runs_inside_qemu is a small no_std-lib that checks if the binary is running inside a
QEMU virtual machine. It doesn't need heap allocations and only works on x86/x86_64 platform.
Under the hood, this is a wrapper around the awesome crate https://crates.io/crates/raw-cpuid.
```rust use runsinsideqemu::runsinsideqemu;
fn main() {
// If we are in QEMU, we use the nice "debugcon"-feature which maps
// the x86 I/O-port 0xe9 to stdout or a file.
if runsinsideqemu() {
unsafe {
x86::io::outb(0xe9, b'H');
x86::io::outb(0xe9, b'e');
x86::io::outb(0xe9, b'l');
x86::io::outb(0xe9, b'l');
x86::io::outb(0xe9, b'o');
x86::io::outb(0xe9, b'\n');
}
}
}
```