Failure to assign a drive letter to 3rd partition

[acromano]

Failure to assign a drive letter to 3rd partition

[pbatard]

If we manually assign a drive letter to Partition 3 the image works correctly.

Please define "correctly". I'm going to assume that you are not actually creating a bootable drive but something very custom, since drive letter assignation from Windows has absolutely no bearing on bootability.

So what is "correctly" in this case?

I hope that you can appreciate is that if you want a third party custom Windows application to be able to work with your drive, that goes beyond the scope of what Rufus (and probably) other software is designed to do and that, before a (busy) developer decides to commit their spare time on something, they will need to understand the context behind it.

So, what is the software you are using that appears to need to use 2 separate partitions on Windows?

Also, please bear in mind that, for anybody using older versions of Windows 10, or any versions of Windows 8.x, Windows does not allow assigning multiple drive letters to a USB drive with the REMOVABLE drive (most USB Flash Drives), so, even if we wanted to, we wouldn't be able to accomplish what you want for all platforms due to intrinsics limitations of Windows.

Personally, I have to state that I fail to see how this is not an image issue in the first place, when you clearly could (and probably should) merge the 2 FAT partitions into a single one, so I'd also very much like you to explain what is the constraint on that...

[acromano]

We are creating a bootable USB for a Yocto image which has 3 partitions. By correctly, I mean when you assign a drive letter to the 3rd partition it is accessible by Windows and files can be copied to the 3rd partition.

From reading your response I understand that rufus needs to be backward compatible for Windows versions that do not allow assigning multiple drive letters to a USB drive.

[pbatard]

and files can be copied to the 3rd partition.

But by what application?

My point was to understand in which fashion being able to access the 3rd partition from Windows or not could be detrimental to the ability of creating a drive that, when used as bootable media, will effectively boot a computer, which is the main design goal of Rufus.

But it appears that you are using Rufus for a different purpose, and with a custom application or process that does not concern itself with using the resulting drive for booting, but instead for a specific purpose that you still have yet to disclose.

As you may understand, it is not my goal to spend time trying to support custom process or application usage with Rufus as, if I were to do that, I would essentially be providing free support for companies which I do estimate have more than enough resources to sort out these kind of custom issues, which are the result of their own design, by themselves.

Therefore, I was asking about your process or application, and the purpose of your image, to find out if there was a chance this could translate to something that the general public was likely to use and be faced with, which is the only kind of scenario that really matters to me, or to confirm that, as I am currently assuming, this requirement is part of a custom business process or application that you have, and that is unlikely to translate to a real requirement for the general public.

[acromano]

Thank you for explaining your reason for the inquiry. I will try explain.

We developed a Linux application using Visual Studio on Windows.

We have a created a Yocto(Linux) image for a custom embedded system which has a boot partition, an ext4 partition for the Yocto runtime filesystem and an additional partition for the application. After creating the bootable USB, the application files are manually copied from Windows to the 3rd partition on the USB drive.

The target is then booted with the freshly made USB drive. When booting the target, Yocto creates a bootable partition and an ext4 partition for the OS. The application files are copied from the USB to the correct location on the target. This was done to simplify and streamline the manufacturing process and product updates in the field.