.\" $NetBSD: kver.8,v 1.4 2013/07/20 21:50:53 wiz Exp $
.\"
.Dd October 31, 2012
.Os
.Dt KVER 8
.Sh NAME
.Nm kver
.Nd run a command with overriden system version
.Sh SYNOPSIS
.Nm
.Op Fl m Ar machine
.Op Fl p Ar machine_arch
.Op Fl r Ar osrelease
.Op Fl s Ar ostype
.Ar command
.Op Ar argument ...
.Sh DESCRIPTION
The
.Nm
utility
provides a simple wrapper around the
.Xr kver 3
library.
It converts its options to environment variables understood by
.Xr kver 3 ,
sets the
.Ev LD_PRELOAD
environment variable to ensure that the
.Xr kver 3
library
.Pq Pa @PREFIX@/lib/libkver.so
is loaded,
and executes the specified
.Ar command
with the specified
.Ar argument Ns s .
.Pp
The following options are accepted:
.Bl -tag -offset indent
.It Fl m Ar machine
The operating hardware platform, e.g.\&
.Dq "amd64" .
Sets the
.Ev LIBKVER_MACHINE
environment variable.
.It Fl p Ar machine_arch
The machine processor architecture, e.g.\&
.Dq "x86_64" .
Sets the
.Ev LIBKVER_MACHINE_ARCH
environment variable.
.It Fl r Ar osrelease
The operating system release, e.g.\&
.Qq "6.0_STABLE" .
Sets the
.Ev LIBKVER_OSRELEASE
environment variable.
.It Fl s Ar ostype
The operating system type, e.g.\&
.Qq Nx .
Sets the
.Ev LIBKVER_OSTYPE
environment variable.
.El
.Pp
If the
.Fl m Ar machine
option is specified and the
.Fl p Ar machine_arch
option is not specified, then
.Nm
checks that
.Ar machine
is valid, and attempts to set an appropriate value for
.Va machine_arch ;
for example,
.Dq "-m macppc"
implies
.Dq "-p powerpc" .
Some aliases for
.Ar machine Ns / Ns Ar machine_arch
pairs are also supported; for example,
.Dq "-m macppc64"
is shorthand for
.Dq "-m macppc -p powerpc64" .
The way
.Nm
handles a
.Ar machine
name without a
.Ar machine_arch
name is intended to be identical to the way the
.Pa build.sh
script in the
.Nx
source tree handles the same situation.
To pass arbitrary values of
.Fl m Ar machine
without any validation, you must also specify
.Fl p Ar machine_arch .
.Sh EXAMPLES
.Bl -tag
.It Li "kver -r 1.5 uname -r"
Run the
.Ql "uname -r"
command with
.Va osrelease
set to
.Ql 1.5 .
.It Li "kver -m i386 chroot ."
Run the
.Ql "chroot ."
command with
.Va machine
set to
.Ql i386
and with
.Va machine_arch
set to
.Ql i386
(which is the default
.Va machine_arch
for that
.Va machine ) .
.It Li "kver -m evbmips sysctl hw.machine_arch"
Error, because there is no default
.Va machine_arch
corresponding to
.Dq "-m evbmips" .
.It Li "kver -m evbmips -p mipseb sysctl hw.machine_arch"
Run the
.Ql "sysctl hw.machine_arch"
command with
.Va machine
set to
.Ql evbmips
and
.Va machine_arch
set to
.Ql mipseb .
.El
.Sh SEE ALSO
.Xr kver 3
.Sh AUTHORS
.An Alan Barrett Aq Mt apb@NetBSD.org