Write image to usb with dd

[SBecker71]

I can't get dd to write a image file (ex. Dos6.22.img) to a usb stick (f:) I am using Win11. Any ideas?

I tried:

dd if=Dos6.22.img of=f:
dd: can't open 'f:': No such file or directory

or

dd if=Dos6.22.img of=\.\f:
dd: can't open '\.\f:': Permission denied

dd if=Dos6.22.img of=f:
dd: can't open 'f:': Is a directory

Regards

[rmyorston]

I think it might be necessary to write to the physical rather than logical drive.

That would be dd if=Dos6.22.img of='\\.\PhysicalDriveN' where N is the disk number.

However, writing to either sort of device on Windows seems to require rather different settings than dd in BusyBox uses. And when it doesn't work the error messages aren't very helpful.

I'll continue to tinker with it, but don't expect a rapid fix. Or any fix at all.

[ale5000-git]

@rmyorston
Is it possible to also add an applet that resolve logical drive to phisical drive?
Like this:
D: => \\.\PhysicalDriveN

[SBecker71]

I tried the suggestion but:

dd if=Dos6.22.img of=\.\PHYSICALDRIVE2
dd: can't open '\.\PHYSICALDRIVE2': Invalid argument

So if i understood you right i have to wait if there (maybe) will be a solution.

Thank you for your help.

P.S.: dd for windows from http://www.chrysocome.net/dd works but i hoped i could use busybox because it is better supported

[rmyorston]

I've made a minimal fix to dd to allow it to write to physical drives (not partitions or volumes). There are some limitations:

• The commands need to be run as Administrator.
• The disk needs to be offline. This can be done using the GUI tool diskmgmt.msc or the command line tool diskpart:

~ # diskpart

Microsoft DiskPart version 6.3.9600

Copyright (C) 1999-2013 Microsoft Corporation.
On computer: WIN81

DISKPART> list disk

  Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online           25 GB      0 B
  Disk 1    Online           10 MB      0 B

DISKPART> select disk 1

Disk 1 is now the selected disk.

DISKPART> offline disk

DiskPart successfully offlined the selected disk.

DISKPART> exit

Leaving DiskPart...
~ #

The dd command is then something like:

~ # dd if=144m/x86BOOT.img  of='\\.\PhysicalDrive1' bs=64k
22+1 records in
22+1 records out
~ #

The default block size is 512 bytes, which is far too small. I used bs=64k above for a floppy. I generally use bs=1M for ISO images.

Note, the path for the physical drive starts with two backslashes.

Prerelease binaries are available (PRE-5444 or above).