基于OHCI的USB主机 ―― UFI读扇区代码

/**  * 读磁盘扇区命令  * @param sect 读取的物理扇区号  * @param *buf 数据缓冲区指针  * @return 0 - 成功  */ short ufiReadSect( DWORD sect, BYTE *buf) {     READ_10 *read10;     CBW *cbw;       // 设置 Bulk-Only 协议参数     cbw = &ufiCmdRunning. cbw ;     cbw-> dCBW_Signature = CBW_SIGNATURE;     cbw-> dCBW_Tag = 0x60a624de;     cbw-> dCBW_DataXferLen = 512;     cbw-> bCBW_Flag =0x80;     cbw-> bCBW_LUN =0;     cbw-> bCBW_CDBLen = 16; //sizeof(CDB_RBC);       // 设置 UFI 命令参数     read10 = &(cbw-> cdbRBC . ufiRead10 );     read10-> OperationCode = 0x28;     read10-> LBA_0 = byteInInt(sect, 0);     read10-> LBA_1 = byteInInt(sect, 1);     read10-> LBA_2 = byteInInt(sect, 2);     read10-> LBA_3 = byteInInt(sect, 3);     read10-> XferLen_0 = 0x01;     read10-> XferLen_1 = 0x00;       // 设置状态扫描函数所需要的参数     ufiCmdRunning. funUfiCmd = bulkRead;     ufiCmdRunning. pBuf = buf;     ufiCmdRunning. state = UFI_STATE_BEGIN;       // 通过 Bulk 端口发送读命令     bulkRead(( unsigned char *)&ufiCmdRunning. cbw , buf, ( unsigned char *)&ufiCmdRunning. csw );       return 0; }

注意：把扇区号由4字节长度的整数转换为4个字节，不能直接使用数据类型转换，因为USB协议要求在传输时是低字节在前，高字节在后。AM9200如果直接进行数据类型转换，则得到的结果正好相反。