This limitation comes in two subclasses:


## <a id="emu"></a>There Is No Built-In CPU Emulation

Docker lets you run an image built for another architecture on your local system through transparent CPU emulation. If you are on an x86_64 host, this command should drop you into an Alpine shell:

     $ docker run --rm -it --platform linux/arm64 alpine:latest
    $ docker run --rm -it --platform linux/arm64 alpine:latest

The same will work on recent versions of Podman, and you can get it to work on old versions of Podman with a bit of manual setup.(^It’s off-topic to go into the details here, but it amounts to “`podman machine ssh`” followed by a “`dnf install qemu-static-*`” command.)

For that to work under `container.npk`, the RouterOS developers would have to ship the QEMU and Linux kernel [`binfmt_misc`](https://en.wikipedia.org/wiki/Binfmt_misc) bridges needed to get the OS to accept these “foreign” binaries. Since it would approximately double the size of RouterOS to do this for all the popular CPU architectures, they naturally chose _not_ to do this.

What this means in practice is that you have to be sure the images you want to use were built for the CPU type in your RouterOS device. This is true even between closely-related platforms. An ARM64 router won’t run a 32-bit ARMv7 image, if only because it will assume a 32-bit Linux kernel syscall interface.