Chore/bacnet-sc-unrelated-cleanup (#620)

* Added required linux Ethernet library for ethernet build

* Added .obj to gitignore

* Fixed BACnet port for APPLE to use BSD in CMake

* Changed format in CMake to enable cleaner SC merge

* Added create-object and delete-object recipes in GCC Makefile

* Added datalink timer to all example OS apps

* Changed most microcontroller ports to use BACAPP_MINIMAL to specify which datatypes can be written.

* Fixed zephyr OS for BACnet/IP warning

* Fixed zephyr OS log to not require log_strdup

* Added writefile API to file object example

* Added API to device-client to make it more robust.

* Added API in network-port object for getting the ASCII object-name

* Added debug print with a timestamp option

* Added debug print with hex dump print

* Added API to network port object for activate and discard

* Added default define for debug with timestamp

* Added prototype in header for disabled debug printf.

* Added fifo peek ahead function to peek at more than one byte.

* Added get-mac value for network port that uses buffer rather than octetstring

src/bacnet/basic/object/bacfile.c

@@ -294,7 +294,7 @@ static long fsize(FILE *pFile)
 /**
  * @brief Read the entire file into a buffer
  * @param  object_instance - object-instance number of the object
- * @param  buffer - pointer to buffer pointer where heap data will be stored
+ * @param  buffer - data store from the file
  * @param  buffer_size - in bytes
  * @return  file size in bytes
  */
@@ -322,6 +322,35 @@ uint32_t bacfile_read(uint32_t object_instance, uint8_t *buffer,
     return (uint32_t)file_size;
 }
 
+/**
+ * @brief Write the entire file from a buffer
+ * @param  object_instance - object-instance number of the object
+ * @param  buffer - data store for the file
+ * @param  buffer_size - in bytes
+ * @return  file size in bytes
+ */
+uint32_t bacfile_write(uint32_t object_instance, uint8_t *buffer,
+    uint32_t buffer_size)
+{
+    const char *pFilename = NULL;
+    FILE *pFile = NULL;
+    long file_size = 0;
+
+    pFilename = bacfile_pathname(object_instance);
+    if (pFilename) {
+        /* open the file as a clean slate when starting at 0 */
+        pFile = fopen(pFilename, "wb");
+        if (pFile) {
+            if (fwrite(buffer, buffer_size, 1, pFile) == 1) {
+                file_size = buffer_size;
+            }
+            fclose(pFile);
+        }
+    }
+
+    return (uint32_t)file_size;
+}
+
 /**
  * @brief Determines the file size for a given file
  * @param  pFile - file handle
@@ -1053,5 +1082,7 @@ void bacfile_cleanup(void)
  */
 void bacfile_init(void)
 {
-    Object_List = Keylist_Create();
+    if (!Object_List) {
+        Object_List = Keylist_Create();
+    }
 }