请帮小弟我分析一下这个错误产生的原因

请帮我分析一下这个异常产生的原因
经过昨天的努力，终于把串口的MDD层代码移植到BSP下了，并且调试成功了2440的三个自带串口的驱动。但是不知道怎么回事，两个外部扩展串口却不行，在加载驱动的时候产生异常。
在SL_Initq函数出现了问题。
SL_Initq, 0x9BA5A0
pRegBase, 0x0
pHWHead->pIER = 1
pHWHead->pIIR_FCR = 2
pHWHead->pLCR = 3
pHWHead->pMCR = 4
pHWHead->pLSR = 5
pHWHead->pMSR = 6
pHWHead->pIER = 7
pBaudTable != NULL 0x98B2BBF0
Data Abort Test@@@@@@-before OUTB(pHWHead, pIER, 0x0f);
Data Abort: Thread=98b2bbf0 Proc=81d46340 'device.exe'
AKY=00001005 PC=03d723bc(ceddk.dll+0x000023bc) RA=01e29f34(wogoser2440.dll+0x00009f34) BVA=06000001 FSR=00000007
RaiseException: Thread=98b2bbf0 Proc=81d46340 'device.exe'
AKY=00001005 PC=03f8dfec(coredll.dll+0x0001dfec) RA=802135e8(NK.EXE+0x000135e8) BVA=00000001 FSR=00000001

经过串口信息+map文件查看，发现代码是在OUTB(pHWHead, pIER, 0x0f);这句发生了异常
OUTB(pHWHead, pIER, 0x0f);原型是
#define OUTB(pInfo, reg, value) (WRITE_PORT_UCHAR((UCHAR *)((pInfo)->reg), (unsigned char)(value)))
WRITE_PORT_UCHAR是属于CEDDK.DLL的
NTKERNELAPI
VOID
WRITE_PORT_UCHAR(
  PUCHAR Port,
  UCHAR Value
  );

说明刚开始我以为是pHWHead这个指针出现了问题，但是我发现不是，因为在前面已经使用了它，并没有发生异常。
关于pHWHead是这样定义的：PSER16550_INFO pHWHead = (PSER16550_INFO)pHead;

在map文件中，直接指明(WRITE_PORT_UCHAR((UCHAR *)((pInfo)->reg), (unsigned char)(value)))出问题。

现在我怎么也想不通是什么造成的。因为这个串口代码本来是在4.2BSP下运行的，现在我只是修改了中断相关代码而已。怎么放到5.0BSP就产生异常对了呢？以前大学都是调试单片机，代码比较简单，对这个异常几乎没有什么经验处理。请大家帮忙分析一下，谢谢。

[解决办法]
没有正确使用WRITE_PORT_UCHAR（ ）这个函数？有没进行参数检查？最好调此函数前进行参数检查，无效指针就不要传了，直接返回。我一次就是因为无效指针引起异常的。
[解决办法]

C/C++ code

//// @doc HWINTERNAL// @struct LS_SERIAL_INFO | Passed to serial lib routines.//         typedef struct __LS_SERIAL_INFO    {         // Store volatile pointers to each 16550 register         volatile PUCHAR pData;           // @field RX data / Transmit Holding Reg        volatile PUCHAR pIER;            // @field Interrupt Enable        volatile PUCHAR pIIR_FCR;        // @field read IIR (Int ID) / Write FCR (FIFO Ctrl)        volatile PUCHAR pLCR;            // @field Line Control        volatile PUCHAR pMCR;            // @field Modem Control        volatile PUCHAR pLSR;            // @field Line Status        volatile PUCHAR pMSR;            // @field Modem Status        volatile PUCHAR pScratch;        // @field Scratch Register         // And we keep shadows of many of the 16550 registers        UCHAR        FCR;            // @field FIFO control state.         UCHAR        IIR;            // @field State of Interrupt Identification Register.         UCHAR        LSR;            // @field Line Status Register.         UCHAR        MSR;            // @field Modem Status Register.          // We wouldn't normally shadow these, except for power on/off        UCHAR        IER;            // @field Interrupt Enable Register.         UCHAR        LCR;            // @field Line Control Register.         UCHAR        MCR;            // @field Modem Control Register.         UCHAR        Scratch;        // @field Scratch Register.                 // We have an event callback into the MDD        EVENT_FUNC EventCallback; // This callback exists in MDD        PVOID        pMddHead;  // This is the first parm to callback                 // Keep a copy of DCB since we rely on may of its parms        DCB         dcb;        // @field Device Control Block (copy of DCB in MDD)         // And the same thing applies for CommTimeouts        COMMTIMEOUTS CommTimeouts;  // @field Copy of CommTimeouts structure                 // Misc fields used by ser16550 library        ULONG        OpenCount;        // @field Count of simultaneous opens.         PLOOKUP_TBL pBaudTable;     // @field Pointer to Baud Table        ULONG        DroppedBytes;    // @field Number of dropped bytes         HANDLE        FlushDone;        // @field Handle to flush done event.        BOOL        CTSFlowOff;        // @field Flag - CTS flow control state.         BOOL        DSRFlowOff;        // @field Flag - DSR flow control state.         BOOL        AddTXIntr;        // @field Flag - Fake a TX intr.        COMSTAT        Status;         // @field Bitfield representing Win32 comm status.         ULONG        CommErrors;        // @field Bitfield representing Win32 comm error status.         ULONG        ModemStatus;    // @field Bitfield representing Win32 modem status.         CRITICAL_SECTION    TransmitCritSec; // @field Protects UART Registers for non-atomic accesses        CRITICAL_SECTION    RegCritSec; // @field Protects UART         ULONG        ChipID;            // @field Chip identifier (CHIP_ID_16550 or CHIP_ID_16450)                BOOL        PowerDown;      // did we power down the chip        BOOL        bSuspendResume; // Indicate Suspend/Resume happens        //        // now hardware specific fields Duplicated Info        DWORD       dwIrq;          // IRQ field        DWORD       dwSysIntr;       // @field System Interrupt number for this peripheral        PVOID       pVirtualStaticAddr;// Static Address.        WCHAR       RegIsrDll[DEVDLL_LEN];// ISR Dll name.        WCHAR       RegIsrHandler[DEVENTRY_LEN];//ISR Handle Name.        volatile ISR16550_INFO * pIsrInfoVirt;        volatile XmitDataBuffer    * pXmitBuffer;        volatile RcvDataBuffer     * pReceiveBuffer;        HANDLE          hIsrHandler;        BOOL            bMoreXmitData;// For software xmit buffering        DWORD           dwIsrIndex; // For test only    } SER16550_INFO, *PSER16550_INFO; 
 
[解决办法]
把串口的MDD层代码移植到BSP,这个想法不错。同一个驱动，放两个地方。不说别的，查看都麻烦！