#define IOP_BASE 0xB1600000
typedef struct {
unsigned int rGPACON; // 00 怎么确定rGPACON为0x56000000？？
unsigned int rGPADAT;
unsigned int rPAD1[2];
unsigned int rGPBCON; // 10
unsigned int rGPBDAT;
unsigned int rGPBUP;
unsigned int rPAD2;
unsigned int rGPCCON; // 20
unsigned int rGPCDAT;
unsigned int rGPCUP;
unsigned int rPAD3;
unsigned int rGPDCON; // 30
unsigned int rGPDDAT;
unsigned int rGPDUP;
unsigned int rPAD4;
unsigned int rGPECON; // 40
unsigned int rGPEDAT;
unsigned int rGPEUP;
unsigned int rPAD5;
unsigned int rGPFCON; // 50
unsigned int rGPFDAT;
unsigned int rGPFUP;
unsigned int rPAD6;
unsigned int rGPGCON; // 60
unsigned int rGPGDAT;
unsigned int rGPGUP;
unsigned int rPAD7;
unsigned int rGPHCON; // 70
unsigned int rGPHDAT;
unsigned int rGPHUP;
unsigned int rPAD8;
unsigned int rMISCCR; // 80
unsigned int rDCKCON;
unsigned int rEXTINT0;
unsigned int rEXTINT1;
unsigned int rEXTINT2; // 90
unsigned int rEINTFLT0;
unsigned int rEINTFLT1;
unsigned int rEINTFLT2;
unsigned int rEINTFLT3; // A0
unsigned int rEINTMASK;
unsigned int rEINTPEND;
unsigned int rGSTATUS0; // AC
unsigned int rGSTATUS1; // B0
unsigned int rGSTATUS2; // B4 ;;; SHL
unsigned int rGSTATUS3; // B8
unsigned int rGSTATUS4; // BC
unsigned int rFLTOUT; // C0
unsigned int rDSC0;
unsigned int rDSC1;
unsigned int rMSLCON;
unsigned int rGPJCON; // D0
unsigned int rGPJDAT;
unsigned int rGPJUP;
unsigned int rPAD9;
}IOPreg;
如上怎样确定rGPACON、rGPADAT、rGPBDAT、rGPBDAT地址？
------解决方案--------------------
结构体里面都是unsigned int的，只要定义好IOPreg所声明的变量的位置就可以了。
struch IOPreg IOReg_var __attribute__((at(0x56000000)))
看到你结构体里面都是顺序放置的，这种情况还比较好，但是如果里面的顺序混乱了？就不好维护了。一般情况下使用楼上的链接里面的方式更直观一些，也好更改。