SharpDevelop Community

Hi i have install the libusb-win32 and i am trying to get a driver for the Microsoft Fingerprint Reader. However when i download SharpUSBLib and run the demo.exe that is the found that i get.

System.AccessViolationException was unhandled
  Message="Attempted to read or write protected memory. This is often an indication that other memory is corrupt."
  Source="ICSharpCode.USBlib"
  StackTrace:
       at ICSharpCode.USBlib.Internal.NativeMethods.usb_open(usb_device dev)
       at ICSharpCode.USBlib.Device..ctor(Descriptor descriptor)
       at ICSharpCode.USBlib.Descriptor.OpenDevice()

I run the demo.exe in debug mode using Visual Studio and found that. 

     libusb0.dll!100032da()     
     [Frames below may be incorrect and/or missing, no symbols loaded for libusb0.dll]    
     ntdll.dll!7c910f46()     
     mscorwks.dll!79e74753()     
     mscorwks.dll!79e783e6()     
     mscorwks.dll!79e7c1d7()     
     mscorwks.dll!79e7c1c5()     

Is there anything to do iwth ntdll.dll?  What can i do in this case?

Thanks you very much for answer my question.

Best regard

Maverick 

hai i'm also facing the same problem..with libusb... since i'm working in vc++ ,i'm getting runtime error as

 C:\WINNT\system32\ntdll.dll', no matching symbolic information found.
Loaded 'C:\WINNT\system32\KERNEL32.DLL', no matching symbolic information found.

if u could suggest me the way what u've done with ur error,it would b gr8!!!

thanks in advance!!!!!! 

hello usha,

yesterday i started on usb developing with #usblib and i had the same problem.

Good news for you: I have fixed the problem.

I've contacted Mike, that i want to take over the project.

So may be in a couple of days i can release a new version.

Greetings 

I have been using ICSharpCode.USBLib for about a year on Windows XP with no problem and ran into similar issue once I switched over to Vista. Precisely, AccessViolationException is thrown from .NET marshaling code after the call to usb_get_busses() function in libusb0. I started deeper exploration of this issue yesterday but could not get it fixed yet.

Best regards,

Alexei Adadurov

Well, it seems that I ran in another issue, not this one. :-)

I managed to fix it last night so if someone needs the patch that makes it work on both Window XP and Windows Vista -- just contact me.

Let me know if you get access to the project files.  In the mean time here is my patch to get things working on Linux.  I haven't got around to fixing this for Win32.

diff -urb SharpUSBlib20041208.Orig/SharpUSBlib/src/ICSharpCode.USBlib/USB/Bus.cs SharpUSBlib20041208/SharpUSBlib/src/ICSharpCode.USBlib/USB/Bus.cs
--- SharpUSBlib20041208.Orig/SharpUSBlib/src/ICSharpCode.USBlib/USB/Bus.cs	2004-12-08 09:20:16.000000000 +1100
+++ SharpUSBlib20041208/SharpUSBlib/src/ICSharpCode.USBlib/USB/Bus.cs	2008-03-03 17:32:13.000000000 +1100
@@ -6,6 +6,7 @@
 //
 using System;
 using ICSharpCode.USBlib.Internal;
+using System.Runtime.InteropServices;
 
 namespace ICSharpCode.USBlib
 {
@@ -23,15 +24,16 @@
 				NativeMethods.usb_init();
 				int rc = NativeMethods.usb_find_busses();
 				if (rc <= 0) {
-					throw new MethodCallUsbException("usb_find_busses", rc);
+					//throw new MethodCallUsbException("usb_find_busses", rc);
 				}
 				
 				rc = NativeMethods.usb_find_devices();
 				if (rc <= 0) {
-					throw new MethodCallUsbException("usb_find_devices", rc);
+					//throw new MethodCallUsbException("usb_find_devices", rc);
 				}
 				
-				for (usb_bus bus = NativeMethods.usb_get_busses(); bus != null; bus = bus.Next) {
+                		usb_bus root_bus = (usb_bus)Marshal.PtrToStructure(NativeMethods.usb_get_busses(), typeof(usb_bus));
+                		for (usb_bus bus = root_bus; bus != null; bus = bus.Next) {
 					busCollection.Add(new Bus(bus));
 				}
 				return busCollection;
@@ -65,5 +67,9 @@
 		{
 			return String.Format("[Bus: DirectoryName = {0}]", DirectoryName);
 		}
+
+		public string GetLastUsbError() {
+			return NativeMethods.usb_strerror();
+		}
 	}
 }
diff -urb SharpUSBlib20041208.Orig/SharpUSBlib/src/ICSharpCode.USBlib/USB/Descriptor.cs SharpUSBlib20041208/SharpUSBlib/src/ICSharpCode.USBlib/USB/Descriptor.cs
--- SharpUSBlib20041208.Orig/SharpUSBlib/src/ICSharpCode.USBlib/USB/Descriptor.cs	2004-12-08 09:20:12.000000000 +1100
+++ SharpUSBlib20041208/SharpUSBlib/src/ICSharpCode.USBlib/USB/Descriptor.cs	2008-03-03 17:34:27.000000000 +1100
@@ -13,7 +13,7 @@
 	/// 
 	/// Description of Descriptor.
 	/// 
-	public class Descriptor
+	public class Descriptor : IEquatable
 	{
 		usb_device nativeDevice;
 		
@@ -73,5 +73,14 @@
 			                     DeviceClass
 			                    );
 		}
+
+		public bool Equals(Descriptor other)
+		{
+			return (this.DescriptorType == other.DescriptorType)
+				&& (this.DeviceClass == other.DeviceClass)
+				&& (this.FileName == other.FileName)
+				&& (this.ProductId == other.ProductId)
+				&& (this.VendorId == other.VendorId);
+		}
 	}
 }
diff -urb SharpUSBlib20041208.Orig/SharpUSBlib/src/ICSharpCode.USBlib/USB/Device.cs SharpUSBlib20041208/SharpUSBlib/src/ICSharpCode.USBlib/USB/Device.cs
--- SharpUSBlib20041208.Orig/SharpUSBlib/src/ICSharpCode.USBlib/USB/Device.cs	2004-12-08 09:20:12.000000000 +1100
+++ SharpUSBlib20041208/SharpUSBlib/src/ICSharpCode.USBlib/USB/Device.cs	2008-03-03 17:26:24.000000000 +1100
@@ -89,21 +89,17 @@
 			if (this.deviceHandle == IntPtr.Zero) {
 				throw new UsbException("Can't open device.");
 			}
-			/*
-			int rc = NativeMethods.usb_set_configuration(deviceHandle, 1);
-			if (rc < 0) {
-				throw new MethodCallUsbException("usb_set_configuration", rc);
-			}
-			rc = NativeMethods.usb_claim_interface(deviceHandle, 0);
-			if (rc < 0) {
-				throw new MethodCallUsbException("usb_claim_interface", rc);
-			}
 			
-			rc = NativeMethods.usb_set_altinterface(deviceHandle, 0);
-			if (rc < 0) {
-				throw new MethodCallUsbException("usb_set_altinterface", rc);
-			}*/
+			int rc;
+			int retries = 4;
+			while (((rc = NativeMethods.usb_claim_interface(this.deviceHandle, 0)) < 0) && (retries-- > 0)) {
+				Console.WriteLine("Attempting to claim interface: rc = " + rc);
 			
+				rc = NativeMethods.usb_detach_kernel_driver_np(this.deviceHandle, 0);
+				Console.WriteLine("Attempting to detach kernel driver: rc = " + rc);
+			}
+			if (rc < 0)
+				throw new MethodCallUsbException("usb_claim_interface", rc);
 		}
 		
 		void CheckDeviceOpen()
@@ -125,16 +121,16 @@
 			NativeMethods.usb_bulk_read(deviceHandle, endpoint, bytes, timeout);
 		}
 		
-		public void InterruptWrite(int endpoint, byte[ bytes)
+		public int InterruptWrite(int endpoint, byte[ bytes)
 		{
 			CheckDeviceOpen();
-			NativeMethods.usb_interrupt_write(deviceHandle, endpoint, bytes, timeout);
+			return NativeMethods.usb_interrupt_write(deviceHandle, endpoint, bytes, timeout);
 		}
 		
-		public void InterruptRead(int endpoint, byte[ bytes)
+		public int InterruptRead(int endpoint, byte[ bytes)
 		{
 			CheckDeviceOpen();
-			NativeMethods.usb_interrupt_read(deviceHandle, endpoint, bytes, timeout);
+			return NativeMethods.usb_interrupt_read(deviceHandle, endpoint, bytes, timeout);
 		}
 		
 		public void SendControlMessage(int requestType, int request, int val, byte[ bytes)
diff -urb SharpUSBlib20041208.Orig/SharpUSBlib/src/ICSharpCode.USBlib/USB/Internal/NativeCode.cs SharpUSBlib20041208/SharpUSBlib/src/ICSharpCode.USBlib/USB/Internal/NativeCode.cs
--- SharpUSBlib20041208.Orig/SharpUSBlib/src/ICSharpCode.USBlib/USB/Internal/NativeCode.cs	2004-12-08 09:20:12.000000000 +1100
+++ SharpUSBlib20041208/SharpUSBlib/src/ICSharpCode.USBlib/USB/Internal/NativeCode.cs	2008-03-03 17:29:06.000000000 +1100
@@ -329,6 +329,10 @@
 		
 		public IntPtr dev    = IntPtr.Zero;		// Darwin support
 		
+		public byte devnum;
+		public byte num_children;
+		public IntPtr children = IntPtr.Zero;
+
 		public override string ToString()
 		{
 			return String.Format("[usb_device: filename={0}, next={1}, prev={2}, bus={3}, descriptor={4}, config={5}, dev={6}]",
@@ -395,6 +399,7 @@
 		
 		public IntPtr devices= IntPtr.Zero;
 		public uint location = 0;
+		public IntPtr root_dev = IntPtr.Zero;
 		
 		public usb_bus Next {
 			get {
@@ -424,12 +429,13 @@
 		
 		public override string ToString()
 		{
-			return String.Format("[usb_bus: dirname={0}, next={1}, prev={2}, Devices={3}, location={4}]",
+			return String.Format("[usb_bus: dirname={0}, next={1}, prev={2}, Devices={3}, location={4}, root_dev={5}]",
 			                     dirname,
 			                     next,
 			                     prev,
 			                     Devices,
-			                     location);
+				location,
+				root_dev);
 		}
 	};
 	
@@ -578,9 +584,12 @@
 		public static extern int usb_find_devices();
 		
 		[DllImport(LIBUSB_NATIVE_LIBRARY, CallingConvention = CALLING_CONVENTION, ExactSpelling = true), SuppressUnmanagedCodeSecurity]
-		public static extern usb_device usb_device(IntPtr dev);
+		public static extern IntPtr usb_device(IntPtr dev);
+		
+		[DllImport(LIBUSB_NATIVE_LIBRARY, CallingConvention = CALLING_CONVENTION, ExactSpelling = true), SuppressUnmanagedCodeSecurity]
+		public static extern IntPtr usb_get_busses();
 		
 		[DllImport(LIBUSB_NATIVE_LIBRARY, CallingConvention = CALLING_CONVENTION, ExactSpelling = true), SuppressUnmanagedCodeSecurity]
-		public static extern usb_bus usb_get_busses();
+		public static extern int usb_detach_kernel_driver_np(IntPtr dev, int interfaceNum);
 	}
 }
diff -urb SharpUSBlib20041208.Orig/SharpUSBlib/src/ICSharpCode.USBlib/USB/USBException.cs SharpUSBlib20041208/SharpUSBlib/src/ICSharpCode.USBlib/USB/USBException.cs
--- SharpUSBlib20041208.Orig/SharpUSBlib/src/ICSharpCode.USBlib/USB/USBException.cs	2004-12-08 09:20:12.000000000 +1100
+++ SharpUSBlib20041208/SharpUSBlib/src/ICSharpCode.USBlib/USB/USBException.cs	2008-03-03 17:26:39.000000000 +1100
@@ -67,7 +67,7 @@
 		{
 		}
 		
-		public MethodCallUsbException(string method, int returnCode) : base(NativeMethods.usb_strerror())
+		public MethodCallUsbException(string method, int returnCode)// : base(NativeMethods.usb_strerror())
 		{
 			this.method     = method;
 			this.returnCode = returnCode;