Push old dev_2 draft to work on other things.

- **NON-FUNCTIONAL**
- Contains an old draft of separating the stepper driver direct access
to the planner buffer. This is designed to keep the stepper and planner
modules independent and prevent overwriting or other complications. In
this way, feedrate override should be able to be installed as well.
- A number of planner optimizations are installed too.
- Not sure where the bugs are. Either in the new planner optimizations,
new stepper module updates, or in both. Or it just could be that the
Arduino AVR is choking with the new things it has to do.

limits.c

@@ -96,16 +96,17 @@ static void homing_cycle(uint8_t cycle_mask, int8_t pos_dir, bool invert_pin, fl
   // and speedy homing routine.
   // NOTE: For each axes enabled, the following calculations assume they physically move 
   // an equal distance over each time step until they hit a limit switch, aka dogleg.
-  uint32_t step_event_count, steps[N_AXIS];
+  uint32_t step_event_count = 0;
   uint8_t i, dist = 0;
+  uint32_t steps[N_AXIS];
   clear_vector(steps);
   for (i=0; i<N_AXIS; i++) {
     if (cycle_mask & (1<<i)) { 
       dist++;
       steps[i] = lround(settings.steps_per_mm[i]); 
+      step_event_count = max(step_event_count,steps[i]);
     }
   }
-  step_event_count = max(steps[X_AXIS], max(steps[Y_AXIS], steps[Z_AXIS]));  
   
   // To ensure global acceleration is not exceeded, reduce the governing axes nominal rate
   // by adjusting the actual axes distance traveled per step. This is the same procedure
@@ -244,23 +245,26 @@ void limits_go_home()
 // and the workspace volume is in all negative space.
 void limits_soft_check(float *target)
 {
-  if ( target[X_AXIS] > 0 || target[X_AXIS] < -settings.max_travel[X_AXIS] || 
-       target[Y_AXIS] > 0 || target[Y_AXIS] < -settings.max_travel[Y_AXIS] || 
-       target[Z_AXIS] > 0 || target[Z_AXIS] < -settings.max_travel[Z_AXIS] ) {
-       
-    // Force feed hold if cycle is active. All buffered blocks are guaranteed to be within 
-    // workspace volume so just come to a controlled stop so position is not lost. When complete
-    // enter alarm mode.
-    if (sys.state == STATE_CYCLE) {
-      st_feed_hold();
-      while (sys.state == STATE_HOLD) {
-        protocol_execute_runtime();
-        if (sys.abort) { return; }
-      }
-    }
+  uint8_t idx;
+  for (idx=0; idx<N_AXIS; idx++) { 
+    if (target[idx] > 0 || target[idx] < settings.max_travel[idx]) {  // NOTE: max_travel is stored as negative
     
-    mc_reset(); // Issue system reset and ensure spindle and coolant are shutdown.
-    sys.execute |= EXEC_CRIT_EVENT; // Indicate soft limit critical event
-    protocol_execute_runtime(); // Execute to enter critical event loop and system abort
+      // Force feed hold if cycle is active. All buffered blocks are guaranteed to be within 
+      // workspace volume so just come to a controlled stop so position is not lost. When complete
+      // enter alarm mode.
+      if (sys.state == STATE_CYCLE) {
+        st_feed_hold();
+        while (sys.state == STATE_HOLD) {
+          protocol_execute_runtime();
+          if (sys.abort) { return; }
+        }
+      }
+      
+      mc_reset(); // Issue system reset and ensure spindle and coolant are shutdown.
+      sys.execute |= EXEC_CRIT_EVENT; // Indicate soft limit critical event
+      protocol_execute_runtime(); // Execute to enter critical event loop and system abort
+      return;
+    
+    }
   }
 }