Mock out mgos_i2c.h to work with Linux.

src/mgos_mock.c

@@ -0,0 +1,44 @@
+/* Some functions mocked from MGOS, so we can run unit tests standalone.
+ */
+
+#include "mgos_mock.h"
+
+int _mgos_timers = 0;
+
+int log_print_prefix(enum cs_log_level l, const char *func, const char *file) {
+  char ll_str[6];
+
+  switch(l) {
+    case LL_ERROR:
+      strncpy(ll_str, "ERROR", sizeof(ll_str));
+      break;
+    case LL_WARN:
+      strncpy(ll_str, "WARN", sizeof(ll_str));
+      break;
+    case LL_INFO:
+      strncpy(ll_str, "INFO", sizeof(ll_str));
+      break;
+    case LL_DEBUG:
+      strncpy(ll_str, "DEBUG", sizeof(ll_str));
+      break;
+    case LL_VERBOSE_DEBUG:
+      strncpy(ll_str, "VERB", sizeof(ll_str));
+      break;
+    default: // LL_NONE
+      return 0;
+  }
+  printf ("%-5s %-20s %-40s| ", ll_str, file, func);
+  return 1;
+}
+
+float mg_time() {
+  struct timeval tod;
+  float time;
+
+  gettimeofday(&tod, NULL);
+
+  time = tod.tv_sec;
+  time += tod.tv_usec/1000000;
+
+  return time;
+}