1.\" Copyright (c) 2001 2.\" Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp> 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer as 10.\" the first lines of this file unmodified. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.\" 28.Dd October 7, 2001 29.Dt DEVICE.HINTS 5 30.Os 31.Sh NAME 32.Nm device.hints 33.Nd device resource hints 34.Sh DESCRIPTION 35The 36.Nm 37file is read in by the boot 38.Xr loader 8 39when the system is about to start and its contents will be 40passed to the kernel. 41It contains various variables to control the boot behavior of 42the kernel. 43These variables are typically 44.Dq device hints . 45.\" .Dq device hints , 46.\" and other control variables. 47.Pp 48The file contains one variable per line. 49Lines starting with the 50.Ql # 51character are comments and are ignored by the boot loader. 52.Pp 53After the file is read by the boot loader, you may examine 54the variables by the 55.Ic show 56command, and may add a new variable, modify existing one, 57or delete one by the 58.Ic set 59and 60.Ic unset 61commands of the boot loader 62(see 63.Xr loader 8 ) . 64.Pp 65After the system has started, you can dump these variables 66by the 67.Xr kenv 1 68command. 69.Sh DEVICE HINTS 70Device hint variables are used by device drivers to set up 71the device. 72They are most often used by ISA device drivers to specify 73where the driver will probe for the relevant devices, and what 74resources it will attempt to use. 75.Pp 76A device hint line looks like: 77.Pp 78.Sm off 79.D1 Li hint. Ar driver Li . Ar unit Li . Ar keyword Li = Qq Ar value 80.Sm on 81.Pp 82where 83.Ar driver 84is the name of a device driver, 85.Ar unit 86is the unit number, 87.Ar keyword 88is the keyword of the hint. 89The keyword may be: 90.Pp 91.Bl -tag -width ".Li disabled" -compact -offset indent 92.It Li at 93specifies a bus to which the device is attached. 94.It Li port 95specifies the start address of I/O ports to be used by the device. 96.It Li irq 97is the interrupt line number to be used. 98.It Li drq 99is the DMA channel number. 100.It Li maddr 101specifies the physical memory address occupied by the device. 102.It Li flags 103sets various flag bits for the device. 104.It Li disabled 105is set to 106.Qq 1 107to disable the device. 108.El 109.Pp 110A device driver may require one or more hint lines with these keywords, 111and may accept other keywords not listed here. 112Consult individual device drivers' manual pages for available 113keywords and their possible values. 114.\" .Sh CONTROL VARIABLES 115.\" Lines not starting with 116.\" .Dq hint. 117.\" specify other control variables for the kernel. 118.\" They look: 119.\" .Pp 120.\" .Dl <name>="<value>" 121.\" XXX 122.\" WE SHOULD LIST AVAILABLE VARIABLE NAMES AND THEIR POSSIBLE VALUES HERE! 123.\" .Pp 124.Sh FILES 125.Bl -tag -width ".Pa /sys/ Ns Ar ARCH Ns Pa /conf/GENERIC.hints" -compact 126.It Pa /boot/device.hints 127Device resource hints file. 128.It Pa /sys/ Ns Ar ARCH Ns Pa /conf/GENERIC.hints 129Sample resource hints for the 130.Pa GENERIC 131kernel. 132.It Pa /sys/ Ns Ar ARCH Ns Pa /conf/NOTES 133Notes on the kernel configuration file and device resource hints. 134.El 135.Sh EXAMPLES 136The following example sets up resources for the 137.Xr sio 4 138driver on the ISA bus. 139.Bd -literal -offset indent 140hint.sio.0.at="isa" 141hint.sio.0.port="0x3F8" 142hint.sio.0.flags="0x10" 143hint.sio.0.irq="4" 144.Ed 145 146The following example disables the ACPI driver 147.Bd -literal -offset indent 148hint.acpi.0.disable="1" 149.Ed 150.\" .Pp 151.\" A control variable may look like: 152.\" .Pp 153.\" .Bd -literal -offset indent 154.\" debug.acpi.layer="ACPI_RESOURCES" 155.\" .Ed 156.Sh SEE ALSO 157.Xr kenv 1 , 158.Xr loader.conf 5 , 159.Xr loader 8 160.Sh HISTORY 161The 162.Nm 163file first appeared in 164.Fx 5.0 . 165