...

makefile

@@ -6,7 +6,7 @@ CFLAGS 	= -m64 -ffreestanding -fno-builtin -Wall -Wextra -Wshadow -std=c23 -g
 LDFLAGS	= -g
 ASFLAGS	= -f elf64 -g -F dwarf
 
-SRC_C   := src/kernel.c src/string.c src/vga.c src/interrupts.c src/keyboard.c
+SRC_C   := src/kernel.c src/string.c src/vga.c src/interrupts.c
 SRC_ASM := src/start.asm
 
 OBJ_C   := $(SRC_C:src/%.c=.build/%.o)

src/interrupts.c

@@ -1,13 +1,30 @@
 #include "interrupts.h"
 #include "vga.h"
 #include "kernel.h"
+#include "util.h"
 
 #define PIC1_COMMAND 0x20
 #define PIC1_DATA 0x21
 #define PIC2_COMMAND 0xA0
 #define PIC2_DATA 0xA1
 
-static irq_handler_t irq_handlers[16] = {0};
+void pic_remap()
+{
+    outb(PIC1_COMMAND, 0x11);
+	outb(PIC2_COMMAND, 0x11);
+
+	outb(PIC1_DATA, 32);
+	outb(PIC2_DATA, 40);
+
+	outb(PIC1_DATA, 4);
+	outb(PIC2_DATA, 2);
+
+	outb(PIC1_DATA, 1);
+	outb(PIC2_DATA, 1);
+
+	outb(PIC1_DATA, 0);
+	outb(PIC2_DATA, 0);
+}
 
 static const char* exception_messages[32] = {
     "divide by zero",
@@ -44,18 +61,45 @@ static const char* exception_messages[32] = {
     "reserved",
 };
 
+void handle_exception(const isr_frame_t* frame)
+{
+    vga_print_error();
+    vga_print(" exception[");
+    vga_print_uint(frame->int_no);
+    vga_print("]: ");
+    vga_print(exception_messages[frame->int_no]);
+    vga_print(", error code: ");
+    vga_print_uint(frame->err_code);
+    vga_print("\n");
+    kernel_panic();
+}
+
+static irq_handler_t irq_handlers[16] = {0};
+
 void register_irq_handler(u8 irq, irq_handler_t handler)
 {
     if (irq >= 16)
     {
-        kernel_panic();
+        vga_print_error();
+        vga_print("Cannot register irq ");
+        vga_print_uint(irq);
+        vga_print(" is out of bounds\n");
+    }
+    else
+    {
+        irq_handlers[irq] = handler;
     }
-
-    irq_handlers[irq] = handler;
 }
 
-static inline void pic_send_eoi(u8 irq)
+void handle_irq(const isr_frame_t* frame)
 {
+    u8 irq = frame->int_no - 32;
+
+    if (irq_handlers[irq])
+    {
+        irq_handlers[irq](frame);
+    }
+
     if (irq >= 8)
     {
         outb(PIC2_COMMAND, 0x20);
@@ -64,36 +108,17 @@ static inline void pic_send_eoi(u8 irq)
     outb(PIC1_COMMAND, 0x20);
 }
 
-void handle_isr(isr_frame_t* frame)
+void handle_isr(const isr_frame_t* frame)
 {
+    vga_print("test");
+
     if (frame->int_no < 32)
     {
-        vga_print_error();
-        vga_print(" exception[");
-        vga_print_uint(frame->int_no);
-        vga_print("]: ");
-        vga_print(exception_messages[frame->int_no]);
-
-        vga_print(", error code: ");
-        vga_print_uint(frame->err_code);
-        vga_print("\n");
-
-        while (true)
-        {
-            __asm__ volatile ("cli");
-            __asm__ volatile ("hlt");
-        }
+        handle_exception(frame);
     }
     else if (frame->int_no < 48)
     {
-        u8 irq = frame->int_no - 32;
-
-        if (irq_handlers[irq])
-        {
-            irq_handlers[irq](frame);
-        }
-
-        pic_send_eoi(irq);
+        handle_irq(frame);
     }
     else
     {
@@ -103,4 +128,4 @@ void handle_isr(isr_frame_t* frame)
         vga_print("]: ");
         vga_print("not implemented\n");
     }
-}
+}

src/interrupts.h

@@ -13,16 +13,16 @@ typedef struct
 
 typedef void (*irq_handler_t)(const isr_frame_t*);
 
-static inline void outb(u16 port, u8 val)
+void pic_remap();
+
+void register_irq_handler(u8 irq, irq_handler_t handler);
+
+static inline void enable_interrupts()
 {
-    __asm__ volatile("outb %0, %1" : : "a"(val), "Nd"(port));
+    __asm__ volatile("sti");
 }
 
-static inline u8 inb(u16 port)
+static inline void disable_interrupts()
 {
-    u8 ret;
-    __asm__ volatile("inb %1, %0" : "=a"(ret) : "Nd"(port));
-    return ret;
-}
-
-void register_irq_handler(u8 irq, irq_handler_t handler);
+    __asm__ volatile("cli");
+}

src/kernel.c

@@ -1,33 +1,21 @@
 #include "kernel.h"
 #include "interrupts.h"
-#include "keyboard.h"
 #include "vga.h"
 
 void kernel_main()
 {
     vga_clear();
-    vga_print_success();
-    vga_print(" VGA intialzied\n");
 
-    init_keyboard();
-    vga_print_success();
-    vga_print(" Keyboard intialzied\n");
+    pic_remap();
+    enable_interrupts();
 
     vga_print("\nWelcome to nub OS\n");
 
-    while (true)
-    {
-        __asm__ volatile ("cli");
-        __asm__ volatile ("hlt");
-    }
+    kernel_halt();
 }
 
 void kernel_panic()
 {
     vga_print("Kernel panic!\n");
-    while (true)
-    {
-        __asm__ volatile ("cli");
-        __asm__ volatile ("hlt");
-    }
+    kernel_halt();
 }

src/kernel.h

@@ -1,3 +1,12 @@
 #pragma once
 
-void kernel_panic();
+void kernel_panic();
+
+static inline void kernel_halt()
+{
+    while (true)
+    {
+        __asm__ volatile ("cli");
+        __asm__ volatile ("hlt");
+    }
+}

src/keyboard.c

@@ -2,6 +2,7 @@
 #include "interrupts.h"
 #include "kernel.h"
 #include "vga.h"
+#include "util.h"
 
 #define SCANCODE_LEFT_SHIFT 42
 #define SCANCODE_RIGHT_SHIFT 54

src/start.asm

@@ -175,7 +175,7 @@ section .text
         mov gs, ax
         mov ss, ax
 
-        ; Set up idt
+        ; Fill in the idt table with the stub functions
         mov rdi, idt64
         mov rsi, isr_stub_table
         mov rcx, 256
@@ -193,8 +193,8 @@ section .text
         add rsi, 8
         loop .loop
         lidt [idt64_descriptor]
-        sti
 
+        ; Finally, we call in to c
         call kernel_main
     .hang:
         hlt

src/util.h

@@ -0,0 +1,18 @@
+#pragma once
+
+static inline void outb(u16 port, u8 val)
+{
+    __asm__ volatile("outb %0, %1" : : "a"(val), "Nd"(port));
+}
+
+static inline u8 inb(u16 port)
+{
+    u8 ret;
+    __asm__ volatile("inb %1, %0" : "=a"(ret) : "Nd"(port));
+    return ret;
+}
+
+static inline void io_wait()
+{
+    outb(0x80, 0);
+}

src/vga.c

@@ -24,7 +24,7 @@ vga_char vga_char_at(u8 row, u8 col)
     return vga_buffer[COLUMNS * row + col];
 }
 
-void vga_clear(void)
+void vga_clear()
 {
     for (u8 row = 0; row < ROWS; row++)
     {
@@ -121,14 +121,14 @@ void vga_print_colored(const char* string, vga_color_t color)
     }
 }
 
-void vga_print_success(void)
+void vga_print_success()
 {
     vga_print("[ ");
     vga_print_colored("success", VGA_GREEN);
     vga_print(" ]");
 }
 
-void vga_print_error(void)
+void vga_print_error()
 {
     vga_print("[ ");
     vga_print_colored("error", VGA_RED);

src/vga.h

@@ -21,14 +21,14 @@
 
 typedef u8 vga_color_t;
 
-void vga_clear(void);
+void vga_clear();
 void vga_set_cursor_position(u8 row, u8 col);
 
 void vga_print_char_colored(char character, vga_color_t color);
 void vga_print_colored(const char* string, vga_color_t color);
 
-void vga_print_success(void);
-void vga_print_error(void);
+void vga_print_success();
+void vga_print_error();
 
 void vga_print_uint(u32 value);
 void vga_print_int(i32 value);