#![no_std]
#![no_main]

use crate::uart::Uart0;
use core::arch::asm;
use core::sync::atomic::{self, Ordering};
use core::{arch::global_asm, fmt::Write, panic::PanicInfo};

mod uart;

global_asm!(include_str!("start.s"));

#[no_mangle]
pub extern "C" fn entry() -> ! {
    let mut uart = Uart0 {};

    for i in 0..3 {
        writeln!(&mut uart, "Hello from Rust {i}!").unwrap();
    }

    for val in 0..64 {
        unsafe {
            asm!("dc cvac, {val}", val = in(reg) &val);
            asm!("dsb sy");
        }
    }

    loop {
        atomic::compiler_fence(Ordering::SeqCst);
    }
}

#[panic_handler]
fn panic(info: &PanicInfo) -> ! {
    writeln!(Uart0, "{info}").unwrap();

    loop {
        atomic::compiler_fence(Ordering::SeqCst);
    }
}