Skip to content

Latest commit

 

History

History
80 lines (51 loc) · 2.45 KB

binfmt-misc.md

File metadata and controls

80 lines (51 loc) · 2.45 KB
Raw

Binfmt support

Binfmt allows you to run binaries from other architectures.

This tutorial describes how to install binfmt-support and force kernel to preload, allowing it to freely run binaries from any architecture without the access to host /usr/bin.

There are two possible method, depending on how new is your system:

  1. For new systems: Ubuntu Artful 17.10, Debian Buster,
  2. For older systems: everything else.

For new systems

1. First make sure that you install needed qemu-user-static

sudo apt-get install -y qemu-user-static

2. Make sure that your kernel is recent enough, at least 4.8 which allows to preload architecture dependent files

3. Add support for binfmts

sed -i '10s/^$/yes/g' /var/lib/binfmts/qemu-arm /var/lib/binfmts/qemu-aarch64

You may need to apply the same trick later if you update qemu-user-static.

4. Reload configuration

systemctl restart binfmt-support

5. Test

docker run --rm -it arm64v8/busybox echo Hello World

For old systems

1. First make sure that you install needed qemu-user-static

sudo apt-get install -y qemu-user-static

2. Make sure that your kernel is recent enough, at least 4.8 which allows to preload architecture dependent files

3. Add support for binfmts to /etc/rc.local

echo -1 > /proc/sys/fs/binfmt_misc/qemu-aarch64 || true
echo -1 > /proc/sys/fs/binfmt_misc/qemu-arm || true
echo ':qemu-aarch64:M::\x7fELF\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\xb7\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/bin/qemu-aarch64-static:OCF' > /proc/sys/fs/binfmt_misc/register
echo ':qemu-arm:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/bin/qemu-arm-static:OCF' > /proc/sys/fs/binfmt_misc/register

Run /etc/rc.local or restart system.

4. Test

docker run --rm -it arm64v8/busybox echo Hello World

Why and not binfmt-support?

binfmt-support does not support F flag to preload architecture files, which is useful when you run container images for different architectures.

Thus, this would not be possible:

docker run --rm -it arm64v8/busybox echo Hello World

The first binfmt-support version with the ability define F flag is 2.17. The 2.18 is distributed starting from Ubuntu Artful and Debian Stretch.