How to Read particular sector of a disk using ATA command?

问题

I want to read a particular sector(MBR Sector) of a disk using ATA commands in vc++. I am new to VC++ so i am facing a problem when sending command to disk using DeviceIoControl. I am providing a code that i am using to read out a sector using command Read Sector(s)(0x20).

  BOOL status = FALSE;
 PATA_PASS_THROUGH_EX pATAData;
DWORD dataSize = sizeof(ATA_PASS_THROUGH_EX) + 512;
BYTE Buffer[sizeof(ATA_PASS_THROUGH_EX) + 512];
DWORD bytescopied = 0;

    pATAData = (ATA_PASS_THROUGH_EX*)Buffer;

    ZeroMemory(pATAData,dataSize); // clears the buffer

    pATAData->Length = sizeof(ATA_PASS_THROUGH_EX);
    pATAData->DataBufferOffset = sizeof(ATA_PASS_THROUGH_EX);
    pATAData->DataTransferLength = 512;
    pATAData->TimeOutValue = 2;

    pATAData->CurrentTaskFile[1] = 0x01;
    pATAData->CurrentTaskFile[2] = 0x00;
    pATAData->CurrentTaskFile[3] = 0x00;
    pATAData->CurrentTaskFile[4] = 0x00;
    pATAData->AtaFlags =ATA_FLAGS_DATA_IN;

    pATAData->CurrentTaskFile[6] = 0x20; // command Read Sector(s)(0x20)
    /* sends the command to the device, **hDevice** is device handle*/
    status = DeviceIoControl(hDevice, IOCTL_ATA_PASS_THROUGH, pATAData, dataSize,Buffer, dataSize, &bytescopied, NULL );

I can't undersatnd that what's wrong in this code and what i am missing here, but it is not working. What i am missing here ? If there is a problem with parametres of PATA_PASS_THROUGH_EX structure than tell how to read first sector(MBR).

回答1:

Thankyou everyone for your help. I got the solution. A little bit thing that i have not noticed. That is Ata Flags. I have to send multiple flags. Eg.

pATAData->ataFlags = ATA_FLAGS_48BIT_COMMAND | ATA_FLAGS_DRDY_REQUIRED | ATA_FLAGS_DATA_IN

and also send the ATA command Opcode in PreviousTaskFile[6] also. And the few things to be noticed is What is the block size of the HDD? It could be more than 512 bytes, especially if it is a large disk like(1TB...4TB). As such, you'll need to adjust the sizes accordingly. You can see what the size is by doing the EC identify ATA command, and then look at the resulting data structure.

回答2:

Thanks for your help guys. I got the solution. I was not assigning the Device Handle in CurrentTaskFile.

pATAData->CurrentTaskFile[5] = (UCHAR)hDevice;

But IDENTIFY_DEVICE(ECh) command was sending succesfully without this. I don't know it's right or wrong but this is working.

回答3:

Thanks guys for your help. After a long discussion i find that i have to send extended commands for large disk. But now i am sending Read Sector(s) Ext(0x24 oppcode) command.

BOOL status = FALSE;
PATA_PASS_THROUGH_EX pATAData;
DWORD dataSize = sizeof(ATA_PASS_THROUGH_EX) + 512;
BYTE Buffer[sizeof(ATA_PASS_THROUGH_EX) + 512];
DWORD bytescopied = 0;

pATAData = (ATA_PASS_THROUGH_EX*)Buffer;

ZeroMemory(pATAData,dataSize); // clears the buffer

pATAData->Length = sizeof(ATA_PASS_THROUGH_EX);
pATAData->DataBufferOffset = sizeof(ATA_PASS_THROUGH_EX);
pATAData->DataTransferLength = 512;
pATAData->TimeOutValue = 2;

pATAData->CurrentTaskFile[0] = 0x00;
pATAData->CurrentTaskFile[1] = 0x01;
pATAData->CurrentTaskFile[2] = 0x01;
pATAData->CurrentTaskFile[3] = 0x00;
pATAData->CurrentTaskFile[4] = 0x00;
pATAData->CurrentTaskFile[5] = 0x40;
pATAData->CurrentTaskFile[7]=  0x00;
pATAData->AtaFlags =ATA_FLAGS_48BIT_COMMAND;

pATAData->PreviousTaskFile[0] = 0x00;
pATAData->PreviousTaskFile[1] = 0x00;
pATAData->PreviousTaskFile[2] = 0x00;
pATAData->PreviousTaskFile[3] = 0x00;
pATAData->PreviousTaskFile[4] = 0x00;
pATAData->PreviousTaskFile[5] = 0x04;
pATAData->PreviousTaskFile[7]=  0x00;

pATAData->CurrentTaskFile[6] = 0x24; // command Read Sector(s) Ext(0x24)
/* sends the command to the device, **hDevice** is device handle*/
status = DeviceIoControl(hDevice, IOCTL_ATA_PASS_THROUGH, pATAData, dataSize,Buffer, dataSize, &bytescopied, NULL );

But here is the same problem. command executed successfully but it does not read any sector. I am unable to find any error.

来源：https://stackoverflow.com/questions/30116092/how-to-read-particular-sector-of-a-disk-using-ata-command

标签

c++

winapi

hard-drive

sata