Merge pull request #5452 from thinkyhead/rc_save_your_mesh

Save Bed Leveling to EEPROM

Marlin/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/Marlin.h

 #endif
 
 #if ENABLED(AUTO_BED_LEVELING_BILINEAR)
-  extern int bilinear_grid_spacing[2];
+  extern int bilinear_grid_spacing[2], bilinear_start[2];
+  extern float bed_level_grid[ABL_GRID_MAX_POINTS_X][ABL_GRID_MAX_POINTS_Y];
   float bilinear_z_offset(float logical[XYZ]);
+  void set_bed_leveling_enabled(bool enable=true);
+#endif
+
+#if PLANNER_LEVELING
+  void reset_bed_level();
 #endif
 
 #if ENABLED(Z_DUAL_ENDSTOPS)

Marlin/Marlin_main.cpp

 #endif
 
 #if ENABLED(AUTO_BED_LEVELING_BILINEAR)
-  int bilinear_grid_spacing[2] = { 0 }, bilinear_start[2] = { 0 };
-  float bed_level_grid[ABL_GRID_POINTS_X][ABL_GRID_POINTS_Y];
+  #define UNPROBED 9999.0f
+  int bilinear_grid_spacing[2], bilinear_start[2];
+  float bed_level_grid[ABL_GRID_MAX_POINTS_X][ABL_GRID_MAX_POINTS_Y];
 #endif
 
 #if IS_SCARA
    * Disable: Current position = physical position
    *  Enable: Current position = "unleveled" physical position
    */
-  void set_bed_leveling_enabled(bool enable=true) {
+  void set_bed_leveling_enabled(bool enable/*=true*/) {
     #if ENABLED(MESH_BED_LEVELING)
 
       if (enable != mbl.active()) {
 
     #elif HAS_ABL
 
-      if (enable != planner.abl_enabled) {
+      #if ENABLED(AUTO_BED_LEVELING_BILINEAR)
+        const bool can_change = (!enable || (bilinear_grid_spacing[0] && bilinear_grid_spacing[1]));
+      #else
+        constexpr bool can_change = true;
+      #endif
+
+      if (can_change && enable != planner.abl_enabled) {
         planner.abl_enabled = enable;
         if (!enable)
           set_current_from_steppers_for_axis(
    * Reset calibration results to zero.
    */
   void reset_bed_level() {
+    set_bed_leveling_enabled(false);
     #if ENABLED(MESH_BED_LEVELING)
       if (mbl.has_mesh()) {
-        set_bed_leveling_enabled(false);
         mbl.reset();
         mbl.set_has_mesh(false);
       }
     #else
-      planner.abl_enabled = false;
       #if ENABLED(DEBUG_LEVELING_FEATURE)
         if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM("reset_bed_level");
       #endif
       #if ABL_PLANAR
         planner.bed_level_matrix.set_to_identity();
       #elif ENABLED(AUTO_BED_LEVELING_BILINEAR)
-        for (uint8_t x = 0; x < ABL_GRID_POINTS_X; x++)
-          for (uint8_t y = 0; y < ABL_GRID_POINTS_Y; y++)
-            bed_level_grid[x][y] = 1000.0;
+        bilinear_start[X_AXIS] = bilinear_start[Y_AXIS] =
+        bilinear_grid_spacing[X_AXIS] = bilinear_grid_spacing[Y_AXIS] = 0;
+        for (uint8_t x = 0; x < ABL_GRID_MAX_POINTS_X; x++)
+          for (uint8_t y = 0; y < ABL_GRID_MAX_POINTS_Y; y++)
+            bed_level_grid[x][y] = UNPROBED;
       #endif
     #endif
   }
         SERIAL_CHAR(']');
       }
     #endif
-    if (bed_level_grid[x][y] < 999.0) {
+    if (bed_level_grid[x][y] != UNPROBED) {
       #if ENABLED(DEBUG_LEVELING_FEATURE)
         if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM(" (done)");
       #endif
           c1 = bed_level_grid[x + xdir][y + ydir], c2 = bed_level_grid[x + xdir * 2][y + ydir * 2];
 
     // Treat far unprobed points as zero, near as equal to far
-    if (a2 > 999.0) a2 = 0.0; if (a1 > 999.0) a1 = a2;
-    if (b2 > 999.0) b2 = 0.0; if (b1 > 999.0) b1 = b2;
-    if (c2 > 999.0) c2 = 0.0; if (c1 > 999.0) c1 = c2;
+    if (a2 == UNPROBED) a2 = 0.0; if (a1 == UNPROBED) a1 = a2;
+    if (b2 == UNPROBED) b2 = 0.0; if (b1 == UNPROBED) b1 = b2;
+    if (c2 == UNPROBED) c2 = 0.0; if (c1 == UNPROBED) c1 = c2;
 
     float a = 2 * a1 - a2, b = 2 * b1 - b2, c = 2 * c1 - c2;
 
-    // Take the average intstead of the median
+    // Take the average instead of the median
     bed_level_grid[x][y] = (a + b + c) / 3.0;
 
     // Median is robust (ignores outliers).
   //#define EXTRAPOLATE_FROM_EDGE
 
   #if ENABLED(EXTRAPOLATE_FROM_EDGE)
-    #if ABL_GRID_POINTS_X < ABL_GRID_POINTS_Y
+    #if ABL_GRID_MAX_POINTS_X < ABL_GRID_MAX_POINTS_Y
       #define HALF_IN_X
-    #elif ABL_GRID_POINTS_Y < ABL_GRID_POINTS_X
+    #elif ABL_GRID_MAX_POINTS_Y < ABL_GRID_MAX_POINTS_X
       #define HALF_IN_Y
     #endif
   #endif
    */
   static void extrapolate_unprobed_bed_level() {
     #ifdef HALF_IN_X
-      const uint8_t ctrx2 = 0, xlen = ABL_GRID_POINTS_X - 1;
+      const uint8_t ctrx2 = 0, xlen = ABL_GRID_MAX_POINTS_X - 1;
     #else
-      const uint8_t ctrx1 = (ABL_GRID_POINTS_X - 1) / 2, // left-of-center
-                    ctrx2 = ABL_GRID_POINTS_X / 2,       // right-of-center
+      const uint8_t ctrx1 = (ABL_GRID_MAX_POINTS_X - 1) / 2, // left-of-center
+                    ctrx2 = ABL_GRID_MAX_POINTS_X / 2,       // right-of-center
                     xlen = ctrx1;
     #endif
 
     #ifdef HALF_IN_Y
-      const uint8_t ctry2 = 0, ylen = ABL_GRID_POINTS_Y - 1;
+      const uint8_t ctry2 = 0, ylen = ABL_GRID_MAX_POINTS_Y - 1;
     #else
-      const uint8_t ctry1 = (ABL_GRID_POINTS_Y - 1) / 2, // top-of-center
-                    ctry2 = ABL_GRID_POINTS_Y / 2,       // bottom-of-center
+      const uint8_t ctry1 = (ABL_GRID_MAX_POINTS_Y - 1) / 2, // top-of-center
+                    ctry2 = ABL_GRID_MAX_POINTS_Y / 2,       // bottom-of-center
                     ylen = ctry1;
     #endif
 
   /**
    * Print calibration results for plotting or manual frame adjustment.
    */
-  static void print_bed_level() {
+  static void print_bilinear_leveling_grid() {
     SERIAL_ECHOPGM("Bilinear Leveling Grid:\n ");
-    for (uint8_t x = 0; x < ABL_GRID_POINTS_X; x++) {
+    for (uint8_t x = 0; x < ABL_GRID_MAX_POINTS_X; x++) {
       SERIAL_PROTOCOLPGM("    ");
       if (x < 10) SERIAL_PROTOCOLCHAR(' ');
       SERIAL_PROTOCOL((int)x);
     }
     SERIAL_EOL;
-    for (uint8_t y = 0; y < ABL_GRID_POINTS_Y; y++) {
+    for (uint8_t y = 0; y < ABL_GRID_MAX_POINTS_Y; y++) {
       if (y < 10) SERIAL_PROTOCOLCHAR(' ');
       SERIAL_PROTOCOL((int)y);
-      for (uint8_t x = 0; x < ABL_GRID_POINTS_X; x++) {
+      for (uint8_t x = 0; x < ABL_GRID_MAX_POINTS_X; x++) {
         SERIAL_PROTOCOLCHAR(' ');
         float offset = bed_level_grid[x][y];
-        if (offset < 999.0) {
+        if (offset != UNPROBED) {
           if (offset > 0) SERIAL_CHAR('+');
           SERIAL_PROTOCOL_F(offset, 2);
         }
   }
 
   #if ENABLED(ABL_BILINEAR_SUBDIVISION)
-    #define ABL_GRID_POINTS_VIRT_X (ABL_GRID_POINTS_X - 1) * (BILINEAR_SUBDIVISIONS) + 1
-    #define ABL_GRID_POINTS_VIRT_Y (ABL_GRID_POINTS_Y - 1) * (BILINEAR_SUBDIVISIONS) + 1
+    #define ABL_GRID_POINTS_VIRT_X (ABL_GRID_MAX_POINTS_X - 1) * (BILINEAR_SUBDIVISIONS) + 1
+    #define ABL_GRID_POINTS_VIRT_Y (ABL_GRID_MAX_POINTS_Y - 1) * (BILINEAR_SUBDIVISIONS) + 1
     float bed_level_grid_virt[ABL_GRID_POINTS_VIRT_X][ABL_GRID_POINTS_VIRT_Y];
-    float bed_level_grid_virt_temp[ABL_GRID_POINTS_X + 2][ABL_GRID_POINTS_Y + 2]; //temporary for calculation (maybe dynamical?)
+    float bed_level_grid_virt_temp[ABL_GRID_MAX_POINTS_X + 2][ABL_GRID_MAX_POINTS_Y + 2]; //temporary for calculation (maybe dynamical?)
     int bilinear_grid_spacing_virt[2] = { 0 };
 
     static void bed_level_virt_print() {
         for (uint8_t x = 0; x < ABL_GRID_POINTS_VIRT_X; x++) {
           SERIAL_PROTOCOLCHAR(' ');
           float offset = bed_level_grid_virt[x][y];
-          if (offset < 999.0) {
+          if (offset != UNPROBED) {
             if (offset > 0) SERIAL_CHAR('+');
             SERIAL_PROTOCOL_F(offset, 5);
           }
       SERIAL_EOL;
     }
     #define LINEAR_EXTRAPOLATION(E, I) (E * 2 - I)
-    static void bed_level_virt_prepare() {
-      for (uint8_t y = 1; y <= ABL_GRID_POINTS_Y; y++) {
+    void bed_level_virt_prepare() {
+      for (uint8_t y = 1; y <= ABL_GRID_MAX_POINTS_Y; y++) {
 
-        for (uint8_t x = 1; x <= ABL_GRID_POINTS_X; x++)
+        for (uint8_t x = 1; x <= ABL_GRID_MAX_POINTS_X; x++)
           bed_level_grid_virt_temp[x][y] = bed_level_grid[x - 1][y - 1];
 
         bed_level_grid_virt_temp[0][y] = LINEAR_EXTRAPOLATION(
           bed_level_grid_virt_temp[2][y]
         );
 
-        bed_level_grid_virt_temp[(ABL_GRID_POINTS_X + 2) - 1][y] =
+        bed_level_grid_virt_temp[(ABL_GRID_MAX_POINTS_X + 2) - 1][y] =
           LINEAR_EXTRAPOLATION(
-            bed_level_grid_virt_temp[(ABL_GRID_POINTS_X + 2) - 2][y],
-            bed_level_grid_virt_temp[(ABL_GRID_POINTS_X + 2) - 3][y]
+            bed_level_grid_virt_temp[(ABL_GRID_MAX_POINTS_X + 2) - 2][y],
+            bed_level_grid_virt_temp[(ABL_GRID_MAX_POINTS_X + 2) - 3][y]
           );
       }
-      for (uint8_t x = 0; x < ABL_GRID_POINTS_X + 2; x++) {
+      for (uint8_t x = 0; x < ABL_GRID_MAX_POINTS_X + 2; x++) {
         bed_level_grid_virt_temp[x][0] = LINEAR_EXTRAPOLATION(
           bed_level_grid_virt_temp[x][1],
           bed_level_grid_virt_temp[x][2]
         );
-        bed_level_grid_virt_temp[x][(ABL_GRID_POINTS_Y + 2) - 1] =
+        bed_level_grid_virt_temp[x][(ABL_GRID_MAX_POINTS_Y + 2) - 1] =
           LINEAR_EXTRAPOLATION(
-            bed_level_grid_virt_temp[x][(ABL_GRID_POINTS_Y + 2) - 2],
-            bed_level_grid_virt_temp[x][(ABL_GRID_POINTS_Y + 2) - 3]
+            bed_level_grid_virt_temp[x][(ABL_GRID_MAX_POINTS_Y + 2) - 2],
+            bed_level_grid_virt_temp[x][(ABL_GRID_MAX_POINTS_Y + 2) - 3]
           );
       }
     }
       }
       return bed_level_virt_cmr(row, 1, tx);
     }
-    static void bed_level_virt_interpolate() {
-      for (uint8_t y = 0; y < ABL_GRID_POINTS_Y; y++)
-        for (uint8_t x = 0; x < ABL_GRID_POINTS_X; x++)
+    void bed_level_virt_interpolate() {
+      for (uint8_t y = 0; y < ABL_GRID_MAX_POINTS_Y; y++)
+        for (uint8_t x = 0; x < ABL_GRID_MAX_POINTS_X; x++)
           for (uint8_t ty = 0; ty < BILINEAR_SUBDIVISIONS; ty++)
             for (uint8_t tx = 0; tx < BILINEAR_SUBDIVISIONS; tx++) {
-              if ((ty && y == ABL_GRID_POINTS_Y - 1) || (tx && x == ABL_GRID_POINTS_X - 1))
+              if ((ty && y == ABL_GRID_MAX_POINTS_Y - 1) || (tx && x == ABL_GRID_MAX_POINTS_X - 1))
                 continue;
               bed_level_grid_virt[x * (BILINEAR_SUBDIVISIONS) + tx][y * (BILINEAR_SUBDIVISIONS) + ty] =
                 bed_level_virt_2cmr(
   // Wait for planner moves to finish!
   stepper.synchronize();
 
-  // For auto bed leveling, clear the level matrix
-  #if HAS_ABL
-    reset_bed_level();
+  // Disable the leveling matrix before homing
+  #if PLANNER_LEVELING
+    set_bed_leveling_enabled(false);
   #endif
 
   // Always home with tool 0 active
   // Save 130 bytes with non-duplication of PSTR
   void say_not_entered() { SERIAL_PROTOCOLLNPGM(" not entered."); }
 
+  void mbl_mesh_report() {
+    SERIAL_PROTOCOLLNPGM("Num X,Y: " STRINGIFY(MESH_NUM_X_POINTS) "," STRINGIFY(MESH_NUM_Y_POINTS));
+    SERIAL_PROTOCOLLNPGM("Z search height: " STRINGIFY(MESH_HOME_SEARCH_Z));
+    SERIAL_PROTOCOLPGM("Z offset: "); SERIAL_PROTOCOL_F(mbl.z_offset, 5);
+    SERIAL_PROTOCOLLNPGM("\nMeasured points:");
+    for (uint8_t py = 0; py < MESH_NUM_Y_POINTS; py++) {
+      for (uint8_t px = 0; px < MESH_NUM_X_POINTS; px++) {
+        SERIAL_PROTOCOLPGM("  ");
+        SERIAL_PROTOCOL_F(mbl.z_values[py][px], 5);
+      }
+      SERIAL_EOL;
+    }
+  }
+
   /**
    * G29: Mesh-based Z probe, probes a grid and produces a
    *      mesh to compensate for variable bed height
     switch (state) {
       case MeshReport:
         if (mbl.has_mesh()) {
-          SERIAL_PROTOCOLPAIR("State: ", mbl.active() ? MSG_ON : MSG_OFF);
-          SERIAL_PROTOCOLLNPGM("\nNum X,Y: " STRINGIFY(MESH_NUM_X_POINTS) "," STRINGIFY(MESH_NUM_Y_POINTS));
-          SERIAL_PROTOCOLLNPGM("Z search height: " STRINGIFY(MESH_HOME_SEARCH_Z));
-          SERIAL_PROTOCOLPGM("Z offset: "); SERIAL_PROTOCOL_F(mbl.z_offset, 5);
-          SERIAL_PROTOCOLLNPGM("\nMeasured points:");
-          for (py = 0; py < MESH_NUM_Y_POINTS; py++) {
-            for (px = 0; px < MESH_NUM_X_POINTS; px++) {
-              SERIAL_PROTOCOLPGM("  ");
-              SERIAL_PROTOCOL_F(mbl.z_values[py][px], 5);
-            }
-            SERIAL_EOL;
-          }
+          SERIAL_PROTOCOLLNPAIR("State: ", mbl.active() ? MSG_ON : MSG_OFF);
+          mbl_mesh_report();
         }
         else
-          SERIAL_PROTOCOLLNPGM("Mesh bed leveling not active.");
+          SERIAL_PROTOCOLLNPGM("Mesh bed leveling has no data.");
         break;
 
       case MeshStart:
    *
    * Enhanced G29 Auto Bed Leveling Probe Routine
    *
-   * Parameters With ABL_GRID:
+   * Parameters With LINEAR and BILINEAR:
    *
    *  P  Set the size of the grid that will be probed (P x P points).
    *     Not supported by non-linear delta printer bed leveling.
    *  L  Set the Left limit of the probing grid
    *  R  Set the Right limit of the probing grid
    *
+   * Parameters with BILINEAR only:
+   * 
+   *  Z  Supply an additional Z probe offset
+   *
    * Global Parameters:
    *
    * E/e By default G29 will engage the Z probe, test the bed, then disengage.
 
         // X and Y specify points in each direction, overriding the default
         // These values may be saved with the completed mesh
-        int abl_grid_points_x = code_seen('X') ? code_value_int() : ABL_GRID_POINTS_X,
-            abl_grid_points_y = code_seen('Y') ? code_value_int() : ABL_GRID_POINTS_Y;
+        int abl_grid_points_x = code_seen('X') ? code_value_int() : ABL_GRID_MAX_POINTS_X,
+            abl_grid_points_y = code_seen('Y') ? code_value_int() : ABL_GRID_MAX_POINTS_Y;
 
         if (code_seen('P')) abl_grid_points_x = abl_grid_points_y = code_value_int();
 
 
       #else
 
-         const int abl_grid_points_x = ABL_GRID_POINTS_X, abl_grid_points_y = ABL_GRID_POINTS_Y;
+         const uint8_t abl_grid_points_x = ABL_GRID_MAX_POINTS_X, abl_grid_points_y = ABL_GRID_MAX_POINTS_Y;
 
       #endif
 
           || left_probe_bed_position != bilinear_start[X_AXIS]
           || front_probe_bed_position != bilinear_start[Y_AXIS]
         ) {
+          // Before reset bed level, re-enable to correct the position
+          planner.abl_enabled = abl_should_enable;
+          // Reset grid to 0.0 or "not probed". (Also disables ABL)
           reset_bed_level();
+
           #if ENABLED(ABL_BILINEAR_SUBDIVISION)
             bilinear_grid_spacing_virt[X_AXIS] = xGridSpacing / (BILINEAR_SUBDIVISIONS);
             bilinear_grid_spacing_virt[Y_AXIS] = yGridSpacing / (BILINEAR_SUBDIVISIONS);
           bilinear_grid_spacing[Y_AXIS] = yGridSpacing;
           bilinear_start[X_AXIS] = RAW_X_POSITION(left_probe_bed_position);
           bilinear_start[Y_AXIS] = RAW_Y_POSITION(front_probe_bed_position);
+
           // Can't re-enable (on error) until the new grid is written
           abl_should_enable = false;
         }
     #if ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
       if (!dryrun) extrapolate_unprobed_bed_level();
-      print_bed_level();
+      print_bilinear_leveling_grid();
 
       #if ENABLED(ABL_BILINEAR_SUBDIVISION)
         bed_level_virt_prepare();
         // Correct the current XYZ position based on the tilted plane.
         //
 
-        // 1. Get the distance from the current position to the reference point.
-        float x_dist = RAW_CURRENT_POSITION(X_AXIS) - X_TILT_FULCRUM,
-              y_dist = RAW_CURRENT_POSITION(Y_AXIS) - Y_TILT_FULCRUM,
-              z_real = current_position[Z_AXIS],
-              z_zero = 0;
-
         #if ENABLED(DEBUG_LEVELING_FEATURE)
           if (DEBUGGING(LEVELING)) DEBUG_POS("G29 uncorrected XYZ", current_position);
         #endif
 
-        matrix_3x3 inverse = matrix_3x3::transpose(planner.bed_level_matrix);
-
-        // 2. Apply the inverse matrix to the distance
-        //    from the reference point to X, Y, and zero.
-        apply_rotation_xyz(inverse, x_dist, y_dist, z_zero);
+        float converted[XYZ];
+        memcpy(converted, current_position, sizeof(converted));
 
-        // 3. Get the matrix-based corrected Z.
-        //    (Even if not used, get it for comparison.)
-        float new_z = z_real + z_zero;
+        planner.abl_enabled = true;
+        planner.unapply_leveling(converted); // use conversion machinery
+        planner.abl_enabled = false;
 
-        // 4. Use the last measured distance to the bed, if possible
+        // Use the last measured distance to the bed, if possible
         if ( NEAR(current_position[X_AXIS], xProbe - (X_PROBE_OFFSET_FROM_EXTRUDER))
           && NEAR(current_position[Y_AXIS], yProbe - (Y_PROBE_OFFSET_FROM_EXTRUDER))
         ) {
-          float simple_z = z_real - (measured_z - (-zprobe_zoffset));
+          float simple_z = current_position[Z_AXIS] - (measured_z - (-zprobe_zoffset));
           #if ENABLED(DEBUG_LEVELING_FEATURE)
             if (DEBUGGING(LEVELING)) {
               SERIAL_ECHOPAIR("Z from Probe:", simple_z);
-              SERIAL_ECHOPAIR("  Matrix:", new_z);
-              SERIAL_ECHOLNPAIR("  Discrepancy:", simple_z - new_z);
+              SERIAL_ECHOPAIR("  Matrix:", converted[Z_AXIS]);
+              SERIAL_ECHOLNPAIR("  Discrepancy:", simple_z - converted[Z_AXIS]);
             }
           #endif
-          new_z = simple_z;
+          converted[Z_AXIS] = simple_z;
         }
 
-        // 5. The rotated XY and corrected Z are now current_position
-        current_position[X_AXIS] = LOGICAL_X_POSITION(x_dist) + X_TILT_FULCRUM;
-        current_position[Y_AXIS] = LOGICAL_Y_POSITION(y_dist) + Y_TILT_FULCRUM;
-        current_position[Z_AXIS] = new_z;
+        // The rotated XY and corrected Z are now current_position
+        memcpy(current_position, converted, sizeof(converted));
 
         #if ENABLED(DEBUG_LEVELING_FEATURE)
           if (DEBUGGING(LEVELING)) DEBUG_POS("G29 corrected XYZ", current_position);
 
     // Disable bed level correction in M48 because we want the raw data when we probe
     #if HAS_ABL
-      reset_bed_level();
+      const bool abl_was_enabled = planner.abl_enabled;
+      set_bed_leveling_enabled(false);
     #endif
 
     setup_for_endstop_or_probe_move();
 
     clean_up_after_endstop_or_probe_move();
 
+    // Re-enable bed level correction if it has been on
+    #if HAS_ABL
+      set_bed_leveling_enabled(abl_was_enabled);
+    #endif
+
     report_current_position();
   }
 
    *
    *       S[bool]   Turns leveling on or off
    *       Z[height] Sets the Z fade height (0 or none to disable)
+   *       V[bool]   Verbose - Print the levelng grid
    */
   inline void gcode_M420() {
-    if (code_seen('S')) set_bed_leveling_enabled(code_value_bool());
+    bool to_enable = false;
+
+    if (code_seen('S')) {
+      to_enable = code_value_bool();
+      set_bed_leveling_enabled(to_enable);
+    }
+
     #if ENABLED(ENABLE_LEVELING_FADE_HEIGHT)
       if (code_seen('Z')) set_z_fade_height(code_value_linear_units());
     #endif
+
+    if (to_enable && !(
+      #if ENABLED(MESH_BED_LEVELING)
+        mbl.active()
+      #else
+        planner.abl_enabled
+      #endif
+    ) ) {
+      to_enable = false;
+      SERIAL_ERROR_START;
+      SERIAL_ERRORLNPGM(MSG_ERR_M420_FAILED);
+    }
+
+    SERIAL_ECHO_START;
+    SERIAL_ECHOLNPAIR("Bed Leveling ", to_enable ? MSG_ON : MSG_OFF);
+
+    // V to print the matrix or mesh
+    if (code_seen('V')) {
+      #if ABL_PLANAR
+        planner.bed_level_matrix.debug("Bed Level Correction Matrix:");
+      #elif ENABLED(AUTO_BED_LEVELING_BILINEAR)
+        if (bilinear_grid_spacing[X_AXIS]) {
+          print_bilinear_leveling_grid();
+          #if ENABLED(ABL_BILINEAR_SUBDIVISION)
+            bed_level_virt_print();
+          #endif
+        }
+      #elif ENABLED(MESH_BED_LEVELING)
+        if (mbl.has_mesh()) {
+          SERIAL_ECHOLNPGM("Mesh Bed Level data:");
+          mbl_mesh_report();
+        }
+      #endif
+    }
+
   }
 #endif
 
     }
   }
 
+#elif ENABLED(AUTO_BED_LEVELING_BILINEAR)
+
+  /**
+   * M421: Set a single Mesh Bed Leveling Z coordinate
+   *
+   *   M421 I<xindex> J<yindex> Z<linear>
+   */
+  inline void gcode_M421() {
+    int8_t px = 0, py = 0;
+    float z = 0;
+    bool hasI, hasJ, hasZ;
+    if ((hasI = code_seen('I'))) px = code_value_axis_units(X_AXIS);
+    if ((hasJ = code_seen('J'))) py = code_value_axis_units(Y_AXIS);
+    if ((hasZ = code_seen('Z'))) z = code_value_axis_units(Z_AXIS);
+
+    if (hasI && hasJ && hasZ) {
+      if (px >= 0 && px < ABL_GRID_MAX_POINTS_X && py >= 0 && py < ABL_GRID_MAX_POINTS_X) {
+        bed_level_grid[px][py] = z;
+        #if ENABLED(ABL_BILINEAR_SUBDIVISION)
+          bed_level_virt_prepare();
+          bed_level_virt_interpolate();
+        #endif
+      }
+      else {
+        SERIAL_ERROR_START;
+        SERIAL_ERRORLNPGM(MSG_ERR_MESH_XY);
+      }
+    }
+    else {
+      SERIAL_ERROR_START;
+      SERIAL_ERRORLNPGM(MSG_ERR_M421_PARAMETERS);
+    }
+  }
+
 #endif
 
 /**
     #define ABL_BG_GRID(X,Y)  bed_level_grid_virt[X][Y]
   #else
     #define ABL_BG_SPACING(A) bilinear_grid_spacing[A]
-    #define ABL_BG_POINTS_X   ABL_GRID_POINTS_X
-    #define ABL_BG_POINTS_Y   ABL_GRID_POINTS_Y
+    #define ABL_BG_POINTS_X   ABL_GRID_MAX_POINTS_X
+    #define ABL_BG_POINTS_Y   ABL_GRID_MAX_POINTS_Y
     #define ABL_BG_GRID(X,Y)  bed_level_grid[X][Y]
   #endif
 

Marlin/SanityCheck.h

 #elif defined(AUTO_BED_LEVELING_FEATURE)
   #error "AUTO_BED_LEVELING_FEATURE is deprecated. Specify AUTO_BED_LEVELING_LINEAR, AUTO_BED_LEVELING_BILINEAR, or AUTO_BED_LEVELING_3POINT."
 #elif defined(ABL_GRID_POINTS)
-  #error "ABL_GRID_POINTS is now ABL_GRID_POINTS_X and ABL_GRID_POINTS_Y. Please update your configuration."
+  #error "ABL_GRID_POINTS is now ABL_GRID_MAX_POINTS_X and ABL_GRID_MAX_POINTS_Y. Please update your configuration."
+#elif defined(ABL_GRID_POINTS_X) || defined(ABL_GRID_POINTS_Y)
+  #error "ABL_GRID_POINTS_[XY] is now ABL_GRID_MAX_POINTS_[XY]. Please update your configuration."
 #elif defined(BEEPER)
   #error "BEEPER is now BEEPER_PIN. Please update your pins definitions."
 #elif defined(SDCARDDETECT)
     #error "You probably want to use Max Endstops for DELTA!"
   #endif
   #if ABL_GRID
-    #if (ABL_GRID_POINTS_X & 1) == 0 || (ABL_GRID_POINTS_Y & 1) == 0
-      #error "DELTA requires ABL_GRID_POINTS_X and ABL_GRID_POINTS_Y to be odd numbers."
-    #elif ABL_GRID_POINTS_X < 3
-      #error "DELTA requires ABL_GRID_POINTS_X and ABL_GRID_POINTS_Y to be 3 or higher."
+    #if (ABL_GRID_MAX_POINTS_X & 1) == 0 || (ABL_GRID_MAX_POINTS_Y & 1) == 0
+      #error "DELTA requires ABL_GRID_MAX_POINTS_X and ABL_GRID_MAX_POINTS_Y to be odd numbers."
+    #elif ABL_GRID_MAX_POINTS_X < 3
+      #error "DELTA requires ABL_GRID_MAX_POINTS_X and ABL_GRID_MAX_POINTS_Y to be 3 or higher."
     #endif
   #endif
 #endif

Marlin/configuration_store.cpp

  *
  */
 
-#define EEPROM_VERSION "V28"
+#define EEPROM_VERSION "V29"
 
 // Change EEPROM version if these are changed:
 #define EEPROM_OFFSET 100
 
 /**
- * V28 EEPROM Layout:
+ * V29 EEPROM Layout:
  *
- *  100  Version (char x4)
- *  104  EEPROM Checksum (uint16_t)
+ *  100  Version                                   (char x4)
+ *  104  EEPROM Checksum                           (uint16_t)
  *
- *  106  E_STEPPERS (uint8_t)
+ *  106            E_STEPPERS (uint8_t)
  *  107  M92 XYZE  planner.axis_steps_per_mm (float x4 ... x7)
  *  123  M203 XYZE planner.max_feedrate_mm_s (float x4 ... x7)
  *  139  M201 XYZE planner.max_acceleration_mm_per_s2 (uint32_t x4 ... x7)
  *  207  M218 XYZ  hotend_offset (float x3 per additional hotend)
  *
  * Mesh bed leveling:
- *  219  M420 S    status (uint8)
- *  220            z_offset (float)
- *  224            mesh_num_x (uint8 as set in firmware)
- *  225            mesh_num_y (uint8 as set in firmware)
- *  226 G29 S3 XYZ z_values[][] (float x9, by default, up to float x 81)
+ *  219  M420 S    from mbl.status (bool)
+ *  220            mbl.z_offset (float)
+ *  224            MESH_NUM_X_POINTS (uint8 as set in firmware)
+ *  225            MESH_NUM_Y_POINTS (uint8 as set in firmware)
+ *  226 G29 S3 XYZ z_values[][] (float x9, by default, up to float x 81) +288
  *
  * AUTO BED LEVELING
  *  262  M851      zprobe_zoffset (float)
  *
- * DELTA:
- *  266  M666 XYZ  endstop_adj (float x3)
- *  278  M665 R    delta_radius (float)
- *  282  M665 L    delta_diagonal_rod (float)
- *  286  M665 S    delta_segments_per_second (float)
- *  290  M665 A    delta_diagonal_rod_trim_tower_1 (float)
- *  294  M665 B    delta_diagonal_rod_trim_tower_2 (float)
- *  298  M665 C    delta_diagonal_rod_trim_tower_3 (float)
+ * ABL_PLANAR (or placeholder):                    36 bytes
+ *  266            planner.bed_level_matrix        (matrix_3x3 = float x9)
  *
- * Z_DUAL_ENDSTOPS:
- *  302  M666 Z    z_endstop_adj (float)
+ * AUTO_BED_LEVELING_BILINEAR (or placeholder):    47 bytes
+ *  302            ABL_GRID_MAX_POINTS_X           (uint8_t)
+ *  303            ABL_GRID_MAX_POINTS_Y           (uint8_t)
+ *  304            bilinear_grid_spacing           (int x2)   from G29: (B-F)/X, (R-L)/Y
+ *  308  G29 L F   bilinear_start                  (int x2)
+ *  312            bed_level_grid[][]              (float x9, up to float x256) +988
  *
- * ULTIPANEL:
- *  306  M145 S0 H lcd_preheat_hotend_temp (int x2)
- *  310  M145 S0 B lcd_preheat_bed_temp (int x2)
- *  314  M145 S0 F lcd_preheat_fan_speed (int x2)
+ * DELTA (if deltabot):                            36 bytes
+ *  348  M666 XYZ  endstop_adj                     (float x3)
+ *  360  M665 R    delta_radius                    (float)
+ *  364  M665 L    delta_diagonal_rod              (float)
+ *  368  M665 S    delta_segments_per_second       (float)
+ *  372  M665 A    delta_diagonal_rod_trim_tower_1 (float)
+ *  376  M665 B    delta_diagonal_rod_trim_tower_2 (float)
+ *  380  M665 C    delta_diagonal_rod_trim_tower_3 (float)
  *
- * PIDTEMP:
- *  318  M301 E0 PIDC  Kp[0], Ki[0], Kd[0], Kc[0] (float x4)
- *  334  M301 E1 PIDC  Kp[1], Ki[1], Kd[1], Kc[1] (float x4)
- *  350  M301 E2 PIDC  Kp[2], Ki[2], Kd[2], Kc[2] (float x4)
- *  366  M301 E3 PIDC  Kp[3], Ki[3], Kd[3], Kc[3] (float x4)
- *  382  M301 L        lpq_len (int)
+ * Z_DUAL_ENDSTOPS:                                4 bytes
+ *  384  M666 Z    z_endstop_adj                   (float)
+ *
+ * ULTIPANEL:                                      6 bytes
+ *  388  M145 S0 H lcd_preheat_hotend_temp         (int x2)
+ *  392  M145 S0 B lcd_preheat_bed_temp            (int x2)
+ *  396  M145 S0 F lcd_preheat_fan_speed           (int x2)
+ *
+ * PIDTEMP:                                        66 bytes
+ *  400  M301 E0 PIDC  Kp[0], Ki[0], Kd[0], Kc[0]  (float x4)
+ *  416  M301 E1 PIDC  Kp[1], Ki[1], Kd[1], Kc[1]  (float x4)
+ *  432  M301 E2 PIDC  Kp[2], Ki[2], Kd[2], Kc[2]  (float x4)
+ *  448  M301 E3 PIDC  Kp[3], Ki[3], Kd[3], Kc[3]  (float x4)
+ *  464  M301 L        lpq_len                     (int)
  *
  * PIDTEMPBED:
- *  384  M304 PID  thermalManager.bedKp, thermalManager.bedKi, thermalManager.bedKd (float x3)
+ *  466  M304 PID  thermalManager.bedKp, thermalManager.bedKi, thermalManager.bedKd (float x3)
  *
- * DOGLCD:
- *  396  M250 C    lcd_contrast (int)
+ * DOGLCD:                                          2 bytes
+ *  478  M250 C    lcd_contrast                     (int)
  *
- * FWRETRACT:
- *  398  M209 S    autoretract_enabled (bool)
- *  399  M207 S    retract_length (float)
- *  403  M207 W    retract_length_swap (float)
- *  407  M207 F    retract_feedrate_mm_s (float)
- *  411  M207 Z    retract_zlift (float)
- *  415  M208 S    retract_recover_length (float)
- *  419  M208 W    retract_recover_length_swap (float)
- *  423  M208 F    retract_recover_feedrate_mm_s (float)
+ * FWRETRACT:                                       29 bytes
+ *  480  M209 S    autoretract_enabled              (bool)
+ *  481  M207 S    retract_length                   (float)
+ *  485  M207 W    retract_length_swap              (float)
+ *  489  M207 F    retract_feedrate_mm_s            (float)
+ *  493  M207 Z    retract_zlift                    (float)
+ *  497  M208 S    retract_recover_length           (float)
+ *  501  M208 W    retract_recover_length_swap      (float)
+ *  505  M208 F    retract_recover_feedrate_mm_s    (float)
  *
- * Volumetric Extrusion:
- *  427  M200 D    volumetric_enabled (bool)
- *  428  M200 T D  filament_size (float x4) (T0..3)
+ * Volumetric Extrusion:                            17 bytes
+ *  509  M200 D    volumetric_enabled               (bool)
+ *  510  M200 T D  filament_size                    (float x4) (T0..3)
  *
- *  444  This Slot is Available!
+ *  526                                Minimum end-point
+ * 1847 (526 + 36 + 9 + 288 + 988)     Maximum end-point
  *
  */
 #include "Marlin.h"
   #include "mesh_bed_leveling.h"
 #endif
 
+#if ENABLED(ABL_BILINEAR_SUBDIVISION)
+  extern void bed_level_virt_prepare();
+  extern void bed_level_virt_interpolate();
+#endif
+
 /**
  * Post-process after Retrieve or Reset
  */
       value++;
     };
   }
+  bool eeprom_read_error;
   void _EEPROM_readData(int &pos, uint8_t* value, uint8_t size) {
     do {
       uint8_t c = eeprom_read_byte((unsigned char*)pos);
-      *value = c;
+      if (!eeprom_read_error) *value = c;
       eeprom_checksum += c;
       pos++;
       value++;
   #define EEPROM_SKIP(VAR) eeprom_index += sizeof(VAR)
   #define EEPROM_WRITE(VAR) _EEPROM_writeData(eeprom_index, (uint8_t*)&VAR, sizeof(VAR))
   #define EEPROM_READ(VAR) _EEPROM_readData(eeprom_index, (uint8_t*)&VAR, sizeof(VAR))
+  #define EEPROM_ASSERT(TST,ERR) if () do{ SERIAL_ERROR_START; SERIAL_ERRORLNPGM(ERR); eeprom_read_error |= true; }while(0)
 
   /**
    * M500 - Store Configuration
         LOOP_XYZ(i) EEPROM_WRITE(hotend_offset[i][e]);
     #endif
 
+    //
+    // Mesh Bed Leveling
+    //
+
     #if ENABLED(MESH_BED_LEVELING)
       // Compile time test that sizeof(mbl.z_values) is as expected
       typedef char c_assert[(sizeof(mbl.z_values) == (MESH_NUM_X_POINTS) * (MESH_NUM_Y_POINTS) * sizeof(dummy)) ? 1 : -1];
-      uint8_t mesh_num_x = MESH_NUM_X_POINTS,
-              mesh_num_y = MESH_NUM_Y_POINTS,
-              dummy_uint8 = mbl.status & _BV(MBL_STATUS_HAS_MESH_BIT);
-      EEPROM_WRITE(dummy_uint8);
+      const bool leveling_is_on = TEST(mbl.status, MBL_STATUS_HAS_MESH_BIT);
+      const uint8_t mesh_num_x = MESH_NUM_X_POINTS, mesh_num_y = MESH_NUM_Y_POINTS;
+      EEPROM_WRITE(leveling_is_on);
       EEPROM_WRITE(mbl.z_offset);
       EEPROM_WRITE(mesh_num_x);
       EEPROM_WRITE(mesh_num_y);
       EEPROM_WRITE(mbl.z_values);
     #else
       // For disabled MBL write a default mesh
-      uint8_t mesh_num_x = 3,
-              mesh_num_y = 3,
-              dummy_uint8 = 0;
+      const bool leveling_is_on = false;
       dummy = 0.0f;
-      EEPROM_WRITE(dummy_uint8);
-      EEPROM_WRITE(dummy);
+      const uint8_t mesh_num_x = 3, mesh_num_y = 3;
+      EEPROM_WRITE(leveling_is_on);
+      EEPROM_WRITE(dummy); // z_offset
       EEPROM_WRITE(mesh_num_x);
       EEPROM_WRITE(mesh_num_y);
-      for (uint8_t q = 0; q < mesh_num_x * mesh_num_y; q++) EEPROM_WRITE(dummy);
+      for (uint8_t q = mesh_num_x * mesh_num_y; q--;) EEPROM_WRITE(dummy);
     #endif // MESH_BED_LEVELING
 
     #if !HAS_BED_PROBE
     #endif
     EEPROM_WRITE(zprobe_zoffset);
 
+    //
+    // Planar Bed Leveling matrix
+    //
+
+    #if ABL_PLANAR
+      EEPROM_WRITE(planner.bed_level_matrix);
+    #else
+      dummy = 0.0;
+      for (uint8_t q = 9; q--;) EEPROM_WRITE(dummy);
+    #endif
+
+    //
+    // Bilinear Auto Bed Leveling
+    //
+
+    #if ENABLED(AUTO_BED_LEVELING_BILINEAR)
+      // Compile time test that sizeof(bed_level_grid) is as expected
+      typedef char c_assert[(sizeof(bed_level_grid) == (ABL_GRID_MAX_POINTS_X) * (ABL_GRID_MAX_POINTS_Y) * sizeof(dummy)) ? 1 : -1];
+      const uint8_t grid_max_x = ABL_GRID_MAX_POINTS_X, grid_max_y = ABL_GRID_MAX_POINTS_Y;
+      EEPROM_WRITE(grid_max_x);            // 1 byte
+      EEPROM_WRITE(grid_max_y);            // 1 byte
+      EEPROM_WRITE(bilinear_grid_spacing); // 2 ints
+      EEPROM_WRITE(bilinear_start);        // 2 ints
+      EEPROM_WRITE(bed_level_grid);        // 9-256 floats
+    #else
+      // For disabled Bilinear Grid write an empty 3x3 grid
+      const uint8_t grid_max_x = 3, grid_max_y = 3;
+      const int bilinear_start[2] = { 0 }, bilinear_grid_spacing[2] = { 0 };
+      dummy = 0.0f;
+      EEPROM_WRITE(grid_max_x);
+      EEPROM_WRITE(grid_max_y);
+      EEPROM_WRITE(bilinear_grid_spacing);
+      EEPROM_WRITE(bilinear_start);
+      for (uint16_t q = grid_max_x * grid_max_y; q--;) EEPROM_WRITE(dummy);
+    #endif // AUTO_BED_LEVELING_BILINEAR
+
     // 9 floats for DELTA / Z_DUAL_ENDSTOPS
     #if ENABLED(DELTA)
       EEPROM_WRITE(endstop_adj);               // 3 floats
       EEPROM_WRITE(dummy);
     }
 
-    uint16_t final_checksum = eeprom_checksum,
-             eeprom_size = eeprom_index;
+    if (!eeprom_write_error) {
+
+      uint16_t final_checksum = eeprom_checksum,
+               eeprom_size = eeprom_index;
 
-    eeprom_index = EEPROM_OFFSET;
-    EEPROM_WRITE(version);
-    EEPROM_WRITE(final_checksum);
+      // Write the EEPROM header
+      eeprom_index = EEPROM_OFFSET;
+      EEPROM_WRITE(version);
+      EEPROM_WRITE(final_checksum);
 
-    // Report storage size
-    SERIAL_ECHO_START;
-    SERIAL_ECHOPAIR("Settings Stored (", eeprom_size);
-    SERIAL_ECHOLNPGM(" bytes)");
+      // Report storage size
+      SERIAL_ECHO_START;
+      SERIAL_ECHOPAIR("Settings Stored (", eeprom_size);
+      SERIAL_ECHOLNPGM(" bytes)");
+    }
   }
 
   /**
   void Config_RetrieveSettings() {
 
     EEPROM_START();
+    eeprom_read_error = false; // If set EEPROM_READ won't write into RAM
 
     char stored_ver[4];
     EEPROM_READ(stored_ver);
       // Get only the number of E stepper parameters previously stored
       // Any steppers added later are set to their defaults
       const float def1[] = DEFAULT_AXIS_STEPS_PER_UNIT, def2[] = DEFAULT_MAX_FEEDRATE;
-      const long def3[] = DEFAULT_MAX_ACCELERATION;
+      const uint32_t def3[] = DEFAULT_MAX_ACCELERATION;
       float tmp1[XYZ + esteppers], tmp2[XYZ + esteppers];
-      long tmp3[XYZ + esteppers];
+      uint32_t tmp3[XYZ + esteppers];
       EEPROM_READ(tmp1);
       EEPROM_READ(tmp2);
       EEPROM_READ(tmp3);
           LOOP_XYZ(i) EEPROM_READ(hotend_offset[i][e]);
       #endif
 
-      uint8_t dummy_uint8 = 0, mesh_num_x = 0, mesh_num_y = 0;
-      EEPROM_READ(dummy_uint8);
+      //
+      // Mesh (Manual) Bed Leveling
+      //
+
+      bool leveling_is_on;
+      uint8_t mesh_num_x, mesh_num_y;
+      EEPROM_READ(leveling_is_on);
       EEPROM_READ(dummy);
       EEPROM_READ(mesh_num_x);
       EEPROM_READ(mesh_num_y);
+
       #if ENABLED(MESH_BED_LEVELING)
-        mbl.status = dummy_uint8;
+        mbl.status = leveling_is_on ? _BV(MBL_STATUS_HAS_MESH_BIT) : 0;
         mbl.z_offset = dummy;
         if (mesh_num_x == MESH_NUM_X_POINTS && mesh_num_y == MESH_NUM_Y_POINTS) {
           // EEPROM data fits the current mesh
         else {
           // EEPROM data is stale
           mbl.reset();
-          for (uint8_t q = 0; q < mesh_num_x * mesh_num_y; q++) EEPROM_READ(dummy);
+          for (uint16_t q = mesh_num_x * mesh_num_y; q--;) EEPROM_READ(dummy);
         }
       #else
         // MBL is disabled - skip the stored data
-        for (uint8_t q = 0; q < mesh_num_x * mesh_num_y; q++) EEPROM_READ(dummy);
+        for (uint16_t q = mesh_num_x * mesh_num_y; q--;) EEPROM_READ(dummy);
       #endif // MESH_BED_LEVELING
 
       #if !HAS_BED_PROBE
       #endif
       EEPROM_READ(zprobe_zoffset);
 
+      //
+      // Planar Bed Leveling matrix
+      //
+
+      #if ABL_PLANAR
+        EEPROM_READ(planner.bed_level_matrix);
+      #else
+        for (uint8_t q = 9; q--;) EEPROM_READ(dummy);
+      #endif
+
+      //
+      // Bilinear Auto Bed Leveling
+      //
+
+      uint8_t grid_max_x, grid_max_y;
+      EEPROM_READ(grid_max_x);                       // 1 byte
+      EEPROM_READ(grid_max_y);                       // 1 byte
+      #if ENABLED(AUTO_BED_LEVELING_BILINEAR)
+        if (grid_max_x == ABL_GRID_MAX_POINTS_X && grid_max_y == ABL_GRID_MAX_POINTS_Y) {
+          set_bed_leveling_enabled(false);
+          EEPROM_READ(bilinear_grid_spacing);        // 2 ints
+          EEPROM_READ(bilinear_start);               // 2 ints
+          EEPROM_READ(bed_level_grid);               // 9 to 256 floats
+          #if ENABLED(ABL_BILINEAR_SUBDIVISION)
+            bed_level_virt_prepare();
+            bed_level_virt_interpolate();
+          #endif
+          //set_bed_leveling_enabled(leveling_is_on);
+        }
+        else // EEPROM data is stale
+      #endif // AUTO_BED_LEVELING_BILINEAR
+        {
+          // Skip past disabled (or stale) Bilinear Grid data
+          int bgs[2], bs[2];
+          EEPROM_READ(bgs);
+          EEPROM_READ(bs);
+          for (uint16_t q = grid_max_x * grid_max_y; q--;) EEPROM_READ(dummy);
+        }
+
       #if ENABLED(DELTA)
         EEPROM_READ(endstop_adj);                // 3 floats
         EEPROM_READ(delta_radius);               // 1 float
       }
 
       if (eeprom_checksum == stored_checksum) {
-        Config_Postprocess();
-        SERIAL_ECHO_START;
-        SERIAL_ECHO(version);
-        SERIAL_ECHOPAIR(" stored settings retrieved (", eeprom_index);
-        SERIAL_ECHOLNPGM(" bytes)");
+        if (eeprom_read_error)
+          Config_ResetDefault();
+        else {
+          Config_Postprocess();
+          SERIAL_ECHO_START;
+          SERIAL_ECHO(version);
+          SERIAL_ECHOPAIR(" stored settings retrieved (", eeprom_index);
+          SERIAL_ECHOLNPGM(" bytes)");
+        }
       }
       else {
         SERIAL_ERROR_START;
  */
 void Config_ResetDefault() {
   const float tmp1[] = DEFAULT_AXIS_STEPS_PER_UNIT, tmp2[] = DEFAULT_MAX_FEEDRATE;
-  const long tmp3[] = DEFAULT_MAX_ACCELERATION;
+  const uint32_t tmp3[] = DEFAULT_MAX_ACCELERATION;
   LOOP_XYZE_N(i) {
     planner.axis_steps_per_mm[i]          = tmp1[i < COUNT(tmp1) ? i : COUNT(tmp1) - 1];
     planner.max_feedrate_mm_s[i]          = tmp2[i < COUNT(tmp2) ? i : COUNT(tmp2) - 1];
     LOOP_XYZ(i) HOTEND_LOOP() hotend_offset[i][e] = tmp4[i][e];
   #endif
 
-  #if ENABLED(MESH_BED_LEVELING)
-    mbl.reset();
+  // Applies to all MBL and ABL
+  #if PLANNER_LEVELING
+    reset_bed_level();
   #endif
 
   #if HAS_BED_PROBE
     endstop_adj[A_AXIS] = adj[A_AXIS];
     endstop_adj[B_AXIS] = adj[B_AXIS];
     endstop_adj[C_AXIS] = adj[C_AXIS];
-    delta_radius =  DELTA_RADIUS;
-    delta_diagonal_rod =  DELTA_DIAGONAL_ROD;
-    delta_segments_per_second =  DELTA_SEGMENTS_PER_SECOND;
+    delta_radius = DELTA_RADIUS;
+    delta_diagonal_rod = DELTA_DIAGONAL_ROD;
+    delta_segments_per_second = DELTA_SEGMENTS_PER_SECOND;
     delta_diagonal_rod_trim_tower_1 = DELTA_DIAGONAL_ROD_TRIM_TOWER_1;
     delta_diagonal_rod_trim_tower_2 = DELTA_DIAGONAL_ROD_TRIM_TOWER_2;
     delta_diagonal_rod_trim_tower_3 = DELTA_DIAGONAL_ROD_TRIM_TOWER_3;
 
     #if ENABLED(MESH_BED_LEVELING)
       if (!forReplay) {
-        SERIAL_ECHOLNPGM("Mesh bed leveling:");
+        SERIAL_ECHOLNPGM("Mesh Bed Leveling:");
         CONFIG_ECHO_START;
       }
-      SERIAL_ECHOPAIR("  M420 S", mbl.has_mesh() ? 1 : 0);
-      SERIAL_ECHOPAIR(" X", MESH_NUM_X_POINTS);
-      SERIAL_ECHOPAIR(" Y", MESH_NUM_Y_POINTS);
-      SERIAL_EOL;
+      SERIAL_ECHOLNPAIR("  M420 S", mbl.has_mesh() ? 1 : 0);
       for (uint8_t py = 1; py <= MESH_NUM_Y_POINTS; py++) {
         for (uint8_t px = 1; px <= MESH_NUM_X_POINTS; px++) {
           CONFIG_ECHO_START;
           SERIAL_EOL;
         }
       }
+    #elif HAS_ABL
+      if (!forReplay) {
+        SERIAL_ECHOLNPGM("Auto Bed Leveling:");
+        CONFIG_ECHO_START;
+      }
+      SERIAL_ECHOLNPAIR("  M420 S", planner.abl_enabled ? 1 : 0);
     #endif
 
     #if ENABLED(DELTA)

Marlin/example_configurations/Cartesio/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/example_configurations/Felix/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/example_configurations/Felix/DUAL/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/example_configurations/Hephestos/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/example_configurations/Hephestos_2/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION  X_MIN_POS + X_PROBE_OFFSET_FROM_EXTRUDER

Marlin/example_configurations/K8200/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/example_configurations/K8400/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/example_configurations/K8400/Dual-head/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/example_configurations/RepRapWorld/Megatronics/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/example_configurations/RigidBot/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/example_configurations/SCARA/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/example_configurations/TAZ4/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/example_configurations/WITBOX/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/example_configurations/adafruit/ST7565/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/example_configurations/delta/biv2.5/Configuration.h

 
   // Set the number of grid points per dimension.
   // Works best with 5 or more points in each dimension.
-  #define ABL_GRID_POINTS_X 9
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 9
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define DELTA_PROBEABLE_RADIUS (DELTA_PRINTABLE_RADIUS - 10)

Marlin/example_configurations/delta/generic/Configuration.h

 
   // Set the number of grid points per dimension.
   // Works best with 5 or more points in each dimension.
-  #define ABL_GRID_POINTS_X 9
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 9
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define DELTA_PROBEABLE_RADIUS (DELTA_PRINTABLE_RADIUS - 10)

Marlin/example_configurations/delta/kossel_mini/Configuration.h

 
   // Set the number of grid points per dimension.
   // Works best with 5 or more points in each dimension.
-  #define ABL_GRID_POINTS_X 9
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 9
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define DELTA_PROBEABLE_RADIUS (DELTA_PRINTABLE_RADIUS - 10)

Marlin/example_configurations/delta/kossel_pro/Configuration.h

 
   // Set the number of grid points per dimension.
   // Works best with 5 or more points in each dimension.
-  #define ABL_GRID_POINTS_X 7
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 7
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define DELTA_PROBEABLE_RADIUS (DELTA_PRINTABLE_RADIUS-25)

Marlin/example_configurations/delta/kossel_xl/Configuration.h

 
   // Set the number of grid points per dimension.
   // Works best with 5 or more points in each dimension.
-  #define ABL_GRID_POINTS_X 5
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 5
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define DELTA_PROBEABLE_RADIUS (DELTA_PRINTABLE_RADIUS - 10)

Marlin/example_configurations/makibox/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/example_configurations/tvrrug/Round2/Configuration.h

 #if ENABLED(AUTO_BED_LEVELING_LINEAR) || ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
   // Set the number of grid points per dimension.
-  #define ABL_GRID_POINTS_X 3
-  #define ABL_GRID_POINTS_Y ABL_GRID_POINTS_X
+  #define ABL_GRID_MAX_POINTS_X 3
+  #define ABL_GRID_MAX_POINTS_Y ABL_GRID_MAX_POINTS_X
 
   // Set the boundaries for probing (where the probe can reach).
   #define LEFT_PROBE_BED_POSITION 15

Marlin/language.h

 #define MSG_Z2_MAX                          "z2_max: "
 #define MSG_Z_PROBE                         "z_probe: "
 #define MSG_ERR_MATERIAL_INDEX              "M145 S<index> out of range (0-1)"
-#define MSG_ERR_M421_PARAMETERS             "M421 requires XYZ or IJZ parameters"
-#define MSG_ERR_MESH_XY                     "Mesh XY or IJ cannot be resolved"
+#define MSG_ERR_M421_PARAMETERS             "M421 required parameters missing"
+#define MSG_ERR_MESH_XY                     "Mesh point cannot be resolved"
 #define MSG_ERR_ARC_ARGS                    "G2/G3 bad parameters"
 #define MSG_ERR_PROTECTED_PIN               "Protected Pin"
+#define MSG_ERR_M420_FAILED                 "Failed to enable Bed Leveling"
 #define MSG_ERR_M428_TOO_FAR                "Too far from reference point"
 #define MSG_ERR_M303_DISABLED               "PIDTEMP disabled"
 #define MSG_M119_REPORT                     "Reporting endstop status"

Marlin/planner.h

     static float max_feedrate_mm_s[XYZE_N],     // Max speeds in mm per second
                  axis_steps_per_mm[XYZE_N],
                  steps_to_mm[XYZE_N];
-    static unsigned long max_acceleration_steps_per_s2[XYZE_N],
-                         max_acceleration_mm_per_s2[XYZE_N]; // Use M201 to override by software
+    static uint32_t max_acceleration_steps_per_s2[XYZE_N],
+                    max_acceleration_mm_per_s2[XYZE_N]; // Use M201 to override by software
 
     static millis_t min_segment_time;
     static float min_feedrate_mm_s,