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:
  1. board-specific options
  2. 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:
Options Mode Software flow control
-E Raw Disabled
-s -E Raw Disabled
-E -s Raw Enabled
You can set individual terminal flags to supplement raw mode, through the -o termflags option.
-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:
Options Mode Software flow control
-e Edited Enabled
-S -e Edited Enabled
-e -S Edited Disabled
You can set individual terminal flags to supplement edited mode, through the -o termflags option.
-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)
Hardware flow control isn't supported in edited mode.
-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)
Hardware flow control isn't supported in edited mode.
-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 only
    • rx — receive data only
    • all — 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)
-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)
-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).
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