DragonFly On-Line Manual Pages
DIGI(4) DragonFly/i386 Kernel Interfaces Manual DIGI(4)
NAME
digi -- DigiBoard intelligent serial cards driver
SYNOPSIS
To compile this driver into the kernel, place the following line in your
kernel configuration file:
device digi
To load this driver as a module at boot time, place the following line in
loader.conf(5):
digi_load="YES"
DESCRIPTION
The digi driver provides support for DigiBoard PC/Xe and PC/Xi series
intelligent serial multiport cards with asynchronous interfaces based on
the EIA RS-232C (CCITT V.24) standard.
Input and output for each line may set to one of following baud rates;
50, 75, 110, 134.5, 150, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200,
38400, 57600, or for newer versions of cards 115200.
The driver doesn't use any interrupts, it is ``polling-based''. This
means that it uses clock interrupts instead of interrupts generated by
DigiBoard cards and checks the state of cards 25 times per second. This
is practical because the DigiBoard cards have large input and output buf-
fers (more than 1Kbyte per port) and hardware that allows efficiently
finding the port that needs attention. The only problem seen with this
policy is slower SLIP and PPP response.
Each line in the kernel configuration file describes one card, not one
port as in the sio(4) driver.
Serial ports controlled by the digi driver can be used for both
``callin'' and ``callout''. For each port there is a callin device and a
callout device. The minor number of the callout device is 128 higher
than that of the corresponding callin port. The callin device is general
purpose. Processes opening it normally wait for carrier and for the
callout device to become inactive. The callout device is used to steal
the port from processes waiting for carrier on the callin device. Pro-
cesses opening it do not wait for carrier and put any processes waiting
for carrier on the callin device into a deeper sleep so that they do not
conflict with the callout session. The callout device is abused for han-
dling programs that are supposed to work on general ports and need to
open the port without waiting but are too stupid to do so.
The digi driver also supports an initial-state and a lock-state control
device for each of the callin and the callout ``data'' devices. The
minor number of the initial-state device is 32 higher than that of the
corresponding data device. The minor number of the lock-state device is
64 higher than that of the corresponding data device. The termios set-
tings of a data device are copied from those of the corresponding ini-
tial-state device on first opens and are not inherited from previous
opens. Use stty(1) in the normal way on the initial-state devices to
program initial termios states suitable for your setup.
The lock termios state acts as flags to disable changing the termios
state. E.g., to lock a flag variable such as CRTSCTS, use ``stty
crtscts'' on the lock-state device. Speeds and special characters may be
locked by setting the corresponding value in the lock-state device to any
nonzero value.
Correct programs talking to correctly wired external devices work with
almost arbitrary initial states and no locking, but other setups may ben-
efit from changing some of the default initial state and locking the
state. In particular, the initial states for non (POSIX) standard flags
should be set to suit the devices attached and may need to be locked to
prevent buggy programs from changing them. E.g., CRTSCTS should be
locked on for devices that support RTS/CTS handshaking at all times and
off for devices that don't support it at all. CLOCAL should be locked on
for devices that don't support carrier. HUPCL may be locked off if you
don't want to hang up for some reason. In general, very bad things hap-
pen if something is locked to the wrong state, and things should not be
locked for devices that support more than one setting. The CLOCAL flag
on callin ports should be locked off for logins to avoid certain security
holes, but this needs to be done by getty if the callin port is used for
anything else.
FILES
/dev/ttyD?? for callin ports
/dev/ttyiD??
/dev/ttylD?? corresponding callin initial-state and lock-state devices
/dev/cuaD?? for callout ports
/dev/cuaiD??
/dev/cualD?? corresponding callout initial-state and lock-state devices
/etc/rc.d/serial examples of setting the initial-state and lock-state
devices
The first question mark in these device names is short for the card num-
ber (a decimal number between 0 and 65535 inclusive). The second ques-
tion mark is short for the port number (a letter in the range [0-9a-v]).
DIAGNOSTICS
You may enable extended diagnostics by defining DEBUG at the start of the
source file digi.c.
digiX: warning: address N truncated to M The memory address for the
PC/Xe's 8K window is misaligned (it should be on an 8K boundary) or out-
side of the first megabyte.
digiX: 1st reset failed Problems with accessing I/O port of the card,
probably the wrong port value is specified in the kernel config file.
digiX: 2nd reset failed Problems with hardware.
digiX: N[st,nd,rd,th] memory test failed Problems with accessing the
memory of the card, probably the wrong iomem value is specified in the
kernel config file.
digiX: BIOS start failed Problems with starting the on-board BIOS.
Probably the memory addresses of the DigiBoard overlap with some other
device or with RAM.
digiX: BIOS download failed Problems with the on-board BIOS. Probably
the memory addresses of the DigiBoard overlap with some other device or
with RAM.
digiX: FEP code download failed Problems with downloading of the Front-
End Processor's micro-OS. Probably the memory addresses of the DigiBoard
overlap with some other device or with RAM.
digiX: FEP/OS start failed Problems with starting of the Front-End Pro-
cessor's micro-OS. Probably the memory addresses of the DigiBoard over-
lap with some other device or with RAM.
digiX: too many ports This DigiBoard reports that it has more than 32
ports. Perhaps a hardware problem or the memory addresses of the Digi-
Board overlap with some other device or with RAM.
digiX: port Y is broken The on-board diagnostic has reported that the
specified port has hardware problems.
digiX: polling of disabled board stopped Internal problems in the
polling logic of driver.
digiX: event queue's head or tail is wrong! Internal problems in the
driver or hardware.
digiX: port Y: got event on nonexisting port Some status changed on a
port that is physically present but is unusable due to misconfiguration.
digiX: port Y: event N mstat M lstat K The driver got a strange event
from card. Probably this means that you have a newer card with an
extended list of events or some other hardware problem.
digiX: port Y: overrun Input buffer has filled up. Problems in polling
logic of driver.
digiX: port Y: FEP command on disabled port Internal problems in driver.
digiX: port Y: timeout on FEP command Problems in hardware.
SEE ALSO
stty(1), termios(4), tty(4), comcontrol(8)
HISTORY
The digi driver is derived from the sio(4) driver and the DigiBoard
driver from Linux and is currently under development.
BUGS
The implementation of sending BREAK is broken. BREAK of fixed length of
1/4 s is sent anyway.
There was a bug in implementation of select(2). It is fixed now but not
widely tested yet.
There is no ditty command. Most of its functions (alternate pinout,
speed up to 115200 baud, etc.) are implemented in the driver itself.
Some other functions are missing.
DragonFly 4.3 August 6, 2009 DragonFly 4.3