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diff --git a/share/man/man4/uart.4 b/share/man/man4/uart.4 new file mode 100644 index 000000000000..be9d70031d5f --- /dev/null +++ b/share/man/man4/uart.4 @@ -0,0 +1,185 @@ +.\" +.\" Copyright (c) 2003 Marcel Moolenaar +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR +.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES +.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. +.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, +.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT +.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF +.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd March 12, 2008 +.Dt UART 4 +.Os +.\" +.Sh NAME +.Nm uart +.Nd driver for Universal Asynchronous Receiver/Transmitter (UART) devices +.\" +.Sh SYNOPSIS +.Cd "device uart" +.Pp +.Cd "device puc" +.Cd "device uart" +.Pp +.Cd "device scc" +.Cd "device uart" +.Pp +.Bd -ragged offset -compact +In +.Pa /boot/device.hints : +.Cd hint.uart.0.disabled="1" +.Cd hint.uart.0.baud="38400" +.Cd hint.uart.0.port="0x3f8" +.Cd hint.uart.0.flags="0x10" +.Ed +.Pp +With +.Ar flags +encoded as: +.Bl -tag -compact -width 0x000000 +.It 0x00010 +device is potential system console +.It 0x00080 +use this port for remote kernel debugging +.It 0x00100 +set RX FIFO trigger level to ``low'' (NS8250 only) +.It 0x00200 +set RX FIFO trigger level to ``medium low'' (NS8250 only) +.It 0x00400 +set RX FIFO trigger level to ``medium high'' (default, NS8250 only) +.It 0x00800 +set RX FIFO trigger level to ``high'' (NS8250 only) +.El +.\" +.Sh DESCRIPTION +The +.Nm +device driver provides support for various classes of UARTs implementing the +EIA RS-232C (CCITT V.24) serial communications interface. +Each such interface is controlled by a separate and independent instance of +the +.Nm +driver. +The primary support for devices that contain multiple serial interfaces or +that contain other functionality besides one or more serial interfaces is +provided by the +.Xr puc 4 , +or +.Xr scc 4 +device drivers. +However, the serial interfaces of those devices that are managed by the +.Xr puc 4 , +or +.Xr scc 4 +driver are each independently controlled by the +.Nm +driver. +As such, the +.Xr puc 4 , +or +.Xr scc 4 +driver provides umbrella functionality for the +.Nm +driver and hides the complexities that are inherent when elementary components +are packaged together. +.Pp +The +.Nm +driver has a modular design to allow it to be used on differing hardware and +for various purposes. +In the following sections the components are discussed in detail. +Options are described in the section that covers the component to which each +option applies. +.\" +.Ss CORE COMPONENT +At the heart of the +.Nm +driver is the core component. +It contains the bus attachments and the low-level interrupt handler. +.\" +.Ss HARDWARE DRIVERS +The core component and the kernel interfaces talk to the hardware through the +hardware interface. +This interface serves as an abstraction of the hardware and allows varying +UARTs to be used for serial communications. +.\" +.Ss SYSTEM DEVICES +System devices are UARTs that have a special purpose by way of hardware +design or software setup. +For example, Sun UltraSparc machines use UARTs as their keyboard interface. +Such an UART cannot be used for general purpose communications. +Likewise, when the kernel is configured for a serial console, the +corresponding UART will in turn be a system device so that the kernel can +output boot messages early on in the boot process. +.\" +.Ss KERNEL INTERFACES +The last but not least of the components is the kernel interface. +This component ultimately determines how the UART is made visible to the +kernel in particular and to users in general. +The default kernel interface is the TTY interface. +This allows the UART to be used for terminals, modems and serial line IP +applications. +System devices, with the notable exception of serial consoles, generally +have specialized kernel interfaces. +.\" +.Sh HARDWARE +The +.Nm +driver supports the following classes of UARTs: +.Pp +.Bl -bullet -compact +.It +NS8250: standard hardware based on the 8250, 16450, 16550, 16650, 16750 or +the 16950 UARTs. +.It +SCC: serial communications controllers supported by the +.Xr scc 4 +device driver. +.El +.\" +.Sh FILES +.Bl -tag -width ".Pa /dev/ttyu?.init" -compact +.It Pa /dev/ttyu? +for callin ports +.It Pa /dev/ttyu?.init +.It Pa /dev/ttyu?.lock +corresponding callin initial-state and lock-state devices +.Pp +.It Pa /dev/cuau? +for callout ports +.It Pa /dev/cuau?.init +.It Pa /dev/cuau?.lock +corresponding callout initial-state and lock-state devices +.El +.Sh SEE ALSO +.Xr puc 4 , +.Xr scc 4 +.\" +.Sh HISTORY +The +.Nm +device driver first appeared in +.Fx 5.2 . +.Sh AUTHORS +The +.Nm +device driver and this manual page were written by +.An Marcel Moolenaar Aq marcel@xcllnt.net . |