feat(gdt): add gdt, tss, stack in dedicated section to no overwrite pagination pages

Signed-off-by: Julien CLEMENT <julien.clement@epita.fr>

src/boot/boot.asm

@@ -163,8 +163,9 @@ p3_table:
 p2_table:
     resb 4096
 
+section .stack
 stack_bottom:
-    resb 4096
+    resb 0x800000
 stack_top:
 
 
@@ -184,7 +185,5 @@ long_mode_start:
     extern julios_main
     call julios_main
 
-    mov rax, 0x2f592f412f4b2f4f
-    mov qword [0xb8000], rax
 .loop:
     jmp .loop

src/gdt.rs

@@ -0,0 +1,45 @@
+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};
+
+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,
+}

src/interrupts.rs

@@ -0,0 +1,36 @@
+use crate::gdt;
+use crate::println;
+use crate::vga::{self, Color, ColorCode};
+use lazy_static::lazy_static;
+use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame};
+
+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)
+                .set_stack_index(gdt::DOUBLE_FAULT_IST_INDEX);
+        }
+        idt
+    };
+}
+
+pub fn init_idt() {
+    println!("Loading IDT");
+    IDT.load();
+}
+
+extern "x86-interrupt" fn breakpoint_handler(stack_frame: InterruptStackFrame) {
+    let color: vga::ColorCode = vga::get_color();
+    vga::change_color(ColorCode::new(Color::Pink, Color::Black));
+    println!("EXCEPTION: BREAKPOINT\n{:#?}", stack_frame);
+    vga::change_color(color);
+}
+
+extern "x86-interrupt" fn double_fault_handler(
+    stack_frame: InterruptStackFrame,
+    _error_code: u64,
+) -> ! {
+    panic!("EXCEPTION: DOUBLE FAULT\n{:#?}", stack_frame);
+}

src/lib.rs

@@ -1,21 +1,39 @@
 #![no_std]
 #![no_main]
+#![feature(abi_x86_interrupt)]
 
+mod gdt;
+mod interrupts;
 mod serial;
 mod vga;
+
 use core::panic::PanicInfo;
-use vga::Color;
+use vga::{Color, ColorCode};
 
 #[panic_handler]
 fn panic_handler(info: &PanicInfo) -> ! {
-    vga::change_color(Color::LightRed, Color::Black);
+    vga::change_color(ColorCode::new(Color::LightRed, Color::Black));
     println!("{}", info);
     loop {}
 }
 
+pub fn init() {
+    vga::change_color(ColorCode::new(Color::LightCyan, Color::Black));
+    println!("Starting init");
+    gdt::init_gdt();
+    interrupts::init_idt();
+    vga::change_color(ColorCode::new(Color::LightGreen, Color::Black));
+}
+
 #[no_mangle]
 pub extern "C" fn julios_main() -> ! {
+    init();
     println!("***JuliOS V0.1.0***");
-    serial_println!("Hello serial");
+    fn stack_overflow() {
+        stack_overflow(); // for each recursion, the return address is pushed
+    }
+
+    stack_overflow();
+
     panic!("Kernel end of flow");
 }

src/serial.rs

@@ -16,7 +16,7 @@ const ENABLE_TRANSMITTER: u8 = 0x1 << 1;
 const FIFO: u8 = 0x1;
 const TRIGGER_LVL_14: u8 = 0x3 << 6;
 const CLEAR_TRANSMIT_FIFO: u8 = 0x1 << 2;
-const CLEAR_REVEIVE_FIFO: u8 = 0x1 << 1;
+const CLEAR_RECEIVE_FIFO: u8 = 0x1 << 1;
 
 const NO_PARITY: u8 = 0x0;
 const EIGHT_BITS_LENGTH: u8 = 0x3;
@@ -118,7 +118,7 @@ impl SerialPort {
         unsafe {
             self.line_control.write(NO_PARITY | EIGHT_BITS_LENGTH);
             self.fifo_control
-                .write(FIFO | TRIGGER_LVL_14 | CLEAR_TRANSMIT_FIFO | CLEAR_REVEIVE_FIFO);
+                .write(FIFO | TRIGGER_LVL_14 | CLEAR_TRANSMIT_FIFO | CLEAR_RECEIVE_FIFO);
             self.interrupt_enable.write(ENABLE_TRANSMITTER);
         }
     }

src/vga.rs

@@ -30,8 +30,11 @@ pub fn _print(args: fmt::Arguments) {
     use core::fmt::Write;
     WRITER.lock().write_fmt(args).unwrap();
 }
-pub fn change_color(fg: Color, bg: Color) {
+pub fn change_color(color: ColorCode) {
-    WRITER.lock().change_color(ColorCode::new(fg, bg))
+    WRITER.lock().change_color(color)
+}
+pub fn get_color() -> ColorCode {
+    WRITER.lock().get_color()
 }
 
 #[allow(dead_code)]
@@ -58,10 +61,10 @@ pub enum Color {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 #[repr(transparent)]
-struct ColorCode(u8);
+pub struct ColorCode(u8);
 
 impl ColorCode {
-    fn new(fg: Color, bg: Color) -> ColorCode {
+    pub fn new(fg: Color, bg: Color) -> ColorCode {
         ColorCode((bg as u8) << 4 | (fg as u8))
     }
 }
@@ -139,6 +142,10 @@ impl Writer {
     fn change_color(&mut self, color: ColorCode) {
         self.color_code = color;
     }
+
+    fn get_color(&mut self) -> ColorCode {
+        self.color_code
+    }
 }
 
 impl fmt::Write for Writer {