ember_os 0.1.3

A simple OS kernel implemented in rust, which has referenced https://os.phil-opp.com/
Documentation 
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use core::ptr::addr_of;

use lazy_static::lazy_static;
use x86_64::{structures::tss::TaskStateSegment, VirtAddr};

pub const DOUBLE_FAULT_IST_INDEX: u16 = 0;

lazy_static! {
    static ref TSS: TaskStateSegment = {
        let mut tss = TaskStateSegment::new();
        tss.interrupt_stack_table[DOUBLE_FAULT_IST_INDEX as usize] = {
            const STACK_SIZE: usize = 4096 * 5;
            static mut STACK: [u8; STACK_SIZE] = [0; STACK_SIZE];
            let stack_start = VirtAddr::from_ptr(addr_of!(STACK));
            stack_start + STACK_SIZE as u64 // stack_end
        };
        tss
    };
}

use x86_64::structures::gdt::{Descriptor, GlobalDescriptorTable, SegmentSelector};

struct Selectors {
  code_selector: SegmentSelector,
  tss_selector: SegmentSelector,
}

lazy_static! {
  static ref GDT: (GlobalDescriptorTable, Selectors) = {
    let mut gdt = GlobalDescriptorTable::new();
    let code_selector = gdt.append(Descriptor::kernel_code_segment());
    let tss_selector = gdt.append(Descriptor::tss_segment(&TSS));
    (
      gdt,
      Selectors {
        code_selector,
        tss_selector,
      },
    )
  };
}

pub fn init() {
  use x86_64::instructions::{
    segmentation::{Segment, CS},
    tables::load_tss,
  };
  GDT.0.load();
  unsafe {
    CS::set_reg(GDT.1.code_selector);
    load_tss(GDT.1.tss_selector);
  }
}