I know there is tons of documentation on using USB mass storage with Linux. However, is there a way to have Linux emulate a USB mass storage device?

That is, can I plug my Linux box into a windows machine via USB and have Linux behave as a mass storage device? That would be great.

Thanks

There are drivers in the linux kernel to pull this off. It's called the "USB gadget API". However, the hardware must support this as well, and almost all USB chipsets in PC's don't support this mode!! It's really only meant for embedded devices running linux, like mp3 players and the like, who have specialized chipsets.
Maybe there exist one or two of these chipsets on a PCI board that can be plugged into a PC, but I wouldn't count too much on it

It would be quite cool, however...

Read more about it on http://www.linux-usb.org/gadget/
they have a list of supported chips as well, but again, finding these on a PCI card will be very hard if not impossible...

greets
nukkel

Just checked... The NetChip 2280 is available as a PCI card version, for testing and developing purposes...

So if you can locate one (and are prepared to pay $$$ for it -- development cards are limited numbers so tend to be expensive) have fun

That kind of sucks. I figured it could be emulated in software but I guess the USB ports only let you go so low. The problem is trying to find a supported PC/104 usb board.

Yeah, things like the vendor string, device name, device class, and host/device mode are all "hardwired" in the chip, no software can ever change these low level settings

Probably not a lot of use to you, but most recent Apple laptops can do this over Firewire. I believe it's called 'Target Mode'.

Dave

Thats cool. I was thinking that I could possibly have a usb port talk to a microcontroller with built in USB. The controller can act as a bridge. Microchip's PICs have USB support but I think it is only 1.1. Not to mention how slow the chip is. The firewire sounds like the same sort of thing. I guess I will have to abandon this one.

I'm making a In-dash Linux based media player for my car. My hope was I could use it as an external harddrive too. I'll just have to stick with Ethernet.