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BINMISCCTL(8) FreeBSD System Manager's Manual BINMISCCTL(8) NAME binmiscctl - manage binary image activators SYNOPSIS binmiscctl add name --interpreter path --magic magic --size size [--mask mask] [--offset offset] [--set-enabled] [--pre-open] binmiscctl disable name binmiscctl enable name binmiscctl list binmiscctl lookup name binmiscctl remove name DESCRIPTION The binmiscctl 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. The first argument on the command line indicates the operation to be performed. Operation must be one of the following: add name --interpreter path --magic magic --size size [--mask mask] [--offset offset] [--set-enabled] [--pre-open] Add a new activator entry in the kernel. You must specify a unique name, a path to the interpreter, header magic bytes that uniquely identify a suitable binary for the activator, and the size of the magic in bytes. Optionally, you may specify a 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. An offset may be specified for the magic bytes using the --offset option. By default the offset is zero. To enable the activator entry the --set-enabled option is used. The activator default state is disabled. To make the interpreter automatically available in jails and chroots, use the --pre-open option to allow the kernel to open the binary at configuration time rather then lazily when the the interpreted program is started. The interpreter path may also contain arguments for the interpreter including #a which gets replaced by the old argv0 value in the interpreter string. disable name Disable the activator entry identified with name. enable name Enable the activator entry identified with name. list Take a snapshot and print all the activator entries currently configured. Add an image activator to run the LLVM interpreter (lli(1)) on bitcode compiled files and set its state to enabled. In this example #a is replaced with the old argv0 value so that lli(1) can fake its argv0: # binmiscctl add llvmbc --interpreter ''/usr/bin/lli \ --fake-argv0=#a'' --magic ''BC\xc0\xde'' --size 4 \ --set-enabled Set the state of the llvmbc image activator to disabled: # binmiscctl disable llvmbc Set the state of the llvmbc image activator to enabled: # binmiscctl enable llvmbc Delete the llvmbc image activator: # binmiscctl remove llvmbc Look up and list the record for the llvmbc image activator: # binmiscctl lookup llvmbc Add QEMU bsd-user program as an image activator for ARM AARCH64 binaries: # binmiscctl add arm64 \ --interpreter "/usr/local/bin/qemu-aarch64-static" \ --magic "\x7f\x45\x4c\x46\x02\x01\x01\x00\x00\x00\ \x00\x00\x00\x00\x00\x00\x02\x00\xb7\x00" \ --mask "\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\ \xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff" \ --size 20 --set-enabled Add QEMU bsd-user program as an image activator for ARM little-endian binaries: # binmiscctl add armelf \ --interpreter "/usr/local/bin/qemu-arm-static" \ --magic "\x7f\x45\x4c\x46\x01\x01\x01\x00\x00\x00\ \x00\x00\x00\x00\x00\x00\x02\x00\x28\x00" \ --mask "\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\ \xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff" \ --size 20 --set-enabled Add QEMU bsd-user program as an image activator for ARM big-endian binaries: # binmiscctl add armebelf \ --interpreter "/usr/local/bin/qemu-arm-static" \ --magic "\x7f\x45\x4c\x46\x01\x02\x01\x00\x00\x00\ \x00\x00\x00\x00\x00\x00\x00\x02\x00\x28" \ --mask "\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\ \xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff" \ --size 20 --set-enabled Add QEMU bsd-user program as an image activator for MIPS32 binaries: # binmiscctl add mips32 \ Add QEMU bsd-user program as an image activator for MIPS64 binaries: # binmiscctl add mips64 \ --interpreter "/usr/local/bin/qemu-mips64-static" \ --magic "\x7f\x45\x4c\x46\x02\x02\x01\x00\x00\x00\ \x00\x00\x00\x00\x00\x00\x00\x02\x00\x08" \ --mask "\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\ \xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff" \ --size 20 --set-enabled Add QEMU bsd-user program as an image activator for PowerPC binaries: # binmiscctl add powerpc \ --interpreter "/usr/local/bin/qemu-ppc-static" \ --magic "\x7f\x45\x4c\x46\x01\x02\x01\x00\x00\x00\ \x00\x00\x00\x00\x00\x00\x00\x02\x00\x14" \ --mask "\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\ \xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff" \ --size 20 --set-enabled Add QEMU bsd-user program as an image activator for PowerPC64 binaries: # binmiscctl add powerpc64 \ --interpreter "/usr/local/bin/qemu-ppc64-static" \ --magic "\x7f\x45\x4c\x46\x02\x02\x01\x00\x00\x00\ \x00\x00\x00\x00\x00\x00\x00\x02\x00\x15" \ --mask "\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\ \xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff" \ --size 20 --set-enabled Add QEMU bsd-user program as an image activator for 64-bit RISC-V binaries: # binmiscctl add riscv64 \ --interpreter "/usr/local/bin/qemu-riscv64-static" \ --magic "\x7f\x45\x4c\x46\x02\x01\x01\x00\x00\x00\ \x00\x00\x00\x00\x00\x00\x02\x00\xf3\x00" \ --mask "\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\ \xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff" \ --size 20 --set-enabled Create and use an ARMv6 chroot on an AMD64 host Use an existing source tree to build a chroot host with architecture overrides: 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 With emulators/qemu-user-static from the FreeBSD Ports Collection, the emulator must be copied into the jail path specified in the binmiscctl command. Using the example above: mkdir $D/usr/local/bin cp /usr/local/bin/qemu-arm-static $D/usr/local/bin Now the user can chroot into the environment normally, as root: The binmiscctl command was added in FreeBSD 10.1. It was developed to support the imgact_binmisc kernel module. AUTHORS Stacey D Son <sson@FreeBSD.org> FreeBSD 14.0-RELEASE-p11 April 30, 2020 FreeBSD 14.0-RELEASE-p11