4.22 USB - Support For USB Devices

OPT_USB

Supprt for USB devices in general is activated here. Only if 'yes' is entered here USB devices will get usable at all. If you have chosen an USB device in base.txt entering 'yes' here is mandatory. Otherwise the device can't be used. This activates support for USB sticks, external USB drives and USB keyboards as well.

Default setting: OPT_USB='no'

USB_EXTRA_DRIVER_N

Number of drivers to load.

Default setting: USB_EXTRA_DRIVER_N='0'

USB_EXTRA_DRIVER_x

Driver that should be loaded.

Possible values at the moment

printer - support for USB printers
belkin_sa - USB Belkin Serial converter
cyberjack - REINER SCT cyberJack pinpad/e-com USB Chipcard Reader
digi_acceleport - Digi AccelePort USB-2/USB-4 Serial Converter
empeg - USB Empeg Mark I/II
ftdi_sio - USB FTDI Serial Converter
io_edgeport - Edgeport USB Serial
io_ti - Edgeport USB Serial
ipaq - USB PocketPC PDA
ir-usb - USB IR Dongle
keyspan - Keyspan USB to Serial Converter
keyspan_pda - USB Keyspan PDA Converter
kl5kusb105 - KLSI KL5KUSB105 chipset USB->Serial Converter
kobil_sct - KOBIL USB Smart Card Terminal (experimental)
mct_u232 - Magic Control Technology USB-RS232 converter
omninet - USB ZyXEL omni.net LCD PLUS
pl2303 - Prolific PL2303 USB to serial adaptor
visor - USB HandSpring Visor / Palm OS
whiteheat - USB ConnectTech WhiteHEAT

Default setting: USB_EXTRA_DRIVER_x=''

USB_EXTRA_DRIVER_x_PARAM

Parameters for the driver. Usually you won't need this.

Default setting: USB_EXTRA_DRIVER_x_PARAM=''

USB_MODEM_WAITSECONDS

Default setting: USB_MODEM_WAITSECONDS='21'

Unfortunately Speedtouch USB Modems need a long time to get ready. In most cases the default setting of about 21 seconds is sufficient for initialisation. Sometimes the value can be halved and the Speedtouch USB modem is ready after 10 seconds. If this is the case you could set the value to 10 seconds. If you are unlucky the value has to be raised. Only testing can help you here.

4.22.1 Problems With USB Devices

There may be problems with some USB devices. This can have different causes, for example the driver software or the USB controller.

4.22.2 Hints For Use

It is important to ensure that the hardware USB support is enabled. Especially with onboard USB controllers that is important. For example a WRAP is shipped without USB port. USB is added only by an additional module and is therefore disabled in the BIOS by default.

4.22.3 Mounting Of USB Devices

Plugged USB devices will be detected automatically but must be mounted and unmounted 'by hand'. When plugging an USB stick it is recognized as a SCSI block device. For this reason is accomplished via device sd# for SuperFloppy devices or sd#<Partition-number> for devices with a partition table. USB drives are treated as hard disks and addressed as sda1 and sdb1 if plugged in two USB ports. USB floppies are addressed via sda or sdb without specifying a partition number.

Thus a first USB stick can be mounted to /mnt by executing

mount /dev/sda1 /mnt

A second one at the same would need

mount /dev/sdb1 /mnt

to be mounted. Devices are numbered in the sequence of plugging - first USB device = sda, second USB device = sdb a.s.o. This means that device numbering is not fixed but depending on the sequence of plugin. Unmounting is done via

umount /mnt

If using more that one USB device never mount all devices to the same directoy. Create directories under /mnt for each device to be mounted. Make the directories by executing:

mkdir /mnt/usba
mkdir /mnt/usbb

Then specify the directories as destinations when mounting:

mount /dev/sda1 /mnt/usba
mount /dev/sdb1 /mnt/usbb

The content of the USB devices can be found at /mnt/usba res. /mnt/usbb. Unmounting can be done via

umount /mnt/usba
umount /mnt/usbb

If an USB device has more partitions the device directories under /mnt have to reflect this structure in subdirectories.