Separate the initialization and main step into two different functions.

For testing, it is useful to have the loop be separated from the
initialization so that an external function can step through the
main loop.

src/main/main.c

@@ -26,7 +26,6 @@
 
 #include "common/axis.h"
 #include "common/color.h"
-#include "common/atomic.h"
 #include "common/maths.h"
 
 #include "drivers/nvic.h"
@@ -658,7 +657,7 @@ void processLoopback(void) {
 #define processLoopback()
 #endif
 
-int main(void) {
+void main_init(void) {
     init();
 
     /* Setup scheduler */
@@ -729,12 +728,22 @@ int main(void) {
 #ifdef USE_BST
     setTaskEnabled(TASK_BST_MASTER_PROCESS, true);
 #endif
+}
 
-    while (1) {
-        scheduler();
-        processLoopback();
+void main_step(void) {
+    scheduler();
+    processLoopback();
+}
+
+#ifndef NOMAIN
+int main(void)
+{
+    main_init();
+    while(1) {
+        main_step();
     }
 }
+#endif
 
 #ifdef DEBUG_HARDFAULTS
 //from: https://mcuoneclipse.com/2012/11/24/debugging-hard-faults-on-arm-cortex-m/