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.Dd $Mdocdate: August 6 2021 $
.Dt INTRO 4 riscv64
.Os
.Sh NAME
.Nm intro
.Nd introduction to special files and hardware support
.Sh DESCRIPTION
The manual pages in section 4 describe the special files,
related driver functions, and networking support
available in the system.
In this part of the manual, the SYNOPSIS section of
each configurable device gives a sample specification
for use in constructing a system description for the
.Xr config 8
program.
The DIAGNOSTICS section lists messages which may appear on the console
and/or in the system error log
.Pa /var/log/messages
due to errors in device operation;
see
.Xr syslogd 8
for more information.
.Pp
This section contains both devices
which may be configured into the system
and network related information.
The networking support is introduced in
.Xr netintro 4 .
.Sh DEVICE SUPPORT
This section describes the hardware supported on the
riscv64
platform.
Software support for these devices comes in two forms.
A hardware device may be supported with a character or block
.Em device driver ,
or it may be used within the networking subsystem and have a
.Em network interface driver .
Block and character devices are accessed through files in the file
system of a special type; see
.Xr mknod 8 .
Network interfaces are indirectly accessed through the interprocess
communication facilities provided by the system; see
.Xr socket 2 .
.Pp
A hardware device is identified to the system at configuration time
and the appropriate device or network interface driver is then compiled
into the system.
When the resultant system is booted, the autoconfiguration facilities
in the system probe for the device and, if found, enable the software
support for it.
If a device does not respond at autoconfiguration
time it is not accessible at any time afterwards.
To enable a device which did not autoconfigure,
the system will have to be rebooted.
.Pp
The autoconfiguration system is described in
.Xr autoconf 4 .
.Sh LIST OF DEVICES
A complete list of available devices is contained within the pages
describing the system buses and controllers.
For example, a PCI device would be listed in the
.Xr pci 4
man page.
The following buses and controllers list these devices:
.Pp
.Bl -tag -width "cardbus(4)XX" -offset 3n -compact
.It Xr iic 4
Inter IC (I2C) bus
.It Xr pci 4
introduction to PCI bus support
.It Xr usb 4
introduction to Universal Serial Bus support
.El
.Sh SEE ALSO
.Xr autoconf 4 ,
.Xr config 8
.Sh HISTORY
The
riscv64
.Nm intro
first appeared in
.Ox 7.0 .