add circuitpython code

1 files changed, 131 insertions, 0 deletions

diff --git a/circuitpython/lib/nrfutil/nordicsemi/dfu/init_packet.py b/circuitpython/lib/nrfutil/nordicsemi/dfu/init_packet.py
new file mode 100644
index 0000000..ccf8c34
--- /dev/null
+++ b/circuitpython/lib/nrfutil/nordicsemi/dfu/init_packet.py
@@ -0,0 +1,131 @@
+# Copyright (c) 2015, Nordic Semiconductor
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# * Redistributions of source code must retain the above copyright notice, this
+#   list of conditions and the following disclaimer.
+#
+# * Redistributions in binary form must reproduce the above copyright notice,
+#   this list of conditions and the following disclaimer in the documentation
+#   and/or other materials provided with the distribution.
+#
+# * Neither the name of Nordic Semiconductor ASA nor the names of its
+#   contributors may be used to endorse or promote products derived from
+#   this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from enum import Enum
+import struct
+
+
+INIT_PACKET_USES_CRC16 = 0
+INIT_PACKET_USES_HASH = 1
+INIT_PACKET_EXT_USES_ECDS = 2
+
+
+class PacketField(Enum):
+    DEVICE_TYPE = 1
+    DEVICE_REVISION = 2
+    APP_VERSION = 3
+    REQUIRED_SOFTDEVICES_ARRAY = 4
+    OPT_DATA = 5
+    NORDIC_PROPRIETARY_OPT_DATA_EXT_PACKET_ID = 6
+    NORDIC_PROPRIETARY_OPT_DATA_FIRMWARE_LENGTH = 7
+    NORDIC_PROPRIETARY_OPT_DATA_FIRMWARE_HASH = 8
+    NORDIC_PROPRIETARY_OPT_DATA_FIRMWARE_CRC16 = 9
+    NORDIC_PROPRIETARY_OPT_DATA_INIT_PACKET_ECDS = 10
+
+
+class Packet(object):
+    """
+    Class that implements the INIT packet format.
+    http://developer.nordicsemi.com/nRF51_SDK/doc/7.1.0/s110/html/a00065.html
+    """
+
+    UNSIGNED_SHORT = "H"
+    UNSIGNED_INT = "I"
+    UNSIGNED_CHAR = "B"
+    CHAR_ARRAY = "s"
+
+    def __init__(self, init_packet_fields):
+        """
+
+            :param init_packet_fields: Dictionary with packet fields
+        """
+        self.init_packet_fields = init_packet_fields
+
+    def generate_packet(self):
+        """
+        Generates a binary packet from provided init_packet_fields provided in constructor.
+        This version includes the extended data
+
+        :return str: Returns a string representing the init_packet (in binary)
+
+        """
+        # Create struct format string based on keys that are
+        # present in self.init_packet_fields
+        format_string = self.__generate_struct_format_string()
+        args = []
+
+        # If you got error message AttributeError: 'int' object has no attribute 'value'.
+        # Uncomment line 84 and comment out line 85 and run 'python setup.py install'
+        #for key in sorted(self.init_packet_fields.keys(), key=lambda x: x):
+        for key in sorted(self.init_packet_fields.keys(), key=lambda x: x.value):
+            # Add length to fields that required that
+            if key in [PacketField.REQUIRED_SOFTDEVICES_ARRAY,
+                       PacketField.OPT_DATA]:
+                args.append(len(self.init_packet_fields[key]))
+                args.extend(self.init_packet_fields[key])
+            else:
+                args.append(self.init_packet_fields[key])
+
+        return struct.pack(format_string, *args)
+
+    def __generate_struct_format_string(self):
+        format_string = "<"  # Use little endian format with standard sizes for python,
+        # see https://docs.python.org/2/library/struct.html
+
+        # If you got error message AttributeError: 'int' object has no attribute 'value'.
+        # Uncomment line 102 and comment out line 103 and run 'python setup.py install'
+        #for key in sorted(self.init_packet_fields.keys(), key=lambda x: x):
+        for key in sorted(self.init_packet_fields.keys(), key=lambda x: x.value):
+            if key in [PacketField.DEVICE_TYPE,
+                       PacketField.DEVICE_REVISION,
+                       ]:
+                format_string += Packet.UNSIGNED_SHORT
+
+            elif key in [PacketField.APP_VERSION]:
+                format_string += Packet.UNSIGNED_INT
+            elif key in [PacketField.REQUIRED_SOFTDEVICES_ARRAY]:
+                array_elements = self.init_packet_fields[key]
+                format_string += Packet.UNSIGNED_SHORT  # Add length field to format packet
+
+                for _ in range(len(array_elements)):
+                    format_string += Packet.UNSIGNED_SHORT
+            elif key in [PacketField.OPT_DATA]:
+                format_string += Packet.UNSIGNED_SHORT  # Add length field to optional data
+                format_string += "{0}{1}".format(len(self.init_packet_fields[key]), Packet.CHAR_ARRAY)
+            elif key in [PacketField.NORDIC_PROPRIETARY_OPT_DATA_EXT_PACKET_ID]:
+                format_string += Packet.UNSIGNED_INT  # Add the extended packet id field
+            elif key == PacketField.NORDIC_PROPRIETARY_OPT_DATA_FIRMWARE_LENGTH:
+                format_string += Packet.UNSIGNED_INT  # Add the firmware length field
+            elif key == PacketField.NORDIC_PROPRIETARY_OPT_DATA_FIRMWARE_HASH:
+                format_string += "32{0}".format(Packet.CHAR_ARRAY)  # SHA-256 requires 32 bytes
+            elif key == PacketField.NORDIC_PROPRIETARY_OPT_DATA_FIRMWARE_CRC16:
+                format_string += Packet.UNSIGNED_SHORT
+            elif key == PacketField.NORDIC_PROPRIETARY_OPT_DATA_INIT_PACKET_ECDS:
+                format_string += "64{0}".format(Packet.CHAR_ARRAY)  # ECDS based on P-256 using SHA-256 requires 64 bytes
+
+        return format_string