Import grbl v1.1h
diff --git a/grbl/system.h b/grbl/system.h
new file mode 100644
index 0000000..cfc9273
--- /dev/null
+++ b/grbl/system.h
@@ -0,0 +1,212 @@
+/*
+ system.h - Header for system level commands and real-time processes
+ Part of Grbl
+
+ Copyright (c) 2014-2016 Sungeun K. Jeon for Gnea Research LLC
+
+ Grbl is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ Grbl is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with Grbl. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef system_h
+#define system_h
+
+#include "grbl.h"
+
+// Define system executor bit map. Used internally by realtime protocol as realtime command flags,
+// which notifies the main program to execute the specified realtime command asynchronously.
+// NOTE: The system executor uses an unsigned 8-bit volatile variable (8 flag limit.) The default
+// flags are always false, so the realtime protocol only needs to check for a non-zero value to
+// know when there is a realtime command to execute.
+#define EXEC_STATUS_REPORT bit(0) // bitmask 00000001
+#define EXEC_CYCLE_START bit(1) // bitmask 00000010
+#define EXEC_CYCLE_STOP bit(2) // bitmask 00000100
+#define EXEC_FEED_HOLD bit(3) // bitmask 00001000
+#define EXEC_RESET bit(4) // bitmask 00010000
+#define EXEC_SAFETY_DOOR bit(5) // bitmask 00100000
+#define EXEC_MOTION_CANCEL bit(6) // bitmask 01000000
+#define EXEC_SLEEP bit(7) // bitmask 10000000
+
+// Alarm executor codes. Valid values (1-255). Zero is reserved.
+#define EXEC_ALARM_HARD_LIMIT 1
+#define EXEC_ALARM_SOFT_LIMIT 2
+#define EXEC_ALARM_ABORT_CYCLE 3
+#define EXEC_ALARM_PROBE_FAIL_INITIAL 4
+#define EXEC_ALARM_PROBE_FAIL_CONTACT 5
+#define EXEC_ALARM_HOMING_FAIL_RESET 6
+#define EXEC_ALARM_HOMING_FAIL_DOOR 7
+#define EXEC_ALARM_HOMING_FAIL_PULLOFF 8
+#define EXEC_ALARM_HOMING_FAIL_APPROACH 9
+#define EXEC_ALARM_HOMING_FAIL_DUAL_APPROACH 10
+
+// Override bit maps. Realtime bitflags to control feed, rapid, spindle, and coolant overrides.
+// Spindle/coolant and feed/rapids are separated into two controlling flag variables.
+#define EXEC_FEED_OVR_RESET bit(0)
+#define EXEC_FEED_OVR_COARSE_PLUS bit(1)
+#define EXEC_FEED_OVR_COARSE_MINUS bit(2)
+#define EXEC_FEED_OVR_FINE_PLUS bit(3)
+#define EXEC_FEED_OVR_FINE_MINUS bit(4)
+#define EXEC_RAPID_OVR_RESET bit(5)
+#define EXEC_RAPID_OVR_MEDIUM bit(6)
+#define EXEC_RAPID_OVR_LOW bit(7)
+// #define EXEC_RAPID_OVR_EXTRA_LOW bit(*) // *NOT SUPPORTED*
+
+#define EXEC_SPINDLE_OVR_RESET bit(0)
+#define EXEC_SPINDLE_OVR_COARSE_PLUS bit(1)
+#define EXEC_SPINDLE_OVR_COARSE_MINUS bit(2)
+#define EXEC_SPINDLE_OVR_FINE_PLUS bit(3)
+#define EXEC_SPINDLE_OVR_FINE_MINUS bit(4)
+#define EXEC_SPINDLE_OVR_STOP bit(5)
+#define EXEC_COOLANT_FLOOD_OVR_TOGGLE bit(6)
+#define EXEC_COOLANT_MIST_OVR_TOGGLE bit(7)
+
+// Define system state bit map. The state variable primarily tracks the individual functions
+// of Grbl to manage each without overlapping. It is also used as a messaging flag for
+// critical events.
+#define STATE_IDLE 0 // Must be zero. No flags.
+#define STATE_ALARM bit(0) // In alarm state. Locks out all g-code processes. Allows settings access.
+#define STATE_CHECK_MODE bit(1) // G-code check mode. Locks out planner and motion only.
+#define STATE_HOMING bit(2) // Performing homing cycle
+#define STATE_CYCLE bit(3) // Cycle is running or motions are being executed.
+#define STATE_HOLD bit(4) // Active feed hold
+#define STATE_JOG bit(5) // Jogging mode.
+#define STATE_SAFETY_DOOR bit(6) // Safety door is ajar. Feed holds and de-energizes system.
+#define STATE_SLEEP bit(7) // Sleep state.
+
+// Define system suspend flags. Used in various ways to manage suspend states and procedures.
+#define SUSPEND_DISABLE 0 // Must be zero.
+#define SUSPEND_HOLD_COMPLETE bit(0) // Indicates initial feed hold is complete.
+#define SUSPEND_RESTART_RETRACT bit(1) // Flag to indicate a retract from a restore parking motion.
+#define SUSPEND_RETRACT_COMPLETE bit(2) // (Safety door only) Indicates retraction and de-energizing is complete.
+#define SUSPEND_INITIATE_RESTORE bit(3) // (Safety door only) Flag to initiate resume procedures from a cycle start.
+#define SUSPEND_RESTORE_COMPLETE bit(4) // (Safety door only) Indicates ready to resume normal operation.
+#define SUSPEND_SAFETY_DOOR_AJAR bit(5) // Tracks safety door state for resuming.
+#define SUSPEND_MOTION_CANCEL bit(6) // Indicates a canceled resume motion. Currently used by probing routine.
+#define SUSPEND_JOG_CANCEL bit(7) // Indicates a jog cancel in process and to reset buffers when complete.
+
+// Define step segment generator state flags.
+#define STEP_CONTROL_NORMAL_OP 0 // Must be zero.
+#define STEP_CONTROL_END_MOTION bit(0)
+#define STEP_CONTROL_EXECUTE_HOLD bit(1)
+#define STEP_CONTROL_EXECUTE_SYS_MOTION bit(2)
+#define STEP_CONTROL_UPDATE_SPINDLE_PWM bit(3)
+
+// Define control pin index for Grbl internal use. Pin maps may change, but these values don't.
+#ifdef ENABLE_SAFETY_DOOR_INPUT_PIN
+ #define N_CONTROL_PIN 4
+ #define CONTROL_PIN_INDEX_SAFETY_DOOR bit(0)
+ #define CONTROL_PIN_INDEX_RESET bit(1)
+ #define CONTROL_PIN_INDEX_FEED_HOLD bit(2)
+ #define CONTROL_PIN_INDEX_CYCLE_START bit(3)
+#else
+ #define N_CONTROL_PIN 3
+ #define CONTROL_PIN_INDEX_RESET bit(0)
+ #define CONTROL_PIN_INDEX_FEED_HOLD bit(1)
+ #define CONTROL_PIN_INDEX_CYCLE_START bit(2)
+#endif
+
+// Define spindle stop override control states.
+#define SPINDLE_STOP_OVR_DISABLED 0 // Must be zero.
+#define SPINDLE_STOP_OVR_ENABLED bit(0)
+#define SPINDLE_STOP_OVR_INITIATE bit(1)
+#define SPINDLE_STOP_OVR_RESTORE bit(2)
+#define SPINDLE_STOP_OVR_RESTORE_CYCLE bit(3)
+
+
+// Define global system variables
+typedef struct {
+ uint8_t state; // Tracks the current system state of Grbl.
+ uint8_t abort; // System abort flag. Forces exit back to main loop for reset.
+ uint8_t suspend; // System suspend bitflag variable that manages holds, cancels, and safety door.
+ uint8_t soft_limit; // Tracks soft limit errors for the state machine. (boolean)
+ uint8_t step_control; // Governs the step segment generator depending on system state.
+ uint8_t probe_succeeded; // Tracks if last probing cycle was successful.
+ uint8_t homing_axis_lock; // Locks axes when limits engage. Used as an axis motion mask in the stepper ISR.
+ #ifdef ENABLE_DUAL_AXIS
+ uint8_t homing_axis_lock_dual;
+ #endif
+ uint8_t f_override; // Feed rate override value in percent
+ uint8_t r_override; // Rapids override value in percent
+ uint8_t spindle_speed_ovr; // Spindle speed value in percent
+ uint8_t spindle_stop_ovr; // Tracks spindle stop override states
+ uint8_t report_ovr_counter; // Tracks when to add override data to status reports.
+ uint8_t report_wco_counter; // Tracks when to add work coordinate offset data to status reports.
+ #ifdef ENABLE_PARKING_OVERRIDE_CONTROL
+ uint8_t override_ctrl; // Tracks override control states.
+ #endif
+ #ifdef VARIABLE_SPINDLE
+ float spindle_speed;
+ #endif
+} system_t;
+extern system_t sys;
+
+// NOTE: These position variables may need to be declared as volatiles, if problems arise.
+extern int32_t sys_position[N_AXIS]; // Real-time machine (aka home) position vector in steps.
+extern int32_t sys_probe_position[N_AXIS]; // Last probe position in machine coordinates and steps.
+
+extern volatile uint8_t sys_probe_state; // Probing state value. Used to coordinate the probing cycle with stepper ISR.
+extern volatile uint8_t sys_rt_exec_state; // Global realtime executor bitflag variable for state management. See EXEC bitmasks.
+extern volatile uint8_t sys_rt_exec_alarm; // Global realtime executor bitflag variable for setting various alarms.
+extern volatile uint8_t sys_rt_exec_motion_override; // Global realtime executor bitflag variable for motion-based overrides.
+extern volatile uint8_t sys_rt_exec_accessory_override; // Global realtime executor bitflag variable for spindle/coolant overrides.
+
+#ifdef DEBUG
+ #define EXEC_DEBUG_REPORT bit(0)
+ extern volatile uint8_t sys_rt_exec_debug;
+#endif
+
+// Initialize the serial protocol
+void system_init();
+
+// Returns bitfield of control pin states, organized by CONTROL_PIN_INDEX. (1=triggered, 0=not triggered).
+uint8_t system_control_get_state();
+
+// Returns if safety door is open or closed, based on pin state.
+uint8_t system_check_safety_door_ajar();
+
+// Executes an internal system command, defined as a string starting with a '$'
+uint8_t system_execute_line(char *line);
+
+// Execute the startup script lines stored in EEPROM upon initialization
+void system_execute_startup(char *line);
+
+
+void system_flag_wco_change();
+
+// Returns machine position of axis 'idx'. Must be sent a 'step' array.
+float system_convert_axis_steps_to_mpos(int32_t *steps, uint8_t idx);
+
+// Updates a machine 'position' array based on the 'step' array sent.
+void system_convert_array_steps_to_mpos(float *position, int32_t *steps);
+
+// CoreXY calculation only. Returns x or y-axis "steps" based on CoreXY motor steps.
+#ifdef COREXY
+ int32_t system_convert_corexy_to_x_axis_steps(int32_t *steps);
+ int32_t system_convert_corexy_to_y_axis_steps(int32_t *steps);
+#endif
+
+// Checks and reports if target array exceeds machine travel limits.
+uint8_t system_check_travel_limits(float *target);
+
+// Special handlers for setting and clearing Grbl's real-time execution flags.
+void system_set_exec_state_flag(uint8_t mask);
+void system_clear_exec_state_flag(uint8_t mask);
+void system_set_exec_alarm(uint8_t code);
+void system_clear_exec_alarm();
+void system_set_exec_motion_override_flag(uint8_t mask);
+void system_set_exec_accessory_override_flag(uint8_t mask);
+void system_clear_exec_motion_overrides();
+void system_clear_exec_accessory_overrides();
+
+
+#endif