Octagon Systems X-COM-2 Reference Manual page 14

Operating system setup
The following sections show how to load the appropriate drivers for the X–
COM–2.
Linux
To configure Linux to use the X–COM–2 card, you must do the following:
Assuming your system (without the X–COM–2) has four or fewer COM ports
already, the X–COM–2 will use ttyS4 and ttyS5 (ttyS0 through ttyS3 are the
first four ports). If your system has more than four ports, the X–COM–2 will
use the next available ttyS number. DO NOT TRY TO USE ttyS0
THROUGH ttyS3 for the X–COM–2 CARD.
The commands to configure the Linux operating system for the card are as
follows:
setserial /dev/<porta> uart 16550a port <base> irq <irq>
^fourport
setserial /dev/<portb> uart 16550a port <base+8> irq <irq>
^fourport
Where <porta> is the first ttyS device, <portb> is the second device, <base> is
the base address of the card (see page 11), <base+8> is 0x8 added to <base>,
and <irq> is the IRQ the card is configured to use (see page 11).
The setserial utility may be located in various directories on your system. If it
is not in the path, a fully qualified path filename may be required. Typically,
this would be /sbin/setserial.
For example, assume the X–COM–2 card will be ttyS4 and ttyS5, the board is
configured for a base address of 0x300, and irq 5, the commands would be:
setserial /dev/ttyS4 uart 16550a port 0x300 irq 5
^fourport
setserial /dev/ttyS5 uart 16550a port 0x308 irq 5
^fourport
After using setserial, use the stty command to set the baud rate for the ports
you just configured.
Note The kernel used in your system must be configured to allow sharing of
interrupts for serial devices.
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