Feature/mstp zero config option (#564)

* Added a MS/TP zero-config (automatically choose an unused MAC address) using an algorithm that starts with MAC=64 and waits for a random number of PFM (minimum of 8 plus modulo 64) before attempting to choose a MAC sequentially from 64..127. The confirmation uses a 128-bit UUID with the MSTP Test Request frame. The modifications are in src/bacnet/datalink/mstp.c and src/bacnet/datalink/dlmstp.c modules enabling any device to use zero-config if enabled. A working demonstration is in the ports/stm32f4xx for the NUCLEO board. Complete unit testing is included.  Options include lurking forever (wait for a router or another master node before joining) or lurking for a minimum time (enables self forming automatic MAC addressing device nodes).

test/CMakeLists.txt

@@ -158,6 +158,7 @@ list(APPEND testdirs
   bacnet/datalink/cobs
   bacnet/datalink/crc
   bacnet/datalink/bvlc
+  bacnet/datalink/mstp
   )
 
 enable_testing()

test/bacnet/datalink/mstp/CMakeLists.txt

@@ -0,0 +1,54 @@
+# SPDX-License-Identifier: MIT
+
+cmake_minimum_required(VERSION 3.10 FATAL_ERROR)
+
+get_filename_component(basename ${CMAKE_CURRENT_SOURCE_DIR} NAME)
+project(test_${basename}
+	VERSION 1.0.0
+	LANGUAGES C)
+
+
+string(REGEX REPLACE
+    "/test/bacnet/[a-zA-Z_/-]*$"
+    "/src"
+    SRC_DIR
+    ${CMAKE_CURRENT_SOURCE_DIR})
+string(REGEX REPLACE
+    "/test/bacnet/[a-zA-Z_/-]*$"
+    "/test"
+    TST_DIR
+    ${CMAKE_CURRENT_SOURCE_DIR})
+set(ZTST_DIR "${TST_DIR}/ztest/src")
+
+add_compile_definitions(
+	BIG_ENDIAN=0
+	CONFIG_ZTEST=1
+	BACDL_MSTP=1
+	)
+
+include_directories(
+	${SRC_DIR}
+	${TST_DIR}/ztest/include
+	)
+
+add_executable(${PROJECT_NAME}
+    # File(s) under test
+	${SRC_DIR}/bacnet/datalink/mstp.c
+	${SRC_DIR}/bacnet/datalink/mstptext.c
+	${SRC_DIR}/bacnet/datalink/crc.c
+	${SRC_DIR}/bacnet/datalink/cobs.c
+	${SRC_DIR}/bacnet/basic/sys/fifo.c
+	${SRC_DIR}/bacnet/indtext.c
+	# core files needed
+	${SRC_DIR}/bacnet/bacdcode.c
+	${SRC_DIR}/bacnet/bacint.c
+	${SRC_DIR}/bacnet/bacstr.c
+	${SRC_DIR}/bacnet/bacreal.c
+	${SRC_DIR}/bacnet/npdu.c
+	${SRC_DIR}/bacnet/basic/sys/bigend.c
+    # Support files and stubs (pathname alphabetical)
+    # Test and test library files
+	./src/main.c
+	${ZTST_DIR}/ztest_mock.c
+	${ZTST_DIR}/ztest.c
+	)