这篇文章主要描述我们如何在litos工程中,自定义一个demo出来。
1.环境及MCU 小熊派(IOT开发板)+linux环境+litos
提示:以下是本篇文章正文内容,下面案例可供参考
1.如果你想完成自定义demo,首先你需要去看一下其它demo中是如何定义这个demo的。比如说Kconfig,makefile,需要什么文件等等。
2.你需要对makefile,Kconfig这种文件语法懂一些。
3.自己要会编译下载。(不会的话,参考我的一篇环境搭建的文章,里面包含了如何下载程序)
DEMOS_JSON_INCLUDE := \
-I $(LITEOSTOPDIR)/demos/utility/cjson
config LOSCFG_DEMOS_CJSON
bool "Enable cJson Demo"
default n
help
Answer y to enable json demo.
include $(LITEOSTOPDIR)/config.mk
include $(LITEOSTOPDIR)/demos/utility/cjson/json-c.mk
MODULE_NAME := cjson_demo
JSON_DEMO_SRCS = $(wildcard *.c)
JSON_DEMO_INCLUDE := \
-I $(LITEOSTOPDIR)/lib/libc/include \
-I $(LITEOSTOPDIR)/components/lib/cjson/$(CJSON_VERSION)\
-I $(LITEOSTOPDIR)/demos/utility/cjson
LOCAL_INCLUDE := $(JSON_DEMO_INCLUDE) $(COMPONENTS_JSON_INCLUDE)
LOCAL_SRCS := $(subst $(CURDIR)/,, $(JSON_DEMO_SRCS))
LOCAL_EXT_FLAG := -Wno-error -fstack-protector-strong
LOCAL_FLAGS := $(LOCAL_EXT_FLAG) $(LOCAL_INCLUDE)
include $(MODULE)
(1)找到utility目录下的Makefile
(2)Makefile添加这条数据
(3)同理,此目录中找到Kconfig文件,并添加如下箭头数据
(3)找到utility.mk文件,添加如下箭头数据
(1)使能cjson库
(2)使能cjson_demo
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "cJSON.h"
#include "los_task.h"
#define CJSON_TASK_PRIORITY 3
#define CJSON_TASK_STACK_SIZE 0x1000
STATIC UINT32 g_demoTaskId;
/* Used by some code below as an example datatype. */
struct record
{
const char *precision;
double lat;
double lon;
const char *address;
const char *city;
const char *state;
const char *zip;
const char *country;
};
/* Create a bunch of objects as demonstration. */
static int print_preallocated(cJSON *root)
{
/* declarations */
char *out = NULL;
char *buf = NULL;
char *buf_fail = NULL;
size_t len = 0;
size_t len_fail = 0;
/* formatted print */
out = cJSON_Print(root);
/* create buffer to succeed */
/* the extra 5 bytes are because of inaccuracies when reserving memory */
len = strlen(out) + 5;
buf = (char*)malloc(len);
if (buf == NULL)
{
printf("Failed to allocate memory.\n");
exit(1);
}
/* create buffer to fail */
len_fail = strlen(out);
buf_fail = (char*)malloc(len_fail);
if (buf_fail == NULL)
{
printf("Failed to allocate memory.\n");
exit(1);
}
/* Print to buffer */
if (!cJSON_PrintPreallocated(root, buf, (int)len, 1)) {
printf("cJSON_PrintPreallocated failed!\n");
if (strcmp(out, buf) != 0) {
printf("cJSON_PrintPreallocated not the same as cJSON_Print!\n");
printf("cJSON_Print result:\n%s\n", out);
printf("cJSON_PrintPreallocated result:\n%s\n", buf);
}
free(out);
free(buf_fail);
free(buf);
return -1;
}
/* success */
printf("%s\n", buf);
/* force it to fail */
if (cJSON_PrintPreallocated(root, buf_fail, (int)len_fail, 1)) {
printf("cJSON_PrintPreallocated failed to show error with insufficient memory!\n");
printf("cJSON_Print result:\n%s\n", out);
printf("cJSON_PrintPreallocated result:\n%s\n", buf_fail);
free(out);
free(buf_fail);
free(buf);
return -1;
}
free(out);
free(buf_fail);
free(buf);
return 0;
}
/* Create a bunch of objects as demonstration. */
static void create_objects(void)
{
/* declare a few. */
cJSON *root = NULL;
cJSON *fmt = NULL;
cJSON *img = NULL;
cJSON *thm = NULL;
cJSON *fld = NULL;
int i = 0;
/* Our "days of the week" array: */
const char *strings[7] =
{
"Sunday",
"Monday",
"Tuesday",
"Wednesday",
"Thursday",
"Friday",
"Saturday"
};
/* Our matrix: */
int numbers[3][3] =
{
{
0, -1, 0},
{
1, 0, 0},
{
0 ,0, 1}
};
/* Our "gallery" item: */
int ids[4] = {
116, 943, 234, 38793 };
/* Our array of "records": */
struct record fields[2] =
{
{
"zip",
37.7668,
-1.223959e+2,
"",
"SAN FRANCISCO",
"CA",
"94107",
"US"
},
{
"zip",
37.371991,
-1.22026e+2,
"",
"SUNNYVALE",
"CA",
"94085",
"US"
}
};
volatile double zero = 0.0;
/* Here we construct some JSON standards, from the JSON site. */
printf("Version: %s\n", cJSON_Version());
/* Our "Video" datatype: */
root = cJSON_CreateObject();
cJSON_AddItemToObject(root, "name", cJSON_CreateString("Jack (\"Bee\") Nimble"));
cJSON_AddItemToObject(root, "format", fmt = cJSON_CreateObject());
cJSON_AddStringToObject(fmt, "type", "rect");
cJSON_AddNumberToObject(fmt, "width", 1920);
cJSON_AddNumberToObject(fmt, "height", 1080);
cJSON_AddFalseToObject (fmt, "interlace");
cJSON_AddNumberToObject(fmt, "frame rate", 24);
/* Print to text */
if (print_preallocated(root) != 0) {
cJSON_Delete(root);
exit(EXIT_FAILURE);
}
cJSON_Delete(root);
printf("1333331111\n");
/* Our "days of the week" array: */
root = cJSON_CreateStringArray(strings, 7);
if (print_preallocated(root) != 0) {
cJSON_Delete(root);
exit(EXIT_FAILURE);
}
cJSON_Delete(root);
/* Our matrix: */
root = cJSON_CreateArray();
for (i = 0; i < 3; i++)
{
cJSON_AddItemToArray(root, cJSON_CreateIntArray(numbers[i], 3));
}
/* cJSON_ReplaceItemInArray(root, 1, cJSON_CreateString("Replacement")); */
if (print_preallocated(root) != 0) {
cJSON_Delete(root);
exit(EXIT_FAILURE);
}
cJSON_Delete(root);
/* Our "gallery" item: */
root = cJSON_CreateObject();
cJSON_AddItemToObject(root, "Image", img = cJSON_CreateObject());
cJSON_AddNumberToObject(img, "Width", 800);
cJSON_AddNumberToObject(img, "Height", 600);
cJSON_AddStringToObject(img, "Title", "View from 15th Floor");
cJSON_AddItemToObject(img, "Thumbnail", thm = cJSON_CreateObject());
cJSON_AddStringToObject(thm, "Url", "http:/*www.example.com/image/481989943");
cJSON_AddNumberToObject(thm, "Height", 125);
cJSON_AddStringToObject(thm, "Width", "100");
cJSON_AddItemToObject(img, "IDs", cJSON_CreateIntArray(ids, 4));
if (print_preallocated(root) != 0) {
cJSON_Delete(root);
exit(EXIT_FAILURE);
}
cJSON_Delete(root);
/* Our array of "records": */
root = cJSON_CreateArray();
for (i = 0; i < 2; i++)
{
cJSON_AddItemToArray(root, fld = cJSON_CreateObject());
cJSON_AddStringToObject(fld, "precision", fields[i].precision);
cJSON_AddNumberToObject(fld, "Latitude", fields[i].lat);
cJSON_AddNumberToObject(fld, "Longitude", fields[i].lon);
cJSON_AddStringToObject(fld, "Address", fields[i].address);
cJSON_AddStringToObject(fld, "City", fields[i].city);
cJSON_AddStringToObject(fld, "State", fields[i].state);
cJSON_AddStringToObject(fld, "Zip", fields[i].zip);
cJSON_AddStringToObject(fld, "Country", fields[i].country);
}
/* cJSON_ReplaceItemInObject(cJSON_GetArrayItem(root, 1), "City", cJSON_CreateIntArray(ids, 4)); */
if (print_preallocated(root) != 0) {
cJSON_Delete(root);
exit(EXIT_FAILURE);
}
cJSON_Delete(root);
root = cJSON_CreateObject();
cJSON_AddNumberToObject(root, "number", 1.0 / zero);
if (print_preallocated(root) != 0) {
cJSON_Delete(root);
exit(EXIT_FAILURE);
}
cJSON_Delete(root);
}
int CJSON_CDECL cjson_test(void)
{
/* print the version */
UINT32 ret;
TSK_INIT_PARAM_S taskInitParam = {
0};
taskInitParam.usTaskPrio = CJSON_TASK_PRIORITY;
taskInitParam.pcName = "CJSONTask";
taskInitParam.pfnTaskEntry = (TSK_ENTRY_FUNC)create_objects;
taskInitParam.uwStackSize = CJSON_TASK_STACK_SIZE;
taskInitParam.uwResved = LOS_TASK_STATUS_DETACHED;
ret = LOS_TaskCreate(&g_demoTaskId, &taskInitParam);
if (ret != LOS_OK) {
printf("Create libevent demo task failed.\n");
}
/* Now some samplecode for building objects concisely: */
// create_objects();
return 0;
}
#ifndef _CJSON_DEMO_H
#define _CJSON_DEMO_H
#include "los_typedef.h"
#ifdef __cplusplus
#if __cplusplus
extern "C" {
#endif /* __cplusplus */
#endif /* __cplusplus */
int cjson_test(void);
#ifdef __cplusplus
#if __cplusplus
}
#endif /* __cplusplus */
#endif /* __cplusplus */
#endif /* _CJSON_DEMO_H */
添加头文件
添加调用demo的入口
(1)编译后现象
(2)下载 ,不会下载的看我上一篇关于litos文章
我只截取了一部分内容,如果有什么不会的,留言,我会回复。觉得ok,点个赞吧。
文章浏览阅读2.5w次,点赞6次,收藏50次。官方解释是,docker 容器是机器上的沙盒进程,它与主机上的所有其他进程隔离。所以容器只是操作系统中被隔离开来的一个进程,所谓的容器化,其实也只是对操作系统进行欺骗的一种语法糖。_docker菜鸟教程
文章浏览阅读5.7k次,点赞3次,收藏14次。该如何避免的,今天小编给大家推荐两个下载Windows系统官方软件的资源网站,可以杜绝软件捆绑等行为。该站提供了丰富的Windows官方技术资源,比较重要的有MSDN技术资源文档库、官方工具和资源、应用程序、开发人员工具(Visual Studio 、SQLServer等等)、系统镜像、设计人员工具等。总的来说,这两个都是非常优秀的Windows系统镜像资源站,提供了丰富的Windows系统镜像资源,并且保证了资源的纯净和安全性,有需要的朋友可以去了解一下。这个非常实用的资源网站的创建者是国内的一个网友。_msdn我告诉你
文章浏览阅读1.2k次。vue2封装对话框el-dialog组件_
文章浏览阅读4.7k次,点赞5次,收藏6次。MFC 文本框换行 标签: it mfc 文本框1.将Multiline属性设置为True2.换行是使用"\r\n" (宽字符串为L"\r\n")3.如果需要编辑并且按Enter键换行,还要将 Want Return 设置为 True4.如果需要垂直滚动条的话将Vertical Scroll属性设置为True,需要水平滚动条的话将Horizontal Scroll属性设_c++ mfc同一框内输入二行怎么换行
文章浏览阅读832次。检查Linux是否是否开启所需端口,默认为6379,若未打开,将其开启:以root用户执行iptables -I INPUT -p tcp --dport 6379 -j ACCEPT如果还是未能解决,修改redis.conf,修改主机地址:bind 192.168.85.**;然后使用该配置文件,重新启动Redis服务./redis-server redis.conf..._redis-server doesn't support auth command or ismisconfigured. try
文章浏览阅读4.9k次。济大数电实验报告_数据选择器及其应用
文章浏览阅读236次。1研究内容消费在生产中占据十分重要的地位,是生产的最终目的和动力,是保持省内经济稳定快速发展的核心要素。预测河南省社会消费品零售总额,是进行宏观经济调控和消费体制改变创新的基础,是河南省内人民对美好的全面和谐社会的追求的要求,保持河南省经济稳定和可持续发展具有重要意义。本文建立灰色预测模型,利用MATLAB软件,预测出2019年~2023年河南省社会消费品零售总额预测值分别为21881...._灰色预测模型用什么软件
文章浏览阅读1.2k次。12.4-在Qt中使用Log4Qt输出Log文件,看这一篇就足够了一、为啥要使用第三方Log库,而不用平台自带的Log库二、Log4j系列库的功能介绍与基本概念三、Log4Qt库的基本介绍四、将Log4qt组装成为一个单独模块五、使用配置文件的方式配置Log4Qt六、使用代码的方式配置Log4Qt七、在Qt工程中引入Log4Qt库模块的方法八、获取示例中的源代码一、为啥要使用第三方Log库,而不用平台自带的Log库首先要说明的是,在平时开发和调试中开发平台自带的“打印输出”已经足够了。但_log4qt
文章浏览阅读786次。全局观思维模型,一个教我们由点到线,由线到面,再由面到体,不断的放大格局去思考问题的思维模型。_计算机中对于全局观的
文章浏览阅读330次。一、CountDownLatch介绍CountDownLatch采用减法计算;是一个同步辅助工具类和CyclicBarrier类功能类似,允许一个或多个线程等待,直到在其他线程中执行的一组操作完成。二、CountDownLatch俩种应用场景: 场景一:所有线程在等待开始信号(startSignal.await()),主流程发出开始信号通知,既执行startSignal.countDown()方法后;所有线程才开始执行;每个线程执行完发出做完信号,既执行do..._countdownluach于cyclicbarrier的用法
文章浏览阅读508次。Prometheus 算是一个全能型选手,原生支持容器监控,当然监控传统应用也不是吃干饭的,所以就是容器和非容器他都支持,所有的监控系统都具备这个流程,_-自动化监控系统prometheus&grafana实战
文章浏览阅读4.7k次。输入关键字,可以通过键盘的搜索按钮完成搜索功能。_react search