Accessing FAT32 disk(partitioned in QNX) in Windows


I want to copy some files from an embedded system running QNX into a CF and then access it on a windows pc for my project. So i partioned the CF as FAT32 in QNX system, but was not able to read it in a windows PC.

This is what i did

  1. Connected the CF to QNX system
  2. fdisk /dev/hd1 -s 1 -t 12 -p100
  3. dinit -h /dev/hd1t12
  4. Copied some files into the CF
  5. Then umounted and connected it to a windows(XP) pc using a CF card reader. It showed the disk but when i opened it asked whether to partition it or not and was not able to get the files???

Can anyone help me on this regard!!!



fdisk/dinit creates a QNX file system not a DOS one.

So there is no way a windows machine is going to read this filesystem.

What you need to do is format the CF disk under windows as a FAT32. Then in QNX you mount the CF as a DOS file sytem and copy your files to the CF card.


Hi Tim,

Thanks a lot.

Is there any utility in QNX to format the CF in FAT32 and access it in Windows?


I’m only aware of FAT32 formatting being available for floppies not for HD/CF cards.

I’m curious why you’d want or need to format in FAT32 in QNX. Every CF card I’ve ever bought already comes formatted for FAT32. You just insert the card and read/write to it. All you will need to do in QNX is specify DOS format to the mount command.


A cheap and questionable way to format would be to first format under Windows, and make an image of the first sectors that represent the root directory and FAT tables. Then you can just copy this back when you want to re-initialize. The questionable part is that Windows puts some random serial number on the front of the disk so that it knows when the disk is replaced. This is true for removable media, like floppies.

Hi Tim,

This is what we want to do

Create two partitions in the CF: one supporting QNX file system and another partition supporting DOS file system.

We will have some files in QNX partition that we will load into an embedded system and those should not be accessed in Windows. The files we download from embebbed system will be stored in the DOS partition and those should be accessible in both QNX and Windows.

Please help???



This is going to be a multi-step process in order to put 2 file systems on the CF.

  1. On a Windows PC, you have to partition the CF into 2 parts, one for FAT32 and one for QNX. After partitioning the CF, you can format one partition for FAT32 from the Windows PC. This gives you your Fat32 partition and splits the CF into 2 parts.

You didn’t say whether or not you wanted to install the QNX O/S on the other partition and run from it or whether it was just going to hold files and you were running the QNX O/S from another drive/flash memory. So I’ll give you a hint on doing both.

If you want to install the QNX O/S and run from the QNX partition then…

  1. Install QNX to the 2nd partition. This should be a straight forward QNX installation. You’ll have to specify which partition you want to install to and make sure you set the active partition (the one you boot from) to be the QNX partition.

If you want to have a QNX filesystem and no QNX O/S then…

  1. On a QNX machine, use the fdisk command to create a QNX partition. Use the dinit command to initialize the QNX file system (basically everything you wrote in your initial post).


Thanks a lot Tim…

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