.\"-
.\" Copyright (c) 2013 Stacey D. Son
.\" 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
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.\" 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.
.\"
.\" Support for miscellaneous binary image activators
.\"
.Dd April 30, 2020
.Dt BINMISCCTL 8
.Os
.Sh NAME
.Nm binmiscctl
.Nd manage binary image activators
.Sh SYNOPSIS
.Nm
.Cm add
.Ar name
.Fl -interpreter
.Ar path
.Fl -magic
.Ar magic
.Fl -size
.Ar size
.Op Fl -mask Ar mask
.Op Fl -offset Ar offset
.Op Fl -set-enabled
.Op Fl -pre-open
.Nm
.Cm disable
.Ar name
.Nm
.Cm enable
.Ar name
.Nm
.Cm list
.Nm
.Cm lookup
.Ar name
.Nm
.Cm remove
.Ar name
.Sh DESCRIPTION
The
.Nm
utility
is the management utility for configuring miscellaneous binaries image
activators in the kernel.
It allows adding, deleting, disabling,
enabling, and looking up interpreters.
Also, all the interpreters can
be listed.
.Pp
The first argument on the command line indicates the operation to be
performed.
Operation must be one of the following:
.Bl -tag -width indent
.It Xo
.Cm add
.Ar name
.Fl -interpreter
.Ar path
.Fl -magic
.Ar magic
.Fl -size
.Ar size
.Op Fl -mask Ar mask
.Op Fl -offset Ar offset
.Op Fl -set-enabled
.Op Fl -pre-open
.Xc
Add a new activator entry in the kernel.
You must specify a
unique
.Ar name ,
a
.Ar path
to the interpreter,
header
.Ar magic
bytes that uniquely identify a suitable binary for the activator,
and the
.Ar size
of the
.Ar magic
in bytes.
.Pp
Optionally, you may specify a
.Ar mask
to do a bitwise AND with the header bytes.
This effectively allows you to ignore fields in the binary header that
do not uniquely indentify the binary file's type.
.Pp
An
.Ar offset
may be specified for the magic bytes using the
.Fl -offset
option.
By default the
.Ar offset
is zero.
.Pp
To enable the activator entry the
.Fl -set-enabled
option is used.
The activator default state is disabled.
.Pp
To make the interpreter automatically available in jails and chroots,
use the
.Fl -pre-open
option to allow the kernel to open the binary at configuration time
rather then lazily when the interpreted program is started.
.Pp
The interpreter
.Ar path
may also contain arguments for the interpreter including
.Ar #a
which gets replaced by the old
.Dv argv0
value in the interpreter string.
.It Cm disable Ar name
Disable the activator entry identified with
.Ar name .
.It Cm enable Ar name
Enable the activator entry identified with
.Ar name .
.It Cm list
Take a snapshot and print all the activator entries currently configured.
.It Cm lookup Ar name
Look up and print out the activator entry identified with
.Ar name .
.It Cm remove Ar name
Remove the activator entry identified with
.Ar name .
.El
.Sh EXAMPLES
Add an image activator to run the LLVM interpreter
.Po
.Xr lli 1
.Pc
on bitcode
compiled files and set its state to enabled.
In this example
.Ar #a
is replaced with the old
.Dv argv0
value so that
.Xr lli 1
can fake its
.Dv argv0 :
.Bd -literal -offset indent
# binmiscctl add llvmbc --interpreter ''/usr/bin/lli \e
  --fake-argv0=#a'' --magic ''BC\\xc0\\xde'' --size 4 \e
  --set-enabled
.Ed
.Pp
Set the state of the
.Ar llvmbc
image activator to disabled:
.Bd -literal -offset indent
# binmiscctl disable llvmbc
.Ed
.Pp
Set the state of the
.Ar llvmbc
image activator to enabled:
.Bd -literal -offset indent
# binmiscctl enable llvmbc
.Ed
.Pp
Delete the
.Ar llvmbc
image activator:
.Bd -literal -offset indent
# binmiscctl remove llvmbc
.Ed
.Pp
Look up and list the record for the
.Ar llvmbc
image activator:
.Bd -literal -offset indent
# binmiscctl lookup llvmbc
.Ed
.Pp
Add QEMU bsd-user program as an image activator for ARM AARCH64 binaries:
.Bd -literal -offset indent
# binmiscctl add arm64 \e
  --interpreter "/usr/local/bin/qemu-aarch64-static" \e
  --magic "\ex7f\ex45\ex4c\ex46\ex02\ex01\ex01\ex00\ex00\ex00\e
           \ex00\ex00\ex00\ex00\ex00\ex00\ex02\ex00\exb7\ex00" \e
  --mask  "\exff\exff\exff\exff\exff\exff\exff\ex00\exff\exff\e
           \exff\exff\exff\exff\exff\exff\exfe\exff\exff\exff" \e
  --size 20 --set-enabled
.Ed
.Pp
Add QEMU bsd-user program as an image activator for ARM little-endian binaries:
.Bd -literal -offset indent
# binmiscctl add armelf \e
  --interpreter "/usr/local/bin/qemu-arm-static" \e
  --magic "\ex7f\ex45\ex4c\ex46\ex01\ex01\ex01\ex00\ex00\ex00\e
           \ex00\ex00\ex00\ex00\ex00\ex00\ex02\ex00\ex28\ex00" \e
  --mask  "\exff\exff\exff\exff\exff\exff\exff\ex00\exff\exff\e
           \exff\exff\exff\exff\exff\exff\exfe\exff\exff\exff" \e
  --size 20 --set-enabled
.Ed
.Pp
Add QEMU bsd-user program as an image activator for ARM big-endian binaries:
.Bd -literal -offset indent
# binmiscctl add armebelf \e
  --interpreter "/usr/local/bin/qemu-arm-static" \e
  --magic "\ex7f\ex45\ex4c\ex46\ex01\ex02\ex01\ex00\ex00\ex00\e
           \ex00\ex00\ex00\ex00\ex00\ex00\ex00\ex02\ex00\ex28" \e
  --mask  "\exff\exff\exff\exff\exff\exff\exff\ex00\exff\exff\e
           \exff\exff\exff\exff\exff\exff\exff\exfe\exff\exff" \e
  --size 20 --set-enabled
.Ed
.Pp
Add QEMU bsd-user program as an image activator for MIPS32 binaries:
.Bd -literal -offset indent
# binmiscctl add mips32 \e
  --interpreter "/usr/local/bin/qemu-mips-static" \e
  --magic "\ex7f\ex45\ex4c\ex46\ex01\ex02\ex01\ex00\ex00\ex00\e
           \ex00\ex00\ex00\ex00\ex00\ex00\ex00\ex02\ex00\ex08" \e
  --mask  "\exff\exff\exff\exff\exff\exff\exff\ex00\exff\exff\e
           \exff\exff\exff\exff\exff\exff\exff\exfe\exff\exff" \e
  --size 20 --set-enabled
.Ed
.Pp
Add QEMU bsd-user program as an image activator for MIPS64 binaries:
.Bd -literal -offset indent
# binmiscctl add mips64 \e
  --interpreter "/usr/local/bin/qemu-mips64-static" \e
  --magic "\ex7f\ex45\ex4c\ex46\ex02\ex02\ex01\ex00\ex00\ex00\e
           \ex00\ex00\ex00\ex00\ex00\ex00\ex00\ex02\ex00\ex08" \e
  --mask "\exff\exff\exff\exff\exff\exff\exff\ex00\exff\exff\e
          \exff\exff\exff\exff\exff\exff\exff\exfe\exff\exff" \e
  --size 20 --set-enabled
.Ed
.Pp
Add QEMU bsd-user program as an image activator for PowerPC binaries:
.Bd -literal -offset indent
# binmiscctl add powerpc \e
  --interpreter "/usr/local/bin/qemu-ppc-static" \e
  --magic "\ex7f\ex45\ex4c\ex46\ex01\ex02\ex01\ex00\ex00\ex00\e
           \ex00\ex00\ex00\ex00\ex00\ex00\ex00\ex02\ex00\ex14" \e
  --mask  "\exff\exff\exff\exff\exff\exff\exff\ex00\exff\exff\e
           \exff\exff\exff\exff\exff\exff\exff\exfe\exff\exff" \e
  --size 20 --set-enabled
.Ed
.Pp
Add QEMU bsd-user program as an image activator for PowerPC64 binaries:
.Bd -literal -offset indent
# binmiscctl add powerpc64 \e
  --interpreter "/usr/local/bin/qemu-ppc64-static" \e
  --magic "\ex7f\ex45\ex4c\ex46\ex02\ex02\ex01\ex00\ex00\ex00\e
           \ex00\ex00\ex00\ex00\ex00\ex00\ex00\ex02\ex00\ex15" \e
  --mask  "\exff\exff\exff\exff\exff\exff\exff\ex00\exff\exff\e
           \exff\exff\exff\exff\exff\exff\exff\exfe\exff\exff" \e
  --size 20 --set-enabled
.Ed
.Pp
Add QEMU bsd-user program as an image activator for 64-bit RISC-V binaries:
.Bd -literal -offset indent
# binmiscctl add riscv64 \e
  --interpreter "/usr/local/bin/qemu-riscv64-static" \e
  --magic "\ex7f\ex45\ex4c\ex46\ex02\ex01\ex01\ex00\ex00\ex00\e
           \ex00\ex00\ex00\ex00\ex00\ex00\ex02\ex00\exf3\ex00" \e
  --mask  "\exff\exff\exff\exff\exff\exff\exff\ex00\exff\exff\e
           \exff\exff\exff\exff\exff\exff\exfe\exff\exff\exff" \e
  --size 20 --set-enabled
.Ed
.Ss "Create and use an ARMv7 chroot on an AMD64 host"
Use an existing source tree to build a chroot host with architecture
overrides:
.Bd -literal -offset ident
D=/path/to/chroot
cd /usr/src
mkdir -p $D
make world TARGET=arm TARGET_ARCH=armv7 DESTDIR=$D
make distribution TARGET=arm TARGET_ARCH=armv7 DESTDIR=$D
.Ed
.Pp
With
.Pa emulators/qemu-user-static
from the
.Fx
Ports Collection, the emulator must be copied into the jail path
specified in the
.Nm
command.
Using the example above:
.Bd -literal -offset indent
mkdir $D/usr/local/bin
cp /usr/local/bin/qemu-arm-static $D/usr/local/bin
.Ed
.Pp
Now the user can chroot into the environment normally, as root:
.Bd -literal -offset indent
chroot $D
.Ed
.Sh SEE ALSO
.Xr lli 1 ,
.Xr execve 2 ,
.Xr jail 8
.Sh HISTORY
The
.Nm
command was added in
.Fx 10.1 .
It was developed to support the imgact_binmisc kernel module.
.Sh AUTHORS
.An Stacey D Son Aq Mt sson@FreeBSD.org