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hi,can anyone please tell me how the switching from user mode to kernel mode in windows happens?
i mean what ensures that a user mode application does not make a cpu-mode switch and then jump into the kernel
or access hw directly?a short description of how and where the switching procedure happens would help a lot.
thanks
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Thread priority and time slicing take care of it.
When an app calls CreateFile(), the IO manager calls into the driver that owns this symbolic link, hitting its dispatch handler with an IRP_MJ_CREATE.
Same for WriteFIle() IRP_MJ_WRITE etc.
And, if the app has opened the file for sync IO, that calling thread in the app will be blocked untill the driver completes that IRP (IO Request Packet).
For data coming in, the driver will get an interupt, and this will absoloutely throw anything at a lower priority off the CPU and the system will call the drivers Interrupt handling routine.
You should look at stuff online about the NT scheduler, kernel, interupts, and so on (XP is still windows NT by the way)
Truth is the subjection of reality to an individuals perception
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Ah, and security. Memory in the virtual address space an app sits in is secured. So the app can only get to the bottom 2 gig on a 32 bit PC. The kernel has the top 2 gig.
Truth is the subjection of reality to an individuals perception
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I can only assume that you want to try and switch to Kernal Mode in the midst of your User Program. This is something that generally should not be needed in any user program. Windows puts up several layers of defence to stop you from doing so!, and for good reasons! (Remember Dos??)Read your Windows Documentation, find a way around whatever you want to achieve! In the long run, it is the better way, it is likely to continue on running with the next version of windows. If your program relies on anything in the kernal, it probably won't survive the next windows upgrade! (Don't be Stupid, I've Been there);)
LateNightsInNewry
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The Switching between User and Kernal mode, happens in the background, and is an issue that User Mode programmers(as opposed to System Mose Programmers, which are mostly those working for Microsoft, writing the Next version of Windows), should have NO Concern about! There are ways of putting the system in Kernal Mode, but, I'm Not going to tell you, because you sound like someone who has not a notion about how windows works. believe me, I am saving yourself, and the friends to whom you propose to pass your software on, from a lot of hassle which would ensue if you went that way!
Go the Windows Way, and use the WIN32 Api. Excepting special programs (e.g. Specialist Debuggers) Kernal Mode switching IS Not Needed!!!
LateNightsInNewry
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My cdrom worked well before. But now, when i put CD in it and read the content of the cd. The CPU shutdown. I dont known why!
May be i config bios wrong.
Please help before i mad.
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hey man some possible solutions could be:
1 Check out the connections inside the cabinet their could be an possible problem their ,provided u now thoroughly all the internal conections.
2 Ia'm not sure it could be an O.S problem ,so try reinstalling ur O.S aggain coz' i don't think their is any pboblem with ur CDROM
3 Since u haven't mentioned ur motherboard details so i can't say that a change in CDROM details would cost u those problems!
4 If notin works out then call an technician!!!!
hope I hade solved ur problem .
SOLutION for everytin !
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Hi!Sir,
I am a firmware designer of usb mass storage device. But every time when attach my device to a
new pc(to which my device ever not be attached),a system reboot message accur,but in fact i do not
need to reboot my system and my device still work well.
The title of the message is :"System Settings Change"
The message says:"Windows2000 has finishedinstalling new device,You must restart your computer before the new settimgs will take effect,do you want to restart your computer now?"
So my question is:
Which settings of my system have been changed to let system need restart?
Thanks for any answer!
momer
-- modified at 9:21 Tuesday 25th July, 2006
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2k is a pig. Ehat is it like on XP? If it OK, ignore 2k, it will be dead soon.
Truth is the subjection of reality to an individuals perception
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Hi Dear,
My Key board is UK based but it works like a USA based key baord.
How can I change it back to UK based Key board
as you know there are some key characters are different among them.
thanks
Naveed Kamboh
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Alt+Shift (left shift key)
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The keyboard layout - which characters appear when a given key is pressed - is under the control of the operating system, not the keyboard itself. In Windows XP and Server 2003, go to Control Panel, Regional and Language Options, Languages tab, click Details, then click Add. Select 'English - United Kingdom' from the Input Language drop-down, then 'United Kingdom' or 'United Kingdom Extended' from the Keyboard Layout/IME drop-down. Click OK.
You probably won't want the US keyboard layout even available for selection, so select 'US' under 'English - United States' and click Remove.
United Kingdom Extended is a new keyboard layout in Windows XP SP2 and Windows Server 2003 SP1. It allows a few more accented characters to be typed, compared to the standard UK layout. The standard layout only allows áÁéÉíÍóÓúÚ to be typed directly (press AltGr and the base character, plus Shift to get uppercase). The extended layout adds ẃẂýÝçÇ by typing with AltGr.
It converts the backquote key ` into a so-called dead key, which combines the grave accent with the key that follows (if available), e.g. ` followed by a = à. Pressing a key that doesn't combine produces the backquote followed by the key you pressed, so ` followed by c = `c. To get a backquote alone, press ` then the spacebar.
Four other key combinations produce dead keys which work in the same way: AltGr+2 combines an umlaut (two dots) with the next character, e.g. AltGr+2, a = ä. AltGr+6 combines a circumflex, e.g. AltGr+6, a = â. AltGr+# combines a tilde, e.g. AltGr+#, n = ñ. Finally AltGr+' combines an acute accent, e.g. AltGr+', a = á.
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What do you guys think?
A friend of mine is about to buy a new computer.. But he doesn't know wich to choose:
AMD X2 3800+. If the SKT is 939, DDRII 480MHz, else DDR, offcourse
So you guys think he should choose SKT939 or AM2? Why?
best regards
hint_54
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The performance gain between the two sockets is extremely close to zero since AMD's architecture is much less memory limited than Intel's. AM2 only adds DDR2 support, and the only reason it came out when it did is that the pricegap between DDR1 and DDR2 has shrank to almost zero, and in the future will swing in favor of DDR2 as DDR1 becomes an obsolesent technology and doesn't benefit from factory improvements. IF your friend doesn't plan on upgrading anything on the mobo, and can find a 939 system for significantly less buy it. IF he might need to add memory or a better CPU in the future or if the prices are almost identical, get the more futureproof AM2 system.
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I had the same dilema, did some research and ended up buying the 939 after discovering that AM2 has no real advantage (speedwise) over the 939 at the moment. In some cases (sorry cant remember the benchmark URL's) the 939 actually outperformed the AM2.
Going with AM2 meant i had to buy new RAM as well so, i just got the 939.
you can't forget something you never knew...
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Hi,
i lost my password in xp ,how to solve this problem
thanks
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If you haven't used windows to encrypt your files there're bootable linux iso's that have utilities to write a new password for a user account. If you've encrypted files they'll be inaccessable unles you recover the original password to unlock them.
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for (index=0; SetupDiEnumDeviceInterfaces(deviceInfo, 0, (LPGUID)&GUID_CLASS_USB, index, &DeviceInterfaceData); index++) {
memset(tempstr, 0, 1024);
deviceDetailData = (PSP_DEVICE_INTERFACE_DETAIL_DATA)tempstr;
deviceDetailData->cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA);
SetupDiGetDeviceInterfaceDetail(deviceInfo, &DeviceInterfaceData, deviceDetailData, 1024, &requiredLength, NULL);
hUSBHandle = CreateFile(deviceDetailData->DevicePath, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
CloseHandle(hUSBHandle);
}
I would like enumerate all usb devices and get their device address.
How could I do?
I counld use the following codes to get DeviceAddress.
DeviceIoControl(hHubDevice,IOCTL_USB_GET_NODE_CONNECTION_INFORMATION,connectionInfo, nBytes,connectionInfo,nBytes,&nBytes, NULL) ;
But how to get device address without through usbHub.
Thanks and regards
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how does the deviceDetailData->DevicePath look like???
I use GetLogicalDrives to retrieve all removable drives and get:
A:\, I:\...............(I:\ is my USB drive mount point).
But my application needs to determine which drive letter (mount point) is for the USB. Then use this mount point to access files stored in the root directory of the USB flash drive.
hUSBHandle = CreateFile(deviceDetailData->DevicePath, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
CloseHandle(hUSBHandle);
ReadFile returns false using this handle.
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Hi,
I am a newbie to DirectShow. Recently I am developing an Image Acquisition
software for a microscope. I want to save the parameters such as brightness,
hue and whitebalance, which are got from the IAMVideoProAmp interface to be
the default parameters for the next startup. However, I found if I set the
ColorEnable property to be manual, the saved values can not make a correct
display, especially the color, while the vidcap32.exe can. The following is
copied from the camera driver info ( *.set file):
;[OVT.9600.Properties]
;Standard properties
;PROPSETID_VIDCAP_VIDEOPROCAMP
; KSPROPERTY_VIDEOPROCAMP_BRIGHTNESS, // RW O 0
; KSPROPERTY_VIDEOPROCAMP_CONTRAST, // RW O 1
; KSPROPERTY_VIDEOPROCAMP_HUE, // RW O 2
; KSPROPERTY_VIDEOPROCAMP_SATURATION, // RW O 3
; KSPROPERTY_VIDEOPROCAMP_SHARPNESS, // RW O 4
; KSPROPERTY_VIDEOPROCAMP_GAMMA, // RW O 5
; KSPROPERTY_VIDEOPROCAMP_COLORENABLE, // RW O 6
; KSPROPERTY_VIDEOPROCAMP_WHITEBALANCE, // RW O 7
; KSPROPERTY_VIDEOPROCAMP_BACKLIGHT_COMPENSATION,// RW O 8
HKR,%9600Brit%,PropertyId,0x10001, 0
;Control method 0-->just write calculated value to register (one register)
;Control method 1-->Range look up table, write one or more registers for
value within a range
HKR,%9600Brit%,MapMethod,0x10001, 0
HKR,%9600Brit%,RelatedRegister,1,6
;true or false
HKR,%9600Brit%,RelateUsbRegister,1,0
HKR,%9600Brit%,SupportAuto,0x10001,0 ;0 not support, 1 support
;Auto control method 0-->when turn off auto, just write current value to
register
;Auto control method 1-->when turn off auto, just read register value as
current value
HKR,%9600Brit%,PropertyId,0x10001, 0
HKR,%9600Brit%,MapMethod,0x10001, 0
HKR,%9600Brit%,RelatedRegister,1,ec
;true or false
HKR,%9600Brit%,RelateUsbRegister,1,1
HKR,%9600Brit%,DefaultValue,0x10001, 0x00
HKR,%9600Brit%,DefaultFlags,0x10001, 1
HKR,%9600Brit%,MinValue,0x10001, 0xffffff80
HKR,%9600Brit%,MaxValue,0x10001, 0x7f
HKR,%9600Brit%,Step,0x10001, 1
;#####################################
HKR,%9600Cntr%,PropertyId,0x10001, 1
HKR,%9600Cntr%,MapMethod,0x10001, 0
HKR,%9600Cntr%,RelatedRegister,1,eb
;true or false
HKR,%9600Cntr%,RelateUsbRegister,1,1
HKR,%9600Cntr%,DefaultValue,0x10001, 0x80
HKR,%9600Cntr%,DefaultFlags,0x10001, 1
HKR,%9600Cntr%,MinValue,0x10001, 0
HKR,%9600Cntr%,MaxValue,0x10001, 255
HKR,%9600Cntr%,Step,0x10001, 1
;#####################################
HKR,%9600Col%,PropertyId,0x10001, 6
HKR,%9600Col%,MapMethod,0x10001, 1
HKR,%9600Col%,NumberOfValues,0x10001, 2
HKR,%9600Col%\0000,Value,0x10001, 0
HKR,%9600Col%\0000,UsbRegisters,1, f0,00,ff
HKR,%9600Col%\0000,CamRegisters,1, 01,80,ff,02,80,ff,24,80,ff,25,70,ff
HKR,%9600Col%\0001,Value,0x10001, 1
HKR,%9600Col%\0001,UsbRegisters,1, f0,01,ff
HKR,%9600Col%\0001,CamRegisters,1, 24,b0,ff,25,90,ff
HKR,%9600Col%,DefaultValue,0x10001, 1
HKR,%9600Col%,MinValue,0x10001, 0
HKR,%9600Col%,MaxValue,0x10001, 1
HKR,%9600Col%,Step,0x10001, 1
;#####################################
;HKR,%9600Wb%,Registers,0x10001,
;#####################################
;HKR,%9600Wb%,PropertyId,0x10001, 7
;HKR,%9600Wb%,MapMethod,0x10001, 0
;HKR,%9600Wb%,RelatedRegister,1,01
;HKR,%9600Wb%,DefaultValue,0x10001, 80
;HKR,%9600Wb%,DefaultFlags,0x10001, 1
;HKR,%9600Wb%,MinValue,0x10001, 0
;HKR,%9600Wb%,MaxValue,0x10001, 255
;HKR,%9600Wb%,Step,0x10001, 1
I guess the vidcap32.exe buffers the register values. How can I read/write
the registers?
Any comments should be appreciated!
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Let me detail the problem.
I use IAMVideoProAmp to Get/Set the properties to control the video display. I get the properties and save them in an ini file. I found a question:
1. I set the ColorEnable property to be the Auto mode to obtain a correct color display;
2. then I switch the ColorEnable Item to be the Manual mode(after this,the video display does not change the color);
3. now I save all the properties that I can get from IAMVideoProAmp.
4. However, when I restart my program to read the ini file to set the saved properties to the camera, the color display is not the original one.
The same procedures are taken by using vidcap32 except that the properties can not be saved. Namely,
1. open the video source dialog to set the ColorEnable item to be the auto mode to obtain a correct color display;
2. then switch it to manual mode (after this,the video display does not change the color);
3. close the vidcap32.
4. If I restart the vidcap32, the color display remains the same as it was before I close the vidcap32.
I have checked the Registry but I did not find any solution. So I guess the vidcap32 buffers the video register values. How can I read/write the values?
Thanks a lot.
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using SetupDiXxx functions:
I have got a DevicePath
\\?\usbstor#disk&ven_fujitsu&prod_memorybird&rev_1.14#0739035033a1&0#{53f563
07-b6bf-11d0-94f2-00a0c91efb8b}.
then use function GetLogicalDrives get all removable drives :
A:\, I:\.
Then I feed all these removable drive mountpoint to function
GetVolumeNameForVolumeMountPoint
but the volumeName returned from the function:
\\?\Volume{84ec96be-1682-11db-8e5c-001111c4d88f}
doesn't match with the device path.
So how can I determine which removable drive in the list is the one for the USB flash drive??? I need exact drive letter for the USB flash drive plugged into the PC in order to access files stored in it.
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hi,
how i am get serial of my hard disk.
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DWORD GetSerialNumber(int nDrive)
{
DWORD dwHDSerialNum = 0;
if (!GetVolumeInformation(GetRoot(nDrive), NULL, 0, &dwHDSerialNum,NULL,NULL, NULL, 0))
return (DWORD)-1;
return dwHDSerialNum;
}
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Not the true serial number, for that (I think) you have to go through WMI.
What this gets is Windows internal Volume ID which may change randomly (reformatting of disk etc)
Formula 1 - Short for "F1 Racing" - named after the standard "help" key in Windows, it's a sport where participants desperately search through software help files trying to find actual documentation. It's tedious and somewhat cruel, most matches ending in a draw as no participant is able to find anything helpful. - Shog9
Ed
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