much stuff

Cargo.lock

@@ -13,11 +13,28 @@ name = "kernel"
 version = "0.1.0"
 dependencies = [
  "bootloader",
+ "lazy_static",
+ "spin",
  "volatile",
 ]
 
 [[package]]
-name = "volatile"
-version = "0.4.5"
+name = "lazy_static"
+version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e3ca98349dda8a60ae74e04fd90c7fb4d6a4fbe01e6d3be095478aa0b76f6c0c"
+checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+dependencies = [
+ "spin",
+]
+
+[[package]]
+name = "spin"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
+
+[[package]]
+name = "volatile"
+version = "0.2.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f6b06ad3ed06fef1713569d547cdbdb439eafed76341820fb0e0344f29a41945"

Cargo.toml

@@ -5,10 +5,17 @@ edition = "2018"
 
 [profile.dev]
 panic = "abort"
+overflow-checks = false
 
 [profile.release]
 panic = "abort"
 
+
+[dependencies.lazy_static]
+version = "1.0"
+features = ["spin_no_std"]
+
 [dependencies]
 bootloader = "0.9.23"
-volatile = "0.4.5"
+volatile = "0.2.6"
+spin = "0.5.2"

run.sh

@@ -1,5 +1,5 @@
 #!/bin/sh
 
-cargo +nightly build
+cargo +nightly build || exit 1
 cargo +nightly bootimage
 qemu-system-x86_64 -drive format=raw,file=target/x86_64-none-generic/debug/bootimage-kernel.bin

src/interrupts.rs

@@ -0,0 +1,91 @@
+// IDT - Interrupt Descriptor Table
+
+use core::arch::asm;
+use core::mem::size_of;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct IdtEntry {
+    pub offset_low: u16,
+    pub selector: u16,
+    pub flags: u8,
+    pub offset_middle: u16,
+    pub offset_high: u32,
+    pub zero: u32,
+}
+
+pub struct InterruptStackFrame {
+    pub instruction_pointer: u64,
+    pub code_segment: u64,
+    pub cpu_flags: u64,
+    pub stack_pointer: u64,
+    pub stack_segment: u64,
+}
+
+pub type HandlerFunc = extern "C" fn(&mut InterruptStackFrame);
+
+pub struct Idt {
+    pub entries: [IdtEntry; 256],
+}
+
+#[allow(dead_code)]
+impl Idt {
+    pub fn new() -> Idt {
+        Idt {
+            entries: [IdtEntry {
+                offset_low: 0,
+                selector: 0,
+                flags: 0,
+                offset_middle: 0,
+                offset_high: 0,
+                zero: 0,
+            }; 256],
+        }
+    }
+
+    pub fn set_handler(&mut self, index: u8, handler: HandlerFunc) {
+        let offset = handler as u64;
+        let offset_low = offset as u16;
+        let offset_middle = (offset >> 16) as u16;
+        let offset_high = (offset >> 32) as u32;
+
+        self.entries[index as usize] = IdtEntry {
+            offset_low,
+            selector: 0x08,
+            flags: 0x8e,
+            offset_middle,
+            offset_high,
+            zero: 0,
+        };
+    }
+
+    pub fn load(&self) {
+        let mut idtr: [u16; 3] = [0; 3];
+        idtr[0] = (size_of::<Idt>() - 1) as u16;
+        idtr[1] = self as *const _ as u16;
+        idtr[2] = (self as *const _ as u32 >> 16) as u16;
+        unsafe {
+            asm!(
+                "lidt ({0})",
+                in(reg) &idtr,
+            );
+        }
+    }
+
+    pub fn load_idt() -> Idt {
+        let mut idt = Idt::new();
+        idt.load();
+        idt
+    }
+
+    pub fn enable_interrupts() {
+        unsafe {
+            asm!("sti");
+        }
+    }
+
+    pub fn disable_interrupts() {
+        unsafe {
+            asm!("cli");
+        }
+    }
+}

src/io/mod.rs

@@ -1 +1,3 @@
+use core::arch::asm;
+
 pub mod vga;

src/io/vga/buffer.rs

@@ -1,3 +1,5 @@
+use core::fmt;
+use volatile::Volatile;
 use crate::io::vga::colors::ColorCode;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -12,13 +14,13 @@ const BUFFER_WIDTH: usize = 80;
 
 #[repr(transparent)]
 pub struct Buffer {
-    chars: [[ScreenChar; BUFFER_WIDTH]; BUFFER_HEIGHT],
+    chars: [[Volatile<ScreenChar>; BUFFER_WIDTH]; BUFFER_HEIGHT],
 }
 
 pub struct Writer {
-    pub(crate) column_position: usize,
-    pub(crate) color_code: ColorCode,
-    pub(crate) buffer: &'static mut Buffer,
+    pub column_position: usize,
+    pub color_code: ColorCode,
+    pub buffer: &'static mut Buffer,
 }
 
 impl Writer {
@@ -34,22 +36,36 @@ impl Writer {
                 let col = self.column_position;
 
                 let color_code = self.color_code;
-                self.buffer.chars[row][col] = ScreenChar {
+                self.buffer.chars[row][col].write(ScreenChar {
                     ascii_character: byte,
                     color_code,
-                };
+                });
                 self.column_position += 1;
             }
         }
     }
 
-    fn new_line(&mut self) {
-        unimplemented!();
+    pub fn new_line(&mut self) {
+        for row in 1..BUFFER_HEIGHT {
+            for col in 0..BUFFER_WIDTH {
+                let character = self.buffer.chars[row][col].read();
+                self.buffer.chars[row - 1][col].write(character);
+            }
+        }
+        self.clear_row(BUFFER_HEIGHT - 1);
+        self.column_position = 0;
+    }
+
+    pub fn clear_row(&mut self, row: usize) {
+        let blank = ScreenChar {
+            ascii_character: b' ',
+            color_code: self.color_code,
+        };
+        for col in 0..BUFFER_WIDTH {
+            self.buffer.chars[row][col].write(blank);
         }
     }
 
-
-impl Writer {
     pub fn write_string(&mut self, s: &str) {
         for byte in s.bytes() {
             match byte {
@@ -58,7 +74,14 @@ impl Writer {
                 // not part of printable ASCII range
                 _ => self.write_byte(0xfe),
             }
+        }
+    }
+}
 
-        }
+
+impl fmt::Write for Writer {
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        self.write_string(s);
+        Ok(())
     }
 }

src/io/vga/mod.rs

@@ -1,2 +1,31 @@
 pub mod colors;
 pub mod buffer;
+
+use core::fmt;
+use lazy_static::lazy_static;
+use spin::Mutex;
+
+lazy_static! {
+    pub static ref WRITER: Mutex<buffer::Writer> = Mutex::new(buffer::Writer {
+        column_position: 0,
+        color_code: colors::ColorCode::new(colors::Color::Yellow, colors::Color::Black),
+        buffer: unsafe { &mut *(0xb8000 as *mut buffer::Buffer) },
+    });
+}
+
+#[macro_export]
+macro_rules! println {
+    () => (print!("\n"));
+    ($($arg:tt)*) => (print!("{}\n", format_args!($($arg)*)));
+}
+
+#[macro_export]
+macro_rules! print {
+    ($($arg:tt)*) => ($crate::io::vga::_print(format_args!($($arg)*)));
+}
+
+#[doc(hidden)]
+pub fn _print(args: fmt::Arguments) {
+    use core::fmt::Write;
+    WRITER.lock().write_fmt(args).unwrap();
+}

src/main.rs

@@ -1,27 +1,31 @@
 #![no_std]
 #![no_main]
 
+use core::arch::asm;
 use core::panic::PanicInfo;
-use crate::io::vga::buffer::{Buffer, Writer};
+use bootloader::{BootInfo, entry_point};
 use crate::io::vga::colors::{Color, ColorCode};
 
 mod io;
+mod mem;
+mod interrupts;
+
+entry_point!(kernel_main);
+fn kernel_main(boot_info: &'static BootInfo) -> ! {
+    mem::gdt::init();
+    let mut idt = interrupts::Idt::new();
+    fn test_interrupt_handler(_stack_frame: &mut interrupts::InterruptStackFrame) {
+        println!("test interrupt handler");
+    }
+
+    loop {}
+}
 
 #[no_mangle]
 #[panic_handler]
 pub extern "C" fn panic_handler(_info: &PanicInfo) -> ! {
-    loop {}
-}
-
-#[no_mangle]
-pub extern "C" fn _start() -> ! {
-    let mut writer = Writer {
-        column_position: 0,
-        color_code: ColorCode::new(Color::Yellow, Color::Black),
-        buffer: unsafe { &mut *(0xb8000 as *mut Buffer) }
-    };
-
-    writer.write_string("Hello World\n");
-
+    io::vga::WRITER.lock().color_code = ColorCode::new(Color::Red, Color::Black);
+    println!("\n!!! PANIC !!!");
+    println!("{}", _info);
     loop {}
 }

src/mem/gdt.rs

@@ -0,0 +1,98 @@
+use core::arch::asm;
+
+pub const GDT_NULL: u64 = 0x0000000000000000;        // Null descriptor
+pub const GDT_KERNEL_CODE: u64 = 0x00af9a000000ffff; // Kernel code descriptor
+pub const GDT_KERNEL_DATA: u64 = 0x00cf92000000ffff; // Kernel data descriptor
+pub const GDT_USER_CODE: u64 = 0x00afba000000ffff;   // User code descriptor
+pub const GDT_USER_DATA: u64 = 0x00cfb2000000ffff;   // User data descriptor
+pub const GDT_TSS: u64 = 0x0080890000000067;         // TSS descriptor
+
+pub struct GdtEntry {
+    pub limit_low: u16,
+    pub base_low: u16,
+    pub base_middle: u8,
+    pub access: u8,
+    pub granularity: u8,
+    pub base_high: u8,
+}
+
+pub struct Gdt {
+    pub entries: [GdtEntry; 6],
+}
+
+#[allow(dead_code)]
+impl Gdt {
+    pub fn new() -> Gdt {
+        Gdt {
+            entries: [
+                GdtEntry {
+                    limit_low: 0,
+                    base_low: 0,
+                    base_middle: 0,
+                    access: 0,
+                    granularity: 0,
+                    base_high: 0,
+                },
+                GdtEntry {
+                    limit_low: 0,
+                    base_low: 0,
+                    base_middle: 0,
+                    access: 0x9a,
+                    granularity: 0xa0,
+                    base_high: 0,
+                },
+                GdtEntry {
+                    limit_low: 0,
+                    base_low: 0,
+                    base_middle: 0,
+                    access: 0x92,
+                    granularity: 0xc0,
+                    base_high: 0,
+                },
+                GdtEntry {
+                    limit_low: 0,
+                    base_low: 0,
+                    base_middle: 0,
+                    access: 0xfa,
+                    granularity: 0xa0,
+                    base_high: 0,
+                },
+                GdtEntry {
+                    limit_low: 0,
+                    base_low: 0,
+                    base_middle: 0,
+                    access: 0xf2,
+                    granularity: 0xc0,
+                    base_high: 0,
+                },
+                GdtEntry {
+                    limit_low: 0,
+                    base_low: 0,
+                    base_middle: 0,
+                    access: 0x89,
+                    granularity: 0x67,
+                    base_high: 0,
+                },
+            ],
+        }
+    }
+
+    pub fn load(&self) {
+        let mut gdtr: [u16; 3] = [0; 3];
+        gdtr[0] = (core::mem::size_of::<Gdt>() - 1) as u16;
+        gdtr[1] = self as *const _ as u16;
+        gdtr[2] = (self as *const _ as u32 >> 16) as u16;
+        unsafe {
+            asm!(
+                "lgdt ({0})",
+                in(reg) gdtr.as_ptr(),
+                options(nostack)
+            );
+        }
+    }
+}
+
+pub fn init() {
+    let gdt = Gdt::new();
+    gdt.load();
+}

src/mem/mod.rs

@@ -0,0 +1 @@
+pub mod gdt;