Interacting with a device driver in Visual Studio .NET

Maker QR-Code in Visual Studio .NET Interacting with a device driver
12.4.6 Interacting with a device driver
Reading QR Code ISO/IEC18004 In VS .NET
Using Barcode Control SDK for Visual Studio .NET Control to generate, create, read, scan barcode image in Visual Studio .NET applications.
In previous sections, I have explained how device drivers are loaded and channels are opened using the device driver framework. The next stage is to service requests issued from user-side code. There are three main classes involved: 1. RBusLogicalChannel the user-side channel handle 2. DlogicalChannelBase the kernel-side requests in the context of the client thread) channel (receives
QR Code Generator In Visual Studio .NET
Using Barcode maker for .NET Control to generate, create QR Code image in VS .NET applications.
3. DLogicalChannel the kernel-side channel (receives requests in the context of a separate kernel thread).
QR-Code Recognizer In VS .NET
Using Barcode recognizer for VS .NET Control to read, scan read, scan image in .NET framework applications.
DEVICE DRIVERS AND EXTENSIONS
Barcode Creator In Visual Studio .NET
Using Barcode creator for Visual Studio .NET Control to generate, create bar code image in .NET framework applications.
Note: In fact, there are four classes if you include the physical channel, DPhysicalChannel, but since this is a device speci c interface, I won t discuss its use until we start looking at our serial driver in more detail. I have already touched on these classes when discussing how device drivers are loaded and the channel is opened. Now I shall discuss how these are actually used in the context of a real device driver. 12.4.6.1 RBusLogicalChannel the user-side channel handle
Decode Barcode In VS .NET
Using Barcode recognizer for .NET Control to read, scan read, scan image in VS .NET applications.
The RBusLogicalChannel class is a user-side handle to a kernel-side logical channel (DLogicalChannelBase), and provides the functions required to open a channel to a device driver and to make requests:
Generate QR Code JIS X 0510 In C#
Using Barcode maker for .NET Control to generate, create QR Code JIS X 0510 image in VS .NET applications.
class RBusLogicalChannel : public RHandleBase { public: IMPORT_C TInt Open(RMessagePtr2 aMessage, TInt aParam, TOwnerType aType=EOwnerProcess); IMPORT_C TInt Open(TInt aArgumentIndex, TOwnerType aType=EOwnerProcess); protected: inline TInt DoCreate(const TDesC& aDevice, const TVersion& aVer, TInt aUnit, const TDesC* aDriver, const TDesC8* anInfo, TOwnerType aType=EOwnerProcess, TBool aProtected=EFalse); IMPORT_C void DoCancel(TUint aReqMask); IMPORT_C void DoRequest(TInt aReqNo, TRequestStatus& aStatus); IMPORT_C void DoRequest(TInt aReqNo, TRequestStatus& aStatus, TAny* a1); IMPORT_C void DoRequest(TInt aReqNo, TRequestStatus& aStatus, TAny* a1,TAny* a2); IMPORT_C IMPORT_C IMPORT_C private: IMPORT_C TInt DoControl(TInt aFunction); TInt DoControl(TInt aFunction, TAny* a1); TInt DoControl(TInt aFunction, TAny* a1,TAny* a2); TInt DoCreate(const TDesC& aDevice, const TVersion& aVer, TInt aUnit, const TDesC* aDriver, const TDesC8* aInfo, TInt aType);
Quick Response Code Printer In VS .NET
Using Barcode creation for ASP.NET Control to generate, create QR Code image in ASP.NET applications.
Note: If you have access to the EKA2 source code, you will nd that the real class is slightly more complex than the version given here. The extra methods and data are mainly provided to maintain binary compatibility with the EKA1 kernel, since this is the user-side interface to the device
Generate QR Code JIS X 0510 In VB.NET
Using Barcode drawer for .NET framework Control to generate, create QR-Code image in Visual Studio .NET applications.
DEVICE DRIVERS
Print GS1 - 13 In .NET
Using Barcode generator for .NET Control to generate, create EAN-13 image in VS .NET applications.
driver. See Section 12.5 for more on the differences between the EKA1 and EKA2 device driver framework. RBusLogicalChannel provides the following functionality: Creation of the logical channel (discussed in the previous section) DoRequest performs an asynchronous operation DoControl perform a synchronous operation DoCancel cancel an outstanding asynchronous request. See Figure 12.7. All but two of the methods provided by RBusLogicalChannel are protected, so the client can do nothing useful with this class directly; it needs a derived interface, speci c to the implementation of the device driver. The usual way to do this is to provide a header le to de ne the class and an inline le to provide the implementation, and include both in the client-side code at build time. As an example, let s look at how I would provide an interface to my example serial driver:
Bar Code Creation In VS .NET
Using Barcode drawer for .NET framework Control to generate, create bar code image in .NET applications.
class RSimpleSerialChannel : public RBusLogicalChannel { public: enum TVer { EMajorVersionNumber=1, EMinorVersionNumber=0, EBuildVersionNumber=KE32BuildVersionNumber }; enum TRequest { ERequestRead=0x0, ERequestReadCancel=0x1, ERequestWrite=0x1, ERequestWriteCancel=0x2, }; enum TControl { EControlConfig, EControlSetConfig }; public: #ifndef __KERNEL_MODE__ inline TInt Open(TInt aUnit); inline TVersion VersionRequired() const; inline void Read(TRequestStatus& aStatus, TDes8& aDes); inline void ReadCancel(); inline void Write(TRequestStatus& aStatus, const TDesC8& aDes); inline void WriteCancel(); inline void Config(TDes8& aConfig); inline TInt SetConfig(const TDesC8& aConfig); #endif }; #include <simpleserial.inl>
Bar Code Printer In .NET
Using Barcode encoder for Visual Studio .NET Control to generate, create bar code image in .NET applications.
The shaded box represents a class implemented by the example driver RDriver1 GetConfig()
RM4SCC Encoder In VS .NET
Using Barcode maker for .NET framework Control to generate, create British Royal Mail 4-State Customer Barcode image in .NET applications.
DEVICE DRIVERS AND EXTENSIONS
Scanning UPC - 13 In .NET
Using Barcode reader for .NET Control to read, scan read, scan image in VS .NET applications.
RBusLogicalChannel
Recognize Code-39 In Visual Studio .NET
Using Barcode decoder for VS .NET Control to read, scan read, scan image in Visual Studio .NET applications.
DoControl() SetConfig() SendData() DoRequest() ReceiveData() SendDataCancel() DoCancel() ReceiveDataCancel()
Making Bar Code In .NET Framework
Using Barcode maker for ASP.NET Control to generate, create barcode image in ASP.NET applications.
user kernel DLogicalChannel Request() DLogicalChannelBase Request() = 0
UPC-A Supplement 2 Printer In Java
Using Barcode maker for Java Control to generate, create UPC-A Supplement 2 image in Java applications.
Figure 12.7 Mapping the user-side API to RBusLogicalChannel
Making ECC200 In C#
Using Barcode generator for .NET Control to generate, create Data Matrix image in VS .NET applications.
The implementation is in the corresponding inline le:
EAN / UCC - 13 Generator In Java
Using Barcode creator for Java Control to generate, create EAN-13 image in Java applications.
#ifndef __KERNEL_MODE__ _LIT(KDeviceName,"Serial"); inline TInt RSimpleSerialChannel::Open(TInt aUnit) { return(DoCreate(KDeviceName,VersionRequired(), aUnit,NULL,NULL)); } inline TVersion RSimpleSerialChannel::VersionRequired() const { return(TVersion(EMajorVersionNumber, EMinorVersionNumber, EBuildVersionNumber)); } inline void RSimpleSerialChannel::Read(TRequestStatus&aStatus, TDes8& aDes) { TInt len=aDes.MaxLength(); DoRequest(ERequestRead,aStatus,&aDes,&len); } inline void RSimpleSerialChannel::ReadCancel() DoCancel(ERequestReadCancel); inline void RSimpleSerialChannel::Write(TRequestStatus& aStatus, const TDesC8& aDes)
Barcode Scanner In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
Recognize ECC200 In Visual Studio .NET
Using Barcode recognizer for Visual Studio .NET Control to read, scan read, scan image in Visual Studio .NET applications.