datahandle.c

讲述LPC2468在无操作系统条件下使用YAFFS文件系统是如何实现的以及完整的测试代码,代码部分详见lpc2468_yaffs2.rar

//#include "type.h"
//#include "DataHandle.h"
#include <target.h>

uint32_t GetValueFromBuff(uint8_t *p_str,uint32_t pos)
{
	uint32_t value = 0;
	uint8_t i;
	for(i=0; i<4; i++)
	{
		value <<= 8;
		value += *(p_str+pos+i);
	}
	return value;
}
		
void InsertValueToBuff(uint8_t *p_str,uint32_t pos, uint32_t value, uint8_t len)
{
	uint8_t i;
	for(i=0; i<len; i++)
	{
		*(p_str + pos+ len-1 -i) = value;
		value >>= 8;
	}
}

uint32_t Reverse(uint32_t data)
{
	
	uint32_t roll_data1;
	uint32_t roll_data2;
	
	roll_data1 = data & 0x000000ff;
	roll_data2 = (data >> 24) & 0x000000ff;
	
	data = (data & 0x00ffff00)|(roll_data1 << 24)|roll_data2;
	
		roll_data1 = data>>8 & 0x000000ff;
	roll_data2 = (data >> 16) & 0x000000ff;	
	
	data = (data & 0xff0000ff)|(roll_data1 << 16)|(roll_data2<<8);
	
	roll_data1 = data;
	return roll_data1;
}