Is it possible to write a FAT32 image file to a partition, like a second partition, programmaticaly?
Mmmm did you try using linux dd???
boot with a liveCD (maybe this one)an then $ dd if=/image/fat32/file of=/dev/other/partition
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The system has an MMC with FAT partition. The FAT partition contains some files, two of them are called "file_A" and "file_B".
I need to prepare a script to toggle between file_A and file_B at the u-boot stage without knowing the file's size in advance.
I thought to use fatload and fatwrite commands.
I loaded the file to the RAM using fatload without issues using:
fatload mmc 0:1 0x0 file_A
Now I have issues with copying the file residing in the RAM to the fat partition using fatwrite, again I don't now the file size in advance (I've noticed that the fatload print information contains the file size, maybe I can use it somehow?).
Most commands to load something in to memory set the filesize variable to how much was loaded in to memory.
I am trying to process a .raw image file captured using vrl2, it's a h264 encoded image with yuv422 color space from a Logitech c920 webcam, dcraw is not working for me however from my previous question this command is working fine with low performance (a 32kb jpg image however using opencv capture I get a 900kb image for the same 640x480 resolution):
ffmpeg -f rawvideo -s 640x480 -pix_fmt yuyv422 -i frame-1.raw
frame-1.jpg
I need a code written in C or the ffmpeg api/OpenCV etc .. to do the same as this command,I don't want to use QProcess in Qt(I am working on a server using Qt where I am trying to send the raw file from a Raspberry PI to the server and process it their), dcraw output is a corrupted image.
http://ffmpeg.org/doxygen/trunk/examples.html
There should be some api samples in there that show how to get the image out with that specific encoding.
When interacting with a RAW file, I have also used IrfanView. If you know the headersize of the file and the width and the height and the bits per pixel per color, you can see what it looks like quickly that way.
EDIT: I tried using Irfanview with your RAW, and I got something close, but not quite. The coloring was always off. I don't think it can handle that particular encoding of a RAW file right now.
I want to write a program that can print out the information of a FAT32 file systerm like Number of of sectors per cluster by reading a device file, for example, a device file called fat32.disk
How can I do this in C? should I read the file by using fopen("fat32.disk","r") ?
Then how can I locate the information stored on Volume ID in fat32.disk? something like sectors_per_cluster = 0x0D in my script?
I need to clear sector 0 for removable media devices (custom USB memory devices) which I have been trying to clear within a WPF/C# application. My first attempt was to use DD, but I ran into problems. During the manufacturing of the devices a MBR is created at sector 0 and the volume (logical?) starts at sector 40. When I issue the following command it clears sector 40 and not sector 0:
dd bs=512 count=1 if=/dev/zero of=\.\E:
I found another version of DD here which includes a wipe utility. I tried this version and I am seeing the same behavior. I am using both HxD and Runtime's DiskExplorer that sector 40 is being cleared and not sector 0. I could use HxD or Runtime's DiskExplorer, but this needs to be scriptable.
Does anyone know of any other methods of clearing (filling) sector 0 within Windows XP SP2?? Any help would be greatly appreciated. Thanks.
Mark
Solution: My solution used WMI to find the physical drive based upon the logical drive letter. First, query the Win32_LogicalDiskToPartition class to find the logical drive I am looking for. This provides the Antecedent field which constains something like '...DeviceID="Disk #X, Partition #Y"'. Next, I query Win32_DiskDriveToDiskPartition class while searching against the Dependent field to find the match for the Antecedent field within the Win32_LogicalDiskToPartition class. Once found, the Antecedent field from Win32_LogicalDiskToPartition will yield the physical drive. I selected atzz since it is the closes to my solution. I wanted to use Eugene's suggestion, but I only had a few hours to implement this so I selected the easier of the two. I will need to revisit this at a later time though.
There are two ways to format a USB drive, from Windows standpoint:
As a floppy disk. In this case entire USB drive contains a single file system, and its boot record is located in sector 0.
As a hard drive. In this case, sector 0 contains MBR with partition table. Actual file system(s) with their individual boot records are located further on the drive.
I think you are observing the second case. Using \.\E: to identify the device, you end up accessing file system's boot record instead of MBR.
Here is how you can access sector 0 of the USB drive.
Load WinObj from here.
In WinObj, under GLOBAL??, find E:. It will be a SymbolicLink pointing to something like \Device\Harddisk2\DP(1)0-0+30.
Under GLOBAL??, find a PhysicalDrive# symlink referring to the same Harddisk# that you found on step 2. Most probably it will have the same numeric suffix as Harddisk#. E.g.: SymbolicLink PhysicalDrive2 refers to \Device\Harddisk2\DR47.
Use the PhysicalDrive# you've found in DD command:
dd bs=512 count=1 if=\\.\PhysicalDrive2 of=mbr.dat
You are trying to clear logical device E: and not physical device. Try doing the following:
call CreateFile() WinAPI function to open "\\.\PhysicalDriveX" where X is the number of the device (see Remarks in description of CreateFile function for information about how to open the physical device properly). Then use WriteFile API function to write 512 bytes at offset 0 of the opened device.
If you get permission denied error when opening the device for writing, you can take our RawDisk product (trial version will work fine for you) which lets one bypass this security measure of Windows.
upd: As for calling CreateFile from C#, see PInvoke.net.
Is there a way to determine if a USB drive has been formatted as FAT, FAT32 or NTFS?
I think you can plug it into a Linux box and figure out what is the device (dmesg), then something like fdisk -l [device] will print out the partitions and their types.
use "mount" to show all mounted file systems. It shows the file system type and mount parameters.