Dual Ported USB Memory Stick - Such a thing exists?

[johnsa]

Hey all,

I haven't worked on my OS code for quite some time and was thinking of starting up again now that I have the Intel documentation to be able to implement native graphics support.

When I left off last time I was very hapilly transferring my boot/kernel/loaders etc to a USB stick and booting from it which kept the development process clean and simple (not having a floppy drive anymore).

However, in a quest to make my life even less painful .. and bearing in mind I have multiple machines, it would be fantastic if I could plug a single memory stick into multiple machines.. code on one, deploy and reboot the other so as to not have to reboot my main machine during coding to test the OS code.

Has anyone seen anything like this or set something similar up?
Thanks!
John

[Combuster]

USB sticks with multiple ends, no.

Try netbooting or sharing a SCSI bus between machines.

[souradipm]

No, nothing such as a dual-ended USB stick exists, but you can just put your binaries onto the usb stick and take it out, then plug it in to the other pc.

[hidnplayr]

I wonder if you can boot from this: http://www.linkusb.com/

I personally would go with etherboot and a TFTP server.

[xDDunce]

i guess you could make a cable that enables you to plug it into 2(or more) computers at once. but you would need to know which lines go one way, and which can oscilate. i've thought of doing this my self but haven't got the time at the moment. in theory all you would need are:

USB ports (one female, 2+ male)
couple of wires
a few diodes

aslong as you know which lines can only go one way, diodes will make sure the current does not turn back on them. although if it goes wrong, i guess the worst that could happen is frying the motherboard but 5 volts aint really enough(i think...)

hope you find a solution.

James.

[Owen]

USB has 4 lines

5V D+ D- 0V

5v and 0v are power rails.
D+ and D- are bidirectional data lines. USB is completely host driven. If you were to connect the lines on two PCs together all you would do is open the self resetting breaker, if it had one, else the PSU would shut down, and the USB controller possibly be damaged.

So firstly, no method can connect two hosts via USB without intermediating intelligence
Seccondly, diodes don't work for even single direction communications lines because current has to flow both ways.
Thirdly, 5v can and will fry the USB host controller chip... which will run at 3.3v and will not tolerate 5v (The data lines are 3.3v)

If you want to connect computer to computer to boot, a better idea would be to connect both up to a network, setup a TFTP server on the dev box and use PXEBoot to download and run the kernel (However PXEBoot doesn't do Multiboot if your using that)