diff -r 000000000000 -r 88d965579617 components/u8g2/csrc/u8x8_display.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/components/u8g2/csrc/u8x8_display.c	Tue Oct 08 12:00:31 2019 +0200
@@ -0,0 +1,165 @@
+/*
+  
+  u8x8_display.c
+  
+  Universal 8bit Graphics Library (https://github.com/olikraus/u8g2/)
+
+  Copyright (c) 2016, olikraus@gmail.com
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without modification, 
+  are permitted provided that the following conditions are met:
+
+  * Redistributions of source code must retain the above copyright notice, this list 
+    of conditions and the following disclaimer.
+    
+  * Redistributions in binary form must reproduce the above copyright notice, this 
+    list of conditions and the following disclaimer in the documentation and/or other 
+    materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
+  CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
+  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 
+  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
+  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 
+  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
+  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
+  STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
+  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
+  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  
+  
+  
+  Abstraction layer for the graphics controller.
+  Main goal is the placement of a 8x8 pixel block (tile) on the display.
+  
+*/
+
+
+#include "u8x8.h"
+
+
+/*==========================================*/
+/* internal library function */
+
+/*
+  this is a helper function for the U8X8_MSG_DISPLAY_SETUP_MEMORY function.
+  It can be called within the display callback function to carry out the usual standard tasks.
+  
+*/
+void u8x8_d_helper_display_setup_memory(u8x8_t *u8x8, const u8x8_display_info_t *display_info)
+{
+      /* 1) set display info struct */
+      u8x8->display_info = display_info;
+      u8x8->x_offset = u8x8->display_info->default_x_offset;
+}
+
+/*
+  this is a helper function for the U8X8_MSG_DISPLAY_INIT function.
+  It can be called within the display callback function to carry out the usual standard tasks.
+  
+*/
+void u8x8_d_helper_display_init(u8x8_t *u8x8)
+{
+      /* 2) apply port directions to the GPIO lines and apply default values for the IO lines*/
+      u8x8_gpio_Init(u8x8);
+      u8x8_cad_Init(u8x8);
+
+      /* 3) do reset */
+      u8x8_gpio_SetReset(u8x8, 1);
+      u8x8_gpio_Delay(u8x8, U8X8_MSG_DELAY_MILLI, u8x8->display_info->reset_pulse_width_ms);
+      u8x8_gpio_SetReset(u8x8, 0);
+      u8x8_gpio_Delay(u8x8, U8X8_MSG_DELAY_MILLI, u8x8->display_info->reset_pulse_width_ms);
+      u8x8_gpio_SetReset(u8x8, 1);
+      u8x8_gpio_Delay(u8x8, U8X8_MSG_DELAY_MILLI, u8x8->display_info->post_reset_wait_ms);
+}    
+
+/*==========================================*/
+/* official functions */
+
+uint8_t u8x8_DrawTile(u8x8_t *u8x8, uint8_t x, uint8_t y, uint8_t cnt, uint8_t *tile_ptr)
+{
+  u8x8_tile_t tile;
+  tile.x_pos = x;
+  tile.y_pos = y;
+  tile.cnt = cnt;
+  tile.tile_ptr = tile_ptr;
+  return u8x8->display_cb(u8x8, U8X8_MSG_DISPLAY_DRAW_TILE, 1, (void *)&tile);
+}
+
+/* should be implemented as macro */
+void u8x8_SetupMemory(u8x8_t *u8x8)
+{
+  u8x8->display_cb(u8x8, U8X8_MSG_DISPLAY_SETUP_MEMORY, 0, NULL);  
+}
+
+void u8x8_InitDisplay(u8x8_t *u8x8)
+{
+  u8x8->display_cb(u8x8, U8X8_MSG_DISPLAY_INIT, 0, NULL);  
+}
+
+void u8x8_SetPowerSave(u8x8_t *u8x8, uint8_t is_enable)
+{
+  u8x8->display_cb(u8x8, U8X8_MSG_DISPLAY_SET_POWER_SAVE, is_enable, NULL);  
+}
+
+void u8x8_SetFlipMode(u8x8_t *u8x8, uint8_t mode)
+{
+  u8x8->display_cb(u8x8, U8X8_MSG_DISPLAY_SET_FLIP_MODE, mode, NULL);  
+}
+
+void u8x8_SetContrast(u8x8_t *u8x8, uint8_t value)
+{
+  u8x8->display_cb(u8x8, U8X8_MSG_DISPLAY_SET_CONTRAST, value, NULL);  
+}
+
+void u8x8_RefreshDisplay(u8x8_t *u8x8)
+{
+  u8x8->display_cb(u8x8, U8X8_MSG_DISPLAY_REFRESH, 0, NULL);  
+}
+
+void u8x8_ClearDisplayWithTile(u8x8_t *u8x8, const uint8_t *buf)
+{
+  u8x8_tile_t tile;
+  uint8_t h;
+
+  tile.x_pos = 0;
+  tile.cnt = 1;
+  tile.tile_ptr = (uint8_t *)buf;		/* tile_ptr should be const, but isn't */
+  
+  h = u8x8->display_info->tile_height;
+  tile.y_pos = 0;
+  do
+  {
+    u8x8->display_cb(u8x8, U8X8_MSG_DISPLAY_DRAW_TILE, u8x8->display_info->tile_width, (void *)&tile);
+    tile.y_pos++;
+  } while( tile.y_pos < h );
+}
+
+void u8x8_ClearDisplay(u8x8_t *u8x8)
+{
+  uint8_t buf[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
+  u8x8_ClearDisplayWithTile(u8x8, buf);
+}
+
+void u8x8_FillDisplay(u8x8_t *u8x8)
+{
+  uint8_t buf[8] = { 255, 255, 255, 255, 255, 255, 255, 255 };
+  u8x8_ClearDisplayWithTile(u8x8, buf);
+}
+
+void u8x8_ClearLine(u8x8_t *u8x8, uint8_t line)
+{
+  uint8_t buf[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
+  u8x8_tile_t tile;
+  if ( line < u8x8->display_info->tile_height )
+  {
+    tile.x_pos = 0;
+    tile.y_pos = line;
+    tile.cnt = 1;
+    tile.tile_ptr = (uint8_t *)buf;		/* tile_ptr should be const, but isn't */
+    u8x8->display_cb(u8x8, U8X8_MSG_DISPLAY_DRAW_TILE, u8x8->display_info->tile_width, (void *)&tile);
+  }  
+}
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