From 618e528f35f8e16464d196e5273776bfaf2ba390 Mon Sep 17 00:00:00 2001
From: Julien CLEMENT <julien.clement@epita.fr>
Date: Sat, 4 Dec 2021 20:03:25 +0100
Subject: [PATCH] feat(pic): add pic init

Signed-off-by: Julien CLEMENT <julien.clement@epita.fr>
---
 Cargo.lock        | 10 ++++++++++
 Cargo.toml        |  1 +
 src/gdt.rs        | 17 +++++++++++++----
 src/interrupts.rs | 37 +++++++++++++++++++++++++++++++++++--
 src/lib.rs        |  2 ++
 5 files changed, 61 insertions(+), 6 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 6605e31..6bba807 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -19,6 +19,7 @@ name = "julios"
 version = "0.1.0"
 dependencies = [
  "lazy_static",
+ "pic8259",
  "spin",
  "volatile 0.2.7",
  "x86_64",
@@ -33,6 +34,15 @@ dependencies = [
  "spin",
 ]
 
+[[package]]
+name = "pic8259"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24ec21f514e2e16e94649f1d041ca4a7069b512c037ac156360652a775e6229d"
+dependencies = [
+ "x86_64",
+]
+
 [[package]]
 name = "spin"
 version = "0.5.2"
diff --git a/Cargo.toml b/Cargo.toml
index 1e66036..4dd8fb2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,6 +12,7 @@ crate-type = ["staticlib"]
 volatile = "0.2.6"
 spin = "0.5.2"
 x86_64 = "0.14.2"
+pic8259 = "0.10.1"
 
 [dependencies.lazy_static]
 version = "1.0"
diff --git a/src/gdt.rs b/src/gdt.rs
index 7ab41cb..275f5d6 100644
--- a/src/gdt.rs
+++ b/src/gdt.rs
@@ -1,8 +1,11 @@
 use crate::println;
 use lazy_static::lazy_static;
-use x86_64::{VirtAddr, structures::tss::TaskStateSegment};
-use x86_64::structures::gdt::{GlobalDescriptorTable, Descriptor, SegmentSelector};
-use x86_64::instructions::{segmentation::{CS, Segment}, tables::load_tss};
+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;
 
@@ -26,7 +29,13 @@ lazy_static! {
         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 })
+        (
+            gdt,
+            Selectors {
+                code_selector,
+                tss_selector,
+            },
+        )
     };
 }
 
diff --git a/src/interrupts.rs b/src/interrupts.rs
index ee67b4b..ac58e4b 100644
--- a/src/interrupts.rs
+++ b/src/interrupts.rs
@@ -1,17 +1,44 @@
 use crate::gdt;
-use crate::println;
+use crate::{println, print};
 use crate::vga::{self, Color, ColorCode};
 use lazy_static::lazy_static;
+use pic8259::ChainedPics;
+use spin;
 use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame};
 
+pub const PIC_1_OFFSET: u8 = 32;
+pub const PIC_2_OFFSET: u8 = PIC_1_OFFSET + 8;
+
+#[derive(Debug, Clone, Copy)]
+#[repr(u8)]
+pub enum InterruptIndex {
+    Timer = PIC_1_OFFSET,
+}
+
+impl InterruptIndex {
+    fn as_u8(self) -> u8 {
+        self as u8
+    }
+
+    fn as_usize(self) -> usize {
+        usize::from(self.as_u8())
+    }
+}
+
+pub static PICS: spin::Mutex<ChainedPics> =
+    spin::Mutex::new(unsafe { ChainedPics::new(PIC_1_OFFSET, PIC_2_OFFSET) });
+
 lazy_static! {
     static ref IDT: InterruptDescriptorTable = {
         let mut idt = InterruptDescriptorTable::new();
         idt.breakpoint.set_handler_fn(breakpoint_handler);
         unsafe {
-            idt.double_fault.set_handler_fn(double_fault_handler)
+            idt.double_fault
+                .set_handler_fn(double_fault_handler)
                 .set_stack_index(gdt::DOUBLE_FAULT_IST_INDEX);
         }
+        idt[InterruptIndex::Timer.as_usize()]
+            .set_handler_fn(timer_interrupt_handler);
         idt
     };
 }
@@ -34,3 +61,9 @@ extern "x86-interrupt" fn double_fault_handler(
 ) -> ! {
     panic!("EXCEPTION: DOUBLE FAULT\n{:#?}", stack_frame);
 }
+
+extern "x86-interrupt" fn timer_interrupt_handler(
+    _stack_frame: InterruptStackFrame)
+{
+    print!(".");
+}
diff --git a/src/lib.rs b/src/lib.rs
index 3bff3d0..e7166c1 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -22,6 +22,8 @@ pub fn init() {
     println!("Starting init");
     gdt::init_gdt();
     interrupts::init_idt();
+    unsafe { interrupts::PICS.lock().initialize() };
+    x86_64::instructions::interrupts::enable();
     vga::change_color(ColorCode::new(Color::LightGreen, Color::Black));
 }