-
Notifications
You must be signed in to change notification settings - Fork 0
/
gdt.rs
46 lines (39 loc) · 1.34 KB
/
gdt.rs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
use x86_64::VirtAddr;
use x86_64::structures::gdt::{GlobalDescriptorTable, Descriptor, SegmentSelector};
use x86_64::structures::tss::TaskStateSegment;
use lazy_static::lazy_static;
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 })
};
}
struct Selectors {
code_selector: SegmentSelector,
tss_selector: SegmentSelector,
}
pub fn init() {
use x86_64::instructions::segmentation::{CS, Segment};
use x86_64::instructions::tables::load_tss;
GDT.0.load();
unsafe {
CS::set_reg(GDT.1.code_selector);
load_tss(GDT.1.tss_selector);
}
}
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
};
}