This is an old revision of the document!
MSI 3070 (wifi) lsusb identifies the wireless network adaptor as 0db0:3822 (or 0db0:3871) - Micro Star International. There are currently three-and-a-half options for drivers for this device:
The one bundled in the Toshiba kernel sources, under /drivers/net/wireless/DPA_RT3070_WiFiBTCombo/ . This compiles to three separate modules, which have to be inserted in the right order, and will mark the kernel as “tainted”.
The GPL'd ralink sources, available at http://www.ralinktech.com/support.php?s=2 . Currently at version 2.4.0.1 . You'll have to edit the Makefile to add paths to your ARM cross-compiler and kernel sources, and os/linux/config.mk to set the necessary -I flags and enable support for WPA supplicant. Results in a single GPL-licensed kernel module.
The in-kernel sources. If you look under drivers/staging/rt2870/, you'll find a slightly cleaned-up version of ralink's driver. It requires you to enable “STAGING” drivers when configuring the kernel.
Finally, the rt2x00 drivers are in the mainline kernel, under drivers/net/wireless/rt2x00, but these report only testing/development support for the 3070.