📄 fat16.c

📁 合众达的DM642示例工程
💻 C
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//-------------------------------------------------------------------------
//#include	<avr/io.h>
//#include 	<stdint.h>

#include "FAT16.h"
#include "mmc.h"
#include "sdconfig.h"
#include "sdhal.h"   
#include "sdcmd.h"   
#include "sddriver.h"
#include "sdcrc.h" 
//------------------------------------------------------------------------
#define	SEC_Size				512
#define	MBR_Sector				0				//绝对地址
#define	FAT_Sector				0				//逻辑地址
//-------------------------------------------------------------------------
Uint8		BUFFER[514];
Uint8		PB_RelativeSector;
Uint16	    BPB_BytesPerSec;
Uint8		BPB_SecPerClus;
Uint16	    BPB_RsvdSecCnt;
Uint8		BPB_NumFATs;
Uint16	    BPB_RootEntCnt;
Uint16	    BPB_TotSec16;
Uint16	    BPB_FATSz16;							//FAT占用的sectors
Uint32	    BPB_HiddSec;
Uint8       tee=0;
//extern Uint16 clsre;
//extern volatile Uint8 tras[];

//-------------------------------------------------------------------------
Uint8 ReadBlock(Uint32 LBA){					//绝对地址读一个扇区
	Uint8 ret;
	    //ret = SD_ResetSD();								/* 5. 发出CMDO命令复位SD卡 send CMD0 command to reset sd card */
 	    //if (ret != 0)
        //printf("Invalid data Response token.\n");

        //EVMDM642_waitusec(60000);
        	    
	//EVMDM642_waitusec(600000);
	if(SD_ReadBlock(LBA,BUFFER)!=0)
	return SD_FAIL;
	ret = SD_ActiveInit();							/* 6. 激活卡进入初始化过程. active card initialize process */
 	    if (ret != 0)
        printf("Invalid data Response token.\n");
	return SD_SUCC;
}
//-------------------------------------------------------------------------
Uint8 WriteBlock(Uint32 LBA){					//绝对地址写一个扇区
    Uint8 ret;
    /*ret = SD_ResetSD();							
 	    if (ret != 0)
        printf("Invalid data Response token.\n");
    EVMDM642_waitusec(60000);

    ret = SD_ActiveInit();						
 	    if (ret != 0)
        printf("Invalid data Response token.\n");*/
 	
	if(SD_WriteBlock(LBA,BUFFER)!=0)
	return SD_FAIL;
	ret = SD_ActiveInit();
	if (ret != 0)
    printf("Invalid data Response token.\n");
	return SD_SUCC;
}
//-------------------------------------------------------------------------
Uint8 ReadFatBlock(Uint32 Add){					//逻辑地址读一个扇区
	return ReadBlock(Add+PB_RelativeSector);
}
//-------------------------------------------------------------------------
Uint8 WriteFatBlock(Uint32 Add){				//逻辑地址写一个扇区
	return WriteBlock(Add+PB_RelativeSector);
}
//-------------------------------------------------------------------------
void CopyBytes(Uint8 *ps,Uint8 *pd,Uint16 size){	//内存拷贝
	for(;size;size--)*pd++=*ps++;
}
//-------------------------------------------------------------------------
Uint8 IsEqual(Uint8 *pa,Uint8 *pb,Uint8 size){	//内存比较
	for(;size;size--)if(*pa++!=*pb++)return 0;
	return 1;
}
//-------------------------------------------------------------------------
void EmptyBytes(Uint8 *pd,Uint16 size){			//内存清空
	for(;size;size--)*pd++ =0;
}
//-------------------------------------------------------------------------
void correctdir(Uint8 *ad,Uint32 size,Uint16 start)
{
  
  *(ad+26)=start&0xff;
  *(ad+27)=start>>8;
  
  *(ad+28)=size&0xff;
  *(ad+29)=(size>>8)&0xff;
  *(ad+30)=(size>>16)&0xff;
  *(ad+31)=(size>>24)&0xff;
  }
  /**************************************************************************/
  void recorrectdir(Uint8 *ad)
{
  
  *(ad+28)=*(ad+26);
  *(ad+29)=*(ad+27);
  
  }
/****************************************************************************/
Uint8 ReadMBR(void){
    									//读取MBR数据结构
	Uint8 ok,exchange[66];
	Uint8 i;
	FAT_MBR * MBR=(FAT_MBR*)BUFFER;
	ok=ReadBlock(MBR_Sector);
	if(ok==SD_FAIL)return SD_FAIL;
	for(i=0;i<66;i++)
	exchange[i]=BUFFER[i+446];
	for(i=0;i<66;i++)
	BUFFER[i+448]=exchange[i];
	if(MBR->MBR_Signature!=0xAA55)return SD_FAIL;		//读有效标志
		
	//获取参数
	PB_RelativeSector=MBR->MBR_pb[0].PB_RelativeSector;//读逻辑地址与绝对地址的偏移
	return SD_SUCC;
}
//-------------------------------------------------------------------------
Uint8 ReadBPB(void){									//读取BPB数据结构
	Uint8 ok;
	char BS_FilSysType[8];
	FAT_BPB * BPB=(FAT_BPB*)BUFFER;
	ok=ReadFatBlock(FAT_Sector);
	if(ok==SD_FAIL)return SD_FAIL;

	/*for(i=0;i<512;i++)
	{
	  exchange[i]=BUFFER[i];
	  }
	BUFFER[12]=exchange[11];
	BUFFER[13]=exchange[12];
	
	BUFFER[14]=exchange[13];
	
	BUFFER[14]=exchange[13];*/
	//获取参数
	BPB_BytesPerSec = BUFFER[11]+(BUFFER[12]<<8);//BPB->BPB_BytesPerSec;
	BPB_SecPerClus = BUFFER[13];//BPB->BPB_SecPerClus;
	BPB_RsvdSecCnt = BUFFER[14]+(BUFFER[15]<<8);//BPB->BPB_RsvdSecCnt;
	BPB_NumFATs = BUFFER[16];//BPB->BPB_NumFATs;
	BPB_RootEntCnt = BUFFER[17]+(BUFFER[18]<<8);//BPB->BPB_RootEntCnt;
	BPB_TotSec16 = BUFFER[19]+(BUFFER[20]<<8);//BPB->BPB_TotSec16;
	BPB_FATSz16 = BUFFER[22]+(BUFFER[23]<<8);//BPB->BPB_FATSz16;
	BPB_HiddSec = BUFFER[28]+(BUFFER[29]<<8)+(BUFFER[30]<<16)+(BUFFER[31]<<24);//BPB->BPB_HiddSec;
	BS_FilSysType[0] = BUFFER[54];
	BS_FilSysType[1] = BUFFER[55];
	BS_FilSysType[2] = BUFFER[56];
	BS_FilSysType[3] = BUFFER[57];
	BS_FilSysType[4] = BUFFER[58];
	BS_FilSysType[5] = BUFFER[59];
	BS_FilSysType[6] = BUFFER[60];
	BS_FilSysType[7] = BUFFER[61];
	return SD_SUCC;
}
//-------------------------------------------------------------------------
Uint32 DirStartSec(void){							//获取根目录开始扇区号
	return BPB_RsvdSecCnt+BPB_NumFATs*BPB_FATSz16;
}
//-------------------------------------------------------------------------
Uint16 GetDirSecCount(void){							//目录项占用的扇区数
	return BPB_RootEntCnt*32/BPB_BytesPerSec;
}
//-------------------------------------------------------------------------
Uint32 DataStartSec(void){							//获取数据区开始扇区号
	return DirStartSec()+GetDirSecCount();
}
//-------------------------------------------------------------------------
Uint32 ClusConvLBA(Uint16 ClusID){					//获取一个簇的开始扇区
	return DataStartSec()+BPB_SecPerClus*(ClusID-2);
}
//-------------------------------------------------------------------------
Uint16 ReadFAT(Uint16 Index){						//读取文件分配表的指定项
	Uint16 *RAM=(Uint16*)BUFFER;
	Uint32 SecID;
	
	SecID=BPB_RsvdSecCnt+Index/256;
	ReadFatBlock(SecID);
	return RAM[Index%256];
}
//-------------------------------------------------------------------------
void WriteFAT(Uint16 Index,Uint16 Value,Uint32 j){		
	Uint16 *RAM=(Uint16*)BUFFER;
	Uint32 SecID;
		tee=tee+1;
	SecID=BPB_RsvdSecCnt+Index/256;
	ReadFatBlock(SecID);
	RAM[Index%256]=Value;
	WriteFatBlock(SecID);
	if((j==0)/*||(j==1)*/)
	EVMDM642_waitusec(1000000);
	else
	EVMDM642_waitusec(6000);
	SD_ResetSD();	
	SD_ActiveInit();
	WriteFatBlock(SecID+BPB_FATSz16);
 	EVMDM642_waitusec(30);
}
/*void WriteFAT1(Uint16 Index,Uint16 Value){			//写文件分配表的指定项
	Uint16 *RAM=(Uint16*)BUFFER;
	Uint32 SecID;
	
	SecID=BPB_RsvdSecCnt+Index/256;
	ReadFatBlock(SecID);
	RAM[Index%256]=Value;
	WriteFatBlock(SecID);
}*/
//-------------------------------------------------------------------------
Uint16 GetEmptyDIR(void){							//获取根目录中可以使用的一项
	Uint16 i,DirSecCut,DirStart,m,ID=0;
	Uint8 ret;
	DirSecCut=GetDirSecCount();
	DirStart=DirStartSec();
	ret = SD_ResetSD();								/* 5. 发出CMDO命令复位SD卡 send CMD0 command to reset sd card */
 	    if (ret != 0)
        printf("Invalid data Response token.\n");

        EVMDM642_waitusec(60000);
        	    
	//EVMDM642_waitusec(600000);

	ret = SD_ActiveInit();							/* 6. 激活卡进入初始化过程. active card initialize process */
 	    if (ret != 0)
        printf("Invalid data Response token.\n");
	for(i=0;i<DirSecCut;i++){
		ReadFatBlock(DirStart+i);
		for(m=0;m<16;m++){
			if(BUFFER[m*32]==0)return ID;
			if(BUFFER[m*32]==0xe5)return ID;
			ID++;
		}
	}
	return ID;
}

//-------------------------------------------------------------------------
Uint16 GetNextFAT(Uint16 clsid){							//获取一个空的FAT项
	Uint16 FAT_Count,i;
	FAT_Count=BPB_FATSz16*256; 						//FAT表总项数
	for(i=clsid;i<FAT_Count;i++){
		if(ReadFAT(i)==0)return i;
	}
	return 0;
}
//-------------------------------------------------------------------------
void ReadDIR(Uint16 Index, DIR* Value){			//读取根目录的指定项
	Uint32 LBA = DirStartSec()+Index/16;
	ReadFatBlock(LBA);
	CopyBytes((Uint8 *)&BUFFER[(Index%16)*32],(Uint8 *)Value,32);
}
//-------------------------------------------------------------------------
void WriteDIR(Uint16 Index, DIR* Value){			//写根目录的指定项
	Uint32 LBA = DirStartSec()+Index/16;
	ReadFatBlock(LBA);
	CopyBytes((Uint8 *)Value,(Uint8 *)&BUFFER[(Index%16)*32],32);
	WriteFatBlock(LBA);
}
//-------------------------------------------------------------------------
void CopyFAT(void){					
	Uint16 i;
    Uint8 ret;
    //Uint32 fat=0x80500000;
    ret = SD_ResetSD();								
 	    if (ret != 0)
        printf("Invalid data Response token.\n");

        EVMDM642_waitusec(60000);
        	    
	//EVMDM642_waitusec(600000);

	ret = SD_ActiveInit();
12 下一页
💿 文件大小 580 K
👤 上传用户 haibokaishi2006
📂 所属分类 DSP编程
🏷️ 相关标签

#642 #DM #合众达 #工程
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