devc-*, devc-ser* options
QNX SDP8.0Utilities ReferenceUtilities
Generic options for serial drivers (QNX OS)
Description:
All serial character drivers support the generic options described below.
Note:
Individual serial drivers can override these options and typically support additional driver-specific options. The order of precedence is as follows:
- board-specific options
- generic options
devc-* generic options (Apply for all devc-*)
- -C number
- The size of the canonical buffer in bytes (default 256).
- -E
- Set options to
raw
(this is the default). Software flow control is disabled by default.When set in raw mode, the following terminal flags are initialized:c_cflag = CREAD | CS8 | IHFLOW | OHFLOW | HUPCL; c_iflag = IMAXBEL | INPCK; c_lflag = 0; c_oflag = ONLCR;
The order in which you specify the -E, and -S or -s options matters:You can set individual terminal flags to supplement raw mode, through the -o termflags option.Options Mode Software flow control -E Raw Disabled -s -E Raw Disabled -E -s Raw Enabled - -e
- Start in
edited
mode (the default is raw). Software flow control is enabled by default.When set in edited mode, the following terminal flags are initialized:c_cflag = CREAD | CS8 | HUPCL; c_iflag = IMAXBEL | INPCK | BRKINT | ICRNL | IXON | IXOFF; c_lflag = ECHO | ECHOCTL | ECHOE | ECHOKE | ICANON | ISIG | IEXTEN; c_oflag = ONLCR | OPOST;
The order in which you specify the -e, and -S or -s options matters:You can set individual terminal flags to supplement edited mode, through the -o termflags option.Options Mode Software flow control -e Edited Enabled -S -e Edited Enabled -e -S Edited Disabled - -F
- Disable hardware flow control.
The default depends on the mode:
- in
raw
mode (-E), it's enabled (-f) - in
edited
mode (-e), it's disabled (-F)
edited
mode. - in
- -f
- Enable hardware flow control.
The default depends on the mode:
- in
raw
mode (-E), it's enabled (-f) - in
edited
mode (-e), it's disabled (-F)
edited
mode. - in
- -I number
- The size of the raw input buffer in bytes. The default is 2048.
- -O number
- (
Oh
) The size of the output buffer in bytes. The default is 2048. - -o opt[,opt...]
- Additional options, separated by commas.
The options include:
- devperm — Set permissions to the serial device.
- disable=rx — Disable the UART receiver on driver startup.
- highwater=value — Set the
receive highwater mark for input flow control. This specifies when to assert
input flow control based on the byte level in
ibuf
. - kdebug — Enable kernal tracing of events on the system.
- log=flow[@directory_path]—Specify whether to log
data for receive, transmit, or both. If directory_path isn't specified, the default log directory is /dev/shmem.
Specify one of these values for flow:
tx
— transmit data onlyrx
— receive data onlyall
— both transmit and receive
- nodaemon — Don't call procmgr_daemon() to make the driver run in the background. Use this option if you need to know when the device terminates.
- priority=prio — Set the working priority of the internal pulse as a numeric value.
- smmu=0|1|off|on —
Specify whether or not support for the system memory management unit (IOMMU/SMMU) manager is required:
- 0 or off — disable SMMU support. This is the default.
- 1 or on — SMMU support is required; the driver exits if it isn't available
For more information, see the SMMUMAN User's Guide.
- termflags=[-]flag[:[-]flag]* —
Specify terminal flag settings.
This option should be used to supplement the raw or edited mode by setting (enabling) and/or clearing (disabling)
individual terminal flags that were initialized by -E or -e.
Because the driver options are processed in the order in which they appear,
the -o termflags option must be provided after other options that affect terminal flags.
This is to ensure that other options don't negate the effects of this option.
If you put a dash (-) in front of a flag's name, the flag is disabled; no dash means the flag is enabled.
For input modes, the supported flag values are:- brkint
- icrnl
- ignbrk
- igncr
- ignpar
- inlcr
- inpcl
- istrip
- ixoff
- ixon
- parmrk
For output modes, you can specify these flag values:- opost
For control modes, you can specify these flag values:- clocal
- cread
- csize
- cs5
- cs6
- cs7
- cs8
- cstopb
- hupcl
- ihflow
- ohflow
- parenb
- parodd
- parstk
For local modes, you can specify these flag values:- echo
- echoe
- echok
- echonl
- icanon
- iexten
- isig
- noflsh
- tostop
For the meanings of these flags, see the c_iflag, c_oflag, c_cflag, and c_lflag descriptions in the termios entry in the C Library Reference.
- ticksize_ms=value — Timer granularity in microseconds (default 50ms).
- -S
- Disable software flow control.
The default depends on the mode:
- in
raw
mode (-E), it's disabled (-S) - in
edited
mode (-e), it's enabled (-s)
- in
- -s
- Enable software flow control.
The default depends on the mode:
- in
raw
mode (-E), it's disabled (-S) - in
edited
mode (-e), it's enabled (-s)
- in
- -v[v]...
- Be verbose; additional
v
characters cause more verbosity.
devc-ser* generic options (Apply for all devc-ser* and devc-virtio only)
- -b number
- Set the baud rates. The supported baud rates depend on the board that the driver is running on. The default baud rate is 57600.
- -c clock[/divisor]
- Set a custom clock rate, in Hertz, and a divisor for the serial port. The default (-c 1843200/16) is suitable for compatible PC serial ports.
- -u unit
- Set the serial unit number (default 1).
Page updated: