fat32_access.c

来自「hd driver for S3C44B0。44b0 + ide + fat32」· C语言 代码 · 共 49 行

#include "fat_include.h"


//-----------------------------------------------------------------------------
// FAT32_LoadFAT: Load FAT32 Parameters
//-----------------------------------------------------------------------------
void FAT32_LoadFAT(void)
{
 	 s3c44b0x_Printf("\r\nLoading Partition 1");
	 FAT32_FindFAT32Details();
	 s3c44b0x_Printf("\r\nFAT Parameters Loaded Successfully");
}

//-----------------------------------------------------------------------------
// FAT32_SectorReader: From the provided startcluster and sector offset, load using 
//		   IDE_BufferSector the required sector into memory.
//-----------------------------------------------------------------------------
int FAT32_SectorReader(UI32 Startcluster, UI32 offset)
{
 	  UI32 SectortoRead = 0;
	  UI32 ClustertoRead = 0;
	  UI32 ClusterChain = 0;
	  int i;
	  
	  // Set start of cluster chain to initial value
	  ClusterChain = Startcluster;

	  // Find parameters
	  ClustertoRead = offset / FAT32.SectorsPerCluster;	  
	  SectortoRead = offset - (ClustertoRead*FAT32.SectorsPerCluster);

	  // Follow chain to find cluster to read
	  for (i=0; i<ClustertoRead; i++)
	  	  ClusterChain = FAT32_FindNextCluster(ClusterChain);

	  // If end of cluster chain then return 1
	  if (ClusterChain==0xFFFFFFFF) return 1;

	  // Else read sector and return 0
	  IDE_BufferSector(FAT32_LBAofCluster(ClusterChain)+SectortoRead);
	  
	  return 0;
}