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+ COMX drivers for the 2.2 kernel
+Originally written by: Tivadar Szemethy, <tiv@itc.hu>
+Currently maintained by: Gergely Madarasz <gorgo@itc.hu>
+Last change: 21/06/1999.
+This document describes the software drivers and their use for the
+COMX line of synchronous serial adapters for Linux version 2.2.0 and
+The cards are produced and sold by ITC-Pro Ltd. Budapest, Hungary
+For further info contact <info@itc.hu>
+or http://www.itc.hu (mostly in Hungarian).
+The firmware files and software are available from ftp://ftp.itc.hu
+Currently, the drivers support the following cards and protocols:
+COMX (2x64 kbps intelligent board)
+CMX (1x256 + 1x128 kbps intelligent board)
+HiCOMX (2x2Mbps intelligent board)
+LoCOMX (1x512 kbps passive board)
+MixCOM (1x512 or 2x512kbps passive board with a hardware watchdog an
+ optional BRI interface and optional flashROM (1-32M))
+SliceCOM (1x2Mbps channelized E1 board)
+PciCOM (X21)
+At the moment of writing this document, the (Cisco)-HDLC, LAPB, SyncPPP and
+Frame Relay (DTE, rfc1294 IP encapsulation with partially implemented Q933a
+LMI) protocols are available as link-level protocol.
+X.25 support is being worked on.
+Load the comx.o module and the hardware-specific and protocol-specific
+modules you'll need into the running kernel using the insmod utility.
+This creates the /proc/comx directory.
+See the example scripts in the 'etc' directory.
+The COMX driver set has a new type of user interface based on the /proc
+filesystem which eliminates the need for external user-land software doing
+IOCTL calls.
+Each network interface or device (i.e. those ones you configure with 'ifconfig'
+and 'route' etc.) has a corresponding directory under /proc/comx. You can
+dynamically create a new interface by saying 'mkdir /proc/comx/comx0' (or you
+can name it whatever you want up to 8 characters long, comx[n] is just a
+Generally the files contained in these directories are text files, which can
+be viewed by 'cat filename' and you can write a string to such a file by
+saying 'echo _string_ >filename'. This is very similar to the sysctl interface.
+Don't use a text editor to edit these files, always use 'echo' (or 'cat'
+where appropriate).
+When you've created the comx[n] directory, two files are created automagically
+in it: 'boardtype' and 'protocol'. You have to fill in these files correctly
+for your board and protocol you intend to use (see the board and protocol
+descriptions in this file below or the example scripts in the 'etc' directory).
+After filling in these files, other files will appear in the directory for
+setting the various hardware- and protocol-related informations (for example
+irq and io addresses, keepalive values etc.) These files are set to default
+values upon creation, so you don't necessarily have to change all of them.
+When you're ready with filling in the files in the comx[n] directory, you can
+configure the corresponding network interface with the standard network
+configuration utilities. If you're unable to bring the interfaces up, look up
+the various kernel log files on your system, and consult the messages for
+a probable reason.
+To create the interface 'comx0' which is the first channel of a COMX card:
+insmod comx
+# insmod comx-hw-comx ; insmod comx-proto-ppp (these are usually
+autoloaded if you use the kernel module loader)
+mkdir /proc/comx/comx0
+echo comx >/proc/comx/comx0/boardtype
+echo 0x360 >/proc/comx/comx0/io <- jumper-selectable I/O port
+echo 0x0a >/proc/comx/comx0/irq <- jumper-selectable IRQ line
+echo 0xd000 >/proc/comx/comx0/memaddr <- software-configurable memory
+ address. COMX uses 64 KB, and this
+ can be: 0xa000, 0xb000, 0xc000,
+ 0xd000, 0xe000. Avoid conflicts
+ with other hardware.
+cat </etc/siol1.rom >/proc/comx/comx0/firmware <- the firmware for the card
+echo HDLC >/proc/comx/comx0/protocol <- the data-link protocol
+echo 10 >/proc/comx/comx0/keepalive <- the keepalive for the protocol
+ifconfig comx0 pointopoint netmask <-
+ finally configure it with ifconfig
+Check its status:
+cat /proc/comx/comx0/status
+If you want to use the second channel of this board:
+mkdir /proc/comx/comx1
+echo comx >/proc/comx/comx1/boardtype
+echo 0x360 >/proc/comx/comx1/io
+echo 10 >/proc/comx/comx1/irq
+echo 0xd000 >/proc/comx/comx1/memaddr
+echo 1 >/proc/comx/comx1/channel <- channels are numbered
+ as 0 (default) and 1
+Now, check if the driver recognized that you're going to use the other
+channel of the same adapter:
+cat /proc/comx/comx0/twin
+cat /proc/comx/comx1/twin
+You don't have to load the firmware twice, if you use both channels of
+an adapter, just write it into the channel 0's /proc firmware file.
+Default values: io 0x360 for COMX, 0x320 (HICOMX), irq 10, memaddr 0xd0000
+The LoCOMX driver doesn't require firmware, and it doesn't use memory either,
+but it uses DMA channels 1 and 3. You can set the clock rate (if enabled by
+jumpers on the board) by writing the kbps value into the file named 'clock'.
+Set it to 'external' (it is the default) if you have external clock source.
+(Note: currently the LoCOMX driver does not support the internal clock)
+On the HICOMX, COMX and CMX, you have to load the firmware (it is different for
+the three cards!). All these adapters can share the same memory
+address (we usually use 0xd0000). On the CMX you can set the internal
+clock rate (if enabled by jumpers on the small adapter boards) by writing
+the kbps value into the 'clock' file. You have to do this before initializing
+the card. If you use both HICOMX and CMX/COMX cards, initialize the HICOMX
+first. The I/O address of the HICOMX board is not configurable by any
+method available to the user: it is hardwired to 0x320, and if you have to
+change it, consult ITC-Pro Ltd.
+The MixCOM board doesn't require firmware, the driver communicates with
+it through I/O ports. You can have three of these cards in one machine.
+The SliceCOM board doesn't require firmware. You can have 4 of these cards
+in one machine. The driver doesn't (yet) support shared interrupts, so
+you will need a separate IRQ line for every board.
+Read Documentation/networking/slicecom.txt for help on configuring
+this adapter.
+The HDLC/SyncPPP line protocol driver uses the kernel's built-in syncppp
+driver (syncppp.o). You don't have to manually select syncppp.o when building
+the kernel, the dependencies compile it in automatically.
+(setting up hw parameters, see above)
+# using HDLC:
+echo hdlc >/proc/comx/comx0/protocol
+echo 10 >/proc/comx/comx0/keepalive <- not necessary, 10 is the default
+ifconfig comx0 pointopoint netmask
+(setting up hw parameters, see above)
+# using PPP:
+echo ppp >/proc/comx/comx0/protocol
+ifconfig comx0 up
+ifconfig comx0 pointopoint netmask
+For this, you'll need to configure LAPB support (See 'LAPB Data Link Driver' in
+'Network options' section) into your kernel (thanks to Jonathan Naylor for his
+excellent implementation).
+comx-proto-lapb.o provides the following files in the appropriate directory
+(the default values in parens): t1 (5), t2 (1), n2 (20), mode (DTE, STD) and
+window (7). Agree with the administrator of your peer router on these
+settings (most people use defaults, but you have to know if you are DTE or
+(setting up hw parameters, see above)
+echo lapb >/proc/comx/comx0/protocol
+echo dce >/proc/comx/comx0/mode <- DCE interface in this example
+ifconfig comx0 pointopoint netmask
+You DON'T need any other frame relay related modules from the kernel to use
+COMX-Frame Relay. This protocol is a bit more complicated than the others,
+because it allows to use 'subinterfaces' or DLCIs within one physical device.
+First you have to create the 'master' device (the actual physical interface)
+as you would do for other protocols. Specify 'frad' as protocol type.
+Now you can bring this interface up by saying 'ifconfig comx0 up' (or whatever
+you've named the interface). Do not assign any IP address to this interface
+and do not set any routes through it.
+Then, set up your DLCIs the following way: create a comx interface for each
+DLCI you intend to use (with mkdir), and write 'dlci' to the 'boardtype' file,
+and 'ietf-ip' to the 'protocol' file. Currently, the only supported
+encapsulation type is this (also called as RFC1294/1490 IP encapsulation).
+Write the DLCI number to the 'dlci' file, and write the name of the physical
+COMX device to the file called 'master'.
+Now you can assign an IP address to this interface and set routes using it.
+See the example file for further info and example config script.
+Notes: this driver implements a DTE interface with partially implemented
+Q933a LMI.
+You can find an extensively commented example in the 'etc' directory.
+Type of the hardware. Valid values are:
+ 'comx', 'hicomx', 'locomx', 'cmx', 'slicecom'.
+Data-link protocol on this channel. Can be: HDLC, LAPB, PPP, FRAD
+You can read the channel's actual status from the 'status' file, for example
+'cat /proc/comx/comx3/status'.
+Interpreted in seconds (default is 1). Used to avoid line jitter: the system
+will consider the line status 'UP' only if it is up for at least this number
+of seconds.
+You can set various debug options through this file. Valid options are:
+'comx_events', 'comx_tx', 'comx_rx', 'hw_events', 'hw_tx', 'hw_rx'.
+You can enable a debug options by writing its name prepended by a '+' into
+the debug file, for example 'echo +comx_rx >comx0/debug'.
+Disabling an option happens similarly, use the '-' prefix
+(e.g. 'echo -hw_rx >debug').
+Debug results can be read from the debug file, for example:
+tail -f /proc/comx/comx2/debug