file.c

ertfs文件系统里面既有完整ucos程序

#include <string.h>

#include "..\inc\option.h"
#include "..\inc\def.h"
#include "..\inc\44b.h"
#include "..\inc\44blib.h"
#include "..\inc\flash.h"
#include "..\inc\download.h"
#include "..\inc\usb.h"
#include "..\inc\file.h"
/*Download and format is OK!*/
/***************************************************************/
/*                       FAT表说明                             */
/*(1)KM29U128T 共有1024个Block/Cluster,1Block=32Page           */
/*                                  或 1Cluster=32Sector       */
/*(2)1Page/Sector=512B,1Block/Cluster=16KB                     */
/*                                 因此共有空间1024*16KB=16MB  */
/*(3)RootDir信息占用Block0,用户数据存放于Block1～1023          */
/*                    可用空间共为1023*32=32736Sector=15.98MB  */
/*(4)FAT信息存放在每个Block的首页(Page)的独立区,该区共有16Bytes*/
/*   这16Bytes的含义如下：                                     */
/*   Offset[0]->该Block的使用情况                              */
/*              0xFF     :unused Block                         */
/*              0x00     :bad Block                            */
/*              0x01~0xFE:used Block                           */
/*   Offset[ 1~ 7]->保留字节(对其中的数据无任何要求)           */
/*   Offset[ 8~11]->Pre Block(MSB)                             */
/*                  若当前Block是FirstBlock,则该值为其本身     */
/*   Offset[12~15]->Next Block(MSB)                            */
/*                  若当前块为LastBlock，则该值为0xFFFF        */
/***************************************************************/
/*                     Root Directory 记录格式                   */
/*                     Offset[ 0~10]->file name                   */
/*                     Offset[11~25]->file attribute              */
/*                     Offset[26~27]->file starting cluster(LSB)  */
/*                     Offset[28~31]->file size in byte(LSB)      */
/*暂存Root Directory数据,每条记录为32Byte,因此共可有512条记录*/
U8 root_buf[512][32];
U32 pre_block,current_block;
U8 Block_1Page_Buf[528];	//Block首页Buffer
U8 Page_Buf[528];
/*void disp_root(void)
{
	U32 s1,s2;
	for(s1=0;s1<16;s1++)
	{
		Uart_Printf("************************************\n");
		for(s2=0;s2<16;s2++)
		{
			Uart_Printf("%2xh ",root_buf[s1][s2]);
		}
		Uart_Printf("\n");
		for(s2=16;s2<32;s2++)
		{
			Uart_Printf("%2xh ",root_buf[s1][s2]);
		}
		Uart_Printf("\n");
	}
	Uart_Printf("++++++++++++++++++++++++++++++++++++\n");
	Uart_Printf("++++++++++++++++++++++++++++++++++++\n");

}*/
/*************************************************/
/*寻找介于StartBlock与EndBlock之间的第一个BlankBlock*/
/*************************************************/
U32 seek_blank_block(U32 StartBlock)
{
	U32 Block_Number;
	
	Block_Number=StartBlock;
	ReadPage(Block_Number,0,Block_1Page_Buf);
	while(Block_1Page_Buf[512]!=UNUSED_MARK)
           ReadPage(++Block_Number,0,Block_1Page_Buf);
	return(Block_Number);
}
/******************************************************/
/*将Root Directory数据读入root_buf[],并在root_buf中修改之*/
/******************************************************/
/*调用方式:*/
void creat_file(U8 *file_information)
{

	U32 page_num,Pointer,i;

	for(page_num=0;page_num<32;page_num++)
	{
		/*将Root information读到root_buf中*/
		ReadPage(Root_Cluster,page_num,Page_Buf);
		for(Pointer=0;Pointer<512;Pointer++)
		{
			root_buf[page_num*16+Pointer/32][Pointer%32]=Page_Buf[Pointer];
		}
	}
		
	/*在root_buf寻找空表项*/
	Pointer=0;
	while(root_buf[Pointer][0]!=0x00)
	{
		Pointer++;
	}
	
	/*copy the file name and file size*/
	for(i=0;i<32;i++)
		root_buf[Pointer][i]= *file_information++;
	
	current_block=seek_blank_block(Start_Cluster);
	pre_block=current_block;
	
	root_buf[Pointer][26]=(U8)(current_block%256);	//store LSB
	root_buf[Pointer][27]=(U8)(current_block/256);	//store MSB
//	disp_root();	
}
/********************************************************/
/*将root_buf中的数据写回Root Directory所处的Block(即Block0)*/
/*********************************************************/
void close_file(void)
{

	U32 page_num,Pointer;
	
	/*Erase Root_information Cluster*/
	Erase_Cluster(0);
	
	/*将root_buf中的数据逐页写入*/
	for(page_num=0;page_num<32;page_num++)
	{
		for(Pointer=0;Pointer<512;Pointer++)
		{
			Page_Buf[Pointer]=root_buf[page_num*16+Pointer/32][Pointer%32];
		}
		/*独立区以0xFF填充*/
		for(Pointer=512;Pointer<(512+16);Pointer++)
		{
			Page_Buf[Pointer]=0xFF;
		}
		WritePage(Root_Cluster,page_num,&(Page_Buf[0]));
	}
}
/*******************/
/*将FlashDisk格式化*/
/******************/
#if 0
void format_disk(void)
{

	U32 Block_Number,page_num,Pointer;

	/*擦除数据区*/
	for(Block_Number=Start_Cluster;Block_Number<=End_Cluster;Block_Number++)
	{
		if(Erase_Cluster(Block_Number)==FAIL)
		{
			/*Mark this Block with BAD flag*/
			Page_Buf[512]=0x00;
			WritePage(Block_Number,0,&Page_Buf[0]);
		}
	}
	
	//将root_buf中全部写0x00//
	for(page_num=0;page_num<32;page_num++)
	{
		for(Pointer=0;Pointer<512;Pointer++)
		{
			Page_Buf[Pointer]=0;
		}
		//独立区以0xFF填充//
		for(Pointer=512;Pointer<(512+16);Pointer++)
		{
			Page_Buf[Pointer]=0xFF;
		}
		WritePage(Root_Cluster,page_num,&Page_Buf[0]);
	}		
}
#endif
/******************************/
/*将rx_buf中的数据写到1个Block中*/
/******************************/
void write_file(U8 endflag,U8 *block_buf)
{
	U32 next_block,page_num,Pointer;

//Uart_Printf("\nWrite data,Current block is:%d",current_block);
	if(endflag)	//若为文件的最后一个Block,则LastBlock=0xFFFF
		next_block=LAST_BLOCK;
	else
		next_block=seek_blank_block(current_block+1);

	//write USED mark//
	Page_Buf[512+0]=0x01;

	//write pre_block//
	Page_Buf[512+8]=0x00;
	Page_Buf[512+9]=0x00;
	Page_Buf[512+10]=pre_block/256;
	Page_Buf[512+11]=pre_block%256;

	//write next_block//
	Page_Buf[512+12]=0x00;
	Page_Buf[512+13]=0x00;
	Page_Buf[512+14]=next_block/256;
	Page_Buf[512+15]=next_block%256;
																
	for(page_num=0;page_num<32;page_num++)
	{
		for(Pointer=0;Pointer<512;Pointer++)
		{
			Page_Buf[Pointer]=*block_buf;
			*block_buf=0xff;
			block_buf++;
		}
		WritePage(current_block,page_num,Page_Buf);					
	}
	pre_block=current_block;
	current_block=next_block;		
}
void read_file(U8 *block_buf)
{	
	U32 page_num,Pointer;
//Uart_Printf("\nRead data,Current block is:%d",current_block);
	for(page_num=0;page_num<32;page_num++)
	{
		ReadPage(current_block,page_num,Page_Buf);		
		for(Pointer=0;Pointer<512;Pointer++)
		{
			*block_buf=Page_Buf[Pointer];
			block_buf++;
		}
	}
	current_block=Page_Buf[512+14]*256+Page_Buf[512+15];
}
U32 comp_filename(U8 *s1,U8 *s2)
{
	U32 diff_num=0;
	U32 name_pointer;

	for(name_pointer=0;name_pointer<11;name_pointer++)
	{
		if(s1[name_pointer]!=s2[name_pointer])
			diff_num++;
	}
	return (diff_num);
}
//返回值为该文件在Root information区中的位置,即第几条记录//
U32 find_file(U8 *file_name)
{
	U32 page_num,Pointer;

	//read the root information//
	for(page_num=0;page_num<32;page_num++)
	{
		//将Root information读到root_buf中//
		ReadPage(Root_Cluster,page_num,Page_Buf);
		for(Pointer=0;Pointer<512;Pointer++)
		{
			root_buf[page_num*16+Pointer/32][Pointer%32]=Page_Buf[Pointer];
		}
	}

	for(Pointer=0;Pointer<512;Pointer++)
	{
		if(comp_filename(&root_buf[Pointer][0],file_name)==0)
		break;
	}
	return(Pointer);

}
#if 0
void file_rename(U8 *old_new_filename)
{
	U32 Pointer,i;
	//Pointer=find_file(old_new_filename);
	//for(i=0;i<11;i++)
	//	root_buf[Pointer][i]=old_new_filename[11+i];
	//close_file();
}

void del_file(U8 *filename)
{
	U32 root_location,i;

    // get the location of this file via look for its file name in Root Directory //
	root_location=find_file(filename);

	//get the file first cluster//
	current_block=root_buf[root_location][27]*256+root_buf[root_location][26];

	//flush this file's recoder in root information//
	for(i=0;i<32;i++)
		root_buf[root_location][i]=0;

	while(1)
	{
		ReadPage(current_block,0,Page_Buf);
		Erase_Cluster(current_block);
		//get the next block number//
		current_block=Page_Buf[512+14]*256+Page_Buf[512+15];
		if(current_block==65535)
			break;
	}
	close_file();
}
#endif