Linux setup instructions

JTAG

To use JTAG make sure the ppdev module is loaded

modprobe ppdev

If that doesn't work also make sure the user have read and write permission to the parelellport. If connected to the first port the device is usually

/dev/parport0

To give all users access to that port use the command

chmod go+rw /dev/parport0

USB

To enable support for USB the device needs to have the right permissions. Either all users can have access to the device, or access can be restricted to a group.
Follow the steps below depending on the kernel version.

Linux 2.4 - Hotplug

If hotplug is installed (it usually is in recent Linux distributions) it can be used to set the permissions when the device is plugged in. The paths below can vary depending on the Linux distribution.

Open the file

/etc/hotplug/usb.usermap

and add the line

grusb 0x0003 0x1781 0x0aa0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0

Then create the file

/etc/hotplug/usb/grusb

This is a script that will be run when the USB interface is connected. Add the following to give all users access to the device.

#!/bin/bash

if [ "${ACTION}" = "add" ] && [ -f "${DEVICE}" ]
then
        chown root "${DEVICE}"
        chmod 666 "${DEVICE}"
fi

To restrict access to members of a special group, e.g. usb, change to this

#!/bin/bash

if [ "${ACTION}" = "add" ] && [ -f "${DEVICE}" ]
then
        chown root "${DEVICE}"
        chgrp usb "${DEVICE]"
        chmod 660 "${DEVICE}"
fi

The script needs to have exec permission.

chmod 755 /etc/hotplug/usb/grusb

Restart hotplug with

/etc/rc.d/rc.hotplug restart

or reboot to have the changes take effect

Linux 2.4 - without Hotplug

If hotplug is not available the simplest solution is to change permissions for all usbdevices, by changing the options for usbdevfs.

Open the file

/etc/fstab

and find the line similiar to below

none	/proc/bus/usb/	usbdevfs	defaults	0 0

Change it to look like below

none	/proc/bus/usb/	usbdevfs	devmode=0666,busmode=0777,listmode=0666,busuid=0,devuid=0,listuid=0,busgid=100,listgid=100,devgid=100	0 0

This will give all users access to USB devices. To restrict access to a group change the options to this

devmode=0660,busmode=0770,listmode=0660,busuid=0,devuid=0,listuid=0,busgid=XXX,listgid=XXX,devgid=XXX

Where XXX is the id of the desired group (look in /etc/group). This will give access only to members of that group.
Reboot to have the changes take effect.

Linux 2.6 - udev

The 2.6 kernel uses a new system called udev. Before connecting the device, follow the instructions below to create the rules that will set the right permissions for the device. The paths below can vary depending on the Linux distribution.

Open or create

/etc/udev/rules.d/40-permissions.rules

and add the following line

BUS=="usb", SYSFS{idVendor}=="1781", SYSFS{idProduct}=="0aa0", MODE="0666"

This will give all users access to the device. Access can also be restricted to a group, e.g. usb, with

BUS=="usb", SYSFS{idVendor}=="1781", SYSFS{idProduct}=="0aa0", GROUP="usb"

Reread all the rules with

udevcontrol reload_rules