The following driver for IRQ4 loads successfully .
But when an interrupt occurs, the ISR is not called. (the kdprint
statement is not executed!)
Is there any bug in the code ??
Experts please help.
Hope the following info might help:
The values HalGetInterruptVector returns for IRQ 4 are
MappedVector = 0x00000034
Irql = 0x20206F17
Affinity = 1
Please Note: The assembly code is checked correct. I wrote a linux
driver with the same assembly code in appropriate place (init_module( )
function).
And everything worked fine. But on windows, there is a problem. The
ISRis not getting called.
Maybe I should use some extra additional API to enable interrupt
handling ???
The device is a serial port one which generates DCD interrupt on the
RS-232 port.
THE CODE:
BOOLEAN InterruptIsr(IN PKINTERRUPT Interrupt, IN OUT PVOID Context)
{
asm(“movw $0x20, %dx”);
asm(“movb $0x20, %al”);
asm(“out %al, %dx”);
KdPrint( (“Kiran.sys: Interrupt Service Routine\n”) );
return TRUE;
}
NTSTATUS STDCALL
DriverEntry( IN PDRIVER_OBJECT DriverObject, IN PUNICODE_STRING
RegistryPath )
{
NTSTATUS status;
PDEVICE_OBJECT DeviceObject;
UNICODE_STRING DeviceName;
UNICODE_STRING com1name;
UNICODE_STRING SymbolicLinkName;
ULONG MappedVector;
KIRQL Irql;
KAFFINITY Aff;
DriverObject->DriverUnload = kiran_unload;
/* initialize counted unicode strings */
RtlInitUnicodeString( &DeviceName, L"\Device\kiran" );
RtlInitUnicodeString( &SymbolicLinkName, L"\DosDevices\kiran"
);
/* create device object */
status = IoCreateDevice( DriverObject, 0, &DeviceName,
FILE_DEVICE_SERIAL_PORT, 0, FALSE, &DeviceObject );
if (!NT_SUCCESS( status ))
return status;
DeviceObject->Flags |= DO_BUFFERED_IO;
/* create user-visible name for the device */
status = IoCreateSymbolicLink( &SymbolicLinkName, &DeviceName );
if (!NT_SUCCESS( status ))
return status;
/* Create interrupt object */
MappedVector = HalGetInterruptVector(Internal,0, 4, 0, &Irql,
&Aff);
status = IoConnectInterrupt( &InterruptObject,
// InterruptObject
(PKSERVICE_ROUTINE)
InterruptIsr, // ServiceRoutine
DeviceObject,
// ServiceContext
NULL,
// SpinLock
MappedVector,
// Vector
Irql,
// Irql
Irql,
// SynchronizeIrql
Latched,
// InterruptMode
TRUE,
// ShareVector
Aff,
// ProcessorEnableMask
FALSE);
// FloatingSave
if (!NT_SUCCESS (status)) {
KdPrint((“Kiran.sys: IoConnectInterrupt Failed %x\n”,
status));
}
else {
KdPrint((“Kiran.sys: IoConnectInterrupt Succeed\n”));
}
/* Initialize the ports… */
/* The following assembly code read the data reg, modem status reg,
etc, of the UART */
asm(“movw $0x3FD, %dx”);
asm(“in %dx, %al”);
asm(“movw $0x3FA, %dx”);
asm(“in %dx, %al”);
asm(“movw $0x3F8, %dx”);
asm(“in %dx, %al”);
asm(“movw $0x3FE, %dx”);
asm(“in %dx, %al”);
/* The following assembly code sets the UART registers appropriately
so that DCD interrupts are enabled, RTS is set high, etc */
asm(“movw $0x3FB, %dx”);
asm(“movb $0x02, %al”);
asm(“out %al, %dx”);
asm(“movw $0x3FC, %dx”);
asm(“movb $0x0B, %al”);
asm(“out %al, %dx”);
asm(“movw $0x3F9, %dx”);
asm(“movb $0x01, %al”);
asm(“out %al, %dx”);
/* This assembly code enables the IRQ4 on the PIC */
asm(“movw $0x21, %dx”);
asm(“movb $0x00, %al”);
asm(“out %al, %dx”);*/
return STATUS_SUCCESS;
}
