Installation Instructions
Digi AccelePort USB 4
5/15/2000

This note explains how to install the Digi AccelePort USB 4 driver.
If you have questions please contact Peter Berger pberger@brimson.com
or Al Borchers alborchers@steinerpoint.com.


Setting Up a Test System

* You should install this driver on a test system, not a production
  system.  The kernel USB subsystem and our driver are experimental
  and might well have unexpected problems that could crash your system
  and cause a loss of data.

* The test system should have a recent version of Linux installed.
  We have been using Red Hat 6.1 and 6.2 for our tests.

* You will need a Digi AccelePort USB 4 attached to a USB port on
  the system.


Files You Need

* From www.kernel.org get pub/linux/kernel/v2.2/linux-2.2.14.tar.gz.

* Get linux-2.2.14-digi-usb-3.diff.gz, which should have been included
  with this note.

* Copy both of these files to /usr/src.


Installing and Patching the Kernel Sources

* Login or su to root, cd to /usr/src, and run these commands.

  mv linux linux.save
  tar xvzf linux-2.2.14.tar.gz
  cd linux
  zcat ../linux-2.2.14-digi-usb-3.diff.gz | patch -p1
  make mrproper


Configuring and Building the Kernel

* You should be logged in as root and in the /usr/src/linux directory.

* You might be able to copy your current configuration.  In Red Hat
  systems this will be in /usr/src/linux.save/configs.  There will
  probably be several configs here; choose the most appropriate and
  copy it to /usr/scr/linux/.config.

* If you are running X, run "make xconfig"; if not, run "make menuconfig".

* Use the config program to configure the kernel for your system.  In order
  to get the Digi AccelePort USB driver installed you must choose these
  options in addition to any others needed for your system:

  Processor type and features
    n -- Symmetric multi-processing support
         (we haven't tested the driver on an SMP kernel yet)

  USB support
    m -- Support for USB
    n -- USB verbose debug messages
    m -- UHCI (Intel PIIX4, VIA, ...) support
    m -- UHCI Alternate Driver (JE) support
    m -- OHCI (Compaq, iMacs, OPTi, SiS, ALi, ...) support
    m -- USB Serial Converter support
    y -- USB Digi International AccelePort USB Serial Driver (EXPERIMENTAL)
    n -- USB Serial Converter verbose debug

* Note that this configures USB support as loadable modules.  You can
  also link them into the kernel directly by choosing y instead of m.
  The advantage to modules is that you can load and unload them when
  you choose, in case they cause problems.  We have NOT tested linking
  the driver directly into the kernel.

* Save the configuration and exit the config program.

* Run these commands.  Note these commands take a while to run, depending
  on your system and the kernel options you selected.  For example, "make
  bzImage" takes over 6 minutes on my PII400.
  make dep
  make bzImage
  make modules
  make modules_install

* Run these commands to create the device nodes.
  mknod /dev/ttyUSB0 c 188 0
  mknod /dev/ttyUSB1 c 188 1
  mknod /dev/ttyUSB2 c 188 2
  mknod /dev/ttyUSB3 c 188 3
  chmod 666 /dev/ttyUSB[0-3]


Booting the New Kernel

* Assuming you are using LILO, edit /etc/lilo.conf.  Change the
  default= line to read

    default=linux-test

  Add the linux-test configuration like this

    image=/boot/vmlinuz-test
        label=linux-test
        read-only
        root=/dev/XXX

  The XXX will be replaced by the disk name that holds your root (/)
  partition.  You can find this in the root= line for your old default
  configuration in /etc/lilo.conf.  It might be something like hda6
  or sda1.

* As root in /usr/src/linux run these commands.
  cp arch/i386/boot/bzImage /boot/vmlinuz-test
  cp System.map /boot/System.map-test
  rm /boot/System.map
  ln -s /boot/System.map-test /boot/System.map
  /sbin/lilo

* Run "shutdown -r now" to reboot the system.


Starting the USB driver

* Your machine has either the UHCI or OHCI USB controller.  The
  UHCI controller is more common on Intel systems.  If you have
  the OHCI controller you should change "usb-uhci" to "usb-ohci"
  in the commands below.  If you don't know, try usb-uhci first;
  if it doesn't work try usb-ohci.  You can also try just uhci
  in place of usb-uhci; they both support the UHCI controller,
  but one might work better for you.

* As root run these commands
  depmod -a
  sync
  sync
  modprobe usbcore
  modprobe usb-uhci             /* if you have the UHCI controller */
  modprobe usb-serial

  For convenience you might want to put these commands in a shell file.
  The "depmod -a" command only needs to be run the first time after
  installing the driver.

* The Digi AccelePort USB 4 should be working.  To test it out, connect
  a null modem cable between ports 1 and 3 and run these commands in two
  separate windows.

  In the first window:
    cu -l /dev/ttyUSB0

  In the second window
    cu -l /dev/ttyUSB2

  Whatever you type in one window should be sent through the USB AccelePort
  and over to the other window.

  To exit the cu sessions, type return, tilde, and a period.

* To stop the USB driver, run these commands

  sync
  sync
  rmmod usb-uhci
  rmmod usb-serial
  rmmod usbcore

  For convenience, you might want to put these commands in a shell file.


Known Bugs

* Some systems have trouble transfering large amounts of data at baud
  rates above 38400 bps; other systems work fine up to 115200 bps.

* Do not unplug the Digi AccelePort 4 while the usb modules are loaded--
  the system will crash.

* Do not try to unload the usb modules while a USB port is open--the
  system will be left in an unstable state and you must reboot.