PERIPHERAL SUPPORT in .NET framework

Drawer QR Code ISO/IEC18004 in .NET framework PERIPHERAL SUPPORT
PERIPHERAL SUPPORT
Scanning QR Code In .NET Framework
Using Barcode Control SDK for Visual Studio .NET Control to generate, create, read, scan barcode image in Visual Studio .NET applications.
Again, since this user-side interface header is also included in the kernel-side implementation of the driver, I use #ifndef__KERNEL_MODE__ around the user-side speci c methods to prevent compiler errors when building the kernel-side driver see Section 12.4.6.1 for more details. Here is the driver class de nition:
QR Code JIS X 0510 Creator In .NET
Using Barcode printer for VS .NET Control to generate, create QR Code JIS X 0510 image in .NET applications.
// Driver object making use of shared chunks class DMyDevice : public DBase { ... private: TInt CreateChunk(TInt aChunkSize); void CloseChunk(); TInt MakeChunkHandle(DThread* aThread); TInt InitDma(); static void WrDmaService(DDmaRequest::TResult aResult, TAny* aArg); TInt InitiateWrite(TInt aBufNo,TUint aBufOffset, TInt aLen,TRequestStatus* aStatus); private: DThread* iClient; TRequestStatus* iWrStatus; DChunk* iChunk; TLinAddr iChunkKernAddr; TUint32 iBuf1PhysAddr; TUint32 iBuf2PhysAddr; TDmaChannel* iDmaChannel; DDmaRequest* iDmaRequest; };
Read QR-Code In .NET
Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in .NET applications.
The member iChunk is a pointer to the shared chunk created and iChunkKernAddr is the base address of this in the kernel process. The member iClient is the user thread that opened the channel. This will be used when creating a handle on the shared chunk for that thread. The members iBuf1PhysAddr and iBuf2PhysAddr save the physical addresses of the two buffers. This information will allow us to specify physical rather than linear addresses for DMA data transfers from these buffers, which is more ef cient.
Draw Barcode In .NET Framework
Using Barcode maker for VS .NET Control to generate, create barcode image in Visual Studio .NET applications.
13.2.6.1 Operations on opening and closing the driver
Decode Bar Code In .NET Framework
Using Barcode recognizer for Visual Studio .NET Control to read, scan read, scan image in VS .NET applications.
The following code shows how the driver creates the shared chunk and commits memory to the pair of buffers. It commits physically contiguous RAM pages and disables caching. Each buffer is the shared chunk equivalent of that created in the example code, shown in Section 13.1.3. In this case, we leave an uncommitted page either side of each buffer; these act as guard pages. If the user application writes beyond the buffer region when it is lling one of the buffers with the transmission data, this will panic the application rather than corrupting adjacent memory regions in the chunk:
Paint Denso QR Bar Code In C#
Using Barcode encoder for VS .NET Control to generate, create QR image in VS .NET applications.
SHARED CHUNKS
Painting QR-Code In Visual Studio .NET
Using Barcode encoder for ASP.NET Control to generate, create QR image in ASP.NET applications.
TInt DMyDevice::CreateChunk(TInt aChunkSize) { // Round the chunk size supplied upto a multiple of the // MMU page size. Check size specified is large enough. aChunkSize=Kern::RoundToPageSize(aChunkSize); __ASSERT_DEBUG(aChunkSize>=((3*KGuardPageSize)+ (KMyDeviceBufSize<<1)),Panic(KMyDevPanicChunkCreate)); // Thread must be in critical section to create a chunk NKern::ThreadEnterCS(); // Create the shared chunk. TChunkCreateInfo info; info.iType = TChunkCreateInfo::ESharedKernelMultiple; info.iMaxSize = aChunkSize; info.iMapAttr = EMapAttrFullyBlocking; // No caching info.iOwnsMemory = ETrue; // Using RAM pages info.iDestroyedDfc = NULL; // No chunk destroy DFC DChunk* chunk; TUint32 mapAttr; TInt r = Kern::ChunkCreate(info,chunk,iChunkKernAddr, mapAttr); if (r!=KErrNone) { NKern::ThreadLeaveCS(); return(r); } // Map two buffers into the chunk each containing // physically contiguous RAM pages. Both buffers // surrounded by 4K guard pages. TInt bufOffset=KGuardPageSize; r=Kern::ChunkCommitContiguous(chunk,bufOffset, KMyDeviceBufSize,iBuf1PhysAddr); if (r==KErrNone) { bufOffset+=(KMyDeviceBufSize+KGuardPageSize); r=Kern::ChunkCommitContiguous(chunk,bufOffset, KMyDeviceBufSize,iBuf2PhysAddr); } if (r!=KErrNone) Kern::ChunkClose(chunk); // Commit failed tidy-up. else iChunk=chunk; NKern::ThreadLeaveCS(); return(r); }
Generate Denso QR Bar Code In Visual Basic .NET
Using Barcode generator for .NET framework Control to generate, create Denso QR Bar Code image in .NET framework applications.
The following code shows how the driver closes the chunk again:
EAN 13 Creator In Visual Studio .NET
Using Barcode creator for VS .NET Control to generate, create EAN-13 Supplement 5 image in Visual Studio .NET applications.
void DMyDevice::CloseChunk() { // Thread must be in critical section to close a chunk NKern::ThreadEnterCS(); // Close chunk if (iChunk) Kern::ChunkClose(iChunk);
Printing Barcode In Visual Studio .NET
Using Barcode generator for VS .NET Control to generate, create bar code image in VS .NET applications.
PERIPHERAL SUPPORT
Encode GS1 - 12 In Visual Studio .NET
Using Barcode generation for .NET framework Control to generate, create UPC-A Supplement 2 image in .NET applications.
// Can leave critical section now NKern::ThreadLeaveCS(); }
Draw Planet In .NET
Using Barcode creation for Visual Studio .NET Control to generate, create Planet image in Visual Studio .NET applications.
Next we see how the driver initializes the DMA objects required for data transfer. First it opens a DMA channel for data transfer. In this simple example, it only asks the framework to reserve one descriptor, since we assume a controller supporting a single buffer scheme and we allow only one DMA request to be outstanding at any time. KPlatDevice1TxChan is the platform-speci c channel identi er, which in this example selects data transmission over the peripheral device concerned. The driver elects to use DFC thread 0 to queue the DMA channel s DFC. Next it constructs a single request object, specifying the callback function as DMyDevice::WrDmaService() and passing a pointer to itself as the callback argument:
Bar Code Generator In Java
Using Barcode drawer for Java Control to generate, create barcode image in Java applications.
TInt DMyDevice::InitDma() { // Open and configure the channel for data // transmission TDmaChannel::SCreateInfo info; info.iCookie = KPlatDevice1TxChan; info.iDesCount = 1; info.iDfcPriority = 4; info.iDfcQ = Kern::DfcQue0(); TInt r = TDmaChannel::Open(info,iDmaChannel); if (r!=KErrNone) return(r); // We re only ever going to have one // outstanding transfer iDmaRequest = new DDmaRequest(*iDmaChannel, DMyDevice::WrDmaService, this); if (iDmaRequest == NULL) return(KErrNoMemory); return(KErrNone); }
UPC-A Supplement 5 Creator In Java
Using Barcode printer for Java Control to generate, create GTIN - 12 image in Java applications.
Scanning Bar Code In .NET
Using Barcode decoder for .NET Control to read, scan read, scan image in .NET framework applications.
Generate Code 3 Of 9 In Visual Basic .NET
Using Barcode generation for .NET Control to generate, create Code 39 Extended image in .NET framework applications.
Recognizing Code-128 In .NET Framework
Using Barcode scanner for .NET Control to read, scan read, scan image in .NET framework applications.