From 0bbbf653f89b5f39235c7c51e3a43aefcae1277d Mon Sep 17 00:00:00 2001
From: zxq5 <zxq5@zxq5.dev>
Date: Sat, 22 Feb 2025 15:41:41 +0000
Subject: [PATCH] setup GDT & fixed a deadlock

---
 Cargo.lock                           |  7 ++++
 kernel/Cargo.toml                    |  1 +
 kernel/src/arch/x86_64/gdt.rs        | 53 +++++++++++++++++++++++++++-
 kernel/src/arch/x86_64/interrupts.rs | 37 +++++++++++++++++--
 kernel/src/lib.rs                    |  1 +
 5 files changed, 95 insertions(+), 4 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index e7b8c2c..c575ba9 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -38,6 +38,7 @@ dependencies = [
  "lib_framebuffer",
  "lib_serial",
  "limine",
+ "pc-keyboard",
  "pic8259",
  "spin",
  "x86_64",
@@ -105,6 +106,12 @@ dependencies = [
  "scopeguard",
 ]
 
+[[package]]
+name = "pc-keyboard"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0ca629cbb3f0d5b699c338f0129ff78c9bfd7ea8b1258ad529bff490dc8ed5a"
+
 [[package]]
 name = "pic8259"
 version = "0.11.0"
diff --git a/kernel/Cargo.toml b/kernel/Cargo.toml
index 4759c3f..91a92ca 100644
--- a/kernel/Cargo.toml
+++ b/kernel/Cargo.toml
@@ -11,6 +11,7 @@ lib_ascii = { path = "../lib/lib_ascii" }
 x86_64 = "0.15.2"
 spin = "0.9.8"
 pic8259 = "0.11.0"
+pc-keyboard = "0.8.0"
 
 [build-dependencies]
 cc = "1.2.14"
diff --git a/kernel/src/arch/x86_64/gdt.rs b/kernel/src/arch/x86_64/gdt.rs
index bf4c036..8d9bad4 100644
--- a/kernel/src/arch/x86_64/gdt.rs
+++ b/kernel/src/arch/x86_64/gdt.rs
@@ -1,4 +1,12 @@
-use x86_64::{structures::tss::TaskStateSegment, VirtAddr};
+use x86_64::{
+    instructions::tables::load_tss,
+    registers::segmentation::{Segment, CS, DS, ES, SS},
+    structures::{
+        gdt::{Descriptor, GlobalDescriptorTable, SegmentSelector},
+        tss::TaskStateSegment,
+    },
+    VirtAddr,
+};
 
 use spin::Lazy;
 
@@ -16,3 +24,46 @@ static TSS: Lazy<TaskStateSegment> = Lazy::new(|| {
     };
     tss
 });
+
+static GDT: Lazy<(GlobalDescriptorTable, Selectors)> = Lazy::new(|| {
+    let mut gdt = GlobalDescriptorTable::new();
+    let code_selector = gdt.append(Descriptor::kernel_code_segment());
+    let data_selector = gdt.append(Descriptor::kernel_data_segment());
+
+    let user_code_selector = gdt.append(Descriptor::user_code_segment());
+    let user_data_selector = gdt.append(Descriptor::user_data_segment());
+
+    let tss_selector = gdt.append(Descriptor::tss_segment(&TSS));
+
+    (
+        gdt,
+        Selectors {
+            code_selector,
+            data_selector,
+            user_code_selector,
+            user_data_selector,
+            tss_selector,
+        },
+    )
+});
+
+struct Selectors {
+    code_selector: SegmentSelector,
+    data_selector: SegmentSelector,
+    user_code_selector: SegmentSelector,
+    user_data_selector: SegmentSelector,
+    tss_selector: SegmentSelector,
+}
+
+pub fn init() {
+    GDT.0.load();
+
+    unsafe {
+        CS::set_reg(GDT.1.code_selector);
+        load_tss(GDT.1.tss_selector);
+
+        DS::set_reg(self::GDT.1.data_selector);
+        ES::set_reg(self::GDT.1.data_selector);
+        SS::set_reg(self::GDT.1.data_selector);
+    }
+}
diff --git a/kernel/src/arch/x86_64/interrupts.rs b/kernel/src/arch/x86_64/interrupts.rs
index 160cf20..c2c7251 100644
--- a/kernel/src/arch/x86_64/interrupts.rs
+++ b/kernel/src/arch/x86_64/interrupts.rs
@@ -1,4 +1,4 @@
-use lib_ascii::println_log;
+use lib_ascii::{print, println_log};
 use lib_serial::serial_println;
 use x86_64::instructions::port::Port;
 use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame};
@@ -6,10 +6,18 @@ use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame};
 use pic8259::ChainedPics;
 use spin::{Lazy, Mutex};
 
+use super::gdt;
+
 static IDT: Lazy<InterruptDescriptorTable> = Lazy::new(|| {
     let mut idt = InterruptDescriptorTable::new();
     idt.breakpoint.set_handler_fn(breakpoint_handler);
-    idt.double_fault.set_handler_fn(double_fault_handler);
+
+    unsafe {
+        idt.double_fault
+            .set_handler_fn(double_fault_handler)
+            .set_stack_index(gdt::DOUBLE_FAULT_1ST_INDEX);
+    }
+
     idt.general_protection_fault
         .set_handler_fn(general_protection_fault_handler);
 
@@ -71,8 +79,31 @@ extern "x86-interrupt" fn double_fault_handler(
 }
 
 extern "x86-interrupt" fn keyboard_interrupt_handler(_stack_frame: InterruptStackFrame) {
+    use pc_keyboard::{layouts, DecodedKey, HandleControl, Keyboard, ScancodeSet1};
+    use spin::Mutex;
+    use x86_64::instructions::port::Port;
+
+    static KEYBOARD: Lazy<Mutex<Keyboard<layouts::Us104Key, ScancodeSet1>>> = Lazy::new(|| {
+        Mutex::new(Keyboard::new(
+            ScancodeSet1::new(),
+            layouts::Us104Key,
+            HandleControl::Ignore,
+        ))
+    });
+
+    let mut keyboard = KEYBOARD.lock();
     let mut port = Port::new(0x60);
-    let _scancode: u8 = unsafe { port.read() };
+
+    let scancode: u8 = unsafe { port.read() };
+    if let Ok(Some(key_event)) = keyboard.add_byte(scancode) {
+        if let Some(key) = keyboard.process_keyevent(key_event) {
+            match key {
+                DecodedKey::Unicode(character) => print!("{}", character),
+                DecodedKey::RawKey(key) => print!("{:?}", key),
+            }
+        }
+    }
+
     unsafe {
         PICS.lock()
             .notify_end_of_interrupt(InterruptIndex::Keyboard.as_u8());
diff --git a/kernel/src/lib.rs b/kernel/src/lib.rs
index c36854e..aa16295 100644
--- a/kernel/src/lib.rs
+++ b/kernel/src/lib.rs
@@ -53,6 +53,7 @@ pub fn boot() -> Result<(), &'static str> {
     }
 
     lib_serial::init()?;
+    arch::x86_64::gdt::init();
     arch::x86_64::interrupts::init_idt();
 
     x86_64::instructions::interrupts::enable();