嵌入式 linux 下通用 console（控制台）的实现

嵌入式

嵌入式 linux 下通用 console（控制台）的实现

2019-07-12 14:41发布生成海报

站内文章 / 嵌入式Linux

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前言：当我们使用嵌入式linux 进行开发时，kernel 跑起来之后，我们希望能通过串口（标准输入、输出），在应用程序正在运行的过程中，进行一些调试工作，例如，对CPU一些寄存进行调整，以观测调整以后的结果，并且，当我们无法把我们的应用程序放在后台运行，那么我们就需要实现一个基础的控制台。下文中的控制台，虽然简单，但完备的支持上下左右 backspace del 常用控制台操作，使用上下键可以浏览已经输入过的命令（类似 doskey 这样的功能），支持光标左右移动修改命令一般我们在 main 函数最后都会做 while(TRUE) sleep(1000) 这样阻塞住主线程，用这个控制台的实现，替换这个过程，则应用程序可增加控制台应用功能，各部分的具体实现如下：调用代码(main.c)：控制台头文件(app_console.h) 控制台C文件(app_console.c)

#include "app_console.h"
#include "ctype.h"
#include "unistd.h"
#include "app_test.h"

// 说明
// read write 使用的是 POSIX 的标准文件读写函数
// unistd.h 包含了 STDIN_FILENO 等文件描述符的定义
// ctype.h 包含了 isprint 函数的声明
// 经过仔细考虑，决定不支持 ESC 键，因为ESC 键的键值为 0x1b 与 上下左右的键值重复
// 但可以考虑按2下ESC清除本行输入
// 对不可打印字符的处理仅限于以下已经列出的宏定义

// change:
// 放弃对 double ESC 的支持,因为可能出现按了 ESC 又按了 方向键 的情况
// 则用户输入编码为 '/x1b' '/x1b' '[' 'A' (按了ESC 又按了上键)

// change:
// 为了将应用与控制台应用剥离，则将 #define MAX_CMD_LEN 512 房到 app_test.h 中定义
// 二维数组作为参数进行传递时，需要明确第二个维度的大小，否则编译器无法正确定位地址

#define KEY_BACKSPACE    '/x08'    // back space 
#define KEY_DEL          '/x7F'    // del 
#define KEY_ENTER        '/x0A'    // 回车

// 以下为 0x1b 开头的键值
//#define KEY_DOUBLEESC    "/x1B/x1B"// ESC
//#define KEY_ARROW_UP     "/x1B[A"  // 上
//#define KEY_ARROW_DOWN   "/x1B[B"  // 下
//#define KEY_ARROW_LEFT   "/x1B[D"  // 左
//#define KEY_ARROW_RIGHT  "/x1B[C"  // 右

typedef enum 
{
	WKS_WAIT,
	WKS_RECV1B,
	WKS_UDLR,
}T_WaitKeyState;

#define MAX_CMD_HISTORY 32
#define MAX_PAR_COUNT 16

static char szPrompt[] = {"TR_Console> "};

static T_WaitKeyState waitKeyState = WKS_WAIT;
static char szCmdHistory[MAX_CMD_HISTORY][MAX_CMD_LEN];
static char szCmdNow[MAX_CMD_LEN] = {0};

static UINT32 nCmdIndex = 0;
static UINT32 nCmdCursor = 0;
static UINT32 nCmdInputCount = 0;
static UINT32 nCmdInputCursor = 0;

static void App_Console_ParseCmd(const char* pCmd);

static UINT32 App_Console_ReadInput(char *input)
{
	U32    nRead=0;
	struct pollfd p;
	struct termio term,term_old;

/* Get control of the terminal */
	ioctl(STDIN_FILENO,TCGETA,(void *)&term);
	term_old = term;
	term.c_lflag &= ~ICANON;
	term.c_lflag &= ~ECHO;
	ioctl(STDIN_FILENO,TCSETAW,(void *)&term);

/* Get event we want to know */
	p.fd     = STDIN_FILENO;
	p.events = POLLIN;

/* If we receive one thing, get the byte now */
	if (poll(&p,1,-1)>0)
	{
		if (p.revents==POLLIN)
		{
			nRead=read(STDIN_FILENO,input,1);
		}
	}
	/* Purge the byte */
	/* tcflush(0,TCIOFLUSH); */
	/* Leave control */
	ioctl(STDIN_FILENO,TCSETAW,(void *)&term_old);
	return(nRead);
}

static void App_Console_BSChar()
{
	char szTemp[3];
	szTemp[0] = '/b';
	szTemp[1] = ' ';
	szTemp[2] = '/b';
	write(STDOUT_FILENO,szTemp,3);	
}

static void App_Console_OnPrintChar(char input)
{
	if(nCmdInputCount == MAX_CMD_LEN) return;

if(nCmdInputCursor < nCmdInputCount) // 光标不在末尾
	{
		char szTemp[MAX_CMD_LEN] = {0};
		char* pCmd = szCmdNow;
		int nBackCount = nCmdInputCount-nCmdInputCursor;
		szTemp[0] = input;
		memcpy(&szTemp[1],&pCmd[nCmdInputCursor],nBackCount);										
		write(STDOUT_FILENO,szTemp,nBackCount+1);								
		memcpy(&pCmd[nCmdInputCursor],&szTemp,nBackCount+1);

memset(szTemp,'/b',nBackCount);
		write(STDOUT_FILENO,szTemp,nBackCount);	
	}
	else
	{
		write(STDOUT_FILENO,&input,1);
		szCmdNow[nCmdInputCount] = input;
	}

nCmdInputCursor++;
	nCmdInputCount++;
}

static void App_Console_OnBackspace()
{
	if(nCmdInputCursor > 0)
	{
		if(nCmdInputCursor == nCmdInputCount) // 光标在末尾
			App_Console_BSChar();
		else// 光标不在末尾
		{
			char szTemp[MAX_CMD_LEN] = {0};
			char* pCmd = szCmdNow;
			int nBackCount = nCmdInputCount-nCmdInputCursor;
			szTemp[0] = '/b';
			memcpy(&szTemp[1],&pCmd[nCmdInputCursor],nBackCount);
			szTemp[nBackCount+1] = ' ';									
			write(STDOUT_FILENO,szTemp,nBackCount+2);								
			memcpy(&pCmd[nCmdInputCursor-1],&szTemp[1],nBackCount);

memset(szTemp,'/b',nBackCount+1);
			write(STDOUT_FILENO,szTemp,nBackCount+1);				
		}
		nCmdInputCount --;
		nCmdInputCursor--;
	}
}

static void App_Console_OnDel()
{
	if(nCmdInputCursor < nCmdInputCount) // 光标不在末尾
	{							
		char szTemp[MAX_CMD_LEN] = {0};
		char* pCmd = szCmdNow;
		
		int nBackCount = nCmdInputCount-nCmdInputCursor-1;
		memcpy(szTemp,&pCmd[nCmdInputCursor+1],nBackCount);
		szTemp[nBackCount] = ' ';
		write(STDOUT_FILENO,szTemp,nBackCount+1);								
		memcpy(&pCmd[nCmdInputCursor],szTemp,nBackCount);

memset(szTemp,'/b',nBackCount+1);
		write(STDOUT_FILENO,szTemp,nBackCount+1);				
		nCmdInputCount--;								
	}
}

static void App_Console_OnDoubleEsc()
{
	if(nCmdInputCount > 0)
	{
		char* pCmd = szCmdNow;

// 将光标移动到最末尾
		while(nCmdInputCursor < nCmdInputCount)
		{
			write(STDOUT_FILENO,&pCmd[nCmdInputCursor],1);
			nCmdInputCursor++;									
		}

// 清除所有输入的数据
		int i=0;
		for(i=0;i<nCmdInputCount;i++) App_Console_BSChar();
		nCmdInputCount = 0;
		nCmdInputCursor = 0;
	}
}

static void App_Console_OnUp()
{	
	if(nCmdCursor == 0) return;
	nCmdCursor --;

// 清除掉现在所有的输入
	App_Console_OnDoubleEsc();	
	
	char* pCmdHistory = &szCmdHistory[nCmdCursor][0];	
	memcpy(szCmdNow,pCmdHistory,MAX_CMD_LEN);	
	nCmdInputCount = strlen(szCmdNow);
	nCmdInputCursor= nCmdInputCount;
	write(STDOUT_FILENO,szCmdNow,nCmdInputCount);	
}

static void App_Console_OnDown()
{
	if(nCmdCursor >= (nCmdIndex-1)) return;
	nCmdCursor ++;
	
	// 清除掉现在所有的输入
	App_Console_OnDoubleEsc();	
	
	char* pCmdHistory = &szCmdHistory[nCmdCursor][0];	
	memcpy(szCmdNow,pCmdHistory,MAX_CMD_LEN);	
	nCmdInputCount = strlen(szCmdNow);
	nCmdInputCursor= nCmdInputCount;
	write(STDOUT_FILENO,szCmdNow,nCmdInputCount);	
	
}

static void App_Console_OnLeft()
{
	if(nCmdInputCursor > 0)
	{
		char c = '/b';
		write(STDOUT_FILENO,&c,1);
		nCmdInputCursor--;
	}
}

static void App_Console_OnRight()
{
	if(nCmdInputCursor < nCmdInputCount)
	{
		char* pCmd = szCmdNow;
		char c = pCmd[nCmdInputCursor];
		write(STDOUT_FILENO,&c,1);
		nCmdInputCursor++;
	}
}

static void App_Console_OnEnter()
{	
	szCmdNow[nCmdInputCount] = '/0';
	char szTemp[] = {"/r/n"};
	write(STDOUT_FILENO,szTemp,strlen(szTemp));
	nCmdInputCount = 0;
	nCmdInputCursor = 0;

if(strlen(szCmdNow) == 0) return;

if(nCmdIndex == MAX_CMD_HISTORY) // 命令队列满了，移动
	{
		char szTempCmd[MAX_CMD_HISTORY][MAX_CMD_LEN];
		memcpy(szTempCmd,&szCmdHistory[1][0],MAX_CMD_LEN*(MAX_CMD_HISTORY-1));
		memcpy(szCmdHistory,szTempCmd,MAX_CMD_LEN*(MAX_CMD_HISTORY-1));
		nCmdIndex = MAX_CMD_HISTORY-1;
		nCmdCursor = nCmdIndex;
	}

memcpy(szCmdHistory[nCmdIndex],szCmdNow,MAX_CMD_LEN);
	
	nCmdIndex++;
	nCmdCursor = nCmdIndex;

// 解析命令
	App_Console_ParseCmd(szCmdNow);
}

static void App_Console_CmdLoop()
{
	BOOL bGetEnter = FALSE;
	while(TRUE)
	{	
		// 读取一个console输入
		UINT32 nReturn = 0;
		char input;
		nReturn = App_Console_ReadInput (&input);
		if(nReturn > 0)
		{			
			switch(waitKeyState)
			{
				case WKS_WAIT :
					if(isprint(input))// 可打印字符
						App_Console_OnPrintChar(input);
					else
					{
						if(input == KEY_BACKSPACE)
							App_Console_OnBackspace();
						else if(input == KEY_DEL)
							App_Console_OnDel();
						else if(input == KEY_ENTER)
						{
							App_Console_OnEnter();
							bGetEnter = TRUE;
						}
						else if(input == '/x1b')
							waitKeyState = WKS_RECV1B;
						else
							waitKeyState = WKS_WAIT;
					}						
					break;
				case WKS_RECV1B:
					if(input == '/x1b') // 按了ESC 又按了方向键，或者是 ESC
					{
						//App_Console_OnDoubleEsc();
						waitKeyState = WKS_RECV1B;
					}
					else

if(input == '[') //可能为 上下左右 4个键
						waitKeyState = WKS_UDLR;
					else//下面的情况为 按了 ESC 键之后，按了其他的键的处理
					{						
						if(isprint(input)) App_Console_OnPrintChar(input);							
						waitKeyState = WKS_WAIT;
					}
					break;
				case WKS_UDLR:
					if(input == 'A')// 上
						App_Console_OnUp();
					else if(input == 'B')// 下
						App_Console_OnDown();
					else if(input == 'D')// 左
						App_Console_OnLeft();
					else if(input == 'C')// 右
						App_Console_OnRight();
					else
					{
						if(isprint(input)) App_Console_OnPrintChar(input);
					}
					waitKeyState = WKS_WAIT;					
					break;
				default:
					break;
			}
		}

if(bGetEnter) 
		{			
			break;
		}
	}
}

void App_Console_Start()
{
	// 清空 sdtout 缓冲
    fflush(stdout);
	fflush(stdin);

char szTemp[] = {"/r/nStart TR Console.../r/n/r/n"};
	write(STDOUT_FILENO,szTemp,strlen(szTemp));

while(TRUE)
	{
		write(STDOUT_FILENO,szPrompt,strlen(szPrompt));
		App_Console_CmdLoop();
	}
}

// 解析命令
static void App_Console_ParseCmd(const char* pCmd)
{
	int length = strlen(pCmd); 
	
	// 全部转小写
	int i=0;
	char szTempCmd[MAX_CMD_LEN];
	for (i=0; i < length; i++) szTempCmd[i] = tolower(pCmd[i]);

// 将输入的命令各个 part 分开	
	char szPart[MAX_PAR_COUNT][MAX_CMD_LEN];
	int nPartCount = 0;
	int nPartCursor = 0;
	int nCmdCursor = 0;
	memset(szPart,0,sizeof(szPart));

while(TRUE)
	{
		if(nCmdCursor == length) 
		{
			if(nPartCursor > 0)
			{
				nPartCount++;
				nPartCursor = 0;
			}
			break;			
		}
		
		if( (szTempCmd[nCmdCursor] == ',') || (szTempCmd[nCmdCursor] == ' ') ) // part 分割符
		{
			szPart[nPartCount][nPartCursor] = '/0';
			
			nPartCount++;
			nPartCursor = 0;
		}
		else 
		{
			szPart[nPartCount][nPartCursor] = szTempCmd[nCmdCursor];
			nPartCursor++;
		}
		nCmdCursor++;		
	}
	App_Test_OnCmd(szPart,nPartCount);		
}

命令实现头文件(app_test.h) 命令实现c文件(app_test.c)

#include "app_test.h"
#include "stapp_main.h"
#include "app_qam.h"
#include "api_av.h"
#include "api_video.h"
#include "api_audio.h"
#include "api_pcr.h"

static void App_Test_OnHelp();
static void App_Test_OnWriteReg8(char szPart[][MAX_CMD_LEN],int nPartCount);
static void App_Test_OnReadReg8(char szPart[][MAX_CMD_LEN],int nPartCount);
static void App_Test_OnQamConnect(char szPart[][MAX_CMD_LEN],int nPartCount);
static void App_Test_OnAVPlayMpeg(char szPart[][MAX_CMD_LEN],int nPartCount);
static void App_Test_OnAVStop();
static void App_Test_OnVolumeSet(char szPart[][MAX_CMD_LEN],int nPartCount);
static void App_Test_OnMute();
static void App_Test_OnUnmute();
static void App_Test_OnDENCRegDum();
static void App_Test_OnDENCRegSet(char szPart[][MAX_CMD_LEN],int nPartCount);

void App_Test_OnCmd(char szPart[][MAX_CMD_LEN],int nPartCount)
{
	// 这里处理私有的命令

if(nPartCount == 0) return;

if( strcmp(szPart[0],"help") == 0)
	{
		App_Test_OnHelp();
	}
	else if( strcmp(szPart[0],"writereg8") == 0)
	{
		if(nPartCount > 2) App_Test_OnWriteReg8(szPart,nPartCount);
	}
	else if( strcmp(szPart[0],"readreg8") == 0)
	{
		if(nPartCount > 1) App_Test_OnReadReg8(szPart,nPartCount);
	}
	else if( strcmp(szPart[0],"qamconnect") == 0)
	{
		if(nPartCount > 1) App_Test_OnQamConnect(szPart,nPartCount);
	}
	else if( strcmp(szPart[0],"avplaympeg") == 0)
	{
		if(nPartCount > 1) App_Test_OnAVPlayMpeg(szPart,nPartCount);
	}
	else if( strcmp(szPart[0],"avstop") == 0)
	{
		App_Test_OnAVStop();
	}
	else if( strcmp(szPart[0],"volumeset") == 0)
	{
		if(nPartCount > 1) App_Test_OnVolumeSet(szPart,nPartCount);
	}
	else if( strcmp(szPart[0],"mute") == 0)
	{
		App_Test_OnMute();
	}
	else if( strcmp(szPart[0],"unmute") == 0)
	{
		App_Test_OnUnmute();
	}
	else if( strcmp(szPart[0],"dencregdump") == 0)
	{
		App_Test_OnDENCRegDum();
	}
	else if( strcmp(szPart[0],"dencregset") == 0)
	{
		if(nPartCount > 1) App_Test_OnDENCRegSet(szPart,nPartCount);
	}

}

static void App_Test_OnHelp()
{
	printf("**************************************************************/n");	
	printf("* Help        PARAM MUST 0 MAX 0 Eg. help/n");	
	printf("* WriteReg8   PARAM MUST 2 MAX 2 Eg. WriteReg8 0x1920C114 128/n");
	printf("* ReadReg8    PARAM MUST 1 MAX 1 Eg. ReadReg8 0x1920C114/n");
	printf("* QamConnect  PARAM MUST 1 MAX 3 Eg. QamConnect 546000/n");
	printf("* AVPlayMpeg  PARAM MUST 1 MAX 3 Eg. AVPlayMpeg 64 63 32/n");
	printf("* AVStop      PARAM MUST 0 MAX 0 Eg. AVStop/n");
	printf("* VolumeSet   PARAM MUST 1 MAX 1 Eg. VolumeSet 63/n");	
	printf("* Mute        PARAM MUST 0 MAX 0 Eg. Mute/n");
	printf("* Unmute      PARAM MUST 0 MAX 0 Eg. Unmute/n");
	printf("* DENCRegDump PARAM MUST 0 MAX 0 Eg. DENCRegDump/n");
	printf("* DENCRegSet  PARAM MUST 1 MAX 1 Eg. DENCRegSet 1/n");	
	printf("*************************************************************/n");	
	
}

static void App_Test_OnWriteReg8(char szPart[][MAX_CMD_LEN],int nPartCount)
{
	char* pAddress = &szPart[1][0];
	char* pValue = &szPart[2][0];

DWORD dwAddress = 0;
	UINT8 nValue = atoi(pValue);

sscanf(pAddress,"0x%08x",&dwAddress);

SYS_WriteRegDev8(dwAddress,nValue);	
}

static void App_Test_OnQamConnect(char szPart[][MAX_CMD_LEN],int nPartCount)
{
	char* pFreq = &szPart[1][0];
	UINT32 nFreq = atoi(pFreq);
	UINT32 nSymbolRate = 6875;
	T_DMD_Modulation nQAMMode = QAM_64;
	if(nPartCount > 2)
	{
		char* pSymbolRate = &szPart[2][0];
		nSymbolRate = atoi(pSymbolRate);
	}

if(nPartCount > 3)
	{
		char* pQAMMode = &szPart[3][0];
		nQAMMode = atoi(pQAMMode);
	}
	
	App_Qam_Locking(TRUE,nFreq,nSymbolRate,nQAMMode);	
}

static void App_Test_OnAVPlayMpeg(char szPart[][MAX_CMD_LEN],int nPartCount)
{
	UINT16 nVideoPid = 0xFFFF;
	UINT16 nAudioPid = 0xFFFF;
	UINT16 nPcrPid = 0xFFFF;

char* pAudioPid = &szPart[1][0];
	nAudioPid = atoi(pAudioPid);

if(nPartCount > 2)
	{
		char* pVideoPid = &szPart[2][0];
		nVideoPid = atoi(pVideoPid);
	}

if(nPartCount > 3)
	{
		char* pPcr = &szPart[3][0];
		nPcrPid = atoi(pPcr);
	}

Api_Av_Stop();
	Api_Av_Start(nAudioPid,STREAMTYPE_MP2A,nVideoPid,STREAMTYPE_MP2V,nPcrPid);
}

static void App_Test_OnVolumeSet(char szPart[][MAX_CMD_LEN],int nPartCount)
{
	UINT16 nVolume = 0; 
	char* pVolume = &szPart[1][0];
	nVolume = atoi(pVolume);

Api_Audio_Volume_Set(nVolume);
}

static void App_Test_OnMute()
{
	Api_Audio_Mute();
}

static void App_Test_OnUnmute()
{
	Api_Audio_Unmute();
}

static void App_Test_OnAVStop()
{
	Api_Av_Stop();
}

static void App_Test_OnDENCRegDum()
{
	printf("* Brightness   0x1920C114 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C114));	
	printf("* Contrast     0x1920C118 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C118));	
	printf("* Saturation   0x1920C11c value is 0x%02x/n",SYS_ReadRegDev8(0x1920C11c));
	
	printf("* CHROMA_COEF0 0x1920C120 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C120));	
	printf("* CHROMA_COEF1 0x1920C124 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C124));	
	printf("* CHROMA_COEF2 0x1920C128 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C128));	
	printf("* CHROMA_COEF3 0x1920C12c value is 0x%02x/n",SYS_ReadRegDev8(0x1920C12c));	
	printf("* CHROMA_COEF4 0x1920C130 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C130));	
	printf("* CHROMA_COEF5 0x1920C134 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C134));	
	printf("* CHROMA_COEF6 0x1920C138 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C138));	
	printf("* CHROMA_COEF7 0x1920C13c value is 0x%02x/n",SYS_ReadRegDev8(0x1920C13c));	
	printf("* CHROMA_COEF8 0x1920C140 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C140));

printf("* LUM_COEF0    0x1920C148 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C148));	
	printf("* LUM_COEF1    0x1920C14c value is 0x%02x/n",SYS_ReadRegDev8(0x1920C14c));	
	printf("* LUM_COEF2    0x1920C150 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C150));	
	printf("* LUM_COEF3    0x1920C154 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C154));	
	printf("* LUM_COEF4    0x1920C158 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C158));	
	printf("* LUM_COEF5    0x1920C15c value is 0x%02x/n",SYS_ReadRegDev8(0x1920C15c));	
	printf("* LUM_COEF6    0x1920C160 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C160));	
	printf("* LUM_COEF7    0x1920C164 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C164));	
	printf("* LUM_COEF8    0x1920C168 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C168));	
	printf("* LUM_COEF9    0x1920C16c value is 0x%02x/n",SYS_ReadRegDev8(0x1920C16c));

printf("* CFG9         0x1920C144 value is 0x%02x/n",SYS_ReadRegDev8(0x1920C144));		
	
}

static void App_Test_OnDENCRegSet(char szPart[][MAX_CMD_LEN],int nPartCount)
{
	UINT16 nScheme = 1; 
	char* pScheme = &szPart[1][0];
	nScheme = atoi(pScheme);

switch(nScheme)
	{
		case 1:
			
			break;
		case 2:
			
			break;
		case 3:
			
			break;
		case 4:
			
			break;
		default:
			break;
	}

}

static void App_Test_OnReadReg8(char szPart[][MAX_CMD_LEN],int nPartCount)
{
	char* pAddress = &szPart[1][0];
	DWORD dwAddress = 0;
	
	sscanf(pAddress,"0x%08x",&dwAddress);
	printf("* 0x%08x value is 0x%02x/n",dwAddress,SYS_ReadRegDev8(dwAddress));
}

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嵌入式 linux 下通用 console（控制台）的实现

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