/dev/nmdmN[AB]
nullmodem device nodes. Where the A node has a matching B node.
nmdm4
Nullmodem terminal driver
Usage
To compile this driver into the kernel, place the following line in your kernel configuration file:
device nmdm
Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):
nmdm_load="YES"
Overview
The nmdm driver provides two tty(4) devices connected by a virtual “null modem” cable.
If either of the two tty devices have the CDSR_OFLOW bit (“stty dsrflow”) set in their line discipline, the nmdm device will emulate the speed configured in the termios(4) settings. The speed emulation works independently in the two directions, controlled by the slower end's termios settings (c_ispeed, c_ospeed, CS5 ... CS8, CSTOPB and PARENB).
Files
The nmdm driver implements “on-demand device creation” so simply accessing a given instance in /dev will create it.
Diagnostics
None.
Releases
65 releases since FreeBSD 4.4-RELEASE; the text changed 34 times.