Ivo, Did you ever get an MTP responder working on beagleboard?
Claude On Monday, October 27, 2014 at 12:31:40 AM UTC, ivo welch wrote: > > > ok, further research. I discovered that I probably want to write a usb > mtp (media transfer protocol) driver for the BBB. if anyone has already > written one, please let me know. > > On Saturday, October 25, 2014 8:48:38 PM UTC-7, ivo welch wrote: >> >> >> dear BBB experts: I would like to create a high-level filesystem device >> on my BBB that my (possibly malicious) linux PC can communicate with over >> USB in EHCI (USB 2.0 high-speed). I will want to switch off everything >> else, incl ethernet-over-usb, again because I will guess that my PC is >> infected. >> >> from the PC perspective, I want the BBB to operate at roughly at the >> level of a fuse filesystem, albeit with its own processor that can enforce >> separation. >> >> most importantly, I would like the BBB to hook into the "open file" >> request call. for example, I want my BBB to log every file open request to >> its own /tmp/log/file-logged, return an error if I don't like the filename, >> mangle the filename (e.g., shorten it of auto-expand it), or disallow >> opening a file for write when a pin is bridged or when the file resides in >> the /ro/ part of the file system or the filename contains the string "ro". >> >> on the PC, I want to do >> >> PC$ mount -t speak2mybbb /dev/usb1 /mnt/usb1 ## say my BBB sits on >> /dev/usb1 >> PC$ echo "hi" > /mnt/usb1/rw/file2 ## create a file >> PC$ ls /mnt/usb1/rw/ ## note: my BBB has mangled the filename >> file2-mangled-file-name >> PC$ cat /mnt/usb1/rw/file2-remangleme ## note: my BBB can remangle >> and figure this out >> hi >> PC$ echo "hi" > /mnt/usb1/ro/file2 ## note: my BBB knows that /ro/ >> is read-only and does not allow writing here. >> ERROR: no such file or directory >> PC$ umount /dev/usb1 >> >> at first, I thought I should hook into the USB mass storage driver, >> because it already does EHCI and reading the USB spec, there is a lot of >> stuff that can go wrong. but the problem, I believe, is that this layer >> operates at too low a level. I deduct this because it supports many >> different higher-level file systems, like FAT or ext4. presumably, the >> USB-mass storage level is primarily "sector-read" and "sector-write," which >> would make it very difficult to hook into a file-open. >> >> the USB serial driver works and would allow me to filter requests, and I >> could write a fuse driver on the PC (not the BBB), but USB serial is slow. >> >> has anyone created an EHCI fuse-like file-system communication example? >> any pointers by experts would be highly appreciated. >> >> regards, >> >> /iaw >> >> -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
