//! # Kernel
//!
//! Kernel Start

#![no_std] // don't link the Rust standard library
#![no_main] // disable all Rust-level entry points
#![feature(const_mut_refs)]
#![feature(custom_test_frameworks)]
#![test_runner(crate::test_runner)]
#![reexport_test_harness_main = "test_main"]

mod serial;
mod sync;
mod tests;
mod vga;
use core::panic::PanicInfo;
use serial::*;
use vga::*;

#[cfg(test)]
mod qemu;
#[cfg(test)]
use qemu::*;
#[cfg(test)]
use tests::*;

/// This function is called on panic.
#[cfg(test)]
#[panic_handler]
fn panic(info: &PanicInfo) -> ! {
    serial_println!("[failed]\n");
    serial_println!("Error: {}\n", info);
    exit_qemu(QemuExitCode::Failed);
    loop {}
}

/// This function is called on panic.
#[cfg(not(test))]
#[panic_handler]
fn panic(info: &PanicInfo) -> ! {
    println!("{}", info);
    loop {}
}

/// # Initialization
///
/// Provides serial and VGA initialization.
fn kernel_init() {
    WRITER.init();
    SERIAL1.init();
}

/// # x86_64 Kernel
#[no_mangle]
pub extern "C" fn _start() -> ! {
    kernel_init();

    #[cfg(not(test))]
    {
        println!("{}", 5);
    }

    #[cfg(test)]
    test_main();

    loop {}
}