1.\" $OpenBSD: boot_config.8,v 1.33 2021/09/13 17:35:27 jmc Exp $ 2.\" 3.\" Copyright (c) 1996 Mats O Jansson 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 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.\" 4. Neither the name of the author nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.Dd $Mdocdate: September 13 2021 $ 31.Dt BOOT_CONFIG 8 32.Os 33.Sh NAME 34.Nm boot_config 35.Nd how to change kernel configuration at boot 36.Sh DESCRIPTION 37.Nm BOOT_CONFIG 38is a kernel option that makes it possible to change the configuration 39at boot time. 40The same interface is available from userland, using the 41.Fl e 42argument to 43.Xr config 8 . 44.Pp 45The boot time configuration is invoked by passing the 46.Fl c 47option, either from the firmware prompt or, 48depending on the architecture, when the bootstrap loader 49prompts for a kernel to boot: 50.Bd -literal 51>> OpenBSD/i386 BOOT 3.26 52.No "boot>" Ic boot -c 53booting hd0a:/bsd: ... 54\&... 55real mem = 1073086464 (1023MB) 56avail mem = 1043189760 (994MB) 57User Kernel Config 58UKC> 59.Ed 60.Pp 61Changes made can be saved for the next reboot, by using 62.Xr config 8 . 63However, those changes would not persist across system upgrades and would 64prevent kernel relinking. 65To ensure these changes are carried over to upgraded kernels, they can 66be saved to the 67.Xr bsd.re-config 5 68configuration file. 69.Sh COMMANDS 70.Bl -tag -width "disable devno | dev" 71.It Ic add Ar dev 72Add a device through copying another. 73.It Ic base Cm 8 | 10 | 16 74Change the base of numbers displayed and entered. 75.It Ic change Ar devno | dev 76Modify one or more devices. 77.It Ic disable Ar devno | dev 78Disable one or more devices. 79.It Ic enable Ar devno | dev 80Enable one or more devices. 81.It Ic exit 82Continue boot. 83.It Ic find Ar devno | dev 84Find one or more devices. 85.It Ic help 86Give a short summary of all commands and their arguments. 87.It Ic list 88Show all known devices, a screen at a time. 89.It Ic lines Op Ar count 90Set the number of rows per page. 91.It Ic quit 92Continue boot. 93.It Ic show Op Ar attr Op Ar val 94Show all devices for which attribute 95.Ar attr 96has the value 97.Ar val . 98.It Ic verbose 99Toggle the autoconfig verbose variable. 100.El 101.Sh EXAMPLES 102The Ethernet card is not detected at boot because the kernel configuration 103does not match the physical hardware configuration, 104e.g. wrong IRQ in OpenBSD/i386. 105The Ethernet card is supposed to use the 106.Xr ne 4 107driver. 108.Bd -literal 109.No UKC> Ic find ne 11024 ne0 at isa0 port 0x240 size 0 iomem 0xd8000 iosiz 0 irq 9 drq -1 drq2 -1 flags 0x0 11125 ne1 at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 10 drq -1 drq2 -1 flags 0x0 11226 ne* at isapnp0 port -1 size 0 iomem -1 iosiz 0 irq -1 drq -1 flags 0x0 11327 ne* at pci* dev -1 function -1 flags 0x0 11428 ne* at pcmcia* function -1 irq -1 flags 0x0 115UKC> 116.Ed 117.Pp 118ne1 seems to match the configuration except it uses IRQ 5 instead of IRQ 10. 119So the irq on ne1 should be changed via the 120.Fa change 121command. 122The device can be specified by either name or number. 123.Bd -literal 124.No UKC> Ic change ne1 12525 ne1 at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 10 drq -1 drq2 -1 flags 0x0 126.No change (y/n) \&? Ic y 127.No port [0x300] \&? 128.No size [0] \&? 129.No iomem [-1] \&? 130.No iosiz [0] \&? 131.No irq [10] \&? Ic 5 132.No drq [-1] \&? 133.No drq2 [-1] \&? 134.No flags [0] \&? 13525 ne1 changed 13625 ne1 at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 5 drq -1 drq2 -1 flags 0x0 137UKC> 138.Ed 139.Pp 140The show command is useful for finding which devices have a certain attribute. 141It can also be used to find those devices with a particular value for 142an attribute. 143.Bd -literal 144.No UKC> Ic show slot 145 2 ahc* at eisa0 slot -1 flags 0x0 146 10 uha* at eisa0 slot -1 flags 0x0 147 12 ep0 at eisa0 slot -1 flags 0x0 148 17 ep* at eisa0 slot -1 flags 0x0 149102 ahb* at eisa0 slot -1 flags 0x0 150103 fea* at eisa0 slot -1 flags 0x0 151.No UKC> Ic show port 0x300 152 25 ne1 at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 10 drq -1 drq2 -1 flags 0x0 153 72 we1 at isa0 port 0x300 size 0 iomem 0xcc000 iosiz 0 irq 10 drq -1 drq2 -1 flags 0x0 154 75 el0 at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 9 drq -1 drq2 -1 flags 0x0 155 77 ie1 at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 10 drq -1 drq2 -1 flags 0x0 156UKC> 157.Ed 158.Pp 159It is possible to add new devices, but only devices that were linked into the 160kernel. 161If a new device is added, following devices will be renumbered. 162.Bd -literal 163.No UKC> Ic find ep 164 11 ep0 at isa0 port -1 size 0 iomem -1 iosiz 0 irq -1 drq -1 drq2 -1 flags 0x0 165 12 ep0 at eisa0 slot -1 flags 0x0 166 13 ep0 at pci* dev -1 function -1 flags 0x0 167 14 ep* at isapnp0 port -1 size 0 iomem -1 iosiz 0 irq -1 drq -1 flags 0x0 168 15 ep* at isa0 port -1 size 0 iomem -1 iosiz 0 irq -1 drq -1 drq2 -1 flags 0x0 169 16 ep* at eisa0 slot -1 flags 0x0 170 17 ep* at pci* dev -1 function -1 flags 0x0 171 18 ep* at pcmcia* dev -1 irq -1 flags 0x0 172.No UKC> Ic add ep1 173.No "Clone Device (DevNo, 'q' or '\&?') \&?" Ic 13 174.No "Insert before Device (DevNo, 'q' or '\&?')" Ic 14 175 14 ep1 at pci* dev -1 function -1 176.No UKC> Ic change 14 177 14 ep1 at pci* dev -1 function -1 178.No change (y/n) \&? Ic y 179.No dev [-1] \&? Ic 14 180.No function [-1] \&? 181.No flags [0] \&? Ic 18 182 14 ep1 changed 183 14 ep1 at pci* dev 14 function -1 flags 0x12 184UKC> 185.Ed 186.Pp 187When configuration is completed, booting can proceed by issuing the 188.Ic quit 189or 190.Ic exit 191commands. 192.Bd -literal 193.No UKC> Ic quit 194Continuing... 195mainbus0 (root) 196.Ed 197.Sh SEE ALSO 198.Xr bsd.re-config 5 , 199.Xr config 8 200.Sh AUTHORS 201.An Mats O Jansson Aq Mt moj@stacken.kth.se 202.Sh BUGS 203The 204.Ic add 205command is rather restricted, and might be expanded in the future. 206