目录

准备脚手架

修改源码

对接触摸

测试编译

测试运行

---

这一节将以一个已经编写好的 lvgl 小游戏 2048 描述如何将已经编写完成的 lvgl 程序移植到开发板上。

准备脚手架

在这之前，我们先准备基础的 LVGL 脚手架。可以直接从 lv_g2d_test 里复制过来进行修改即可。

首先我们复制源码，在 platform/thirdparty/gui/lvgl-8 源码文件夹里，把 红箭头 所指的 lv_g2d_test 的源码作为模板复制到黄箭头指向的 lv_2048 文件夹里。

如下图所示，并清理下 res 资源文件夹，

同样的，复制一份引索文件，找到 openwrt/package/thirdparty/gui/lvgl-8 并把 lv_g2d_test 复制一份重命名为 lv_2048 作为我们 2048 小游戏使用的引索。

并编辑 Makefile，修改文件名称，把 lv_g2d_test 修改为这里的 lv_2048

include $(TOPDIR)/rules.mk
include $(INCLUDE_DIR)/package.mk
include ../sunxifb.mkPKG_NAME:=lv_2048
PKG_VERSION:=8.1.0
PKG_RELEASE:=1PKG_BUILD_DIR := $(BUILD_DIR)/$(PKG_NAME)
SRC_CODE_DIR := $(LICHEE_PLATFORM_DIR)/thirdparty/gui/lvgl-8/$(PKG_NAME)
define Package/$(PKG_NAME)SECTION:=guiSUBMENU:=LittlevglCATEGORY:=GuiDEPENDS:=+LVGL8_USE_SUNXIFB_G2D:libuapi +LVGL8_USE_SUNXIFB_G2D:kmod-sunxi-g2d \+LVGL8_USE_FREETYPE:libfreetypeTITLE:=lvgl 2048 
endefPKG_CONFIG_DEPENDS := \CONFIG_LVGL8_USE_SUNXIFB_DOUBLE_BUFFER \CONFIG_LVGL8_USE_SUNXIFB_CACHE \CONFIG_LVGL8_USE_SUNXIFB_G2D \CONFIG_LVGL8_USE_SUNXIFB_G2D_ROTATEdefine Package/$(PKG_NAME)/config
endefdefine Package/$(PKG_NAME)/Default
endefdefine Package/$(PKG_NAME)/descriptiona lvgl 2048 v8.1.0
endefdefine Build/Prepare$(INSTALL_DIR) $(PKG_BUILD_DIR)/$(CP) -r $(SRC_CODE_DIR)/src $(PKG_BUILD_DIR)/$(CP) -r $(SRC_CODE_DIR)/../lvgl $(PKG_BUILD_DIR)/src/$(CP) -r $(SRC_CODE_DIR)/../lv_drivers $(PKG_BUILD_DIR)/src/
endefdefine Build/Configure
endefTARGET_CFLAGS+=-I$(PKG_BUILD_DIR)/srcifeq ($(CONFIG_LVGL8_USE_SUNXIFB_G2D),y)
TARGET_CFLAGS+=-DLV_USE_SUNXIFB_G2D_FILL \-DLV_USE_SUNXIFB_G2D_BLEND \-DLV_USE_SUNXIFB_G2D_BLIT \-DLV_USE_SUNXIFB_G2D_SCALE
endifdefine Build/Compile$(MAKE) -C $(PKG_BUILD_DIR)/src\ARCH="$(TARGET_ARCH)" \AR="$(TARGET_AR)" \CC="$(TARGET_CC)" \CXX="$(TARGET_CXX)" \CFLAGS="$(TARGET_CFLAGS)" \LDFLAGS="$(TARGET_LDFLAGS)" \INSTALL_PREFIX="$(PKG_INSTALL_DIR)" \all
endefdefine Package/$(PKG_NAME)/install$(INSTALL_DIR) $(1)/usr/bin/$(INSTALL_DIR) $(1)/usr/share/lv_2048$(INSTALL_BIN) $(PKG_BUILD_DIR)/src/$(PKG_NAME) $(1)/usr/bin/
endef$(eval $(call BuildPackage,$(PKG_NAME)))

完成脚手架的搭建后，可以 make menuconfig 里查看是否出现了 lv_2048 这个选项，选中它。

修改源码

第二步是修改源码。编辑之前复制的 main.c 文件，把不需要的 lv_g2d_test 的部分删去。保留最基础的部分。

#include "lvgl/lvgl.h"
#include "lv_drivers/display/sunxifb.h"
#include "lv_drivers/indev/evdev.h"
#include <unistd.h>
#include <pthread.h>
#include <time.h>
#include <sys/time.h>
#include <stdlib.h>
#include <stdio.h>static lv_style_t rect_style;
static lv_obj_t *rect_obj;
static lv_obj_t *canvas;int main(int argc, char *argv[]) {lv_disp_drv_t disp_drv;lv_disp_draw_buf_t disp_buf;lv_indev_drv_t indev_drv;uint32_t rotated = LV_DISP_ROT_NONE;lv_disp_drv_init(&disp_drv);/*LittlevGL init*/lv_init();/*Linux frame buffer device init*/sunxifb_init(rotated);/*A buffer for LittlevGL to draw the screen's content*/static uint32_t width, height;sunxifb_get_sizes(&width, &height);static lv_color_t *buf;buf = (lv_color_t*) sunxifb_alloc(width * height * sizeof(lv_color_t), "lv_2048");if (buf == NULL) {sunxifb_exit();printf("malloc draw buffer fail\n");return 0;}/*Initialize a descriptor for the buffer*/lv_disp_draw_buf_init(&disp_buf, buf, NULL, width * height);/*Initialize and register a display driver*/disp_drv.draw_buf = &disp_buf;disp_drv.flush_cb = sunxifb_flush;disp_drv.hor_res = width;disp_drv.ver_res = height;disp_drv.rotated = rotated;disp_drv.screen_transp = 0;lv_disp_drv_register(&disp_drv);evdev_init();lv_indev_drv_init(&indev_drv); /*Basic initialization*/indev_drv.type = LV_INDEV_TYPE_POINTER; /*See below.*/indev_drv.read_cb = evdev_read; /*See below.*//*Register the driver in LVGL and save the created input device object*/lv_indev_t *evdev_indev = lv_indev_drv_register(&indev_drv);/*Handle LitlevGL tasks (tickless mode)*/while (1) {lv_task_handler();usleep(1000);}return 0;
}/*Set in lv_conf.h as `LV_TICK_CUSTOM_SYS_TIME_EXPR`*/
uint32_t custom_tick_get(void) {static uint64_t start_ms = 0;if (start_ms == 0) {struct timeval tv_start;gettimeofday(&tv_start, NULL);start_ms = (tv_start.tv_sec * 1000000 + tv_start.tv_usec) / 1000;}struct timeval tv_now;gettimeofday(&tv_now, NULL);uint64_t now_ms;now_ms = (tv_now.tv_sec * 1000000 + tv_now.tv_usec) / 1000;uint32_t time_ms = now_ms - start_ms;return time_ms;
}

接下来则是对接 lv_lib_100ask 与 2048 小游戏，我们先下载 lv_lib_100ask 的源码，放置到 platform/thirdparty/gui/lvgl-8/lv_2048 的 src 文件夹里。并按照 lv_lib_100ask 的说明，复制一份 lv_lib_100ask_conf_template.h 到 src 目录，并改名为 lv_lib_100ask_conf.h

编辑 lv_lib_100ask_conf.h，开启整个库的引用，并配置启用 LV_USE_100ASK_2048 。为了简洁，这里删除了不需要的配置项。

/*** @file lv_lib_100ask_conf.h* Configuration file for v8.2.0**/
/** COPY THIS FILE AS lv_lib_100ask_conf.h*//* clang-format off */
#if 1 /*Set it to "1" to enable the content*/ #ifndef LV_LIB_100ASK_CONF_H
#define LV_LIB_100ASK_CONF_H#include "lv_conf.h"/******************** GENERAL SETTING*******************//********************** USAGE*********************/*2048 game*/
#define LV_USE_100ASK_2048                               1
#if LV_USE_100ASK_2048/* Matrix size*//*Do not modify*/#define  LV_100ASK_2048_MATRIX_SIZE          4/*test*/#define  LV_100ASK_2048_SIMPLE_TEST          1
#endif  #endif /*LV_LIB_100ASK_H*/#endif /*End of "Content enable"*/

再编辑 platform/thirdparty/gui/lvgl-8/lv_2048/src/lv_lib_100ask/lv_lib_100ask.h 中的版本号，修改为 (8,1,0)

之后在 main.c 里修改，对接 lv_100ask_2048_simple_test，具体如下。

（1）头文件加入 lv_lib_100ask/lv_lib_100ask.h

#include <lv_lib_100ask/lv_lib_100ask.h>

（2）在 main 函数里添加接口调用

lv_100ask_2048_simple_test();

完整的 main.c 如下

#include <unistd.h>
#include <pthread.h>
#include <time.h>
#include <sys/time.h>
#include <stdlib.h>
#include <stdio.h>#include "lvgl/lvgl.h"
#include "lv_drivers/display/sunxifb.h"
#include "lv_drivers/indev/evdev.h"#include "lv_lib_100ask/lv_lib_100ask.h"  // 引用头文件static lv_style_t rect_style;
static lv_obj_t *rect_obj;
static lv_obj_t *canvas;int main(int argc, char *argv[]) {lv_disp_drv_t disp_drv;lv_disp_draw_buf_t disp_buf;lv_indev_drv_t indev_drv;uint32_t rotated = LV_DISP_ROT_NONE;lv_disp_drv_init(&disp_drv);/*LittlevGL init*/lv_init();/*Linux frame buffer device init*/sunxifb_init(rotated);/*A buffer for LittlevGL to draw the screen's content*/static uint32_t width, height;sunxifb_get_sizes(&width, &height);static lv_color_t *buf;buf = (lv_color_t*) sunxifb_alloc(width * height * sizeof(lv_color_t), "lv_nes");if (buf == NULL) {sunxifb_exit();printf("malloc draw buffer fail\n");return 0;}/*Initialize a descriptor for the buffer*/lv_disp_draw_buf_init(&disp_buf, buf, NULL, width * height);/*Initialize and register a display driver*/disp_drv.draw_buf = &disp_buf;disp_drv.flush_cb = sunxifb_flush;disp_drv.hor_res = width;disp_drv.ver_res = height;disp_drv.rotated = rotated;disp_drv.screen_transp = 0;lv_disp_drv_register(&disp_drv);evdev_init();lv_indev_drv_init(&indev_drv); /*Basic initialization*/indev_drv.type = LV_INDEV_TYPE_POINTER; /*See below.*/indev_drv.read_cb = evdev_read; /*See below.*//*Register the driver in LVGL and save the created input device object*/lv_indev_t *evdev_indev = lv_indev_drv_register(&indev_drv);lv_100ask_2048_simple_test();  // 调用 2048 小游戏/*Handle LitlevGL tasks (tickless mode)*/while (1) {lv_task_handler();usleep(1000);}return 0;
}/*Set in lv_conf.h as `LV_TICK_CUSTOM_SYS_TIME_EXPR`*/
uint32_t custom_tick_get(void) {static uint64_t start_ms = 0;if (start_ms == 0) {struct timeval tv_start;gettimeofday(&tv_start, NULL);start_ms = (tv_start.tv_sec * 1000000 + tv_start.tv_usec) / 1000;}struct timeval tv_now;gettimeofday(&tv_now, NULL);uint64_t now_ms;now_ms = (tv_now.tv_sec * 1000000 + tv_now.tv_usec) / 1000;uint32_t time_ms = now_ms - start_ms;return time_ms;
}

然后就是 Makefile 修改，增加一个 lv_lib_100ask 的 SRC 引用。

include lv_lib_100ask/lv_lib_100ask.mk

顺便也把 BIN 改为 lv_2048 ，完整的 Makefile 如下

#
# Makefile
#
CC ?= gcc
LVGL_DIR_NAME ?= lvgl
LVGL_DIR ?= ${shell pwd}
CFLAGS ?= -O3 -g0 -I$(LVGL_DIR)/ -Wall -Wshadow -Wundef -Wmissing-prototypes -Wno-discarded-qualifiers -Wall -Wextra -Wno-unused-function -Wno-error=strict-prototypes -Wpointer-arith -fno-strict-aliasing -Wno-error=cpp -Wuninitialized -Wmaybe-uninitialized -Wno-unused-parameter -Wno-missing-field-initializers -Wtype-limits -Wsizeof-pointer-memaccess -Wno-format-nonliteral -Wno-cast-qual -Wunreachable-code -Wno-switch-default -Wreturn-type -Wmultichar -Wformat-security -Wno-ignored-qualifiers -Wno-error=pedantic -Wno-sign-compare -Wno-error=missing-prototypes -Wdouble-promotion -Wclobbered -Wdeprecated -Wempty-body -Wtype-limits -Wshift-negative-value -Wstack-usage=2048 -Wno-unused-value -Wno-unused-parameter -Wno-missing-field-initializers -Wuninitialized -Wmaybe-uninitialized -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers -Wtype-limits -Wsizeof-pointer-memaccess -Wno-format-nonliteral -Wpointer-arith -Wno-cast-qual -Wmissing-prototypes -Wunreachable-code -Wno-switch-default -Wreturn-type -Wmultichar -Wno-discarded-qualifiers -Wformat-security -Wno-ignored-qualifiers -Wno-sign-compare
LDFLAGS ?= -lm
BIN = lv_2048#Collect the files to compile
SRCDIRS   =  $(shell find . -maxdepth 1 -type d)
MAINSRC = $(foreach dir,$(SRCDIRS),$(wildcard $(dir)/*.c))include $(LVGL_DIR)/lvgl/lvgl.mk
include $(LVGL_DIR)/lv_drivers/lv_drivers.mk
include lv_lib_100ask/lv_lib_100ask.mkOBJEXT ?= .oAOBJS = $(ASRCS:.S=$(OBJEXT))
COBJS = $(CSRCS:.c=$(OBJEXT))MAINOBJ = $(MAINSRC:.c=$(OBJEXT))SRCS = $(ASRCS) $(CSRCS) $(MAINSRC)
OBJS = $(AOBJS) $(COBJS)## MAINOBJ -> OBJFILESall: default%.o: %.c@$(CC)  $(CFLAGS) -c $< -o $@@echo "CC $<"default: $(AOBJS) $(COBJS) $(MAINOBJ)$(CC) -o $(BIN) $(MAINOBJ) $(AOBJS) $(COBJS) $(LDFLAGS)clean: rm -f $(BIN) $(AOBJS) $(COBJS) $(MAINOBJ)

对接触摸

做了以上操作，可能会发现触摸没有反应，这是因为触摸绑定的 event 事件号不对，默认的绑定是 event3 而查阅启动 log 可知，开发板的触摸屏对接的是 event0

这时需要修改绑定的 event 事件号，其配置文件在 lv_drv_conf.h 内：

这里将 event3 改为 event0 即可

#  define EVDEV_NAME   "/dev/input/event0"

当然除了这样的方法，另外也可以用命令生成软连接 touchscreen，就会直接以 touchscreen 为触摸节点，方便调试:

ln -s /dev/input/eventX /dev/input/touchscreen

测试编译

修改好了，希望单独编译这个包测试下而不编译完整的 SDK。可以这样做：

（1）确保已经 source build/envsetup.sh 并已经 lunch

（2）在任意文件夹下执行命令 mmo lv_2048 -B

其中 mmo 的意思是 单独编译一个 openWrt 软件包，后面的 lv_2048 是软件包名。-B 参数是先 clean 再编译，不加这个参数就是直接编译了。

测试运行

编译打包后，到开发板上使用 lv_2048 即可运行