164 lines
4.7 KiB
Groff
164 lines
4.7 KiB
Groff
.\" Copyright (c) 2000 Sheldon Hearn
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd July 5, 2020
|
|
.Dt LINUX 4
|
|
.Os
|
|
.Sh NAME
|
|
.Nm linux
|
|
.Nd Linux ABI support
|
|
.Sh SYNOPSIS
|
|
To compile support for this ABI into an i386 kernel
|
|
place the following line in your
|
|
kernel configuration file:
|
|
.Bd -ragged -offset indent
|
|
.Cd "options COMPAT_LINUX"
|
|
.Ed
|
|
.Pp
|
|
for an amd64 kernel use:
|
|
.Bd -ragged -offset indent
|
|
.Cd "options COMPAT_LINUX32"
|
|
.Ed
|
|
.Pp
|
|
Alternatively, to load the ABI as a
|
|
module at boot time, place the following line in
|
|
.Xr loader.conf 5 :
|
|
.Bd -literal -offset indent
|
|
linux_load="YES"
|
|
.Ed
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
module provides limited Linux ABI (application binary interface) compatibility,
|
|
making it possible to run many unmodified Linux applications and libraries
|
|
without the need for virtualization or emulation.
|
|
Some of the facilities provided are:
|
|
.Bl -bullet
|
|
.It
|
|
An image activator
|
|
for correctly branded
|
|
.Xr elf 5
|
|
executable images
|
|
.It
|
|
Special signal handling for activated images
|
|
.It
|
|
Linux to native system call translation
|
|
.It
|
|
Linux-specific system calls
|
|
.El
|
|
.Pp
|
|
Note that dynamically linked Linux executables
|
|
will require a suitable environment in
|
|
.Pa /compat/linux .
|
|
This includes native Linux shared libraries, and Linux-specific virtual
|
|
filesystems.
|
|
To set it up, install the
|
|
.Pa emulators/linux_base-c7
|
|
port or the linux_base-c7
|
|
package, and add the following line to the
|
|
.Xr rc.conf 5
|
|
file:
|
|
.Pp
|
|
.Dl linux_enable="YES"
|
|
.Pp
|
|
To avoid mounting Linux-specific filesystems at startup, also add the following
|
|
line:
|
|
.Pp
|
|
.Dl linux_mounts_enable="NO"
|
|
.Sh SYSCTL VARIABLES
|
|
The following variables are available as both
|
|
.Xr sysctl 8
|
|
variables and
|
|
.Xr loader 8
|
|
tunables:
|
|
.Bl -tag -width indent
|
|
.It Va compat.linux.debug
|
|
Enable debugging messages.
|
|
Set to 0 to silence them.
|
|
Defaults to 1.
|
|
.It Va compat.linux.default_openfiles
|
|
Default soft openfiles resource limit for Linux applications.
|
|
Set to -1 to disable the limit.
|
|
Defaults to 1024.
|
|
.It Va compat.linux.emul_path
|
|
Path to the Linux run-time environment.
|
|
Defaults to
|
|
.Pa /compat/linux .
|
|
.It Va compat.linux.osname
|
|
Linux kernel operating system name.
|
|
.It Va compat.linux.osrelease
|
|
Linux kernel operating system release.
|
|
Changing this to something else is discouraged on non-development systems,
|
|
because it may change the way Linux programs work.
|
|
Recent versions of GNU libc are known to use different syscalls depending
|
|
on the value of this sysctl.
|
|
.It Va compat.linux.oss_version
|
|
Linux Open Sound System version.
|
|
.It Va compat.linux.preserve_vstatus
|
|
When set to 1, it prevents Linux applications from resetting the
|
|
.Xr termios 4
|
|
VSTATUS setting.
|
|
From a user perspective, this makes
|
|
.Va SIGINFO
|
|
work for Linux executables.
|
|
Defaults to 0.
|
|
.Sh FILES
|
|
.Bl -tag -width /compat/linux/dev/shm -compact
|
|
.It Pa /compat/linux
|
|
minimal Linux run-time environment
|
|
.It Pa /compat/linux/dev
|
|
device file system, see
|
|
.Xr devfs 5
|
|
.It Pa /compat/linux/dev/fd
|
|
file descriptor file system mounted with the
|
|
.Cm linrdlnk
|
|
option, see
|
|
.Xr fdescfs 5
|
|
.It Pa /compat/linux/dev/shm
|
|
in-memory file system, see
|
|
.Xr tmpfs 5
|
|
.It Pa /compat/linux/proc
|
|
Linux process file system, see
|
|
.Xr linprocfs 5
|
|
.It Pa /compat/linux/sys
|
|
Linux kernel objects file system, see
|
|
.Xr linsysfs 5
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr brandelf 1 ,
|
|
.Xr pty 4 ,
|
|
.Xr elf 5 ,
|
|
.Xr fdescfs 5 ,
|
|
.Xr linprocfs 5 ,
|
|
.Xr linsysfs 5 ,
|
|
.Xr tmpfs 5
|
|
.Sh HISTORY
|
|
Linux ABI support first appeared in
|
|
.Fx 2.1 .
|
|
.Sh BUGS
|
|
Support for some of the Linux-specific system calls and system call arguments
|
|
is missing.
|