add circuitpython code

1 files changed, 179 insertions, 0 deletions

diff --git a/circuitpython/lib/nrfutil/nordicsemi/dfu/util.py b/circuitpython/lib/nrfutil/nordicsemi/dfu/util.py
new file mode 100644
index 0000000..a7040fb
--- /dev/null
+++ b/circuitpython/lib/nrfutil/nordicsemi/dfu/util.py
@@ -0,0 +1,179 @@
+# 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.
+
+# Nordic libraries
+from nordicsemi.exceptions import NordicSemiException
+
+
+# TODO: Create query function that maps query-result strings with functions
+def query_func(question, default=False):
+    """
+    Ask a string question
+    No input defaults to "no" which results in False
+    """
+    valid = {"yes": True, "y": True, "no": False, "n": False}
+    if default is True:
+        prompt = " [Y/n]"
+    else:
+        prompt = " [y/N]"
+
+    while True:
+        print "%s %s" % (question, prompt)
+        choice = raw_input().lower()
+        if choice == '':
+            return default
+        elif choice in valid:
+            return valid[choice]
+        else:
+            print "Please respond with y/n"
+
+
+def convert_uint16_to_array(value):
+    """
+    Converts a int to an array of 2 bytes (little endian)
+
+    :param int value: int value to convert to list
+    :return list[int]: list with 2 bytes
+    """
+    byte0 = value & 0xFF
+    byte1 = (value >> 8) & 0xFF
+    return [byte0, byte1]
+
+
+def convert_uint32_to_array(value):
+    """
+    Converts a int to an array of 4 bytes (little endian)
+
+    :param int value: int value to convert to list
+    :return list[int]: list with 4 bytes
+    """
+    byte0 = value & 0xFF
+    byte1 = (value >> 8) & 0xFF
+    byte2 = (value >> 16) & 0xFF
+    byte3 = (value >> 24) & 0xFF
+    return [byte0, byte1, byte2, byte3]
+
+
+def slip_parts_to_four_bytes(seq, dip, rp, pkt_type, pkt_len):
+    """
+    Creates a SLIP header.
+
+    For a description of the SLIP header go to:
+    http://developer.nordicsemi.com/nRF51_SDK/doc/7.2.0/s110/html/a00093.html
+
+    :param int seq: Packet sequence number
+    :param int dip: Data integrity check
+    :param int rp: Reliable packet
+    :param pkt_type: Payload packet
+    :param pkt_len: Packet length
+    :return: str with SLIP header
+    """
+    ints = [0, 0, 0, 0]
+    ints[0] = seq | (((seq + 1) % 8) << 3) | (dip << 6) | (rp << 7)
+    ints[1] = pkt_type | ((pkt_len & 0x000F) << 4)
+    ints[2] = (pkt_len & 0x0FF0) >> 4
+    ints[3] = (~(sum(ints[0:3])) + 1) & 0xFF
+
+    return ''.join(chr(b) for b in ints)
+
+
+def int32_to_bytes(value):
+    """
+    Converts a int to a str with 4 bytes
+
+    :param value: int value to convert
+    :return: str with 4 bytes
+    """
+    ints = [0, 0, 0, 0]
+    ints[0] = (value & 0x000000FF)
+    ints[1] = (value & 0x0000FF00) >> 8
+    ints[2] = (value & 0x00FF0000) >> 16
+    ints[3] = (value & 0xFF000000) >> 24
+    return ''.join(chr(b) for b in ints)
+
+
+def int16_to_bytes(value):
+    """
+    Converts a int to a str with 4 bytes
+
+    :param value: int value to convert
+    :return: str with 4 bytes
+    """
+
+    ints = [0, 0]
+    ints[0] = (value & 0x00FF)
+    ints[1] = (value & 0xFF00) >> 8
+    return ''.join(chr(b) for b in ints)
+
+
+def slip_decode_esc_chars(data):
+    """Decode esc characters in a SLIP package.
+
+    Replaces 0xDBDC with 0xCO and 0xDBDD with 0xDB.
+
+    :return: str decoded data
+    :type str data: data to decode
+    """
+    result = []
+    while len(data):
+        char = data.pop(0)
+        if char == 0xDB:
+            char2 = data.pop(0)
+            if char2 == 0xDC:
+                result.append(0xC0)
+            elif char2 == 0xDD:
+                result.append(0xDB)
+            else:
+                raise NordicSemiException('Char 0xDB NOT followed by 0xDC or 0xDD')
+        else:
+            result.append(char)
+    return result
+
+
+def slip_encode_esc_chars(data_in):
+    """Encode esc characters in a SLIP package.
+
+    Replace 0xCO  with 0xDBDC and 0xDB with 0xDBDD.
+
+     :type str data_in: str to encode
+     :return: str with encoded packet
+    """
+    result = []
+    data = []
+    for i in data_in:
+        data.append(ord(i))
+
+    while len(data):
+        char = data.pop(0)
+        if char == 0xC0:
+            result.extend([0xDB, 0xDC])
+        elif char == 0xDB:
+            result.extend([0xDB, 0xDD])
+        else:
+            result.append(char)
+    return ''.join(chr(i) for i in result)