Hello there! I’ve been using QEMU for a while. Recently, I updated my ARM image and found that it has some difficulties to make an ARM image and could be an impossible job for those who are not familiar with embedded systems. I decided to write a comprehensive post to share some knowledge and how to build you own ARM image. This post could be very useful for those who want to know how Linux works with minimum requirements (root file system, in short rootfs). I use Vexpress as the target board in the tutorial.