diff -Nuar lvgl-8.0.2/CMakeLists.txt lvgl-8.0.2-imx6ull/CMakeLists.txt
--- lvgl-8.0.2/CMakeLists.txt	2021-07-16 23:40:51.000000000 +0800
+++ lvgl-8.0.2-imx6ull/CMakeLists.txt	2021-09-27 22:30:20.360008641 +0800
@@ -1,3 +1,7 @@
+
+set(CMAKE_C_COMPILER "/opt/buildroot/cortex-a7/bin/arm-linux-gcc")
+include_directories(..)
+
 if(ESP_PLATFORM)
 
 file(GLOB_RECURSE SOURCES src/*.c)
diff -Nuar lvgl-8.0.2/lv_conf_template.h lvgl-8.0.2-imx6ull/lv_conf_template.h
--- lvgl-8.0.2/lv_conf_template.h	2021-07-16 23:40:51.000000000 +0800
+++ lvgl-8.0.2-imx6ull/lv_conf_template.h	2021-09-27 22:33:47.448012614 +0800
@@ -7,7 +7,7 @@
  * COPY THIS FILE AS `lv_conf.h` NEXT TO the `lvgl` FOLDER
  */
 
-#if 0 /*Set it to "1" to enable content*/
+#if 1 /*Set it to "1" to enable content*/
 
 #ifndef LV_CONF_H
 #define LV_CONF_H
@@ -21,7 +21,7 @@
  *====================*/
 
 /*Color depth: 1 (1 byte per pixel), 8 (RGB332), 16 (RGB565), 32 (ARGB8888)*/
-#define LV_COLOR_DEPTH     32
+#define LV_COLOR_DEPTH     16
 
 /*Swap the 2 bytes of RGB565 color. Useful if the display has a 8 bit interface (e.g. SPI)*/
 #define LV_COLOR_16_SWAP   0
@@ -42,7 +42,7 @@
 #define LV_MEM_CUSTOM      0
 #if LV_MEM_CUSTOM == 0
 /*Size of the memory available for `lv_mem_alloc()` in bytes (>= 2kB)*/
-#  define LV_MEM_SIZE    (32U * 1024U)          /*[bytes]*/
+#  define LV_MEM_SIZE    (128U * 1024U)          /*[bytes]*/

 /*Set an address for the memory pool instead of allocating it as a normal array. Can be in external SRAM too.*/
 #  define LV_MEM_ADR          0     /*0: unused*/
@@ -68,9 +68,10 @@
 
 /*Use a custom tick source that tells the elapsed time in milliseconds.
  *It removes the need to manually update the tick with `lv_tick_inc()`)*/
-#define LV_TICK_CUSTOM     0
+#define LV_TICK_CUSTOM     1
 #if LV_TICK_CUSTOM
-#define LV_TICK_CUSTOM_INCLUDE  "Arduino.h"         /*Header for the system time function*/
+extern uint32_t millis(void);
+#define LV_TICK_CUSTOM_INCLUDE      <stdint.h>      /*Header for the system time function*/
 #define LV_TICK_CUSTOM_SYS_TIME_EXPR (millis())     /*Expression evaluating to current system time in ms*/
 #endif   /*LV_TICK_CUSTOM*/
 
@@ -137,7 +138,7 @@
  *-----------*/
 
 /*Enable the log module*/
-#define LV_USE_LOG      0
+#define LV_USE_LOG      1
 #if LV_USE_LOG
 
 /*How important log should be added:
@@ -151,7 +152,7 @@
 
 /*1: Print the log with 'printf';
  *0: User need to register a callback with `lv_log_register_print_cb()`*/
-#  define LV_LOG_PRINTF   0
+#  define LV_LOG_PRINTF   1
 
 /*Enable/disable LV_LOG_TRACE in modules that produces a huge number of logs*/
 #  define LV_LOG_TRACE_MEM            1
@@ -262,13 +263,13 @@
 
 /*Montserrat fonts with ASCII range and some symbols using bpp = 4
  *https://fonts.google.com/specimen/Montserrat*/
-#define LV_FONT_MONTSERRAT_8     0
-#define LV_FONT_MONTSERRAT_10    0
-#define LV_FONT_MONTSERRAT_12    0
+#define LV_FONT_MONTSERRAT_8     1
+#define LV_FONT_MONTSERRAT_10    1
+#define LV_FONT_MONTSERRAT_12    1
 #define LV_FONT_MONTSERRAT_14    1
-#define LV_FONT_MONTSERRAT_16    0
-#define LV_FONT_MONTSERRAT_18    0
-#define LV_FONT_MONTSERRAT_20    0
+#define LV_FONT_MONTSERRAT_16    1
+#define LV_FONT_MONTSERRAT_18    1
+#define LV_FONT_MONTSERRAT_20    1
 #define LV_FONT_MONTSERRAT_22    0
 #define LV_FONT_MONTSERRAT_24    0
 #define LV_FONT_MONTSERRAT_26    0