Big-Endian Testing with QEMU

> When programming, it is still important to write code that runs correctly on systems with either byte order

What you should do instead is write all your code so it is little-endian only, as the only relevant big-endian architecture is s390x, and if someone wants to run your code on s390x, they can afford a support contract.

If you comes to low level network protocol (e.g. writing a TCP stack), the "network byte order" is always big-endian.
That's a serialization format.