#![no_std]
#![no_main]

use core::panic::PanicInfo;
use cortex_ar::asm::nop;
use zynq7000_rt as _;

/// One user LED is MIO7
const ZEDBOARD_LED_MASK: u32 = 1 << 7;

/// Entry point (not called like a normal main function)
#[unsafe(no_mangle)]
pub extern "C" fn boot_core(cpu_id: u32) -> ! {
    if cpu_id != 0 {
        panic!("unexpected CPU ID {}", cpu_id);
    }
    main();
}

#[unsafe(export_name = "main")]
pub fn main() -> ! {
    let mut gpio = unsafe { zynq7000::gpio::Gpio::new_mmio() };
    gpio.modify_dirm_0(|v| v | ZEDBOARD_LED_MASK);
    gpio.modify_out_en_0(|v| v | ZEDBOARD_LED_MASK);
    loop {
        gpio.modify_out_0(|v| v ^ ZEDBOARD_LED_MASK);
        for _ in 0..1_000_000 {
            nop();
        }
    }
}

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