VMWare USB Emulation

One thing I really wish VMWare did was allow me to create an emulated USB key. 

Well recently I found out you can! 

It is using some fairly undocumented VMX settings. Unfortunately I haven't figured out how to make it boot from the USB key yet (But I haven't really spent a lot of time on that part as I found a simple workaround).

Manual VMX Configuration Changes

  • Open your Emulator VMX image and make sure the following keys are set...
ehci.present = "TRUE"

This enabled the EHCI system in VMWare.

Then you need to add the following keys, the '#' can be any number you are not already using from 0 to 7.

ehci:#.present = "TRUE"
ehci:#.readonly = "FALSE"
ehci:#.deviceType = "disk"
ehci:#.fileName = "pathToFile.vmdk"

As a small side note just for documentation purposes you can also configure a CDRom using the following values.

ehci:#.present = "TRUE"
ehci:#.deviceType = "cdrom"
ehci:#.fileName = "pathToFile.iso"

And then startup your VM, and this VMDK file will now be treated as a USB Key device.


Unfortunately as I mentioned above I haven't seen a way to make it boot from a USB device however, the workaround I use was to download a simple CDROM image from https://plop.at called Plop Boot manager 5. It is tiny (557kb) CDRom image that I attach to the machine to allow it to boot, it then gives me the choice to boot from the USB key. You can get the file on the downloads page, here: https://www.plop.at/en/bootmanager/download.html


There are a couple of experiments in the future I'd like to try:

  1. Can I install any of the Plop boot managers to the USB key?
  2. Can I make the CDRom r/w by using the readonly flag and using a VMDK image of the iso to allow booting and modification of a removable device?

If anyone tries the above before I do and wants to comment, love to hear feedback!

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