path: root/usr.sbin/binmiscctl/binmiscctl.8

.\"-
.\" Copyright (c) 2013 Stacey D. Son
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.\" $FreeBSD$
.\"
.\" Support for miscellaneous binary image activators
.\"
.Dd December 30, 2014
.Dt BINMISCCTL 8
.Os
.Sh NAME
.Nm binmiscctl
.Nd manage binary image activators
.Sh SYNOPSIS
.Nm
.Cm add
.Ar name
.Cm --interpreter
.Ar path
.Cm --magic
.Ar magic
.Cm --size
.Ar size
.Op Cm --mask Ar mask
.Op Cm --offset Ar offset
.Op Cm --set-enabled
.Nm
.Cm remove
.Ar name
.Nm
.Cm disable
.Ar name
.Nm
.Cm enable
.Ar name
.Nm
.Cm lookup
.Ar name
.Nm
.Cm list
.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
.Cm --interpreter
.Ar path
.Cm --magic
.Ar magic
.Cm --size
.Ar size
.Op Cm --mask Ar mask
.Op Cm --offset Ar offset
.Op Cm --set-enabled
.Xc
Add a new activator entry in the kernel.
You must specify a
unique
.Ar name,
interpreter path and its arguments
.Ar path,
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
.Cm --offset
option.
By default the
.Ar offset
is zero.
.Pp
To enable the activator entry the
.Cm --set-enabled
option is used.
The activator default state is disabled.
.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 remove Ar name
Remove the activator entry identified with
.Ar name .
.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 lookup Ar name
Look up and print out the activator entry identified with
.Ar name .
.It Cm list
Take a snapshot and print all the activator entries currently configured.
.El
.Sh EXAMPLES
Add an image activator to run the LLVM interpreter (lli) on bitcode
compiled files:
.Bd -ragged -offset indent
# binmiscctl add llvmbc --interpreter ''/usr/bin/lli --fake-argv0=#a''
--magic ''BC\\xc0\\xde'' --size 4 --set-enabled
.Ed
.Pp
.Ar #a
is replaced with the old
.Dv argv0
value so that 'lli' can fake its
.Dv argv0 .
Set its state to enabled.
.Pp
Set the state of the
.Ar llvmbc
image activator to disabled:
.Dl # binmiscctl disable llvmbc
.Pp
Set the state of the
.Ar llvmbc
image activator to enabled:
.Dl # binmiscctl enable llvmbc
.Pp
Delete the
.Ar llvmbc
image activator:
.Dl # binmiscctl remove llvmbc
.Pp
Look up and list the record for the
.Ar llvmbc
image activator:
.Dl # binmiscctl lookup llvmbc
.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\ex01\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 SPARC64 binaries:
.Bd -literal -offset indent
# binmiscctl add sparc64 \e
  --interpreter "/usr/local/bin/qemu-sparc64-static" \e
  --magic "\ex7f\ex45\ex4c\ex46\ex02\ex02\ex01\ex00\ex00\ex00\e
           \ex00\ex00\ex00\ex00\ex00\ex00\ex00\ex02\ex00\ex2b" \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
.Ss "Create and use an ARMv6 chroot on an AMD64 host"
Use an existing source tree to build a chroot host with architecture
overrides:
.Bd -literal
D=/path/to/chroot
cd /usr/src
mkdir -p $D
make world TARGET=arm TARGET_ARCH=armv6 DESTDIR=$D
make distribution TARGET=arm TARGET_ARCH=armv6 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 binmiscctl command.
Using the example above:
.Bd -literal
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
chroot $D
.Ed
.Sh SEE ALSO
.Xr lli 1 ,
.Xr execve 2 ,
.Xr jail 8
.Sh HISTORY
The
.Cm binmiscctl
command was added in
.Fx 10.1 .
It was developed to support the imgact_binmisc kernel module.
.Sh AUTHORS
Stacey D Son