# Error code E0775

`#[cmse_nonsecure_entry]` is only valid for targets with the TrustZone-M extension.

Erroneous code example:

    #![allow(unused)]
    #![feature(cmse_nonsecure_entry)]

    fn main() {
    #[cmse_nonsecure_entry]
    pub extern "C" fn entry_function() {}
    }

To fix this error, compile your code for a Rust target that supports the TrustZone-M extension. The current possible targets are:

- `thumbv8m.main-none-eabi`
- `thumbv8m.main-none-eabihf`
- `thumbv8m.base-none-eabi`