====== Building LiteOS With Keil ======

===== - 摘要 =====
Porting LiteOS to NRF52832, using Keil to build.

本文使用LiteOS的版本为 <color #ed1c24>V200R001C50B037_20181226</color>，获取方式如下：
  git clone https://gitee.com/LiteOS/LiteOS.git
  git checkout tag_LiteOS_V200R001C50B037_20181226

===== - 准备一个裸机工程 =====

<color #00a2e8>使用SDK中的例子工程，nRF5_SDK_17.0.2_d674dde\examples\peripheral\blinky :</color>

  * 复制工程配置文件 blinky_pca10040.uvprojx (位于目录nRF5_SDK_17.0.2_d674dde\examples\peripheral\blinky\pca10040\blank\arm5_no_packs)
  * 复制代码文件 main.c (位于目录E:\nrfProjects\nRF5_SDK_17.0.2_d674dde\examples\peripheral\blinky)
  * 复制SDK配置文件 sdk_config.h (位于目录E:\nRF5_SDK_17.0.2_d674dde\examples\peripheral\blinky\pca10040\blank\config)
  * 链接（或复制）SDK到工程更目录（mklink /D nRF5_SDK_17.0.2_d674dde ..\nRF5_SDK_17.0.2_d674dde）
  * 在Keil中打开工程（可能会缺少工具包，跳过，在软件内设置或安装工具包）
   
<color #00a2e8>工程经过拷贝后，路径发生已改变，需要重新设置:</color>

  * 代码文件路径(直接在工程配置文件.uvprojx中批量修改)
  * 修改编译参数中的头文件搜索路径(否侧缺失头文件报错)
  * 修改调试器（根据实际使用的调试器设置，例如：J-LINK，SW模式）
  * 编译、加载运行
  * 4个LED交替点亮/熄灭

裸机工程准备完毕。

===== - *准备打印输出端口 =====

<color #00a2e8>使用 RTT 作为打印输出端口 :</color>

  * 链接(或复制)RTT代码包到当前工程(mklink /D RTT ..\SEGGER_RTT_V765b)
  * 添加代码文件 SEGGER_RTT.c， SEGGER_RTT_printf (路径: RTT\RTT)
  * 添加头文件搜索目录 ( RTT\RTT, RTT\Config)
  * 测试打印端口，添加打印代码
<code c>
#include "SEGGER_RTT.h"
...
...
SEGGER_RTT_WriteString(0, "SEGGER Real-Time-Terminal For LiteOS Builder\r\n\r\n");
</code>

^ 模块      ^ 根路径                                         ^ 目录              ^ 文件                                           ^ 说明 ^
| arch    | arch\arm\arm-m                              | cortex-m4\keil  | los_dispatch_keil.S                          | |
| :::     | :::                                         | include         | los_exc.h  los_hw.h los_hw_tick.h los_hwi.h  | |
| :::     | :::                                         | src             | los_hw.c                                     | |
| :::     | :::                                         | :::             | los_hw_tick.c                                | |
| :::     | :::                                         | :::             | los_hwi.c                                    | |
| kernel  | kernel                                      || los_init.c                                                    | |
| :::     | kernel                                      | base\core               | *                                    | |
| :::     | :::                                         | base\ipc                | *                                    | |
| :::     | :::                                         | base\mem\bestfit_little | *                                    | |
| :::     | :::                                         | base\mem\membox         | *                                    | |
| :::     | :::                                         | base\misc               | *                                    | |
| :::     | :::                                         | base\om                 | *                                    | |
| :::     | :::                                         | extended\tickless       | *                                    | |
| config  | targets\Cloud_STM32F429IGTx_FIRE\OS_CONFIG                   || target_config.h                              | 1. 复制所有文件用以建立新的硬件版本（例如targets\NRF52）\\ 2. 修改target_config.h中芯片定义文件引用：#include "stm32f4xx.h" --> #include "nrf52.h" \\ 3. 不接管中断，修改target_config.h， #define LOSCFG_PLATFORM_HWI                    NO  |
| :::     | :::                                                          | :::             | los_printf.h                                 | :::                                                                                                                                                                                                  |
| :::     | :::                                                          | :::             | los_builddef.h                               | :::                                                                                                                                                                                                  |

===== - 代码修改 =====

^ 文件 ^ 修改内容 ^ 说明 ^
|target_config.h| #define LOSCFG_PLATFORM_HWI   YES | 改为  #define LOSCFG_PLATFORM_HWI   NO, LiteOS不接管中断 |
|:::| #include "stm32f4xx.h" | 改为#include "nrf52.h"，使用NRF的器件定义|
|los_printf.h|添加 \\ #include "SEGGER_RTT.h" \\ #define printf(fmt,args...) SEGGER_RTT_printf(0,fmt, ##args) | 通过RTT实现LiteOS打印输出 |


修改 main.c，测试建立任务和调度任务。

<code c main.c>
#include <stdbool.h>
#include <stdint.h>
#include "nrf_delay.h"
#include "SEGGER_RTT.h"
#include "boards.h"

#include "los_sys.h"
#include "los_task.h"

#define __HEAP_SIZE__		(16384)
uint8_t _heap[__HEAP_SIZE__];
uint32_t __LOS_HEAP_ADDR_START__;
uint32_t __LOS_HEAP_ADDR_END__;

void* led_task(UINT32 arg)
{
	for(;;)
	{
		if( arg < 4 ) bsp_board_led_invert(arg);
		LOS_TaskDelay(1000);
	}
}

UINT32 led1_task_handle;
UINT32 led2_task_handle;

int main(void)
{
	TSK_INIT_PARAM_S task_param;
	TSK_INIT_PARAM_S task_param2;	
	
	__LOS_HEAP_ADDR_START__ = (UINT32)_heap;
	__LOS_HEAP_ADDR_END__ = __LOS_HEAP_ADDR_START__ + __HEAP_SIZE__ -1;	
	
	SEGGER_RTT_WriteString(0, "SEGGER Real-Time-Terminal For LiteOS Builder\r\n\r\n");
	
	/* Configure board. */
	bsp_board_init(BSP_INIT_LEDS);

	uint32_t retcd;
	retcd = LOS_KernelInit();
	if( retcd == LOS_OK ) {
		PRINT_EMG("Initialize LiteOS Kernel successful!\r\n");
	}
	else {
		PRINT_ERR("Initialize LiteOS Kernel failed!\r\n");
	}
		
	task_param.pcName = "led1_task";
	task_param.pfnTaskEntry = led_task;
	task_param.uwStackSize = 512;
	task_param.usTaskPrio = 4;
	task_param.uwArg = 0;
	retcd = LOS_TaskCreate(&led1_task_handle, &task_param);
	
	if( retcd == LOS_OK) {
		PRINT_EMG("Create led1 task successful!\r\n");
	}
	else {
		PRINT_ERR("Create led1 task failed!\r\n");
	}
	
	
	task_param2.pcName = "led2_task";
	task_param2.pfnTaskEntry = led_task;
	task_param2.uwStackSize = 512;
	task_param2.usTaskPrio = 4;
	task_param2.uwArg = 3;
	
	retcd = LOS_TaskCreate(&led2_task_handle, &task_param2);
	
	if( retcd == LOS_OK) {
		PRINT_EMG("Create led2 task successful!\r\n");
	}
	else {
		PRINT_ERR("Create led2 task failed!\r\n");
	}
	
	LOS_Start();	
	
	/* Toggle LEDs. */
	while (true) {
		for (int i = 0; i < LEDS_NUMBER; i++) {
			bsp_board_led_invert(i);
			nrf_delay_ms(500);
		}
	}
}



</code>