//! project hosted on [github](https://github.com/jzck/kernel)

#![no_std]
#![feature(lang_items)]
#![feature(const_fn)]
#![feature(ptr_internals)]
#![feature(asm)]
#![feature(alloc)]
#![feature(allocator_api)]
#![feature(global_allocator)]

extern crate rlibc;
extern crate multiboot2;
#[macro_use] extern crate bitflags;
#[macro_use] extern crate alloc;

/// 80x25 screen and simplistic terminal driver
#[macro_use] pub mod vga;
/// PS/2 detection and processing
pub mod keyboard;
/// simplisitc kernel commands
pub mod console;
/// wrappers around the x86-family I/O instructions.
pub mod cpuio;
/// ACPI self-content module
pub mod acpi;
/// physical frame allocator + paging module
pub mod memory;
/// a few x86 register and instruction wrappers
pub mod x86;

#[no_mangle]
pub extern fn kmain(multiboot_info_addr: usize) -> ! {
    acpi::init().unwrap();

    let boot_info = unsafe { multiboot2::load(multiboot_info_addr) };
    enable_paging();
    enable_write_protect_bit();

    memory::init(&boot_info);
    vga::init();

    use alloc::boxed::Box;
    let mut heap_test = Box::new(42);
    *heap_test -= 15;
    let heap_test2 = Box::new("Hello");
    println!("{:?} {:?}", heap_test, heap_test2);

    let mut vec_test = vec![1,2,3,4,5,6,7];
    vec_test[3] = 42;
    for i in &vec_test {
        print!("{} ", i);
    }

    loop { keyboard::kbd_callback(); }
}

fn enable_paging() {
    unsafe { x86::cr0_write(x86::cr0() | (1 << 31)) };
}

fn enable_write_protect_bit() {
    unsafe { x86::cr0_write(x86::cr0() | (1 << 16)) };
}

#[lang = "eh_personality"] #[no_mangle]
pub extern fn eh_personality() {

}

#[lang = "panic_fmt"] #[no_mangle]
pub extern fn panic_fmt(fmt: core::fmt::Arguments, file: &'static str, line: u32)
-> ! {
    println!("PANIC: {}", fmt);
    println!("FILE: {}", file);
    println!("LINE: {}", line);
    flush!();
    loop {}

}

use memory::BumpAllocator;

pub const HEAP_START: usize = (1 << 22); //first entry of p2
pub const HEAP_SIZE: usize = 100 * 1024; //100 KiB

#[global_allocator]
static HEAP_ALLOCATOR: BumpAllocator = BumpAllocator::new(HEAP_START,
                                                          HEAP_START + HEAP_SIZE);