JuliOS/src/gdt.rs
Julien CLEMENT 618e528f35 feat(pic): add pic init
Signed-off-by: Julien CLEMENT <julien.clement@epita.fr>
2021-12-04 20:03:25 +01:00

55 lines
1.4 KiB
Rust

use crate::println;
use lazy_static::lazy_static;
use x86_64::instructions::{
segmentation::{Segment, CS},
tables::load_tss,
};
use x86_64::structures::gdt::{Descriptor, GlobalDescriptorTable, SegmentSelector};
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(unsafe { &STACK });
let stack_end = stack_start + STACK_SIZE;
stack_end
};
tss
};
}
lazy_static! {
static ref GDT: (GlobalDescriptorTable, Selectors) = {
let mut gdt = GlobalDescriptorTable::new();
let code_selector = gdt.add_entry(Descriptor::kernel_code_segment());
let tss_selector = gdt.add_entry(Descriptor::tss_segment(&TSS));
(
gdt,
Selectors {
code_selector,
tss_selector,
},
)
};
}
pub fn init_gdt() {
println!("Loading GDT");
GDT.0.load();
unsafe {
CS::set_reg(GDT.1.code_selector);
load_tss(GDT.1.tss_selector);
}
}
struct Selectors {
code_selector: SegmentSelector,
tss_selector: SegmentSelector,
}