_BOOL self.value = True @@ -145,7 +146,7 @@ class Prop: if type == TYPE_BYTE: return chr(0) elif type == TYPE_INT: - return struct.pack('<I', 0); + return struct.pack('>I', 0); elif type == TYPE_STRING: return '' else: @@ -160,6 +161,55 @@ class Prop: self._node._fdt.CheckCache() return self._node._fdt.GetStructOffset(self._offset) + def SetInt(self, val): + """Set the integer value of the property + + The device tree is marked dirty so that the value will be written to + the block on the next sync. + + Args: + val: Integer value (32-bit, single cell) + """ + self.bytes = struct.pack('>I', val); + self.value = val + self.type = TYPE_INT + self.dirty = True + + def SetData(self, bytes): + """Set the value of a property as bytes + + Args: + bytes: New property value to set + """ + self.bytes = str(bytes) + self.type, self.value = self.BytesToValue(bytes) + self.dirty = True + + def Sync(self, auto_resize=False): + """Sync property changes back to the device tree + + This updates the device tree blob with any changes to this property + since the last sync. + + Args: + auto_resize: Resize the device tree automatically if it does not + have enough space for the update + + Raises: + FdtException if auto_resize is False and there is not enough space + """ + if self._offset is None or self.dirty: + node = self._node + fdt_obj = node._fdt._fdt_obj + if auto_resize: + while fdt_obj.setprop(node.Offset(), self.name, self.bytes, + (libfdt.NOSPACE,)) == -libfdt.NOSPACE: + fdt_obj.resize(fdt_obj.totalsize() + 1024) + fdt_obj.setprop(node.Offset(), self.name, self.bytes) + else: + fdt_obj.setprop(node.Offset(), self.name, self.bytes) + + class Node: """A device tree node @@ -284,25 +334,125 @@ class Node: Args: prop_name: Name of property """ - fdt_obj = self._fdt._fdt_obj - if fdt_obj.setprop_u32(self.Offset(), prop_name, 0, - (libfdt.NOSPACE,)) == -libfdt.NOSPACE: - fdt_obj.resize(fdt_obj.totalsize() + 1024) - fdt_obj.setprop_u32(self.Offset(), prop_name, 0) - self.props[prop_name] = Prop(self, -1, prop_name, '\0' * 4) - self._fdt.Invalidate() + self.props[prop_name] = Prop(self, None, prop_name, '\0' * 4) + + def AddEmptyProp(self, prop_name, len): + """Add a property with a fixed data size, for filling in later + + The device tree is marked dirty so that the value will be written to + the blob on the next sync. + + Args: + prop_name: Name of property + len: Length of data in property + """ + value = chr(0) * len + self.props[prop_name] = Prop(self, None, prop_name, value) def SetInt(self, prop_name, val): """Update an integer property int the device tree. This is not allowed to change the size of the FDT. + The device tree is marked dirty so that the value will be written to + the blob on the next sync. + Args: prop_name: Name of property val: Value to set """ - fdt_obj = self._fdt._fdt_obj - fdt_obj.setprop_u32(self.Offset(), prop_name, val) + self.props[prop_name].SetInt(val) + + def SetData(self, prop_name, val): + """Set the data value of a property + + The device tree is marked dirty so that the value will be written to + the blob on the next sync. + + Args: + prop_name: Name of property to set + val: Data value to set + """ + self.props[prop_name].SetData(val) + + def SetString(self, prop_name, val): + """Set the string value of a property + + The device tree is marked dirty so that the value will be written to + the blob on the next sync. + + Args: + prop_name: Name of property to set + val: String value to set (will be \0-terminated in DT) + """ + self.props[prop_name].SetData(val + chr(0)) + + def AddString(self, prop_name, val): + """Add a new string property to a node + + The device tree is marked dirty so that the value will be written to + the blob on the next sync. + + Args: + prop_name: Name of property to add + val: String value of property + """ + self.props[prop_name] = Prop(self, None, prop_name, val + chr(0)) + + def AddSubnode(self, name): + """Add a new subnode to the node + + Args: + name: name of node to add + + Returns: + New subnode that was created + """ + path = self.path + '/' + name + subnode = Node(self._fdt, self, None, name, path) + self.subnodes.append(subnode) + return subnode + + def Sync(self, auto_resize=False): + """Sync node changes back to the device tree + + This updates the device tree blob with any changes to this node and its + subnodes since the last sync. + + Args: + auto_resize: Resize the device tree automatically if it does not + have enough space for the update + + Raises: + FdtException if auto_resize is False and there is not enough space + """ + if self._offset is None: + # The subnode doesn't exist yet, so add it + fdt_obj = self._fdt._fdt_obj + if auto_resize: + while True: + offset = fdt_obj.add_subnode(self.parent._offset, self.name, + (libfdt.NOSPACE,)) + if offset != -libfdt.NOSPACE: + break + fdt_obj.resize(fdt_obj.totalsize() + 1024) + else: + offset = fdt_obj.add_subnode(self.parent._offset, self.name) + self._offset = offset + + # Sync subnodes in reverse so that we don't disturb node offsets for + # nodes that are earlier in the DT. This avoids an O(n^2) rescan of + # node offsets. + for node in reversed(self.subnodes): + node.Sync(auto_resize) + + # Sync properties now, whose offsets should not have been disturbed. + # We do this after subnodes, since this disturbs the offsets of these + # properties. + prop_list = sorted(self.props.values(), key=lambda prop: prop._offset, + reverse=True) + for prop in prop_list: + prop.Sync(auto_resize) class Fdt: @@ -322,6 +472,20 @@ class Fdt: with open(self._fname) as fd: self._fdt_obj = libfdt.Fdt(fd.read()) + @staticmethod + def FromData(data): + """Create a new Fdt object from the given data + + Args: + data: Device-tree data blob + + Returns: + Fdt object containing the data + """ + fdt = Fdt(None) + fdt._fdt_obj = libfdt.Fdt(bytearray(data)) + return fdt + def LookupPhandle(self, phandle): """Look up a phandle @@ -381,6 +545,19 @@ class Fdt: with open(self._fname, 'wb') as fd: fd.write(self._fdt_obj.as_bytearray()) + def Sync(self, auto_resize=False): + """Make sure any DT changes are written to the blob + + Args: + auto_resize: Resize the device tree automatically if it does not + have enough space for the update + + Raises: + FdtException if auto_resize is False and there is not enough space + """ + self._root.Sync(auto_resize) + self.Invalidate() + def Pack(self): """Pack the device tree down to its minimum size |