ZCL Advanced Platform (ZAP) Application Layer for CHIP (project-chip#587)

* adding first plugins for chip's application layer zcl implementation

* Updated readme.md for inclusion in CHIP repo

* updated to conform with formatting required by CHIP and updates to the README.md

* removing binaries accidentally added

* updated prefixes to CHIP_ZCL, ChipZcl, chipZcl from zap etc...

* Added identify cluster server plugin and test

* Ignore *.o and *.out.

* adding more unit testing with actual generated message dispatch layer

* addressed some points about constants, bool check etc...

* Added inherited copyrights and other headers with comments

* Resolving comments around special values in level-control command handling

* Add the attribute db plugin.

* Start adding in the attribute database.

* Moved some files around, added some more generated files, and beginnings of general message dispatch

* Add attribute database. It compiles now, still has few linker problems since the current org of stubs is not what generator expects.

* Get to a point where only callbacks are left.

* Ok, attribute db now compiles, links and executes a unittest.

* Include attribute DB to identify.

* Add the generated stubs.

* Resolve all linker problems via generated stubs file.

* Added testing for message dispatch

* Fixing formatting issues

* Start tying together the API with the core internal functions.

0. Location of metadata.
1. Proper translation of search records and actual metadata structs.
2. Callback orchestration.

* Add a unit test that perform attribute locating.

* Some cleanup.

* Minor resorting of functions so that the folded view makes more sense.

* Remove the masks that define callbacks. That is done completely differently in this case and should not be propagated into CHIP world.

* Rename a mis-named "attribute-db" into a "zcl-data-model", since that's what it really is.

* Adding beginnings of general command handling, space for interaction with zcl-data-model and codecs

Co-authored-by: Timotej Ecimovic <timotej.ecimovic@silabs.com>

Author: Ezra Hale

src/app/.gitignore

@@ -0,0 +1,2 @@
+*.o
+*.out

src/app/Makefile

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+PLUGINS = basic-server on-off-server level-control-server identify-server zcl-data-model message-dispatch
+SAMPLES = utest
+
+subsystem:
+	for p in $(PLUGINS); do cd plugin/$$p && $(MAKE); cd ../..; done
+	cd utest && $(MAKE)
+
+clean:
+	for p in $(PLUGINS); do cd plugin/$$p && $(MAKE) clean; cd ../..; done
+	cd utest && $(MAKE) clean
+
+test:
+	for p in $(PLUGINS); do cd plugin/$$p && $(MAKE) test; cd ../..; done
+	cd utest && $(MAKE) test

src/app/README.md

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+# Application layer for CHIP
+
+## What is this?
+
+The purpose of this folder is to contain functional ZCL Advanced Platform (CHIP)
+plugins. A plugin is a discrete piece of Zigbee Cluster Library (ZCL)
+functionality. Each plugin contains message processing code for a "Cluster"
+within the Zigbee Cluster Library. Each plugin can be individually tested
+through its own unit test code and Makefile.
+
+## Usage
+
+To build and run unit tests on these CHIP plugins run
+
+| make test