A simple rust program without stdlib that links to the win32 libs

Cargo.toml

[package]
name = "bassietest"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[profile.dev]
panic = "abort"

[profile.release]
panic = "abort"

[dependencies]

main.rs

#![no_std]
#![no_main]

use core::panic::PanicInfo;

// Bindings
#[link(name = "kernel32")]
extern "C" {
    fn ExitProcess(uExitCode: u32) -> !;
}

const HWND_DESKTOP: u64 = 0;
const MB_OK: u32 = 0;

#[link(name = "user32")]
extern "C" {
    fn MessageBoxA(hWnd: u64, lpText: *const u8, lpCaption: *const u8, uType: u32) -> i32;
}

// Main
#[no_mangle]
pub extern "C" fn _start() -> ! {
    unsafe {
        MessageBoxA(HWND_DESKTOP, "World!\0".as_ptr(), "Hello\0".as_ptr(), MB_OK);
        ExitProcess(0);
    }
}

// Panic handler
#[panic_handler]
fn panic(_info: &PanicInfo) -> ! {
    loop {}
}