总算把问题解决了

April 26, 2006 at 3:22 am · Filed under Uncategorized

找来找去还是那个XB_BUF的边界问题

XSEG     AT  0000H
PRD:  DS 8 ;PRD has to be defined at WORD boundary.  
XB_BUF0:   DS   512
XB_BUF1:   DS  512
XB_BUF2:     DS  512 ;use by the media function as backup

三点

1，创建文件名时 反复拷贝 常常会重名  导致错误退出

2，fatGetNextClusterChain的程序里就有逻辑不严的问题

ULONG fatGetNextClusterChain(PCLUSTERCHAININFO PChainInfo)
{
   ULONG Len;
   BYTE byStatus;
/*
   if(ccbuf.ChainBufferCount==1) byStatus = fatGetFreeArea();
   if (byStatus == 0) return 0;
*/
   if(ccbuf.ChainBufferCount==1)
   { byStatus = fatGetFreeArea();
    if (byStatus == 0) return 0;
   }

   memcpy(PChainInfo,(PCLUSTERCHAININFO)&ccbuf.ChainBuffer[ccbuf.ChainBufferRp],sizeof(CLUSTERCHAININFO));
   if(ccbuf.ChainBufferRp>CHAINBUFLEN-2)
    ccbuf.ChainBufferRp =0;
   else
    ccbuf.ChainBufferRp++;
   ccbuf.ChainBufferCount–;
   Len = PChainInfo->EndCluster – PChainInfo->StartCluster ;
   return Len;
}
3

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