rust helloworld

rust-helloworld.rs

#![no_std]
#![no_main]
#![feature(asm)]

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

#[no_mangle]
fn _start() -> ! {
    let h: &str = "Hello, World!";
    unsafe {
        asm!(
            "syscall",
            in("rax") 1,
            in("rdi") 1,
            in("rsi") h.as_ptr() as u64,
            in("rdx") h.len() as u64,
            out("rcx") _,
            out("r11") _,
            lateout("rax") _,            
        );
        //exit
        asm!(
            "syscall",
            in("rax") 60,
            in("rdi") 0,
            out("rcx") _,
            out("r11") _,
            lateout("rax") _,
        );
    };
    loop {}
}