#![no_std]
#![no_main]

extern crate panic_halt;

use core::{arch::asm, ptr::write};

use riscv_rt::entry;

mod eth;

// use `main` as the entry point of this application
// `main` is not allowed to return
#[entry]
fn main() -> ! {
    eth::init();

    let blink_period = if eth::is_wishbone_correct() {
        10_000_000
    } else {
        500_000
    };

    // do something here
    loop {
        unsafe {
            //eth::tranmsit();
            write_led(0);
            busy_wait(blink_period);
            write_led(1);
            busy_wait(blink_period);
        }
    }
}

fn busy_wait(num_nops: u32) {
    for _ in 0..num_nops {
        unsafe {
            asm!("nop");
        }
    }
}

fn write_led(val: u32) {
    unsafe {
        write(0x01002000 as *mut u32, val);
    }
}