WMI接口设计实现

WMI是Windows操作系统管理数据和操作的基础设施，系统管理员可以使用VB Script、PowerShell及Windows API（C++、C#等）管理本地或远程计算机。
使用WMI框架应用程序可以直接访问EC RAM、 I/O端口、Memory地址、寄存器、Setup NV设定值，以及其他的系统设备资源。

一、Asl code设计

OemWMIDemo.asl

Scope(\_SB)
{
    Device(AMW1)//WMI
    {
        // pnp0c14 is Plug and Play ID assigned to WMI mapper
        Name(_HID, "PNP0C14")
        Name(_UID, "WMIDEMO")    
        // Description of data and events supported
        Name(_WDG, Buffer() {
            //
            // Event
            // GUID 93B56635-6D54-42D7-BB7D-DF77D452CCE4
            // BIOS can generator WMI event by Notify (<<WMI device name>>, 0xAC)
			//
            0x35, 0x66, 0xB5, 0x93, 0x54, 0x6D, 0xD7, 0x42, 0xBB, 0x7D, 0xDF, 0x77, 0xD4, 0x52, 0xCC, 0xE4,     // GUID
            0xAC, 0,       // Event Notification ID
            1,             // Instance Count
            0x08,          // Flags (WMIACPI_REGFLAG_EVENT)
			//
			// Method
            // GUID ABBC0FB8-8EA1-11D1-A000-C90629100000
            //
            0xB8, 0x0F, 0xBC, 0xAB, 0xA1, 0x8E, 0xD1, 0x11, 0xA0, 0x00, 0xC9, 0x06, 0x29, 0x10, 0, 0,
			0x44, 0x45,    // Object Id (DE)
			1,             // Instance Count
			0x02,          // Flags (WMIACPI_REGFLAG_METHOD)
            //
            // This GUID for returning the MOF data
            // 05901221-D566-11D1-B2F0-00A0C9062910
            0x21, 0x12, 0x90, 0x05, 0x66, 0xd5, 0xd1, 0x11, 0xb2, 0xf0, 0x00, 0xa0, 0xc9, 0x06, 0x29, 0x10,
            66, 68,        // Object ID (BD)
            1,             // Instance Count
            0x00,          // Flags(none)
        })

        Name(FEAC, Buffer(0x04)
        {
            0x00, 0x00, 0x00, 0x00
        })
        Method (EVAC, 0)
        {  
            Return (FEAC)               
        } // End of Method EVAC
		
		//
		// EcRAM Method data block
		// Arg0 has the instance being queried
		// Arg1 has the method id
		// Arg2 has the data passed
		Method(WMDE, 3)
		{
			//MethodId 1
			if(LEqual(Arg1, 1))
			{
				Store(Arg2, FEAC)
				Notify(AMW1, 0xAC)
				Return(0)
			}
		}
        
		// More info about an event
		// Arg0 is the event id that was fired
        Method(_WED, 1, NotSerialized)
        {
            If(LEqual(Arg0, 0xAC))
            {
                Return(EVAC())
            }
        }

        // -------- Compiled version of "Associated MOF File" below --------
        // Memo: generated by mofcomp.exe
        Name(WQBD, Buffer()
        {

        })
    }
}//end scope _SB

其中Mof GUID（0x21, 0x12, 0x90, 0x05, 0x66, 0xd5, 0xd1, 0x11, 0xb2, 0xf0, 0x00, 0xa0, 0xc9, 0x06, 0x29, 0x10）为固定值。

二、Mof code设计

OemWMIDemo.mof

[WMI, Dynamic, provider("WMIProv"),
 locale("MS\\0x409"), 
 GUID("{ABBC0FB8-8EA1-11D1-A000-C90629100000}"), 
 Description("Call BIOS Function through WMI")
]
class WmiDemo
{
	[key, read] 
	string InstanceName;
	
	[read] 
	Boolean Active;
	
	[WmiMethodId(1), 
	 Implemented, 
	 read, write, 
	 Description("My method 1")
	] void MyMethod1([inout, Description("My method 1")] uint32 Data);
	
};

[WMI, Dynamic, provider("WMIProv"),
 locale("MS\\0x409"), 
 GUID("{93B56635-6D54-42D7-BB7D-DF77D452CCE4}"), 
 Description("Event generated when machine is hit") 
]
class DemoWmiEvent : WMIEvent
{
	[key, read] 
	string InstanceName;
	
	[read] 
	Boolean Active;
	
	[WmiDataId(1),
	 read, write,
	 Description("Force with which the machine was hit")
	] uint32 Force;
};

三、编译Mof文件

工具：
mofcomp.exe为系统自带
wmimofck.exe可以从Windows WDK拷贝

将mof文件编译成bmf二进制文件

D:\WMI_Demo>mofcomp.exe -B:OemWMIDemo.bmf OemWMIDemo.mof
分析 MOF 文件: OemWMIDemo.mof
已成功分析 MOF 文件
将二进制 MOF 数据存储在 OemWMIDemo.bmf 中

Binary mof file OemWMIDemo.bmf expanded to 3126 bytes

使用wmimofck.exe可生成VBS脚本

D:\WMI_Demo>wmimofck.exe -tOemWMIDemo.vbs OemWMIDemo.bmf
Microsoft (R) WDM Extensions To WMI MOF Checking Utility  Version 1.50.0000
Copyright (c) Microsoft Corp. 1997-2000. All rights reserved.

Binary mof file OemWMIDemo.bmf expanded to 3126 bytes

使用wmimofck.exe将bmf二进制文件转成文本

D:\WMI_Demo>wmimofck.exe -x"WIMDemo.txt" OemWMIDemo.bmf
Microsoft (R) WDM Extensions To WMI MOF Checking Utility  Version 1.50.0000
Copyright (c) Microsoft Corp. 1997-2000. All rights reserved.

将文本中的内容填入asl文件中Name(WQBD, Buffer() { })的Buffer里。
在这里插入图片描述