ubuntu - How to create the ubuntu rootfs for arm ?

1. Install "debootstrap" into your ubuntu system.

$sudo apt-get install debootstrap

2. Create the ubuntu core file system.

$sudo debootstrap --arch=armhf --keyring=/usr/share/keyrings/ubuntu-archive-keyring.gpg --verbose --foreign trusty rootfs

3. Install "qemu" into your ubuntu system.

$sudo apt-get install binfmt-support qemu qemu-user-static

4. Copy the qwmu-arm-static into your target file system.

$sudo cp /usr/bin/qemu-arm-static rootfs/usr/bin

5. Change root to your target file sytem.

$sudo chroot rootfs /bin/bash

6. Create the target file system without on arm.

$/debootstrap/debootstrap --second-stage

7. Next time, you can use "apt-get" to install any deb into target file system on host pc.

Reference：http://berniechenopenvpn.blogspot.tw/2015/07/filesystem.html