Added support for Python actors

Added support for executing actors written in Python by including
MicroPython as a statically linked libray with actors included as
frozen modules. The library includes a gpiohandler and environmental
calvinsys object.

Contributors:
harald.gustafsson@ericsson.com
Rami Baddour rami.baddour@usi.ch
Amardeep Mehta amardeep@cs.umu.se

.gitignore

@@ -2,4 +2,10 @@ calvin_c
 calvin_c.hex
 _build/
 calvin-base/
-test/__pycache__/
+test/__pycache__/
+boards/pca10028/armgcc/_build/
+*.P
+*.o
+libmpy/build
+*.a
+*.mpy

.gitmodules

@@ -1,3 +1,7 @@
+[submodule "micropython"]
+	path = micropython
+	url = https://github.com/micropython/micropython.git
 [submodule "msgpuck"]
 	path = msgpuck
 	url = https://github.com/rtsisyk/msgpuck
+    ignore = dirty

README.md

@@ -1,19 +1,30 @@
 # calvin-constrained
 
-calvin-constrained is a C based implementation of https://github.com/EricssonResearch/calvin-base for constrained devices with limited memory and processing power. All functionality included in the standard calvin-base implementation is not feasible to include on a constrained device and a subset of the calvin-base functionality is implemented and a calvin-base runtime is required acting as a proxy and for offloading functionality from the constrained runtime.
+calvin-constrained is a C based implementation of https://github.com/EricssonResearch/calvin-base targeting constrained devices with limited memory and processing power. All functionality included in the standard calvin-base implementation is not feasible to include on a constrained device and a subset of the calvin-base functionality is implemented and a calvin-base runtime is required and used as a proxy and for offloading functionality from constrained runtimes.
+
+The state of the implementation is experimental and it goes without saying that it should not be used in production in its current state, but it does provide an excellent starting point for further experimentation.
 
 ##Clone
 
     git clone --recursive https://github.com/EricssonResearch/calvin-constrained.git
 
 ##Setup calvin-base
 
-See https://github.com/EricssonResearch/calvin-base for information on how to install and run calvin-base. When started, the calvin-constrained runtime connects to a calvin-base runtime acting as a proxy and for offloading functionality from the constrained runtime.
+See https://github.com/EricssonResearch/calvin-base for information on how to install and start calvin-base.
+
+##Python actors on calvin-constrained
+
+Support for executing Python code is built on MicroPython, https://micropython.org/, setup MicroPython with:
+
+    ./mp_setup.sh
+
+Then use the makefiles ending with _mpy to include support for Python actors in calvin-constrained, MicroPython is included as a statically-linked library with actors in libmpy/modules/ included as frozen modules.
 
 ##Run tests
 
     cd calvin-constrained
     ./test/test.sh
+    ./test/test.sh mpy # test Python actors
 
 ##*nix version
 
@@ -44,7 +55,7 @@ Verify that the connection is made by:
     curl http://127.0.0.1:5001/node/d6b10ff3-593f-75a2-f07b-d1acc06961b6
     {"attributes": {"indexed_public": ["/node/attribute/node_name/////calvin-klein"], "public": {}}, "control_uri": null, "proxy": "acd1e55e-c609-4c00-80ac-a383eb5dbfc5", "authz_server": null, "uri": null}
 
-Actors can now be migrated to the calvin-constrained runtime.
+Actors can now be migrated to and from the calvin-constrained runtime.
 
 ##Nordic Semiconductors NRF52 DK version
 
@@ -61,7 +72,7 @@ Patch the nRF5 IOT SDK to include the MAC address of the connecting peer in the
         patch components/iot/medium/ipv6_medium.h < <calvin-constrained_path>/platform/nrf52/sdk_patches/ipv6_medium.h.patch
         patch components/iot/medium/ipv6_medium_ble.c < <calvin-constrained_path>/platform/nrf52/sdk_patches/ipv6_medium_ble.c.patch
 
-Download and install J-Link Software and Documentation Pack (https://www.segger.com/downloads/jlink)
+And download and install J-Link Software and Documentation Pack (https://www.segger.com/downloads/jlink)
 
 ###Build and flash
 
@@ -71,16 +82,16 @@ Download and install J-Link Software and Documentation Pack (https://www.segger.
 
 ###Run
 
-A Raspberry Pi with a Bluetooth USB dongle is used to connect to the nRF52 and to host the calvin-base runtime acting as a proxy for the calvin-constrained runtimes. On the Raspberry Pi, start with loading and enabling the Bluetooth 6lowpan module:
+Enable the bluetooth_6lowpan kernel module:
 
     sudo modprobe bluetooth_6lowpan
     sudo sh -c  "echo 1 > /sys/kernel/debug/bluetooth/6lowpan_enable"
 
-Then, start the calvin-base runtime:
+On the same system, start a calvin-base runtime listening on port 5000:
 
-    csruntime -n 192.168.0.110 --name constrained_proxy -p 5000
+    csruntime -n 192.168.0.110 -p 5000 -c 5001 --name constrained_proxy
 
-The constrained runtime will connect to the link local address of the btX interface on port 5000. The interface 192.168.0.110 is the external interface of the Rapsberry Pi used for enabling external access to the calvin-base runtime and the calvin-constrained runtimes connected to it.
+The calvin-base runtime listens on all interfaces for incoming connections, the 192.168.0.110 address is the external address and used here to enable external access to the control API on port 5001.
 
 Next, get the nRF52 device address:
 
@@ -90,15 +101,15 @@ Connect to the nRF52 device:
 
     sudo sh -c 'echo "connect 00:33:40:7D:C8:0D 1" > /sys/kernel/debug/bluetooth/6lowpan_control'
 
-When a Bluetooth connection is established the calvin-constrained runtime will connect to the calvin-base runtime, verify that the connection is established:
+When a Bluetooth connection is established the calvin-constrained runtime will connect to the calvin-base runtime using the link local address of the btX interface, verify that the connection is established:
 
     curl http://192.168.0.110:5001/nodes
     ["5ef5de32-e0d9-6ee6-8bab-a7f1d7f72c4a"]
 
     curl http://192.168.0.110:5001/node/5ef5de32-e0d9-6ee6-8bab-a7f1d7f72c4a
     {"attributes": {"indexed_public": ["/node/attribute/node_name/////constrained"], "public": {}}, "control_uri": null, "proxy": "3682cb26-0ae0-4965-952b-86d1e1b1bcbb", "authz_server": null, "uri": null}
 
-Actors can now be migrated to the calvin-constrained runtime.
+Actors can now be migrated to and from the calvin-constrained runtime.
 
 ###Capture logs