Comments by Mohanraj Sam (Top 16 by date)

Thanks Jones. I unable to read intermediate data in the sector. That is i want to read data starting from the offset OEh in the first sector. I tried with the below code,

startinglogicalsector = 1;
SetFilePointer (hDeviceHandle, (startinglogicalsector*14), NULL, FILE_BEGIN);
ReadFile (hDeviceHandle, buff, 512, &dwBytesRead, NULL);

But I get all the values of first sector starting from 0th offset. How can i read from 0Eh offset of 1st sector.

Also i have another question, 0Eh offset represents "Reserved Sectors". Is it gives total number of reserved sectors count or i can use that offset as reserved space. If it says about the count then how can i know which are the sectors are reserved. Any idea about this.

Regards
Mohan

Hi Jones,
Thanks for ur reply. Actually I used ReadFile()/WriteFile() for read/write operations. If i need to write values in the reserved sector of FAT32 of offset 0Eh, how shall i mentined this address in the WriteFile() because it gets only the sector number.

Regards
Mohan

Thanks for your answer.
But API calls or IOCTL call may vary for Windows and Linux, right?

Regards
Mohan

Thanks. I'ad used what is said in the above link, but i get the error code 50(i.e "The request is not supported.
")when using VWIN32_DIOC_DOS_INT25 for read. Can you guess this error.

Regards
Mohan

Ok Thanks for your information

Hi,
Thanks for ur prompt reply. I'm using Windows XP service pack 3. It says that Win CE 3.0 and later, then it should work in XP. Am i right? or any file has to be included. I cant understood What you said to include in the previous post. Can you explain clearly.

Thanks
Mohan

Hi,
Thanks for ur reply. I had used GetLastError(). It gives error code as 2("The system cannot find the file specified"). I dont know why this error i get because the path i had given is correct. Any suggestion?

Regards
Mohan

Hi,
Thanks for ur reply. I paste the code here, plz go through it and suggest me if I went wrong.

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <ctype.h>
#include <io.h>
#include <conio.h>
#include <windows.h>
#include <winioctl.h>
#include <setupapi.h>
#include "hidsdi.h"

int main()
{

HANDLE deviceHandle = INVALID_HANDLE_VALUE;
DWORD index = 1;
HIDD_ATTRIBUTES deviceAttributes;
BOOL matched = FALSE;

DWORD vendorID, productID, versionNumber;

while (!matched && (deviceHandle = connectToUSBDevice (index)) != INVALID_HANDLE_VALUE)
{
if (!HidD_GetAttributes (deviceHandle, &deviceAttributes))
return INVALID_HANDLE_VALUE;

if ((vendorID == 0 || deviceAttributes.VendorID == vendorID) &&
(productID == 0 || deviceAttributes.ProductID == productID) &&
(versionNumber == 0 || deviceAttributes.VersionNumber == versionNumber))
return deviceHandle; /* matched */

CloseHandle (deviceHandle); /* not a match - close and try again */
index++;
}

return INVALID_HANDLE_VALUE;
}


int connectToUSBDevice(DWORD in_dwDeviceIndex)
{
BOOL bDiskFreeSts, bGetPartinfo;
DWORD errStatus;
DWORD BytesReturned;
DWORD result;

HANDLE hDeviceHandle = INVALID_HANDLE_VALUE;
PARTITION_INFORMATION_EX PartitionInfomation; //partition structure
DRIVE_LAYOUT_INFORMATION_EX DriveInformation; //drive layout structure

HDEVINFO hDev;
GUID guid;
SP_DEVICE_INTERFACE_DATA interfaceDev;
PSP_INTERFACE_DEVICE_DETAIL_DATA deviceDetail;
ULONG wSize;

//Get the HID GUID value - used as mask to get list of devices
HidD_GetHidGuid(&guid);

//Get a list of devices matching the criteria (hid interface, present)
hDev = SetupDiGetClassDevs(&guid,
NULL, // Define no enumerator (global)
NULL, // Define no
(DIGCF_PRESENT | // Only Devices present
DIGCF_DEVICEINTERFACE)); // Function class devices.

interfaceDev.cbSize = sizeof(SP_DEVICE_INTERFACE_DATA);

//Go through the list and get the interface data
result = SetupDiEnumDeviceInterfaces (hDev,NULL, &guid, in_dwDeviceIndex, &interfaceDev);

/* Failed to get a device - possibly the index is larger than the number of devices */
if (result == FALSE)
{
errStatus = GetLastError();
printf("\nError in Opening Device....Error Status = %d",errStatus);

SetupDiDestroyDeviceInfoList(hDev);
return INVALID_HANDLE_VALUE;
}

//Get the details with null values to get the required size of the buffer
SetupDiGetDeviceInterfaceDetail(hDev, &interfaceDev, NULL, 0, &wSize,0);

//Allocate the buffer
deviceDetail = (PSP_INTERFACE_DEVICE_DETAIL_DATA)malloc(wSize);
deviceDetail->cbSize = sizeof(SP_INTERFACE_DEVICE_DETAIL_DATA);

//Fill the buffer with the device details
if (!SetupDiGetDeviceInterfaceDetail(hDev,&interfaceDev, deviceDetail,\
wSize, &wSize, NULL))
{
SetupDiDestroyDeviceInfoList(hDev);
free (deviceDetail);
return INVALID_HANDLE_VALUE;
}

/*Open file on the device*/
hDeviceHandle = CreateFile(deviceDetail->DevicePath /*dev1*/,
GENERIC_READ/* | GENERIC_WRITE*/,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL, // no SECURITY_ATTRIBUTES structure
OPEN_EXISTING, // No special create flags
0,
NULL); // No template file

if(hDeviceHandle == INVALID_HANDLE_VALUE) // cannot open the drive
{
errStatus = GetLastError();
printf("\nError in Opening Device....Error Status = %d",errStatus);
}
else
{
/*Retrieves extended information for each entry in the partition tables for a disk */
bGetPartinfo= DeviceIoControl(hDeviceHandle, // handle to a partition
IOCTL_DISK_GET_DRIVE_LAYOUT_EX, // dwIoControlCode
NULL, // lpInBuffer
0, // nInBufferSize
&DriveInformation, // output buffer
sizeof(DriveInformation), // size of output buffer

Hi,
Thanks for ur reply. I am new to MS Visual Studio 2008 can you say where i have to go to add the hid.lib for link input

Regards
Mohan

Hi Igor,
Thanks for ur reply. I realized that there is no hidsdi.lib. Then i included hid.h to fix these problem, but inside hid.h "usb.h" is included. when i compile i get the error as unable to find usb.h. I unable to find in google, where can i get usb.h?

Regards
Mohan

Hi Henry,
Thanks for ur reply. My pen drive is not detected as "C" it is "F". I tried to open the file for C drive also. Mistakenly copy that code and send. Sorry it is detected as "F"
char dev1[512]="\\\\.\\F:";
Any suggestion?

Regards
Mohan