1.\" $NetBSD: newbtconf.8,v 1.18 2004/08/31 17:08:06 uwe Exp $ 2.\" 3.\" Copyright (c) 1999 Darren Reed. 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. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 3. Neither the name of the author nor the names of its contributors 14.\" may be used to endorse or promote products derived from this software 15.\" without specific prior written permission. 16.\" 17.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27.\" SUCH DAMAGE. 28.\" 29.Dd December 31, 2019 30.Dt NEWBTCONF 8 31.Os 32.Sh NAME 33.Nm newbtconf 34.Nd multiple boot-up configurations 35.Sh SYNOPSIS 36.Nm 37.Ar new-conf-name 38.Op Ar orig-conf-name 39.Nm 40.Cm init 41.Nm 42.Cm revert 43.Sh DESCRIPTION 44.Nm 45is used to set up the system in such a way that the user is offered a 46selection of environments in which to boot the system up into. 47The most obvious application being for laptops to provide a network 48and non-network environment after a successful boot into multi-user mode. 49.Ss Background 50In order to accomplish this task, the files usually associated with 51establishing the current system's running configuration are replaced with 52symbolic links which are adjusted with each boot to point to the appropriate 53file for the desired run-time environment. 54This is accomplished by directing all of the symbolic links through a 55directory which itself is a symbolic link 56.Pq Pa /etc/etc.current , 57to the destination files. 58At each bootup, the selection made changes which directory 59.Pa /etc/etc.current 60points to. 61.Pp 62Through doing this and reloading 63.Pa /etc/rc.conf 64in 65.Pa /etc/rc 66after the link has 67been established, the resulting run-time configuration is effectively 68controlled without the need to directly edit any files. 69The default boot-up environment is selected by manually directing which 70configuration directory 71.Pa /etc/etc.default 72points to. 73As opposed to 74.Pa /etc/etc.current 75(which is updated 76with every boot), 77.Pa /etc/etc.default 78is not automatically updated. 79.Ss Getting Started 80By default, 81.Dx 82only has one boot-up configuration - that set in the 83file 84.Pa /etc/rc.conf . 85In order to initialize the system for operating in a 86manner which supports multiple boot configurations, 87.Nm 88must be run with an argument of 89.Sq init . 90This will create two symbolic links 91.Pa /etc/etc.current 92and 93.Pa /etc/etc.default 94to the directory 95.Pa /etc/etc.network . 96The following files are all moved into 97that directory and symbolic links put in their place, in 98.Pa /etc , 99pointing to 100.Pa /etc/etc.current/\*[Lt]filename\*[Gt] : 101.Bd -literal -offset indent 102/etc/defaultdomain 103/etc/dntpd.conf 104/etc/fstab 105/etc/ifconfig.* 106/etc/inetd.conf 107/etc/mygate 108/etc/myname 109/etc/netstart 110/etc/nsswitch.conf 111/etc/rc.conf 112/etc/rc.conf.d 113/etc/resolv.conf 114.Ed 115.Pp 116To test that this has been performed correctly, reboot your system into 117.Dx . 118After the kernel has autoconfigured and tty flags have been set, 119a prompt should appear, preceded by the following like, looking like this: 120.Bd -literal 121[network] 122Which configuration [network] ? 123.Ed 124.Pp 125The []'s are used to indicate the default configuration, which can be 126selected by just pressing return. 127If there were other configurations available at this stage, you would 128have 30 seconds to enter that name and press 129.Sy RETURN . 130.Ss Multiple Configurations 131Once an initial configuration has been set up, we can proceed to set up further 132run time environments. 133This is done by invoking 134.Nm 135with the name of the new configuration to be created. 136By default, this step 137will use the current configuration files as the basis for this setup unless 138a second parameter is given - that of the configuration to use as the basis 139for the new one. 140Upon completion, a new directory, 141.Pa /etc/etc.\*[Lt]newname\*[Gt] , 142will have been created, 143priming the directory with the appropriate files for editing. 144For example, if we do 145.Nm 146.Ar nonet network 147it would create a directory named 148.Pa /etc/etc.nonet 149and copy all the files from 150.Pa /etc/etc.network 151into that directory. 152Upon rebooting, we should see: 153.Bd -literal 154[network] nonet 155Which configuration [network] ? 156.Ed 157.Pp 158To set up the system for booting into the 159.Dq nonet 160configuration, the files in 161.Pa /etc/etc.nonet 162need be edited. 163.Pp 164If you wanted to make 165.Dq nonet 166the default configuration when booting, you 167would need delete the symbolic link 168.Pa /etc/etc.default 169and create a new symbolic link (with the same name) to 170.Pa /etc/etc.nonet . 171Booting up after having made such a change would 172result in the following being displayed: 173.Bd -literal 174network [nonet] 175Which configuration [nonet] ? 176.Ed 177.Ss \&No Network 178Assuming that we performed the above command successfully, in order to 179successfully configure 180.Dx 181to not configure interfaces (or generate no 182errors from attempting to do so), the following settings (at least) should 183be used in 184.Pa /etc/etc.nonet/rc.conf : 185.Bd -literal 186auto_ifconfig=NO 187net_interfaces=NO 188.Ed 189.Pp 190Of course other networking services, such as NTP, routed, etc, are all 191expected to be 192.Dq NO . 193In general, the only setting that should be 194.Dq YES 195is syslogd, and perhaps cron (if your cron scripts don't 196need the network) or screenblank/wscons (if applicable). 197Other actions such as deleting any NFS mounts from 198.Pa /etc/etc.nonet/fstab 199would also need to be undertaken. 200.Ss Reverting multiple boot configurations 201Multiple boot configurations can be deactivated by running 202.Nm 203with an argument of 204.Cm revert . 205All the symlinks mentioned above are then removed and the files they point to 206are copied to their default place. 207This effectively makes the currently selected 208configuration the only one active. 209The symbolic links 210.Pa /etc/etc.current 211and 212.Pa /etc/etc.default 213are also removed so upon rebooting no configuration selection menu is 214displayed. 215Note that the previously created configurations (in 216.Pa /etc/etc.\*[Lt]name\*[Gt] ) 217are not removed. 218.Sh FILES 219.Bl -tag -width ".Pa /etc/nsswitch.conf" -compact 220.It Pa /etc/etc.current 221Symbolic link to current config directory. 222.It Pa /etc/etc.default 223Symbolic link to default config directory. 224.Pp 225.It Pa /etc/defaultdomain 226These files all become symbolic links. 227.It Pa /etc/dntpd.conf 228.It Pa /etc/fstab 229.It Pa /etc/ifconfig.* 230.It Pa /etc/inetd.conf 231.It Pa /etc/mygate 232.It Pa /etc/myname 233.It Pa /etc/netstart 234.It Pa /etc/nsswitch.conf 235.It Pa /etc/rc.conf 236.It Pa /etc/rc.conf.d 237.It Pa /etc/resolv.conf 238.El 239.Sh SEE ALSO 240.Xr rc.conf 5 , 241.Xr rc 8 242.Sh HISTORY 243The 244.Nm 245program first appeared in 246.Nx 1.5 . 247.Sh AUTHORS 248.An -nosplit 249This shell script was written by 250.An Darren Reed Aq Mt darrenr@NetBSD.org 251with initial input from 252.An Matthew Green Aq Mt mrg@NetBSD.org 253on how to approach this problem. 254.Sh BUGS 255It presently does not display a count down timer whilst waiting for input 256to select which configuration and nor does it abort said timer when a key 257is first pressed. 258.Pp 259The management of the overall collection of multiple configurations is much 260more manual than it ought to be. 261A general system configuration tool needs to be written to ease their 262management. 263