.\" $OpenBSD: octboot.4,v 1.2 2020/10/10 10:11:54 visa Exp $ .\" .\" Copyright (c) 2020 Visa Hankala .\" .\" Permission to use, copy, modify, and distribute this software for any .\" purpose with or without fee is hereby granted, provided that the above .\" copyright notice and this permission notice appear in all copies. .\" .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" .Dd $Mdocdate: October 10 2020 $ .Dt OCTBOOT 4 octeon .Os .Sh NAME .Nm octboot .Nd kernel boot interface .Sh SYNOPSIS .Cd "pseudo-device octboot" .Sh DESCRIPTION The .Nm driver provides an .Xr ioctl 2 interface for booting into another kernel from the currently running kernel. .Sh IOCTL INTERFACE .Nm provides the following .Xr ioctl 2 commands, available through .In machine/octboot.h : .Bl -tag -width xxxx .It Dv OBIOC_GETROOTDEV Fa "char rootdev[PATH_MAX]" Get the name of the current root device. .It Dv OBIOC_KEXEC "struct octboot_kexec_args *args" Boot into the given kernel image. .Bd -literal struct octboot_kexec_args { char *kimg; size_t klen; char *argv[OCTBOOT_MAX_ARGS]; }; .Ed .El .Sh FILES .Bl -tag -width /dev/octboot -compact .It Pa /dev/octboot boot interface device. .El .Sh SEE ALSO .Xr ioctl 2 , .Xr intro 4 .Sh HISTORY The .Nm driver first appeared in .Ox 6.6 .