Added some fun GUI primitives

.gitattributes

@@ -1,3 +1,4 @@
 *.pdf filter=lfs diff=lfs merge=lfs -text
 *.png filter=lfs diff=lfs merge=lfs -text
 *.svg filter=lfs diff=lfs merge=lfs -text
+demodisk.img filter=lfs diff=lfs merge=lfs -text

.gitignore

@@ -1 +1,8 @@
 build
+CON
+.vscode
+isodir/
+root/
+*.iso
+*.img
+

Makefile

@@ -5,7 +5,7 @@ CC = ${HOME}/opt/cross/bin/i686-elf-gcc
 CPP = ${HOME}/opt/cross/bin/i686-elf-g++ 
 CFLAGS =  -ffreestanding -O2 -Wall -Wextra
 
-OFILES =	$(BUILD_DIR)/boot.o $(BUILD_DIR)/kterm.o $(BUILD_DIR)/kernel.o $(BUILD_DIR)/io.o $(BUILD_DIR)/MMU.o
+OFILES =  $(BUILD_DIR)/boot.o $(BUILD_DIR)/window.o $(BUILD_DIR)/cursor.o $(BUILD_DIR)/kterm.o $(BUILD_DIR)/kernel.o  $(BUILD_DIR)/PhysicalMemoryManager.o $(BUILD_DIR)/io.o  $(BUILD_DIR)/vesa.o $(BUILD_DIR)/PageDirectory.o $(BUILD_DIR)/gdtc.o $(BUILD_DIR)/idt.o $(BUILD_DIR)/pic.o $(BUILD_DIR)/string.o
 
 SRC_DIR = src
 BUILD_DIR = build
@@ -21,14 +21,27 @@ INTERNAL_OBJS = $(CRTI_OBJ) $(OFILES) $(CRTN_OBJ)
 
 all: clean build 
 
-build: build_kernel run 
+build: build_kernel iso
 
-run:
-	$(EMULATOR) -kernel $(BUILD_DIR)/myos.bin -serial stdio
+
+
+clean_iso: 
+	if [[ -a isodir/boot ]] ; then rm root/boot -rd ; fi
+	if [ -f build/barinkOS.iso ] ; then rm build/barinkOS.iso ; fi
+	
+iso: clean_iso clean build
+	mkdir -p root/boot/grub
+	cp build/myos.bin root/boot/myos.bin
+	cp src/grub.cfg root/boot/grub/grub.cfg
+	grub-mkrescue -o build/barinkOS.iso root
+	
+test:
+	$(EMULATOR)  -kernel $(BUILD_DIR)/myos.bin -serial mon:stdio -vga std  -display gtk -m 2G -cpu core2duo # -monitor stdio
+test_iso:
+	$(EMULATOR) -cdrom build/barinkOS.iso -serial mon:stdio -vga std -display gtk -m 2G -cpu core2duo
 
 build_kernel: $(OBJ_LINK_LIST)
-	
-	$(CC) -T $(SRC_DIR)/kernel/arch/i386/linker.ld -o $(BUILD_DIR)/myos.bin \
+	$(CC) -T $(SRC_DIR)/kernel//linker.ld -o $(BUILD_DIR)/myos.bin \
 	 -ffreestanding -O2 -nostdlib $(OBJ_LINK_LIST) -lgcc
 
 build_x86_64: 
@@ -39,21 +52,47 @@ clean:
 	rm -f $(BUILD_DIR)/myos.bin $(INTERNAL_OBJS)
 
 $(BUILD_DIR)/kernel.o:
-	$(CPP) -c $(SRC_DIR)/kernel/kernel.cpp -o $(BUILD_DIR)/kernel.o $(CFLAGS) -fno-exceptions -fno-rtti
+	$(CPP) -c $(SRC_DIR)/kernel/kernel.cpp -o $(BUILD_DIR)/kernel.o $(CFLAGS) -fno-exceptions -fno-rtti -fpermissive
 
 $(BUILD_DIR)/kterm.o:
-	$(CC) -c $(SRC_DIR)/kernel/arch/i386/tty/kterm.c  -o $(BUILD_DIR)/kterm.o $(CFLAGS) -std=gnu99
+	$(CPP) -c $(SRC_DIR)/kernel/tty/kterm.cpp  -o $(BUILD_DIR)/kterm.o $(CFLAGS) -fno-exceptions -fno-rtti
 
 $(BUILD_DIR)/boot.o:
-	$(AS) $(SRC_DIR)/kernel/arch/i386/boot.s -o $(BUILD_DIR)/boot.o
+	$(AS) $(SRC_DIR)/kernel//boot.S -o $(BUILD_DIR)/boot.o
 
 $(BUILD_DIR)/crti.o:
-	$(AS) $(SRC_DIR)/kernel/arch/i386/crti.s -o $(BUILD_DIR)/crti.o
+	$(AS) $(SRC_DIR)/kernel/crti.s -o $(BUILD_DIR)/crti.o
 
 $(BUILD_DIR)/crtn.o:
-	$(AS) $(SRC_DIR)/kernel/arch/i386/crtn.s -o $(BUILD_DIR)/crtn.o
+	$(AS) $(SRC_DIR)/kernel/crtn.s -o $(BUILD_DIR)/crtn.o
 
 $(BUILD_DIR)/io.o:
 		$(CPP) -c $(SRC_DIR)/kernel/io.cpp  -o $(BUILD_DIR)/io.o $(CFLAGS) -fno-exceptions -fno-rtti
-$(BUILD_DIR)/MMU.o:
-	$(CPP) -c $(SRC_DIR)/kernel/MMU.cpp -o $(BUILD_DIR)/MMU.o $(CFLAGS) -fno-exceptions -fno-rtti 
+
+$(BUILD_DIR)/PageDirectory.o:
+	$(CPP) -c $(SRC_DIR)/kernel/memory/PageDirectory.cpp -o $(BUILD_DIR)/PageDirectory.o $(CFLAGS) -fno-exceptions -fno-rtti 
+
+$(BUILD_DIR)/idt.o:
+	$(CPP) -c $(SRC_DIR)/kernel/idt/idt.cpp -o $(BUILD_DIR)/idt.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+$(BUILD_DIR)/gdtc.o:
+	$(CPP) -c $(SRC_DIR)/kernel/gdt/gdtc.cpp -o $(BUILD_DIR)/gdtc.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+
+$(BUILD_DIR)/pic.o:
+	$(CPP) -c $(SRC_DIR)/kernel/pic/pic.cpp -o $(BUILD_DIR)/pic.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+$(BUILD_DIR)/string.o:
+	$(CC) -c $(SRC_DIR)/libc/include/string.c  -o $(BUILD_DIR)/string.o $(CFLAGS) -std=gnu99
+
+$(BUILD_DIR)/PhysicalMemoryManager.o:
+	$(CPP) -c $(SRC_DIR)/kernel/memory/PhysicalMemoryManager.cpp  -o $(BUILD_DIR)/PhysicalMemoryManager.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+$(BUILD_DIR)/vesa.o:
+	$(CPP) -c $(SRC_DIR)/kernel/drivers/vesa/vesa.cpp  -o $(BUILD_DIR)/vesa.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+$(BUILD_DIR)/window.o:
+	$(CPP) -c $(SRC_DIR)/gui/window.cpp  -o $(BUILD_DIR)/window.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+$(BUILD_DIR)/cursor.o:
+	$(CPP) -c $(SRC_DIR)/gui/cursor.cpp  -o $(BUILD_DIR)/cursor.o $(CFLAGS) -fno-exceptions -fno-rtti

README.md

@@ -6,19 +6,24 @@
 
 ________________________
 ### Screenshot(s)
+![Graphics mode](screenshots/BarinkOS_VBE_GRAPHICS.png) \
+It may not look like much but I am proud of it! We are in graphics mode.
+
 ![Scrolling the terminal](screenshots/Screenshot1.png)   \
 The first scrolling boot screen. 😲
 
 
+![Interrupt handeling](screenshots/WIP_interruptHandling.png)   \
+W.I.P - Working on interrupt handling
+
+
+![Multiboot integration](screenshots/multiboot.png) \
+Multiboot information can be read by the kernel.
 ________________________
 
 ### The goal
 Writing a hobby operating system to better understand the basic building blocks of any operating system.
 
-
-
-
-
 ________________________
 ### Operating System Technical specs/details
 The operating system can print strings to the 
@@ -26,8 +31,8 @@ screen. The terminal/screen has scrolling so the latest messages are visible on
 
 ________________________
 ### Planning
-[See TODO](TODO.md) 
-
+[See TODO](todo.md) \
+[See Features](features.md)
 ________________________
 ### Docs
 [Intro](docs/Intro.md) \

features.md

@@ -3,16 +3,16 @@
 <input type="checkbox" checked/> Setup Cross-Compiler \
 <input type="checkbox" checked/> Multiboot to kernel \
 <input type="checkbox" checked/> Printing string to the screen \
-<input type="checkbox" /> Printing values/numbers to the screen (a.k.k itoa) \
-<input type="checkbox" /> Extend Multiboot implementation \
+<input type="checkbox" checked/> Printing values/numbers to the screen (a.k.k itoa) \
+<input type="checkbox" checked/> Extend Multiboot implementation \
 <input type="checkbox" checked/> Output to serial port \
-<input type="checkbox" /> Move to protected mode \
-<input type="checkbox" /> Enabel CMOS clock \
+<input type="checkbox" checked/> Move to protected mode \
+<input type="checkbox" checked/> Enabel CMOS clock \
 <input type="checkbox" /> Time measurement (PIC &| PIT) \
 <input type="checkbox" /> Detect CPU speed \
-<input type="checkbox" /> Interrupt / exception system (API) \
+<input type="checkbox" checked/> Interrupt / exception system (API) \
 
-<input type="checkbox" /> Plan your memory map (virtual, and physical) : decide where you want the data to be. \
+<input type="checkbox" checked/> Plan your memory map (virtual, and physical) : decide where you want the data to be. \
 <input type="checkbox" /> The heap: allocating memory at runtime (malloc and free) is almost impossible to go without. \
 <input type="checkbox" /> Enable SIMD Extensions (SSE)
 
@@ -23,13 +23,13 @@
 <input type="checkbox" /> ACPI support ( Or some other basic way to support shutdown, reboot and possibly hibernation ) \
 <input type="checkbox" /> ATAPI support \
 <input type="checkbox" /> Keyboard support ( P/S2 Keyboard) \
-<input type="checkbox" /> Memory Management (MMU)\ 
-<input type="checkbox" /> Preemptive multi tasking 
-<input type="checkbox" /> Processes 
+<input type="checkbox" checked/> Memory Management (MMU)   
+<input type="checkbox" /> Preemptive multi tasking \
+<input type="checkbox" /> Processes  \
 <input type="checkbox" /> Threads  
 <input type="checkbox" /> Scheduling (SRV2 Unix OR Priority Based Round Robin) \
-<input type="checkbox" /> System V ABI compliance (partially)
-<input type="checkbox" /> POSIX compliance (partially)
+<input type="checkbox" /> System V ABI compliance (partially) \
+<input type="checkbox" /> POSIX compliance (partially) \
 <input type="checkbox" /> RPC - for interprocess communication \
 <input type="checkbox" /> Sync primitives  - Semaphores, Mutexes, spinlocks et al. \
 <input type="checkbox" /> Basic Terminal \
@@ -37,4 +37,4 @@
 <input type="checkbox" /> Basic Window server/client \
 ## Support for more filesystems if I like the challenge in writing these ...
 <input type="checkbox" /> FAT Filesystem \
-<input type="checkbox" /> EXT2 Filesystem \
+<input type="checkbox" /> EXT2 Filesystem 

src/grub.cfg

@@ -0,0 +1,3 @@
+menuentry "BarinkOS"{
+    multiboot /boot/myos.bin
+}

src/gui/Graphics.h

@@ -0,0 +1,5 @@
+#pragma once
+
+class Graphics {
+
+};

src/gui/Widget.h

@@ -0,0 +1,7 @@
+#pragma once
+
+
+class Widget{
+    virtual void draw();
+
+};

src/gui/cursor.cpp

@@ -0,0 +1,17 @@
+#include "cursor.h"
+
+    void Cursor::draw(){
+        for(int i = 0; i <  this->width; i++){
+            for(int j = 0; j <  this->height; j++){
+                if(this->bitmap[j * this->width + i] == 1 ){
+                        putPixel(i + this->x,j + this->y, 0xFF000000);
+                }
+            }
+        }
+    }
+
+
+    Cursor::Cursor(int x, int y){
+        this->x = x;
+        this->y = y;
+    }

src/gui/cursor.h

@@ -0,0 +1,38 @@
+#pragma once 
+#include "../kernel/drivers/vesa/vesa.h"
+
+
+class Cursor{
+    public:
+    void draw();
+    Cursor(int x, int y);
+
+
+
+    private:
+        int x;
+        int y;
+        const int width= 16;
+        const int height= 10;
+        const int bitmap [160] = {
+            0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+
+            0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,
+
+            0,0,0,0,0,0,0,0,1,1,1,0,0,0,0,0,
+
+            0,0,0,0,0,0,0,1,1,1,1,1,0,0,0,0,
+
+            0,0,0,0,0,0,1,1,1,1,1,1,1,0,0,0,
+
+            0,0,0,0,0,1,1,1,1,1,1,1,1,1,0,0,
+
+            0,0,0,0,0,0,0,0,1,1,1,1,0,0,0,0,
+
+            0,0,0,0,0,0,0,0,1,1,1,1,0,0,0,0,
+
+            0,0,0,0,0,0,0,0,1,1,1,1,0,0,0,0,
+
+            0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+        };
+};

src/gui/window.cpp

@@ -0,0 +1,33 @@
+#include "window.h"
+
+int Window::getWidth(){
+    return this->rect.width;
+}
+
+int Window::getHeight(){
+    return this->rect.height;
+}
+
+void Window::setWidth(int& width){
+    this->rect.width = width;
+}
+void Window::setHeight(int& height){
+    this->rect.height = height;
+}
+
+int Window::getX(){
+    return this->rect.x;
+}
+
+int Window::getY(){
+    return this->rect.y;
+}
+
+Window::Window (Rect& rect , uint32_t colour){
+    this->rect = rect;
+    this->Background_colour = colour;
+}
+
+void Window::draw(){
+    drawRect(this->getX() , this->getY() , this->getWidth() , this->getHeight() ,this->Background_colour );
+}

src/gui/window.h

@@ -0,0 +1,37 @@
+#pragma once
+#include "../kernel/drivers/vesa/vesa.h"
+#include "Widget.h"
+
+struct Rect {
+    int width;
+    int height;
+    int x;
+    int y;
+
+};
+
+
+
+class Window : Widget{
+
+public:
+    int getX();
+    int getY();
+
+    int getWidth();
+    int getHeight();
+    void setWidth(int&);
+    void setHeight(int&);
+
+    Window (Rect& rect , uint32_t colour);
+    void draw();
+
+
+private:
+    Rect rect;
+    uint32_t Background_colour;
+
+
+
+
+};

src/kernel/MMU.h

@@ -1,14 +0,0 @@
-#pragma once 
-#include <stdint.h>
-
-extern "C" void loadPageDirectory (long unsigned int* addr );
-extern "C" void enablePaging();
-
-class MMU {
-    public:
-    void enable ();
-
-    private:
-    uint32_t page_directory[1024] __attribute__((aligned(4096)));
-    uint32_t first_page_table[1024] __attribute__((aligned(4096)));
-};

src/kernel/arch/i386/boot.s

@@ -1,70 +0,0 @@
-/*
- * Multiboot 
- */
-.set ALIGN,    1<<0             /* align loaded modules on page boundaries */
-.set MEMINFO,  1<<1             /* provide memory map */
-.set FLAGS,    ALIGN | MEMINFO  /* this is the Multiboot 'flag' field */
-.set MAGIC,    0x1BADB002       /* 'magic number' lets bootloader find the header */
-.set CHECKSUM, -(MAGIC + FLAGS) /* checksum of above, to prove we are multiboot */
-
-.section .multiboot
-.align 4
-.long MAGIC
-.long FLAGS
-.long CHECKSUM
- 
-
-.section .bss
-.align 16
-stack_bottom:
-.skip 16384 # 16 KiB
-stack_top:
- 
-
-
-
-.text
-.globl enablePaging
-enablePaging:
-	push %ebp
-	mov %esp, %ebp
-	mov %cr0, %eax
-	or $0x80000000, %eax
-	mov %eax, %cr0
-	mov %ebp, %esp
-	pop %ebp
-	ret
-
-.text
-.globl loadPageDirectory
-loadPageDirectory:
-	push %ebp
-	mov %esp, %ebp
-	mov 8(%esp), %eax
-	mov %eax, %cr3
-	mov %ebp, %esp
-	pop %ebp
-	ret
-
-
-.section .text
-.global _start
-.type _start, @function
-_start:
-
- 
-
-	mov $stack_top, %esp
- 
-
-
-	call _init
-	call kernel_main
- 
-
-	cli
-1:	hlt
-	jmp 1b
- 
-
-.size _start, . - _start

src/kernel/arch/i386/tty/kterm.c

@@ -1,92 +0,0 @@
-#include "kterm.h"
-static const size_t VGA_WIDTH = 80;
-static const size_t VGA_HEIGHT = 25;
-
-size_t kterm_row;
-size_t kterm_column;
-uint8_t kterm_color;
-uint16_t* kterm_buffer;
-
-
-static inline uint8_t vga_entry_color( enum vga_color fg, enum vga_color bg) {
-    return fg | bg << 4;
-}
-
-static inline uint16_t vga_entry (unsigned char uc, uint8_t color) {
-    return (uint16_t) uc | (uint16_t) color << 8;
-}
-
-void kterm_init () { 
-    kterm_row = 0;
-    kterm_column = 0;
-    kterm_color = vga_entry_color ( VGA_COLOR_LIGHT_GREY , VGA_COLOR_BLACK);
-    kterm_buffer = (uint16_t*) 0xB8000;
-    for (size_t y = 0; y < VGA_HEIGHT; y++ ){
-        for( size_t x = 0; x < VGA_WIDTH; x++){
-            const size_t index = y * VGA_WIDTH + x;
-            kterm_buffer[index] = vga_entry(' ', kterm_color);
-
-        }
-    }
-}
-
-
-void kterm_resetcolor(){
-     kterm_color = vga_entry_color ( VGA_COLOR_LIGHT_GREY , VGA_COLOR_BLACK);
-}
-
-void kterm_setcolor(uint8_t color){
-    kterm_color = color;
-}
-
-void kterm_putat (char c, uint8_t color, size_t x, size_t y ) {
-    const size_t index = y * VGA_WIDTH + x;
-
-    kterm_buffer[index] = vga_entry(c, color);
-
-}
-
-
-/**
- *  With the help from:
- * https://whiteheadsoftware.dev/operating-systems-development-for-dummies/
- **/ 
-void kterm_scrollup(){
-    size_t i ;
-    for(i=0; i < (VGA_WIDTH * VGA_HEIGHT - VGA_WIDTH); i++)
-        kterm_buffer[i] = kterm_buffer[i+VGA_WIDTH];
-
-    for( i=0; i< VGA_WIDTH; i++)
-        kterm_buffer[(VGA_HEIGHT -1) * VGA_WIDTH + i ] = vga_entry(' ', kterm_color); 
-
-}
-
-void kterm_put (char c) {
- 
-    if(++kterm_column == VGA_WIDTH || c == '\n' ) {
-        kterm_column = 0;
-        if(kterm_row == VGA_HEIGHT-1) {       
-            kterm_scrollup();
-        } else {
-            kterm_row ++;
-        }
-            
-    }
-    
-    if(c == '\n') return;
-    kterm_putat ( c, kterm_color, kterm_column, kterm_row);
-    
-
-}
-
-void kterm_write(const char* data, size_t size) {
-    for(size_t i = 0; i < size; i++){
-        kterm_put(data[i]);
-    }
-}   
-
-void kterm_writestring(const char* data ){
-    AS_KERNEL();
-    kterm_write(data, strlen(data));
-}
-

src/kernel/arch/i386/tty/kterm.h

@@ -1,23 +0,0 @@
-#pragma once 
-#include <stdint.h>
-#include <stddef.h>
-#include <stdint.h>
-#include <stdbool.h>
-
-#include "../vga/colors.h"
-
-void kterm_init();
-
-void kterm_resetcolor();
-void kterm_setcolor(uint8_t);
-
-void kterm_putat(char, uint8_t, size_t, size_t);
-void kterm_put(char);
-void kterm_write(const char*, size_t);
-void kterm_writestring(const char*);
-void kterm_scrollup();
-
-#define KernelTag "[Kernel]: "
-#define AS_KERNEL() (  kterm_setcolor(VGA_COLOR_LIGHT_BLUE),\
-                       kterm_write(KernelTag, 10 ), \
-                       kterm_resetcolor())

src/kernel/boot.S

@@ -0,0 +1,87 @@
+/*
+ * Multiboot 
+ */
+.set ALIGN,    1<<0             		/* align loaded modules on page boundaries */
+.set MEMINFO,  1<<1             		/* provide memory map */
+.set VIDEO,	   1<<2						/* provide video mode */
+.set FLAGS,    ALIGN | MEMINFO | VIDEO  /* this is the Multiboot 'flag' field */
+.set MAGIC,    0x1BADB002       		/* 'magic number' lets bootloader find the header */
+.set CHECKSUM, -(MAGIC + FLAGS) 		/* checksum of above, to prove we are multiboot */
+
+.section .multiboot
+.align 4
+.long MAGIC
+.long FLAGS
+.long CHECKSUM
+.long 0 # unused
+.long 0 # .
+.long 0 # .
+.long 0 # .
+.long 0 # unused
+.long 0 # set graphics mode
+.long 800 # screen witdh
+.long 600 # screen height
+.long 32 # bpp
+
+.section .bss
+.align 16
+stack_bottom:
+.skip 16384 # 16 KiB
+stack_top:
+ 
+.section .text
+.include "./src/kernel/irs_table.s"
+.include "./src/kernel/irq_table.s"
+.include "./src/kernel/idt/idt.s"
+.include "./src/kernel/paging.s"
+
+
+.global _start
+.type _start, @function
+_start:
+	/*Setup the stack pointer to point to the beginning of our stack */
+	/* I believe its a high address growing down to lower adress for the stack on x86*/
+	mov $stack_top, %esp
+
+	/*Reset EFLAGS*/
+	pushl $0 
+	popf 
+
+	/* push the pointer to the Multiboot information structure*/
+	pushl %ebx
+
+	/* push the magic value */
+	pushl %eax
+	
+	call early_main
+	cli
+	
+	
+
+.include "./src/kernel/gdt/gdt.s"
+
+	loadIDT:
+		#load idt
+		call init_idt
+        sti
+        
+        # Try enable A20
+		# mov $0x2401, %ax
+		# int $0x15
+
+
+		# enable protected mode
+		mov %cr0, %eax 
+		or $1, %eax
+		mov %eax, %cr0
+
+		
+		call kernel_main
+
+
+		cli
+	1:	hlt
+		jmp 1b
+
+
+.size _start, . - _start

src/kernel/bootcheck.h

@@ -0,0 +1,108 @@
+#pragma once 
+#include "bootloader/multiboot.h"
+#define CHECK_FLAG(flags, bit) ((flags) & (1 <<(bit)))
+#include "../gui/window.h"
+#include "../gui/cursor.h"
+#include "tty/kterm.h"
+#include "drivers/vesa/vesa.h"
+
+void CheckMBT ( multiboot_info_t*  mbt  ){
+  /* Set MBI to the addresss of the multiboot information structure*/
+  multiboot_info_t * mbi = (multiboot_info_t *) mbt;
+
+  /* Print out the flags */
+  printf("flags = 0x%8x\n", (unsigned) mbi->flags);
+
+  /* Are mem_* valid? */
+  if ( CHECK_FLAG(mbi->flags,0)){
+      printf("mem_lower = %uKB, mem_upper = %uKB\n");
+  }
+
+  /* is boot device valid ? */
+  if (CHECK_FLAG (mbi->flags, 1)){
+      printf("boot_device = 0x0%x\n", (unsigned) mbi->boot_device);
+  }
+
+  /* is the command line passed? */
+  if (CHECK_FLAG ( mbi->flags,2)){
+      printf("cmdline = %s\n", (char *) mbi->cmdline);
+  }
+
+  /* Are mods_* valid? */
+  if(CHECK_FLAG ( mbi->flags, 3)){
+      multiboot_module_t *mod;
+      uint32_t i;
+
+      printf("mods count = %d, mods_addr = 0x%x\n", (int) mbi->mods_count, (int) mbi->mods_addr);
+
+      for(i = 0, mod = (multiboot_module_t *) mbi->mods_addr; i < mbi->mods_count; i++ , mod++){
+          printf(" mod start = 0x%x, mod_end = 0x%x, cmdline = %s\n", (unsigned) mod->mod_start, (unsigned) mod->mod_end, (char*) mod->cmdline);
+      }
+  }
+
+  /* Bits 4 and 5 are mutually exclusive! */
+  if (CHECK_FLAG (mbi->flags, 4) && CHECK_FLAG(mbi->flags, 5)){
+      printf("Both bits 4 and 5 are set.\n");
+      return;
+  }
+
+  /* Is the symbol table of a.out valid? */
+  if (CHECK_FLAG(mbi->flags, 4)){
+      multiboot_aout_symbol_table_t *multiboot_aout_sym = &(mbi->u.aout_sym);
+
+      printf( "multiboot_aout_symbol_table: tabsize = 0x%0x, strsize = 0x%x, addr = 0x%x\n", 
+      (unsigned) multiboot_aout_sym->tabsize,
+      (unsigned) multiboot_aout_sym->strsize,
+      (unsigned) multiboot_aout_sym->addr);
+
+  }
+
+  /* Is the section header table of ELF valid? */
+  if (CHECK_FLAG(mbi->flags, 5)){
+      multiboot_elf_section_header_table_t *multiboot_elf_sec = &(mbi->u.elf_sec);
+
+      printf("multiboot_elf_sec: num = %u, size = 0x%x, addr = 0x%x, shnd = 0x%x\n",
+      (unsigned) multiboot_elf_sec->num, (unsigned) multiboot_elf_sec->size,
+      (unsigned) multiboot_elf_sec->addr, (unsigned)  multiboot_elf_sec->shndx);
+      
+  }
+
+  /* Draw diagonal blue line */
+  if (CHECK_FLAG (mbt->flags, 11)){
+    printf("Can draw!");
+
+
+
+    // Init vesa driver
+    initVBEDevice(mbt); 
+
+    // Fill screen with blue
+                                                // colours AARRGGBB
+    drawRect(0, 0 , VbeModeInfo->width,VbeModeInfo->height, 0xFF0000FF);
+
+    // Create two windows
+    Rect rect_window1 {};
+    Rect rect_window2 {};
+    rect_window1.height =200;
+    rect_window1.width = 300;
+    rect_window1.x = 50;
+    rect_window1.y = 50;
+
+    rect_window2.height =200;
+    rect_window2.width = 300;
+    rect_window2.x = 300;
+    rect_window2.y = 200;
+
+    Window window_1 ( rect_window1, 0xFF00F0FF);
+    Window window_2 (rect_window2, 0xFFAACCDD);
+
+    window_1.draw();
+    window_2.draw();
+
+    Cursor cursor (70,100);
+
+    cursor.draw();
+
+
+  }
+}

src/kernel/bootloader/multiboot.h

@@ -0,0 +1,274 @@
+/* multiboot.h - Multiboot header file. */
+/* Copyright (C) 1999,2003,2007,2008,2009,2010  Free Software Foundation, Inc.
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to
+ *  deal in the Software without restriction, including without limitation the
+ *  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ *  sell copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in
+ *  all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL ANY
+ *  DEVELOPER OR DISTRIBUTOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ *  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+ *  IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef MULTIBOOT_HEADER
+#define MULTIBOOT_HEADER 1
+
+/* How many bytes from the start of the file we search for the header. */
+#define MULTIBOOT_SEARCH                        8192
+#define MULTIBOOT_HEADER_ALIGN                  4
+
+/* The magic field should contain this. */
+#define MULTIBOOT_HEADER_MAGIC                  0x1BADB002
+
+/* This should be in %eax. */
+#define MULTIBOOT_BOOTLOADER_MAGIC              0x2BADB002
+
+/* Alignment of multiboot modules. */
+#define MULTIBOOT_MOD_ALIGN                     0x00001000
+
+/* Alignment of the multiboot info structure. */
+#define MULTIBOOT_INFO_ALIGN                    0x00000004
+
+/* Flags set in the ’flags’ member of the multiboot header. */
+
+/* Align all boot modules on i386 page (4KB) boundaries. */
+#define MULTIBOOT_PAGE_ALIGN                    0x00000001
+
+/* Must pass memory information to OS. */
+#define MULTIBOOT_MEMORY_INFO                   0x00000002
+
+/* Must pass video information to OS. */
+#define MULTIBOOT_VIDEO_MODE                    0x00000004
+
+/* This flag indicates the use of the address fields in the header. */
+#define MULTIBOOT_AOUT_KLUDGE                   0x00010000
+
+/* Flags to be set in the ’flags’ member of the multiboot info structure. */
+
+/* is there basic lower/upper memory information? */
+#define MULTIBOOT_INFO_MEMORY                   0x00000001
+/* is there a boot device set? */
+#define MULTIBOOT_INFO_BOOTDEV                  0x00000002
+/* is the command-line defined? */
+#define MULTIBOOT_INFO_CMDLINE                  0x00000004
+/* are there modules to do something with? */
+#define MULTIBOOT_INFO_MODS                     0x00000008
+
+/* These next two are mutually exclusive */
+
+/* is there a symbol table loaded? */
+#define MULTIBOOT_INFO_AOUT_SYMS                0x00000010
+/* is there an ELF section header table? */
+#define MULTIBOOT_INFO_ELF_SHDR                 0X00000020
+
+/* is there a full memory map? */
+#define MULTIBOOT_INFO_MEM_MAP                  0x00000040
+
+/* Is there drive info? */
+#define MULTIBOOT_INFO_DRIVE_INFO               0x00000080
+
+/* Is there a config table? */
+#define MULTIBOOT_INFO_CONFIG_TABLE             0x00000100
+
+/* Is there a boot loader name? */
+#define MULTIBOOT_INFO_BOOT_LOADER_NAME         0x00000200
+
+/* Is there a APM table? */
+#define MULTIBOOT_INFO_APM_TABLE                0x00000400
+
+/* Is there video information? */
+#define MULTIBOOT_INFO_VBE_INFO                 0x00000800
+#define MULTIBOOT_INFO_FRAMEBUFFER_INFO         0x00001000
+
+#ifndef ASM_FILE
+
+typedef unsigned char           multiboot_uint8_t;
+typedef unsigned short          multiboot_uint16_t;
+typedef unsigned int            multiboot_uint32_t;
+typedef unsigned long long      multiboot_uint64_t;
+
+struct multiboot_header
+{
+  /* Must be MULTIBOOT_MAGIC - see above. */
+  multiboot_uint32_t magic;
+
+  /* Feature flags. */
+  multiboot_uint32_t flags;
+
+  /* The above fields plus this one must equal 0 mod 2^32. */
+  multiboot_uint32_t checksum;
+
+  /* These are only valid if MULTIBOOT_AOUT_KLUDGE is set. */
+  multiboot_uint32_t header_addr;
+  multiboot_uint32_t load_addr;
+  multiboot_uint32_t load_end_addr;
+  multiboot_uint32_t bss_end_addr;
+  multiboot_uint32_t entry_addr;
+
+  /* These are only valid if MULTIBOOT_VIDEO_MODE is set. */
+  multiboot_uint32_t mode_type;
+  multiboot_uint32_t width;
+  multiboot_uint32_t height;
+  multiboot_uint32_t depth;
+};
+
+/* The symbol table for a.out. */
+struct multiboot_aout_symbol_table
+{
+  multiboot_uint32_t tabsize;
+  multiboot_uint32_t strsize;
+  multiboot_uint32_t addr;
+  multiboot_uint32_t reserved;
+};
+typedef struct multiboot_aout_symbol_table multiboot_aout_symbol_table_t;
+
+/* The section header table for ELF. */
+struct multiboot_elf_section_header_table
+{
+  multiboot_uint32_t num;
+  multiboot_uint32_t size;
+  multiboot_uint32_t addr;
+  multiboot_uint32_t shndx;
+};
+typedef struct multiboot_elf_section_header_table multiboot_elf_section_header_table_t;
+
+struct multiboot_info
+{
+  /* Multiboot info version number */
+  multiboot_uint32_t flags;
+
+  /* Available memory from BIOS */
+  multiboot_uint32_t mem_lower;
+  multiboot_uint32_t mem_upper;
+
+  /* "root" partition */
+  multiboot_uint32_t boot_device;
+
+  /* Kernel command line */
+  multiboot_uint32_t cmdline;
+
+  /* Boot-Module list */
+  multiboot_uint32_t mods_count;
+  multiboot_uint32_t mods_addr;
+
+  union
+  {
+    multiboot_aout_symbol_table_t aout_sym;
+    multiboot_elf_section_header_table_t elf_sec;
+  } u;
+
+  /* Memory Mapping buffer */
+  multiboot_uint32_t mmap_length;
+  multiboot_uint32_t mmap_addr;
+
+  /* Drive Info buffer */
+  multiboot_uint32_t drives_length;
+  multiboot_uint32_t drives_addr;
+
+  /* ROM configuration table */
+  multiboot_uint32_t config_table;
+
+  /* Boot Loader Name */
+  multiboot_uint32_t boot_loader_name;
+
+  /* APM table */
+  multiboot_uint32_t apm_table;
+
+  /* Video */
+  multiboot_uint32_t vbe_control_info;
+  multiboot_uint32_t vbe_mode_info;
+  multiboot_uint16_t vbe_mode;
+  multiboot_uint16_t vbe_interface_seg;
+  multiboot_uint16_t vbe_interface_off;
+  multiboot_uint16_t vbe_interface_len;
+
+  multiboot_uint64_t framebuffer_addr;
+  multiboot_uint32_t framebuffer_pitch;
+  multiboot_uint32_t framebuffer_width;
+  multiboot_uint32_t framebuffer_height;
+  multiboot_uint8_t framebuffer_bpp;
+#define MULTIBOOT_FRAMEBUFFER_TYPE_INDEXED 0
+#define MULTIBOOT_FRAMEBUFFER_TYPE_RGB     1
+#define MULTIBOOT_FRAMEBUFFER_TYPE_EGA_TEXT     2
+  multiboot_uint8_t framebuffer_type;
+  union
+  {
+    struct
+    {
+      multiboot_uint32_t framebuffer_palette_addr;
+      multiboot_uint16_t framebuffer_palette_num_colors;
+    };
+    struct
+    {
+      multiboot_uint8_t framebuffer_red_field_position;
+      multiboot_uint8_t framebuffer_red_mask_size;
+      multiboot_uint8_t framebuffer_green_field_position;
+      multiboot_uint8_t framebuffer_green_mask_size;
+      multiboot_uint8_t framebuffer_blue_field_position;
+      multiboot_uint8_t framebuffer_blue_mask_size;
+    };
+  };
+};
+typedef struct multiboot_info multiboot_info_t;
+
+struct multiboot_color
+{
+  multiboot_uint8_t red;
+  multiboot_uint8_t green;
+  multiboot_uint8_t blue;
+};
+
+struct multiboot_mmap_entry
+{
+  multiboot_uint32_t size;
+  multiboot_uint64_t addr;
+  multiboot_uint64_t len;
+#define MULTIBOOT_MEMORY_AVAILABLE              1
+#define MULTIBOOT_MEMORY_RESERVED               2
+#define MULTIBOOT_MEMORY_ACPI_RECLAIMABLE       3
+#define MULTIBOOT_MEMORY_NVS                    4
+#define MULTIBOOT_MEMORY_BADRAM                 5
+  multiboot_uint32_t type;
+} __attribute__((packed));
+typedef struct multiboot_mmap_entry multiboot_memory_map_t;
+
+struct multiboot_mod_list
+{
+  /* the memory used goes from bytes ’mod_start’ to ’mod_end-1’ inclusive */
+  multiboot_uint32_t mod_start;
+  multiboot_uint32_t mod_end;
+
+  /* Module command line */
+  multiboot_uint32_t cmdline;
+
+  /* padding to take it to 16 bytes (must be zero) */
+  multiboot_uint32_t pad;
+};
+typedef struct multiboot_mod_list multiboot_module_t;
+
+/* APM BIOS info. */
+struct multiboot_apm_info
+{
+  multiboot_uint16_t version;
+  multiboot_uint16_t cseg;
+  multiboot_uint32_t offset;
+  multiboot_uint16_t cseg_16;
+  multiboot_uint16_t dseg;
+  multiboot_uint16_t flags;
+  multiboot_uint16_t cseg_len;
+  multiboot_uint16_t cseg_16_len;
+  multiboot_uint16_t dseg_len;
+};
+
+#endif /* ! ASM_FILE */
+
+#endif /* ! MULTIBOOT_HEADER */

src/kernel/cpu.h

@@ -0,0 +1,17 @@
+#include <cpuid.h> // NOTE: Only available in GCC 
+// NOT currently usefull!
+/*    static int get_model(){
+        int ebx, unused;
+        __cpuid(0, unused, ebx, unused, unused);
+        return ebx;
+    }
+
+    enum {
+        CPUID_FEAT_EDX_APIC = 1 << 9
+    };
+    static int check_apic (){
+        unsigned int eax, unused, edx;
+        __get_cpuid(1, &eax, &unused, &unused, &edx);
+        return  edx & CPUID_FEAT_EDX_APIC;
+    }
+*/

src/kernel/disk.h

@@ -0,0 +1,17 @@
+#pragma once
+
+// Let's write an ATA PIO | ATA driver for now. Mostly to show that I can in theory interact with a
+// storage device
+
+// PRIMARY_ATA_BUS
+// 0x1F0 through 0x1F7 
+
+// SECONDARY_ATA_BUS
+// 0x170 through 0x177
+
+#define DEVICE_CONTROL_REGISTER 0x3F6
+#define DEVICE_CONTROL_ALTERNATE 0x376
+
+
+// IRQ14 Primary bus interrupt
+// IRQ15 Secondary bus interrupt

src/kernel/drivers/vesa/vesa.cpp

@@ -0,0 +1,136 @@
+#include "vesa.h"
+VbeInfoBlock* vbeInfo;
+vbe_mode_info_structure* VbeModeInfo;
+
+void initVBEDevice(multiboot_info_t* mbt){
+    print_serial("initVBEDevice");
+
+    vbeInfo = (VbeInfoBlock*) mbt->vbe_control_info;
+    printf_serial("Signature: %s, V0x%x\n", vbeInfo->VbeSignature, vbeInfo->VbeVersion);
+
+    VbeModeInfo = (vbe_mode_info_structure*) mbt->vbe_mode_info;
+
+    printf_serial("VESA video mode info: Width: %d Height: %d BPP: %d\n", VbeModeInfo->width, VbeModeInfo->height , VbeModeInfo->bpp);
+    printf_serial("VideoMemory Location: 0x%x \n", VbeModeInfo->framebuffer );
+}
+
+void putPixel( int x, int y , uint32_t colour){
+   // printf_serial("putPixel x: %d, y: %d\n", x, y);
+                    ///fb + mbt->framebuffer_pitch * y + 4 * x ,NOTE: this calculation is very important 
+    *(uint32_t*) (  VbeModeInfo->framebuffer + VbeModeInfo->pitch * y + 4  * x ) = colour;
+}
+void drawLine(int x1, int y1, int x2, int y2, uint32_t colour ){
+    print_serial("drawline\n");
+    // See Bresenham's line algorithm
+    int deltaX = x2 - x1;
+    int deltaY = y2 - y1;
+    int D = 2 * deltaY - deltaX;
+    int y = y1;
+
+    for ( int x = x1; x < x2; x++){
+      putPixel(x,y, colour);
+      if( D > 0){
+        y +=1;
+        D = D - 2 * deltaX;
+      }
+      D = D + 2 * deltaY;
+    }
+
+
+
+}
+void drawRect ( int x, int y, int width, int height, uint32_t colour ){
+    print_serial("drawRect\n");
+    for ( int i = x; i < x + width; i ++)
+    {
+      for(int j = y; j < y + height; j++){
+        
+        putPixel(i,j, colour);
+      }
+    }
+
+}
+
+
+void blueDiagnalLineTest(multiboot_info_t* mbt){
+    multiboot_uint32_t color;
+    unsigned i;
+    void *fb = (void *) (unsigned long) mbt->framebuffer_addr;
+
+     switch (mbt->framebuffer_type)
+        {
+        case MULTIBOOT_FRAMEBUFFER_TYPE_INDEXED:
+          {
+            unsigned best_distance, distance;
+            struct multiboot_color *palette;
+            
+            palette = (struct multiboot_color *) mbt->framebuffer_palette_addr;
+
+            color = 0;
+            best_distance = 4*256*256;
+            
+            for (i = 0; i < mbt->framebuffer_palette_num_colors; i++)
+              {
+                distance = (0xff - palette[i].blue) * (0xff - palette[i].blue)
+                  + palette[i].red * palette[i].red
+                  + palette[i].green * palette[i].green;
+                if (distance < best_distance)
+                  {
+                    color = i;
+                    best_distance = distance;
+                  }
+              }
+          }
+          break;
+
+        case MULTIBOOT_FRAMEBUFFER_TYPE_RGB:
+          color = ((1 << mbt->framebuffer_blue_mask_size) - 1) 
+            << mbt->framebuffer_blue_field_position;
+          break;
+
+        case MULTIBOOT_FRAMEBUFFER_TYPE_EGA_TEXT:
+          color = '\\' | 0x0100;
+          break;
+
+        default:
+          color = 0xffffffff;
+          break;
+        }
+      for (i = 0; i < mbt->framebuffer_width
+             && i < mbt->framebuffer_height; i++)
+        {
+          switch (mbt->framebuffer_bpp)
+            {
+            case 8:
+              {
+                multiboot_uint8_t *pixel = (multiboot_uint8_t*)fb + mbt->framebuffer_pitch * i + i;
+                *pixel = color;
+              }
+              break;
+            case 15:
+            case 16:
+              {
+                multiboot_uint16_t *pixel
+                  = (multiboot_uint16_t*)fb + mbt->framebuffer_pitch * i + 2 * i;
+                *pixel = color;
+              }
+              break;
+            case 24:
+              {
+                multiboot_uint32_t *pixel
+                  = (multiboot_uint32_t*)fb + mbt->framebuffer_pitch * i + 3 * i;
+                *pixel = (color & 0xffffff) | (*pixel & 0xff000000);
+              }
+              break;
+
+            case 32:
+              {
+                multiboot_uint32_t *pixel
+                  = (multiboot_uint32_t*)fb + mbt->framebuffer_pitch * i + 4 * i;
+                *pixel = color;
+              }
+              break;
+            }
+        }
+}
+

src/kernel/drivers/vesa/vesa.h

@@ -0,0 +1,66 @@
+#pragma once 
+#include <stdint.h>
+#include "../../bootloader/multiboot.h"
+#include "../../serial.h"
+
+struct vbe_mode_info_structure{
+        uint16_t attributes;
+        uint8_t window_a;
+        uint8_t window_b;
+        uint16_t granularity;
+        uint16_t window_size;
+        uint16_t segment_a;
+        uint16_t segment_b;
+        uint32_t win_func_ptr;
+        uint16_t pitch;
+        uint16_t width;
+        uint16_t height;
+        uint8_t w_char;
+        uint8_t y_char;
+        uint8_t planes;
+        uint8_t bpp;
+        uint8_t banks;
+        uint8_t memory_model;
+        uint8_t bank_size;
+        uint8_t image_pages;
+        uint8_t reserved0;
+
+        uint8_t red_mask;
+        uint8_t red_position;
+        uint8_t green_mask;
+        uint8_t green_position;
+        uint8_t blue_mask;
+        uint8_t blue_position;
+        uint8_t reserved_mask;
+        uint8_t reserved_position;
+        uint8_t direct_color_attributes;
+
+        uint32_t framebuffer;
+        uint32_t off_screen_mem_off;
+        uint16_t off_screen_mem_size;
+        uint8_t reserved1[206];
+      }__attribute__((packed));
+
+struct VbeInfoBlock {
+        char VbeSignature[4];
+        uint16_t VbeVersion;
+        uint16_t OemStringPtr;
+        uint8_t Capabilities;
+        uint16_t VideoModePtr;
+        uint16_t TotalMemory;
+      }__attribute__((packed));
+
+extern VbeInfoBlock* vbeInfo;
+extern vbe_mode_info_structure* VbeModeInfo;
+
+
+
+void initVBEDevice(multiboot_info_t* mbt);
+
+void blueDiagnalLineTest(multiboot_info_t* mbt);
+
+
+// Primitive drawing functions  
+void putPixel( int x, int y , uint32_t colour);
+void drawLine(int x1, int y1, int x2, int y2, uint32_t colour );
+void drawRect ( int x, int y, int width, int height, uint32_t colour );

src/kernel/gdt/gdt.s

@@ -0,0 +1,19 @@
+.global LoadGlobalDescriptorTable
+
+	LoadGlobalDescriptorTable:
+		lgdt gdtDescriptor
+
+		movw $16, %ax 
+		movw %ax, %ds
+		movw %ax, %es
+		movw %ax, %fs
+		movw %ax, %gs
+		movw %ax, %ss
+		
+		jmp $8,$flush 
+
+		flush: 
+		ret
+		
+	
+

src/kernel/gdt/gdtc.cpp

@@ -0,0 +1,62 @@
+#include "gdtc.h"
+#include "../tty/kterm.h"
+
+#define NULL_SEGMENT          0
+#define KERNEL_CODE_SEGMENT   1
+#define KERNEL_DATA_SEGMENT   2
+#define USER_CODE_SEGMENT     3
+#define USER_DATA_SEGMENT     4
+
+SegmentDescriptor GlobalDescriptorTable[5];
+GlobalDescriptorTableDescriptor gdtDescriptor;
+
+void add_descriptor(int which , unsigned long base, unsigned long limit, unsigned char access, unsigned char granularity ){
+   GlobalDescriptorTable[which].base_low = (base & 0xFFFF );
+   GlobalDescriptorTable[which].base_middle = (base >> 6) & 0xFF;
+   GlobalDescriptorTable[which].base_high = (base >> 24) & 0xFF;
+   
+   GlobalDescriptorTable[which].limit_low = (limit & 0xFFFF);
+   GlobalDescriptorTable[which].granularity = ((limit >> 16) & 0x0F);
+
+   GlobalDescriptorTable[which].granularity |= (granularity & 0xF0);
+   GlobalDescriptorTable[which].access = access;
+
+
+}
+
+
+
+
+void initGDT(){
+
+      // NULL segment
+      add_descriptor(NULL_SEGMENT, 0,0,0,0);
+
+      // Kernel Code Segment
+      add_descriptor(KERNEL_CODE_SEGMENT, 0, 0xFFFFFFFF, 0x9A, 0xCF);
+
+      // Kernel Data Segment
+      add_descriptor(KERNEL_DATA_SEGMENT, 0, 0xFFFFFFFF, 0x92, 0xCF);      
+
+      // User Code Segment
+      // TODO:
+      
+      // User Data Segement
+      // TODO: 
+      
+      // init Gdt Descriptor
+      gdtDescriptor.limit = ((sizeof(SegmentDescriptor ) * 5 ) - 1);
+      gdtDescriptor.base = (unsigned int) &GlobalDescriptorTable;
+
+      printf("Hello GDT!\n");
+
+
+      LoadGlobalDescriptorTable();
+
+//      while (true)
+//         asm volatile("hlt");
+      
+
+
+
+}

src/kernel/gdt/gdtc.h

@@ -0,0 +1,27 @@
+#include <stdint.h>
+
+
+struct SegmentDescriptor {
+   unsigned short limit_low;
+   unsigned short base_low;
+   unsigned char base_middle;
+   unsigned char access;
+   unsigned char granularity;
+   unsigned char base_high;
+}__attribute__((packed));
+
+
+struct GlobalDescriptorTableDescriptor{
+   unsigned short limit;
+   unsigned int base;
+}__attribute__((packed));
+
+extern SegmentDescriptor GlobalDescriptorTable[];
+extern GlobalDescriptorTableDescriptor gdtDescriptor;
+
+
+void add_descriptor(int which , unsigned long base, unsigned long limit, unsigned char access, unsigned char granularity );
+
+
+extern "C" void LoadGlobalDescriptorTable();
+void initGDT();

src/kernel/idt/idt.cpp

@@ -0,0 +1,149 @@
+#include "idt.h"
+//#include "scancodes/set1.h"
+
+IDT_entry idt_table[256];
+IDT_ptr idt_ptr;
+
+void set_id_entry (uint8_t num , uint32_t base, uint16_t sel,  uint8_t flags){
+    idt_table[num].offset_1 = base & 0xFFFF;
+    idt_table[num].selector = sel;
+    idt_table[num].zero = 0;
+    idt_table[num].type_attr = flags;
+    idt_table[num].offset_2 = (base >> 16) & 0xFFFF;
+
+};
+
+
+void irs_handler (registers regs) {
+        kterm_writestring("received interrupt!\n");
+     
+        printf("(IRS) Interrupt number: %d \n", regs.int_no);
+
+        if( regs.int_no == 13){
+            printf(" Error code: %d \n", regs.err_code);
+
+        }
+        
+  
+       
+
+}
+
+
+
+void irq_handler (registers regs) {
+        
+     
+        if ( regs.int_no != 0) {
+            kterm_writestring("received interrupt!\n");
+            printf("(IRQ) Interrupt number: %d \n", regs.int_no);
+        
+        }
+        
+        if ( regs.int_no == 1 ){
+            // Keyboard interrupt !!
+
+            int scan;
+            /*register*/int i;
+
+            // Read scancode 
+
+            scan = inb(0x60);
+            
+            // Send ack message!
+            i = inb(0x61);
+            outb(0x61, i|0x80);
+            outb(0x61, i);
+            kterm_writestring("A key was pressed/released\n");
+            printf( "Scancode: %x\n", scan);
+
+    
+        }
+
+        
+        
+        outb(0x20, 0x20); // send end of interrupt to master
+
+        if ( regs.int_no > 8 && regs.int_no <= 15) {
+            outb(0xA0, 0x20); // send end of interrupt to slave 
+        }
+       
+       
+        if( regs.int_no == 13){
+            printf(" Error code: %d \n", regs.err_code);
+
+        }
+
+}
+
+
+
+
+
+void init_idt(){
+    // Initialise the IDT pointer
+    idt_ptr.length = sizeof(IDT_entry) * 255;
+    idt_ptr.base = (uint32_t)&idt_table;
+
+
+    // TODO: Set everything to zero first
+
+    set_id_entry(0,  (uint32_t) irs0 , 0x08, 0x8F);
+    set_id_entry(1,  (uint32_t) irs1 , 0x08, 0x8E);
+    set_id_entry(2,  (uint32_t) irs2 , 0x08, 0x8E);
+    set_id_entry(3,  (uint32_t) irs3 , 0x08, 0x8E);
+    set_id_entry(4,  (uint32_t) irs4 , 0x08, 0x8E);
+    set_id_entry(5,  (uint32_t) irs5 , 0x08, 0x8E);
+    set_id_entry(6,  (uint32_t) irs6 , 0x08, 0x8E);
+    set_id_entry(7,  (uint32_t) irs7 , 0x08, 0x8E);
+    set_id_entry(8,  (uint32_t) irs8 , 0x08, 0x8E);
+    set_id_entry(9,  (uint32_t) irs9 , 0x08, 0x8E);
+    set_id_entry(10, (uint32_t) irs10 , 0x08, 0x8E);
+    set_id_entry(11, (uint32_t) irs11 , 0x08, 0x8E);
+    set_id_entry(12, (uint32_t) irs12 , 0x08, 0x8E);
+    set_id_entry(13, (uint32_t) irs13 , 0x08, 0x8E);
+    set_id_entry(14, (uint32_t) irs14 , 0x08, 0x8E);
+    set_id_entry(15, (uint32_t) irs15 , 0x08, 0x8E);
+    set_id_entry(16, (uint32_t) irs16 , 0x08, 0x8E);
+    set_id_entry(17, (uint32_t) irs17 , 0x08, 0x8E);
+    set_id_entry(18, (uint32_t) irs18 , 0x08, 0x8E);
+    set_id_entry(19, (uint32_t) irs19 , 0x08, 0x8E); 
+    set_id_entry(20, (uint32_t) irs20 , 0x08, 0x8E);
+    set_id_entry(21, (uint32_t) irs21 , 0x08, 0x8E);
+    set_id_entry(22, (uint32_t) irs22 , 0x08, 0x8E);
+    set_id_entry(23, (uint32_t) irs23 , 0x08, 0x8E);
+    set_id_entry(24, (uint32_t) irs24 , 0x08, 0x8E);
+    set_id_entry(25, (uint32_t) irs25 , 0x08, 0x8E);
+    set_id_entry(26, (uint32_t) irs26 , 0x08, 0x8E);
+    set_id_entry(27, (uint32_t) irs27 , 0x08, 0x8E); 
+    set_id_entry(28, (uint32_t) irs28 , 0x08, 0x8E);
+    set_id_entry(29, (uint32_t) irs29 , 0x08, 0x8E);
+    set_id_entry(30, (uint32_t) irs30 , 0x08, 0x8E);
+    set_id_entry(31, (uint32_t) irs31 , 0x08, 0x8E);
+
+
+    //print_serial("Remapping PIC\n");
+    PIC_remap(0x20, 0x28);
+
+
+    // pic IRQ Table
+    set_id_entry(32, (uint32_t)irq0, 0x08, 0x8E);
+    set_id_entry(33, (uint32_t)irq1, 0x08, 0x8E);
+    set_id_entry(34, (uint32_t)irq2, 0x08, 0x8E);
+    set_id_entry(35, (uint32_t)irq3, 0x08, 0x8E);
+    set_id_entry(36, (uint32_t)irq4, 0x08, 0x8E);
+    set_id_entry(37, (uint32_t)irq5, 0x08, 0x8E);
+    set_id_entry(38, (uint32_t)irq6, 0x08, 0x8E);
+    set_id_entry(39, (uint32_t)irq7, 0x08, 0x8E);
+    set_id_entry(40, (uint32_t)irq8, 0x08, 0x8E);
+    set_id_entry(41, (uint32_t)irq9, 0x08, 0x8E);
+    set_id_entry(42, (uint32_t)irq10, 0x08, 0x8E);
+    set_id_entry(43, (uint32_t)irq11, 0x08, 0x8E);
+    set_id_entry(44, (uint32_t)irq12, 0x08, 0x8E);
+    set_id_entry(45, (uint32_t)irq13, 0x08, 0x8E);
+    set_id_entry(46, (uint32_t)irq14, 0x08, 0x8E);
+    set_id_entry(47, (uint32_t)irq15, 0x08, 0x8E);
+
+    
+    idt_flush((uint32_t)&idt_ptr);
+}

src/kernel/idt/idt.h

@@ -0,0 +1,77 @@
+#pragma once
+
+#include "stdint.h"
+#include "stddef.h"
+#include "../vga/colors.h"
+#include "../pic/pic.h"
+
+#include "../tty/kterm.h"
+
+
+extern "C" {
+    struct __attribute__((__packed__)) IDT_entry {
+        uint16_t offset_1;
+        uint16_t selector;
+        uint8_t zero;
+        uint8_t type_attr;
+        uint16_t offset_2;
+    };
+
+    struct __attribute__((__packed__)) IDT_ptr {
+        unsigned short length;
+        unsigned long base;
+    };
+
+    struct registers {
+        uint32_t ds;                  // Data segment selector
+        uint32_t edi, esi, ebp, esp, ebx, edx, ecx, eax; // Pushed by pusha.
+        uint32_t int_no, err_code;    // Interrupt number and error code (if applicable)
+        uint32_t eip, cs, eflags, useresp, ss; 
+    };
+
+
+    extern void idt_flush(uint32_t); 
+    void set_id_entry (uint8_t num , uint32_t base, uint16_t sel,  uint8_t flags);
+    void init_idt();
+
+    void irq_handler (registers regs);
+
+    void irs_handler (registers regs);
+
+    extern void irs0 ();
+    extern void irs1 ();
+    extern void irs2 ();
+    extern void irs3 ();
+    extern void irs4 ();
+    extern void irs5 ();
+    extern void irs6 ();
+    extern void irs7 ();
+    extern void irs8 ();
+    extern void irs9 ();
+    extern void irs10 ();
+    extern void irs11 ();
+    extern void irs12 ();
+    extern void irs13 ();
+    extern void irs14 ();
+    extern void irs15 ();
+    extern void irs16 ();
+    extern void irs17 ();
+    extern void irs18 ();
+    extern void irs19 ();
+    extern void irs20 ();
+    extern void irs21 ();
+    extern void irs22 ();
+    extern void irs23 ();
+    extern void irs24 ();
+    extern void irs25 ();
+    extern void irs26 ();
+    extern void irs27 ();
+    extern void irs28 ();
+    extern void irs29 ();
+    extern void irs30 ();
+    extern void irs31 ();
+
+
+
+
+}

src/kernel/idt/idt.s

@@ -0,0 +1,6 @@
+
+.globl idt_flush
+idt_flush:
+	mov 4(%esp), %eax
+	lidt (%eax)
+	ret

src/kernel/idt/scancodes/set1.h

@@ -0,0 +1,184 @@
+#pragma once 
+
+
+
+
+
+
+// ScanCode set 1 
+int ScanCodeToKeyCode [0xD8];
+
+/* key pressed scancode */ 
+ScanCodeToKeyCode[0x01] = 4017;   // escape pressed
+ScanCodeToKeyCode[0x02] = 4018;   // 1 pressed
+ScanCodeToKeyCode[0x03] = 4019;   // 2 pressed
+ScanCodeToKeyCode[0x04] = 4020;   // 3 pressed
+ScanCodeToKeyCode[0x05] =""   // 4 pressed	
+ScanCodeToKeyCode[0x06] =""   // 5 pressed
+ScanCodeToKeyCode[0x07] =""   // 6 pressed
+ScanCodeToKeyCode[0x08] =""   // 7 pressed
+ScanCodeToKeyCode[0x09] =""   // 8 pressed	
+ScanCodeToKeyCode[0x0A] =""   // 9 pressed	
+ScanCodeToKeyCode[0x0B] =""   // 0 (zero) pressed
+ScanCodeToKeyCode[0x0C] =""   // - pressed
+ScanCodeToKeyCode[0x0D] =""   // = pressed	
+ScanCodeToKeyCode[0x0E] =""   // backspace pressed
+ScanCodeToKeyCode[0x0F] =""   // tab pressed
+ScanCodeToKeyCode[0x10] =""  	// Q pressed
+ScanCodeToKeyCode[0x11] =""   // W pressed	
+ScanCodeToKeyCode[0x12] ="" 	// E pressed
+ScanCodeToKeyCode[0x13] ="" 	// R pressed
+ScanCodeToKeyCode[0x14] ="" 	// T pressed
+ScanCodeToKeyCode[0x15] ="" 	// Y pressed	
+ScanCodeToKeyCode[0x16] ="" 	// U pressed
+ScanCodeToKeyCode[0x17] ="" 	// I pressed
+ScanCodeToKeyCode[0x18] ="" 	// O pressed
+ScanCodeToKeyCode[0x19] ="" 	// P pressed	
+ScanCodeToKeyCode[0x1A] =""   // [ pressed
+ScanCodeToKeyCode[0x1B] =""   // ] pressed
+ScanCodeToKeyCode[0x1C] =""   // enter pressed
+ScanCodeToKeyCode[0x1D] =""   // left control pressed
+ScanCodeToKeyCode[0x1E] ="" 	// A pressed
+ScanCodeToKeyCode[0x1F] ="" 	// S pressed
+ScanCodeToKeyCode[0x20] ="" 	// D pressed
+ScanCodeToKeyCode[0x21] ="" 	// F pressed
+ScanCodeToKeyCode[0x22] ="" 	// G pressed
+ScanCodeToKeyCode[0x23] ="" 	// H pressed
+ScanCodeToKeyCode[0x24] ="" 	// J pressed
+ScanCodeToKeyCode[0x25] ="" 	// K pressed
+ScanCodeToKeyCode[0x26] ="" 	// L pressed
+ScanCodeToKeyCode[0x27] =""   //  ; pressed
+ScanCodeToKeyCode[0x28] =""   // ' (single quote) pressed
+ScanCodeToKeyCode[0x29] =""   // ` (back tick) pressed
+ScanCodeToKeyCode[0x2A] =""   // left shift pressed	
+ScanCodeToKeyCode[0x2B] =""   // \ pressed
+ScanCodeToKeyCode[0x2C] ="" 	// Z pressed
+ScanCodeToKeyCode[0x2D] ="" 	// X pressed
+ScanCodeToKeyCode[0x2E] ="" 	// C pressed	
+ScanCodeToKeyCode[0x2F] ="" 	// V pressed
+ScanCodeToKeyCode[0x30] ="" 	// B pressed
+ScanCodeToKeyCode[0x31] ="" 	// N pressed
+ScanCodeToKeyCode[0x32] ="" 	// M pressed
+ScanCodeToKeyCode[0x33] =""   // , pressed
+ScanCodeToKeyCode[0x34] =""   // . pressed
+ScanCodeToKeyCode[0x35] =""   // / pressed
+ScanCodeToKeyCode[0x36] =""   // right shift pressed
+ScanCodeToKeyCode[0x37] =""   // (keypad) * pressed
+ScanCodeToKeyCode[0x38] =""   // left alt pressed	
+ScanCodeToKeyCode[0x39] =""   // space pressed	
+ScanCodeToKeyCode[0x3A] =""   // CapsLock pressed
+ScanCodeToKeyCode[0x3B] =""   // F1 pressed
+ScanCodeToKeyCode[0x3C] =""   // F2 pressed
+ScanCodeToKeyCode[0x3D] =""   // F3 pressed
+ScanCodeToKeyCode[0x3E] ="" 	// F4 pressed
+ScanCodeToKeyCode[0x3F] ="" 	// F5 pressed
+ScanCodeToKeyCode[0x40] ="" 	// F6 pressed
+ScanCodeToKeyCode[0x41] ="" 	// F7 pressed
+ScanCodeToKeyCode[0x42] ="" 	// F8 pressed
+ScanCodeToKeyCode[0x43] ="" 	// F9 pressed
+ScanCodeToKeyCode[0x44] ="" 	// F10 pressed
+ScanCodeToKeyCode[0x45] ="" 	// NumberLock pressed
+ScanCodeToKeyCode[0x46] ="" 	// ScrollLock pressed
+ScanCodeToKeyCode[0x47] ="" 	// (keypad) 7 pressed
+ScanCodeToKeyCode[0x48] ="" 	// (keypad) 8 pressed
+ScanCodeToKeyCode[0x49] ="" 	// (keypad) 9 pressed
+ScanCodeToKeyCode[0x4A] ="" 	// (keypad) - pressed
+ScanCodeToKeyCode[0x4B] ="" 	// (keypad) 4 pressed
+ScanCodeToKeyCode[0x4C] ="" 	// (keypad) 5 pressed
+ScanCodeToKeyCode[0x4D] ="" 	// (keypad) 6 pressed
+ScanCodeToKeyCode[0x4E] ="" 	// (keypad) + pressed
+ScanCodeToKeyCode[0x4F] ="" 	// (keypad) 1 pressed
+ScanCodeToKeyCode[0x50] ="" 	// (keypad) 2 pressed
+ScanCodeToKeyCode[0x51] ="" 	// (keypad) 3 pressed
+ScanCodeToKeyCode[0x52] ="" 	// (keypad) 0 pressed
+ScanCodeToKeyCode[0x53] ="" 	// (keypad) . pressed
+ScanCodeToKeyCode[0x57] ="" 	// F11 pressed
+ScanCodeToKeyCode[0x58] ="" 	// F12 pressed						
+
+
+/* key released scanCode.""*/
+ScanCodeToKeyCode[0x81] ="" 	// escape released
+ScanCodeToKeyCode[0x82] ="" 	// 1 released
+ScanCodeToKeyCode[0x83] ="" 	// 2 released
+ScanCodeToKeyCode[0x84] ="" 	// 3 released
+ScanCodeToKeyCode[0x85] ="" 	// 4 released
+ScanCodeToKeyCode[0x86] ="" 	// 5 released
+ScanCodeToKeyCode[0x87] ="" 	// 6 released
+ScanCodeToKeyCode[0x88] ="" 	// 7 released
+ScanCodeToKeyCode[0x89] ="" 	// 8 released
+ScanCodeToKeyCode[0x8A] ="" 	// 9 released
+ScanCodeToKeyCode[0x8B] ="" 	// 0 (zero) released
+ScanCodeToKeyCode[0x8C] ="" 	// - released
+ScanCodeToKeyCode[0x8D] ="" 	// = released
+ScanCodeToKeyCode[0x8E] ="" 	// backspace released
+ScanCodeToKeyCode[0x8F] ="" 	// tab released
+ScanCodeToKeyCode[0x90] ="" 	// Q released
+ScanCodeToKeyCode[0x91] ="" 	// W released
+ScanCodeToKeyCode[0x92] ="" 	// E released
+ScanCodeToKeyCode[0x93] ="" 	// R released
+ScanCodeToKeyCode[0x94] ="" 	// T released
+ScanCodeToKeyCode[0x95] ="" 	// Y released	
+ScanCodeToKeyCode[0x96] ="" 	// U released
+ScanCodeToKeyCode[0x97] ="" 	// I released
+ScanCodeToKeyCode[0x98] ="" 	// O released	
+ScanCodeToKeyCode[0x99] ="" 	// P released
+ScanCodeToKeyCode[0x9A] ="" 	// [ released	
+ScanCodeToKeyCode[0x9B] ="" 	// ] released
+ScanCodeToKeyCode[0x9C] ="" 	// enter released
+ScanCodeToKeyCode[0x9D] ="" 	// left control released
+ScanCodeToKeyCode[0x9E] ="" 	// A released
+ScanCodeToKeyCode[0x9F] ="" 	// S released
+ScanCodeToKeyCode[0xA0] ="" 	// D released
+ScanCodeToKeyCode[0xA1] ="" 	// F released
+ScanCodeToKeyCode[0xA2] ="" 	// G released
+ScanCodeToKeyCode[0xA3] ="" 	// H released
+ScanCodeToKeyCode[0xA4] ="" 	// J released
+ScanCodeToKeyCode[0xA5] ="" 	// K released
+ScanCodeToKeyCode[0xA6] ="" 	// L released
+ScanCodeToKeyCode[0xA7] ="" 	//  ; released
+ScanCodeToKeyCode[0xA8] ="" 	// ' (single quote) released
+ScanCodeToKeyCode[0xA9] ="" 	// ` (back tick) released
+ScanCodeToKeyCode[0xAA] ="" 	// left shift released
+ScanCodeToKeyCode[0xAB] ="" 	// \ released
+ScanCodeToKeyCode[0xAC] ="" 	// Z released	
+ScanCodeToKeyCode[0xAD] ="" 	// X released	
+ScanCodeToKeyCode[0xAE] ="" 	// C released	
+ScanCodeToKeyCode[0xAF] ="" 	// V released
+ScanCodeToKeyCode[0xB0] ="" 	// B released	
+ScanCodeToKeyCode[0xB1] ="" 	// N released	
+ScanCodeToKeyCode[0xB2] ="" 	// M released	
+ScanCodeToKeyCode[0xB3] ="" 	// , released
+ScanCodeToKeyCode[0xB4] ="" 	// . released	
+ScanCodeToKeyCode[0xB5] ="" 	// / released	
+ScanCodeToKeyCode[0xB6] ="" 	// right shift released
+ScanCodeToKeyCode[0xB7] ="" 	// (keypad) * released
+ScanCodeToKeyCode[0xB8] ="" 	// left alt released	
+ScanCodeToKeyCode[0xB9] ="" 	// space released	
+ScanCodeToKeyCode[0xBA] ="" 	// CapsLock released	
+ScanCodeToKeyCode[0xBB] ="" 	// F1 released
+ScanCodeToKeyCode[0xBC] ="" 	// F2 released	
+ScanCodeToKeyCode[0xBD] ="" 	// F3 released	
+ScanCodeToKeyCode[0xBE] ="" 	// F4 released	
+ScanCodeToKeyCode[0xBF] ="" 	// F5 released
+ScanCodeToKeyCode[0xC0] ="" 	// F6 released	
+ScanCodeToKeyCode[0xC1] ="" 	// F7 released	
+ScanCodeToKeyCode[0xC2] ="" 	// F8 released	
+ScanCodeToKeyCode[0xC3] ="" 	// F9 released
+ScanCodeToKeyCode[0xC4] ="" 	// F10 released
+ScanCodeToKeyCode[0xC5] ="" 	// NumberLock released
+ScanCodeToKeyCode[0xC6] ="" 	// ScrollLock released
+ScanCodeToKeyCode[0xC7] ="" 	// (keypad) 7 released
+ScanCodeToKeyCode[0xC8] ="" 	// (keypad) 8 released	
+ScanCodeToKeyCode[0xC9] ="" 	// (keypad) 9 released	
+ScanCodeToKeyCode[0xCA] ="" 	// (keypad) - released	
+ScanCodeToKeyCode[0xCB] ="" 	// (keypad) 4 released
+ScanCodeToKeyCode[0xCC] ="" 	// (keypad) 5 released	
+ScanCodeToKeyCode[0xCD] ="" 	// (keypad) 6 released	
+ScanCodeToKeyCode[0xCE] ="" 	// (keypad) + released	
+ScanCodeToKeyCode[0xCF] ="" 	// (keypad) 1 released
+ScanCodeToKeyCode[0xD0] ="" 	// (keypad) 2 released	
+ScanCodeToKeyCode[0xD1] ="" 	// (keypad) 3 released	
+ScanCodeToKeyCode[0xD2] ="" 	// (keypad) 0 released	
+ScanCodeToKeyCode[0xD3] ="" 	// (keypad) . released
+ScanCodeToKeyCode[0xD7] ="" 	// F11 released
+ScanCodeToKeyCode[0xD8] ="" 	// F12 released					

src/kernel/io.cpp

@@ -1,19 +1,24 @@
 #include "io.h"
 
 unsigned char inb_p(unsigned short ){
-
+        // TODO: implement me!
+        return 0;
 }
 unsigned short inw(unsigned short ){
-
+// TODO: implement me!
+        return 0;
 }
 unsigned short inw_p(unsigned short ){
-
+// TODO: implement me!
+        return 0;
 }
 unsigned int inl(unsigned short ){
-
+// TODO: implement me!
+        return 0;
 }
 unsigned int inl_p(unsigned short ){
-
+// TODO: implement me!
+        return 0;
 }
 
 
@@ -57,3 +62,11 @@ void outsl(unsigned short , const void *,
         unsigned long ){
 
         }
+
+void io_wait(void)
+{
+    /* TODO: This is probably fragile. */
+    asm volatile ( "jmp 1f\n\t"
+                   "1:jmp 2f\n\t"
+                   "2:" );
+}

src/kernel/io.h

@@ -41,3 +41,4 @@ void outsw(unsigned short port, const void *addr,
         unsigned long count);
 void outsl(unsigned short port, const void *addr,
         unsigned long count);
+void io_wait();

src/kernel/irq_table.s

@@ -0,0 +1,138 @@
+.globl irq0
+irq0:
+	cli 
+	push $0
+	push $0
+	jmp irq_common
+
+.globl irq1
+irq1:
+	cli 
+	push $0
+	push $1
+	jmp irq_common
+
+.globl irq2
+irq2:
+	cli 
+	push $0
+	push $2
+	jmp irq_common
+
+.globl irq3
+irq3:
+	cli 
+	push $0
+	push $3
+	jmp irq_common
+
+.globl irq4
+irq4:
+	cli 
+	push $0
+	push $4
+	jmp irq_common
+
+.globl irq5
+irq5:
+	cli 
+	push $0
+	push $5
+	jmp irq_common
+
+.globl irq6
+irq6:
+	cli 
+	push $0
+	push $6
+	jmp irq_common
+
+.globl irq7
+irq7:
+	cli 
+	push $0
+	push $7
+	jmp irq_common
+
+.globl irq8
+irq8:
+	cli 
+	push $0
+	push $8
+	jmp irq_common
+
+.globl irq9
+irq9:
+	cli 
+	push $0
+	push $9
+	jmp irq_common
+
+.globl irq10
+irq10:
+	cli 
+	push $0
+	push $10
+	jmp irq_common
+
+.globl irq11
+irq11:
+	cli 
+	push $0
+	push $11
+	jmp irq_common
+
+
+.globl irq12
+irq12:
+	cli 
+	push $0
+	push $12
+	jmp irq_common
+
+.globl irq13
+irq13:
+	cli 
+	push $0
+	push $13
+	jmp irq_common
+
+.globl irq14
+irq14:
+	cli 
+	push $0
+	push $14
+	jmp irq_common
+
+.globl irq15
+irq15:
+	cli 
+	push $0
+	push $15
+	jmp irq_common
+
+irq_common:
+	pusha
+
+	mov %ds, %ax
+	push %eax
+
+	mov $0x10, %ax
+	mov %ax, %ds
+	mov %ax, %es
+	mov %ax, %fs
+	mov %ax, %gs
+
+	call irq_handler
+
+	pop %eax
+
+	mov %ax, %ds
+	mov %ax, %es
+	mov %ax, %fs
+	mov %ax, %gs
+
+	popa
+	add  $8, %esp  # cleans push error and irs code
+	sti
+	iret # pops 5 things at once: CS, EIP, EFLAGS, SS, and ESP

src/kernel/irs_table.s

@@ -0,0 +1,256 @@
+/*
+* Interupt handlers
+*/
+
+.globl irs0
+irs0:
+	cli 
+	push $0
+	push $0
+	jmp irs_common
+
+.globl irs1
+irs1:
+	cli 
+	push $0
+	push $1
+	jmp irs_common
+
+.globl irs2
+irs2:
+	cli 
+	push $0
+	push $2
+	jmp irs_common
+
+.globl irs3
+irs3:
+	cli 
+	push $0
+	push $3
+	jmp irs_common
+
+.globl irs4
+irs4:
+	cli 
+	push $0
+	push $4
+	jmp irs_common
+
+.globl irs5
+irs5:
+	cli 
+	push $0
+	push $5
+	jmp irs_common
+
+.globl irs6
+irs6:
+	cli 
+	push $0
+	push $6
+	jmp irs_common
+
+.globl irs7
+irs7:
+	cli 
+	push $0
+	push $7
+	jmp irs_common
+
+.globl irs8
+irs8:
+	cli 
+	push $0
+	push $8
+	jmp irs_common
+
+.globl irs9
+irs9:
+	cli 
+	push $0
+	push $9
+	jmp irs_common
+
+.globl irs10
+irs10:
+	cli 
+	push $0
+	push $10
+	jmp irs_common
+
+.globl irs11
+irs11:
+	cli 
+	push $0
+	push $11
+	jmp irs_common
+
+.globl irs12
+irs12:
+	cli 
+	push $0
+	push $12
+	jmp irs_common
+
+.globl irs13
+irs13:
+	cli 
+	push $13
+	jmp irs_common
+
+.globl irs14
+irs14:
+	cli 
+	push $0
+	push $14
+	jmp irs_common
+
+.globl irs15
+irs15:
+	cli 
+	push $0
+	push $15
+	jmp irs_common
+
+.globl irs16
+irs16:
+	cli 
+	push $0
+	push $16
+	jmp irs_common
+
+.globl irs17
+irs17:
+	cli 
+	push $0
+	push $17
+	jmp irs_common
+
+.globl irs18
+irs18:
+	cli 
+	push $0
+	push $18
+	jmp irs_common
+
+.globl irs19
+irs19:
+	cli 
+	push $0
+	push $19
+	jmp irs_common
+
+.globl irs20
+irs20:
+	cli 
+	push $0
+	push $20
+	jmp irs_common
+
+.globl irs21
+irs21:
+	cli 
+	push $0
+	push $21
+	jmp irs_common
+
+.globl irs22
+irs22:
+	cli 
+	push $0
+	push $22
+	jmp irs_common
+
+.globl irs23
+irs23:
+	cli 
+	push $0
+	push $23
+	jmp irs_common
+
+.globl irs24
+irs24:
+	cli 
+	push $0
+	push $24
+	jmp irs_common
+
+.globl irs25
+irs25:
+	cli 
+	push $0
+	push $25
+	jmp irs_common
+
+.globl irs26
+irs26:
+	cli 
+	push $0
+	push $26
+	jmp irs_common
+
+.globl irs27
+irs27:
+	cli 
+	push $0
+	push $27
+	jmp irs_common
+
+.globl irs28
+irs28:
+	cli 
+	push $0
+	push $28
+	jmp irs_common
+
+.globl irs29
+irs29:
+	cli 
+	push $0
+	push $29
+	jmp irs_common
+
+.globl irs30
+irs30:
+	cli 
+	push $0
+	push $30
+	jmp irs_common
+
+.globl irs31
+irs31:
+	cli 
+	push $0
+	push $31
+	jmp irs_common
+
+
+irs_common:
+	pusha 				# Pushes edi,esi,ebp,esp,ebx,edx,ecx,eax
+
+
+	mov %ds, %ax
+	push %eax
+
+	/* load the kernel data segment descriptor*/
+
+	mov $0x10, %ax
+	mov %ax, %ds
+	mov %ax, %es
+	mov %ax, %fs
+	mov %ax, %gs
+
+	call irs_handler
+
+	pop %eax
+
+	mov %ax, %ds
+	mov %ax, %es
+	mov %ax, %fs
+	mov %ax, %gs
+
+	popa
+	add  $8, %esp  # cleans push error and irs code
+	sti
+	iret # pops 5 things at once: CS, EIP, EFLAGS, SS, and ESP

src/kernel/kernel.cpp

@@ -1,136 +1,60 @@
 #include "kernel.h"
-/**
- *      simple delay function 
- **/
-void delay(int t){
-    volatile int i,j;
-    for(i=0;i<t;i++)
-        for(j=0;j<25000;j++)
-            asm("NOP");
-}
-
-class Test {
-    public:
-         Test();
-        void printMe();
-         ~Test();
-};
+#define GB4 524288
+#define GB2 262144
+extern "C" void kernel_main (void);
+extern "C" void putPixel(int pos_x, int pos_y, unsigned char VGA_COLOR , unsigned char addr , unsigned char pixelWidth, unsigned pitch );
 
 
-Test::Test(){
-    kterm_writestring("Create a test object\n");
-};
-
-void Test::printMe(){
-    kterm_writestring("testObject.printMe()\n");
-}
-
-Test::~Test(){
-    kterm_writestring("Destroy testObject! Bye bye\n");
-}
-
-#define PORT 0x3f8 
-static int init_serial() {
-   outb(PORT + 1, 0x00);    // Disable all interrupts
-   outb(PORT + 3, 0x80);    // Enable DLAB (set baud rate divisor)
-   outb(PORT + 0, 0x03);    // Set divisor to 3 (lo byte) 38400 baud
-   outb(PORT + 1, 0x00);    //                  (hi byte)
-   outb(PORT + 3, 0x03);    // 8 bits, no parity, one stop bit
-   outb(PORT + 2, 0xC7);    // Enable FIFO, clear them, with 14-byte threshold
-   outb(PORT + 4, 0x0B);    // IRQs enabled, RTS/DSR set
-   outb(PORT + 4, 0x1E);    // Set in loopback mode, test the serial chip
-   outb(PORT + 0, 0xAE);    // Test serial chip (send byte 0xAE and check if serial returns same byte)
- 
-   // Check if serial is faulty (i.e: not same byte as sent)
-   if(inb(PORT + 0) != 0xAE) {
-      return 1;
-   }
- 
-   // If serial is not faulty set it in normal operation mode
-   // (not-loopback with IRQs enabled and OUT#1 and OUT#2 bits enabled)
-   outb(PORT + 4, 0x0F);
-   return 0;
-}
-
-
-int is_transmit_empty() {
-   return inb(PORT + 5) & 0x20;
-}
- 
-void write_serial(char a) {
-   while (is_transmit_empty() == 0);
- 
-   outb(PORT,a);
-}
-
-int serial_received() {
-   return inb(PORT + 5) & 1;
-}
- 
-char read_serial() {
-   while (serial_received() == 0);
- 
-   return inb(PORT);
-}
-
-
-void test_serial(){
-        /** Serial test **/
-        kterm_writestring("Writing to COM1 serial port:");
-        init_serial();
-        write_serial('A');
-        write_serial('B');
-        write_serial('C');
-        write_serial('D');
-        write_serial('E');
-
-        char Character_received = read_serial();
-        kterm_writestring("\n");
-        kterm_writestring("received from COM 1: \n");
-        kterm_put(Character_received);
-
-        kterm_writestring("\n");
-}
-
-
-extern "C" {
-    void kernel_main (void) {
+    extern "C" void early_main(unsigned long magic, unsigned long addr){
         /** initialize terminal interface */ 
-        kterm_init();
+       // kterm_init();
         
-        /** Wrtite stuff to the screen to test the terminal**/ 
-        kterm_writestring("Hello world!\n");
-        kterm_writestring("We got newline support!\n");
-
-        /** Test scrolling **/
-        for(int i=0; i < 5; i++){
-            delay(500);
-            kterm_writestring("We have implemented terminal scrolling!\n");
+        printf("Magic flag 0x%8x\n", magic);
+        printf("Magic must be 0x%8x\n", MULTIBOOT_BOOTLOADER_MAGIC);
+        if (magic != MULTIBOOT_BOOTLOADER_MAGIC){
+            printf("Invalid magic number: 0x%8x\n",  magic);
+            return;
         }
 
+        CheckMBT(  (multiboot_info_t *) addr);
 
-        /** Test objective cpp **/
-        kterm_writestring("Testing C++ object support\n");
-        auto testObject = Test();
-        testObject.printMe();
+        multiboot_info_t* mbt = (multiboot_info_t*) addr;
 
-        /** Setup the MMU **/
-        kterm_writestring("Starting MMU...\n");
-        auto mmu = MMU();
-        mmu.enable();
-        kterm_writestring("MMU enabled!\n");
+        /* Are mmap_* valid? */
+        if (CHECK_FLAG(mbt->flags, 6)){
+            PhysicalMemoryManager_initialise( mbt->mmap_addr,  GB2/* Seriously dangerous hardcoded memory value*/);
+            PhysicalMemoryManager_initialise_available_regions(mbt->mmap_addr, mbt->mmap_addr + mbt->mmap_length);
+            PhysicalMemoryManager_deinitialise_kernel();
+            extern uint8_t* kernel_begin;
+            extern uint8_t* kernel_end;
+
+            printf("Kernel MemoryMap:\n");
+            printf("kernel: 0x%x - 0x%x\n", &kernel_begin , &kernel_end);         
+        }
+
+        initGDT();
 
 
-
-
-        /** Lets start using the serial port for debugging .. **/
-        // Hopefully once we go into realmode or do something that
-        // cause the screen to go black.. this serial comms part will give
-        // some situational awareness
-        //Serial serialbus = Serial::init();
-
-        test_serial();
+      kernel_main();
 
        
     }
+
+    extern "C" void kernel_main (void) {
+
+        printf("call to init serial\n");
+        init_serial();
+
+
+        while (true){
+            //Read time indefinetely 
+            read_rtc();
+            printf( "UTC time: %02d-%02d-%02d %02d:%02d:%02d  [ Formatted as YY-MM-DD h:mm:ss]\r" ,year, month, day, hour, minute, second);
+            delay(1000);
         }
+            
+
+        
+       
+    }   
+

src/kernel/kernel.h

@@ -1,7 +1,33 @@
 #pragma once
 extern "C"{
    #include "../libc/include/string.h" 
-#include "arch/i386/tty/kterm.h"
 }
-#include "MMU.h"
+#include "vga/VBE.h"
+#include "tty/kterm.h"
+
+#include "./bootloader/multiboot.h"
+#include "bootcheck.h"
+#include "memory/PhysicalMemoryManager.h"
+
+#include "gdt/gdtc.h"
+#include "idt/idt.h"
+
 #include "io.h"
+#include "time.h"
+#include "cpu.h"
+#include "serial.h"
+
+#define CHECK_FLAG(flags, bit) ((flags) & (1 <<(bit)))
+#define PANIC(message) {  return; }
+
+
+/* This needs to be moved! */
+/**
+ *      simple delay function 
+ **/
+void delay(int t){
+    volatile int i,j;
+    for(i=0;i<t;i++)
+        for(j=0;j<25000;j++)
+            asm("NOP");
+}

src/kernel/kstructures/bitmap.h

@@ -0,0 +1,40 @@
+#pragma once 
+#include <stddef.h>
+#include <stdint.h>
+
+
+inline void bitmap_set( uint32_t* map , int index )
+{
+    map[index/32] |= (1 << (index % 32));
+}
+
+inline void bitmap_unset(uint32_t* map , int index)
+{
+    map[index/32] &= ~(1 << (index % 32));
+}
+
+inline int bitmap_first_unset( uint32_t* map , int size)
+{
+    uint32_t rem_bits = size % 32;
+    for(uint32_t i = 0; i < size/32; i++)
+    {
+        if(map[i] != 0xFFFFFFFF){
+            for(int j = 0; j < 32; j++){
+                if(!(map[i] & (1<< j))){
+                    return (i*32) + j;
+                }
+            }
+        }
+    }
+
+    if(rem_bits){
+        for(uint32_t j = 0; j < rem_bits; j++){
+            if(!(map[size/32] & (1 << j ))){
+                return size + j; // Original author divided size by 32 and then multiplied it by 32 which is a net zero calculation ?!?
+            }
+        }
+    }
+
+    return -1;
+    
+}

src/kernel/linker.ld

@@ -6,10 +6,11 @@ ENTRY(_start)
    kernel image. */
 SECTIONS
 {
+	
 	/* Begin putting sections at 1 MiB, a conventional place for kernels to be
 	   loaded at by the bootloader. */
 	. = 1M;
- 
+ 	kernel_begin = .;
 	/* First put the multiboot header, as it is required to be put very early
 	   early in the image or the bootloader won't recognize the file format.
 	   Next we'll put the .text section. */
@@ -40,4 +41,7 @@ SECTIONS
  
 	/* The compiler may produce other sections, by default it will put them in
 	   a segment with the same name. Simply add stuff here as needed. */
+
+	kernel_end = .;
 }
+

src/kernel/memory/PageDirectory.cpp

@@ -1,9 +1,10 @@
-#include "MMU.h"
+#include "PageDirectory.h"
+#include <stdint.h>
 
 
 
-void MMU::enable(){
-
+void PageDirectory::enable(){
+    // https://wiki.osdev.org/Setting_Up_Paging
     //set each entry to not present
     int i;
     for(i = 0; i < 1024; i++)
@@ -33,3 +34,14 @@ void MMU::enable(){
     loadPageDirectory(this->page_directory);
     enablePaging();
 }
+
+/*
+void IdentityPaging(uint32_t *first_pte, vaddr from, int size)
+{
+    from = from & 0xFFFFF000; // Discard the bits we don't want
+    for (; size > 0; from += 4096, first_pte++)
+    {
+        *first_pte = from | 1; // makr page present.
+    }
+}
+*/

src/kernel/memory/PageDirectory.h

@@ -0,0 +1,28 @@
+#pragma once 
+#include <stdint.h>
+
+extern "C" void loadPageDirectory (uint32_t* addr );
+extern "C" void enablePaging();
+typedef uintptr_t address_t;
+
+
+#define KB 1024
+
+static const int MAX_PAGES =  1024 * KB; // 4GB , 4kB/page
+static volatile address_t pmem_stack[MAX_PAGES];
+static volatile address_t pmem_stack_top = MAX_PAGES; // top down allocation
+
+
+struct page_directory_entry {};
+struct page_table_entry{};
+
+
+
+class PageDirectory {
+    public:
+    void enable ();
+    
+    private:
+    uint32_t page_directory[1024] __attribute__((aligned(4096)));
+    uint32_t first_page_table[1024] __attribute__((aligned(4096)));
+};

src/kernel/memory/PageFrameAllocator.cpp

@@ -0,0 +1,38 @@
+#include "PageFrameAllocator.h"
+
+
+MemoryInfo memInfo {};
+void mapMultibootMemoryMap( multiboot_info_t *mbt){
+    printf("mmap_addr = 0x%x, mmap_length = 0x%x\n",
+    (unsigned) mbt->mmap_addr, (unsigned) mbt->mmap_length);
+    multiboot_memory_map_t *mmap = (multiboot_memory_map_t*) mbt->mmap_addr;
+
+    for (;  (unsigned long) mmap < mbt->mmap_addr + mbt->mmap_length;  mmap = (multiboot_memory_map_t *) ((unsigned long) mmap + mmap->size + sizeof(mmap->size))){
+
+            if ( mmap->type == MULTIBOOT_MEMORY_AVAILABLE){
+                memInfo.memorySizeInBytes +=  mmap->len;   
+            } else {
+                memInfo.reservedMemoryInBytes += mmap->len;
+            }
+            
+            print_Multiboot_memory_Map(mmap);
+            
+        }
+    uint32_t memorySizeInGiB = memInfo.memorySizeInBytes / 1073741824; 
+
+    printf("Available Memory: 0x%x bytes, 0x%x GiB\n",  memInfo.memorySizeInBytes, memorySizeInGiB );
+    printf("Reserved Memory: 0x%x bytes\n",  memInfo.reservedMemoryInBytes );
+
+}
+
+void print_Multiboot_memory_Map(multiboot_memory_map_t* mmap){
+    printf(
+        "size = 0x%x, base_addr = 0x%x%08x, length = 0x%x%08x, type = 0x%x\n",
+        (unsigned) mmap->size,
+        (unsigned) (mmap->addr >> 32),
+        (unsigned) (mmap->addr & 0xffffffff),
+        (unsigned) (mmap->len >> 32),
+        (unsigned) (mmap->len & 0xffffffff),
+        (unsigned) mmap->type
+    );
+}

src/kernel/memory/PageFrameAllocator.h

@@ -0,0 +1,20 @@
+#pragma once
+#include "../arch/i386/tty/kterm.h"
+
+#include <stdint.h>
+#include "../bootloader/multiboot.h"
+
+struct MemoryInfo{
+    uint32_t memorySizeInBytes = 0;
+    uint32_t reservedMemoryInBytes = 0;
+};
+
+
+extern void *kernel_begin;
+extern void *kernel_end;
+
+
+
+
+void print_Multiboot_memory_Map(multiboot_memory_map_t*);
+void mapMultibootMemoryMap(multiboot_info_t*);

src/kernel/memory/PhysicalMemoryManager.cpp

@@ -0,0 +1,118 @@
+#include "PhysicalMemoryManager.h"
+
+size_t mem_size = 0;
+int used_blocks = 0;
+size_t max_blocks = 0;
+uint32_t* pmmap = 0;
+size_t pmmap_size = 0; 
+
+
+void PhysicalMemoryManager_initialise(uint32_t physicalmemorymap_address, size_t size )
+{
+    mem_size = size;
+    max_blocks = KB_TO_BLOCKS(mem_size);
+
+    used_blocks = max_blocks;
+
+    pmmap = (uint32_t*) physicalmemorymap_address;
+
+    if(max_blocks % BLOCKS_PER_WORD)
+        pmmap_size++;
+    
+    memset(pmmap, 0xFF, pmmap_size);
+}
+
+void PhysicalMemoryManager_region_initialise(uint32_t base, size_t size)
+{
+    size_t blocks = size /BLOCK_SIZE;
+    uint32_t align = base / BLOCK_SIZE;
+
+    for(size_t i = 0 ; i < blocks; i ++)
+    {
+        bitmap_unset(pmmap, align++);
+        used_blocks--;
+    }
+
+    bitmap_set(pmmap, 0);
+
+}
+
+void PhysicalMemoryManager_region_deinitialise(uint32_t base, size_t size )
+{
+    size_t blocks = size / BLOCK_SIZE;
+    uint32_t align = base / BLOCK_SIZE;
+
+    for(size_t i = 0 ; i < blocks; i++ )
+    {
+        bitmap_set(pmmap, align++);
+        used_blocks++;
+    }
+
+
+}
+
+void PhysicalMemoryManager_initialise_available_regions(uint32_t mmap_, uint32_t mmap_end_)
+{
+    multiboot_memory_map_t *mmap = (multiboot_memory_map_t*)mmap_;
+    multiboot_memory_map_t *mmap_end= (multiboot_memory_map_t*) mmap_end_;
+
+    for(int i = 0; mmap < mmap_end ; mmap++, i++)
+    {   
+        if(mmap->type == MULTIBOOT_MEMORY_AVAILABLE)
+        {
+            PhysicalMemoryManager_region_initialise((uint32_t) mmap->addr, (size_t) mmap->len);
+        }
+    }
+
+}
+
+void PhysicalMemoryManager_deinitialise_kernel()
+{
+    extern uint8_t kernel_begin;
+    extern uint8_t kernel_end;
+
+    size_t kernel_size = (size_t) &kernel_end - (size_t) &kernel_begin;
+
+    uint32_t pmmap_size_aligned = pmmap_size;
+    if(!IS_ALIGNED(pmmap_size_aligned, BLOCK_SIZE))
+    {
+        pmmap_size_aligned = ALIGN(pmmap_size_aligned, BLOCK_SIZE);
+    }
+    
+    PhysicalMemoryManager_region_deinitialise((uint32_t) &kernel_begin, kernel_size);
+    PhysicalMemoryManager_region_deinitialise((uint32_t) &kernel_end, pmmap_size_aligned);
+    
+}
+
+void* PhysicalMemoryManager_allocate_block()
+{
+    if(used_blocks - max_blocks <= 0)
+    {
+        return 0;
+    }
+
+    int p_index = bitmap_first_unset(pmmap, p_index );
+
+    if(p_index == -1){
+        return 0;
+    }
+
+    bitmap_set(pmmap, p_index);
+    used_blocks++;
+
+    return (void*) (BLOCK_SIZE * p_index);
+}
+
+void PhysicalMemoryManager_free_block(void* p){
+    if(p==0){
+        return ;
+    }
+
+    uint32_t p_addr = (uint32_t) p;
+
+    int index  = p_addr / BLOCK_SIZE;
+    bitmap_unset(pmmap, index);
+
+    used_blocks--;
+
+}

src/kernel/memory/PhysicalMemoryManager.h

@@ -0,0 +1,34 @@
+#pragma once
+
+#include "../bootloader/multiboot.h"
+#include <stdint.h>
+#include <stddef.h>
+#include "../../libc/include/mem.h"
+#include "../kstructures/bitmap.h"
+
+
+#define BLOCK_SIZE 4092
+#define BLOCKS_PER_WORD 32
+
+#define KB_TO_BLOCKS(x) (((x) * 1024 ) / BLOCK_SIZE)
+#define IS_ALIGNED(addr, align) !((addr) & ~((align) - 1))
+#define ALIGN(addr, align) (((addr) & ~((align) - 1 )) + (align))
+
+
+extern void PhysicalMemoryManager_initialise(uint32_t, size_t);
+
+extern void PhysicalMemoryManager_region_initialise(uint32_t, size_t);
+extern void PhysicalMemoryManager_region_deinitialise(uint32_t,size_t);
+
+extern void PhysicalMemoryManager_initialise_available_regions(uint32_t, uint32_t);
+extern void PhysicalMemoryManager_deinitialise_kernel();
+
+extern void* PhysicalMemoryManager_allocate_block();
+extern void PhysicalMemoryManager_free_block(void* p);
+
+
+extern size_t mem_size;
+extern int used_blocks;
+extern size_t max_blocks;
+extern uint32_t* pmmap;
+extern size_t pmmap_size ; 

src/kernel/memory/SlabAllocator.h

@@ -0,0 +1,33 @@
+#pragma once
+/**
+ *  We'll need something to this effect to allocate memory in the kernel
+ *  this will hopefully someday implement a full slab allocator 
+ **/
+enum SlabState {
+    empty,
+    partial,
+    full 
+};
+
+class CacheSlab {
+    const int SlabSize = 4000;
+    void* start = 0x0;
+};
+
+
+class Allocator {
+
+    public:
+        Allocator();
+        ~Allocator();
+
+        void* kmalloc( int size );
+        void kfree (void* address);
+
+    private:
+        CacheSlab** _cache;
+
+
+
+
+};

src/kernel/paging.s

@@ -0,0 +1,20 @@
+.globl enablePaging
+enablePaging:
+	push %ebp
+	mov %esp, %ebp
+	mov %cr0, %eax
+	or $0x80000000, %eax
+	mov %eax, %cr0
+	mov %ebp, %esp
+	pop %ebp
+	ret
+
+.globl loadPageDirectory
+loadPageDirectory:
+	push %ebp
+	mov %esp, %ebp
+	mov 8(%esp), %eax
+	mov %eax, %cr3
+	mov %ebp, %esp
+	pop %ebp
+	ret

src/kernel/pci.cpp

@@ -0,0 +1,108 @@
+#include "pci.h"
+
+uint16_t ConfigReadWord (uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset){
+    uint32_t address;
+    uint32_t lbus = (uint32_t) bus;
+    uint32_t lslot = (uint32_t) slot;
+    uint32_t lfunc = (uint32_t) func;
+    uint16_t tmp = 0;
+
+    /* Create configuration address as per Figure 1 */
+    address = (uint32_t) ((lbus << 16) |  (lslot << 11) | (lfunc << 8) | (offset & 0xFC) |((uint32_t) 0x80000000) );
+    /*write out the address */ 
+    outl(CONFIG_ADDRESS, address);
+    /* read in the data */
+    /* (offset & 2 ) * 8 ) = o will choosse the first word of the 32 bits register*/
+    tmp = (uint16_t)((inl(CONFIG_DATA)) >> ((offset & 2) * 8) & 0xFFFF);
+    return (tmp);
+}
+
+uint16_t CheckVendor (uint8_t bus, uint8_t slot) {
+    uint16_t vendor, device;
+    /* 
+        Try and read the first configuration register. Since there ar no
+        vendors that == 0xFFFF, it must be a non-existent device.
+    */
+   if((vendor = ConfigReadWord(bus, slot, 0,0)) != 0xFFFF) {
+       device = ConfigReadWord(bus, slot, 0,2);
+        // Possible read more config values ...
+   } return (vendor);
+}
+
+void checkDevice (uint8_t bus, uint8_t device ) {
+    uint8_t function = 0;
+
+    uint16_t vendorID = CheckVendor(bus, device);
+    if (vendorID == 0xFFFF) {
+        return;
+    }
+
+    checkFunction (bus, device, function );
+    headerType = getHeaderType(bus, device, function );
+    if( (headerType & 0x80) != 0) {
+        /* It is  a multi-function device, so check remaining functions */
+        for (function = 1; function < 8; function++){
+            if (CheckVendor(bus, device)!= 0xFFFF){
+                checkFunction(bus, device, function );
+            } 
+        }
+    }
+
+}
+
+
+void checkFunction (uint8_t bus, uint8_t device, uint8_t function ){
+    uint8_t baseClass;
+    uint8_t subClass;
+    uint8_t secondaryBus;
+
+    baseClass = getBaseClass(bus, device, function);
+    subClass = getSubClass (bus, device, function );
+    if ( (baseClass == 0x06) && (subClass == 0x04)){
+        secondaryBus = getSecondaryBus(bus,device, function);
+        checkBus(secondaryBus);
+    }
+}
+
+
+// Brute-force scan
+void checkAllBuses (){
+    uint16_t bus;
+    uint8_t device;
+
+    for(bus = 0; bus < 256; bus++){
+        for(device = 0; device < 32; device++){
+            checkDevice(bus,device);
+        }
+    }
+}
+
+// Recursive scan
+void checkBus (uint8_t bus){
+    uint8_t device;
+
+    for(device = 0; device < 32; device ++){
+        checkDevice(bus,device);
+    }
+}
+
+void checkAllBuses(){
+    uint8_t function; 
+    uint8_t bus;
+
+    headerType = getHeaderType(0,0,0);
+    if ( (headerType & 0x80) == 0 ){
+        /* Single PCI host controller */
+        checkBus(0);
+    } else{
+        /* Multiple PCI host controllers */
+        for (function = 0; function < 8; function++){
+            if( CheckVendor(0,0) != 0xFFFF) {
+                break;
+            }
+            bus = function;
+            checkBus(bus);
+        }
+    }
+
+}

src/kernel/pci.h

@@ -0,0 +1,58 @@
+#pragma once
+#include <stdint.h>
+#include "io.h"
+// Configuration Space Access Mechanism #1
+#define CONFIG_ADDRESS 0xCF8 // Configuration adress that is to be accessed
+#define CONFIG_DATA 0xCFC // Will do the actual configuration operation
+
+/*
+CONFIG_ADDRESS 
+
+32 bit register 
+
+bit 31      Enable bit      (Should CONFIG_DATA be translatedc to configuration cycles)      
+bit 30 - 24 Reserved    
+bit 23 - 16 Bus Number      (Choose a specific PCI BUS)
+bit 15 - 11 Device Number   (Selects specific device one the pci bus)
+bit 10 - 8  Function Number (Selects a specific function in a device)
+bit 7 -  0  Register Offset (Offset in the configuration space of 256 Bytes ) NOTE: lowest two bits will always be zero 
+
+*/
+
+
+/* 
+PCI Device structure
+
+Register    offset  bits 31-24  bits 23-16  bits 15-8   bits 7-0
+00          00      Device ID   <----       Vendor  ID  <-------
+01          04      Status      <----       Command     <-------
+02          08      Class code  Sub class   Prog IF     Revision ID
+03          0C      BIST        Header Type Ltncy Timer Cache line Size
+04          10      Base address #0 (BAR0) 
+05          14      Base address #1 (BAR1) 
+06          18      Base address #2 (BAR2) 
+07          1C      Base address #3 (BAR3)
+08          20      Base address #4 (BAR4)
+09          24      Base address #5 (BAR5)
+0A          28      Cardbus CIS Pointer
+0B          2C      Subsystem ID <------   Subsystem Vendor ID  <-------
+0C          30      Expansion ROM base address
+0D          34      Reserved     <-------   Capabilities Pointer <------
+0E          38      Reserved    <-------    <--------   <--------
+0F          3C      Max ltncy   Min Grant   Interrupt PIN   Interrupt Line
+
+*/
+
+
+/*
+The idea for now is to support the minimal things necessary to find ATA supported drives
+ */
+
+
+// Lets write some boiler plate configuration code
+
+uint16_t ConfigReadWord (uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset);
+
+uint16_t CheckVendor (uint8_t bus, uint8_t slot);
+
+void checkDevice (uint8_t bus, uint8_t device );

src/kernel/pic/pic.cpp

@@ -0,0 +1,62 @@
+#include "pic.h"
+
+extern "C" void PIC_sendEOI (unsigned char irq){
+    if(irq >= 8)
+        outb(PIC2_COMMAND, PIC_EOI);
+    outb(PIC1_COMMAND, PIC_EOI);
+}
+
+/* Helper func */
+static uint16_t __pic_get_irq_reg(int ocw3)
+{
+    /* OCW3 to PIC CMD to get the register values.  PIC2 is chained, and
+     * represents IRQs 8-15.  PIC1 is IRQs 0-7, with 2 being the chain */
+    outb(PIC1_COMMAND, ocw3);
+    outb(PIC2_COMMAND, ocw3);
+    return (inb(PIC2_COMMAND) << 8) | inb(PIC1_COMMAND);
+}
+ 
+/* Returns the combined value of the cascaded PICs irq request register */
+uint16_t pic_get_irr(void)
+{
+    return __pic_get_irq_reg(PIC_READ_IRR);
+}
+ 
+/* Returns the combined value of the cascaded PICs in-service register */
+uint16_t pic_get_isr(void)
+{
+    return __pic_get_irq_reg(PIC_READ_ISR);
+}
+
+
+void PIC_remap (int offset1, int offset2 ){
+    unsigned char a1, a2;
+
+    a1 = inb(PIC1_DATA);
+    a2 = inb(PIC2_DATA);
+
+
+    // Start initialization
+
+    outb(PIC1_COMMAND, ICW1_INIT | ICW1_ICW4);
+    io_wait();
+    outb(PIC2_COMMAND, ICW1_INIT | ICW1_ICW4);
+    io_wait();
+    outb(PIC1_DATA, offset1);
+    io_wait();
+    outb(PIC2_DATA, offset2);
+    io_wait();
+    outb(PIC1_DATA, 4);
+    io_wait();
+    outb(PIC2_DATA, 2);
+    io_wait();
+
+    outb(PIC1_DATA, ICW4_8086);
+    io_wait();
+    outb(PIC2_DATA, ICW4_8086);
+    io_wait();
+
+    outb(PIC1_DATA, a1);
+    outb(PIC2_DATA, a2);
+
+}

src/kernel/pic/pic.h

@@ -0,0 +1,57 @@
+#pragma once 
+#include "../io.h"
+
+#define PIC1		0x20		/* IO base address for master PIC */
+#define PIC2		0xA0		/* IO base address for slave PIC */
+#define PIC1_COMMAND	PIC1
+#define PIC1_DATA	(PIC1+1)
+#define PIC2_COMMAND	PIC2
+#define PIC2_DATA	(PIC2+1)
+
+
+#define ICW1_ICW4	0x01		/* ICW4 (not) needed */
+#define ICW1_SINGLE	0x02		/* Single (cascade) mode */
+#define ICW1_INTERVAL4	0x04		/* Call address interval 4 (8) */
+#define ICW1_LEVEL	0x08		/* Level triggered (edge) mode */
+#define ICW1_INIT	0x10		/* Initialization - required! */
+ 
+#define ICW4_8086	0x01		/* 8086/88 (MCS-80/85) mode */
+#define ICW4_AUTO	0x02		/* Auto (normal) EOI */
+#define ICW4_BUF_SLAVE	0x08		/* Buffered mode/slave */
+#define ICW4_BUF_MASTER	0x0C		/* Buffered mode/master */
+#define ICW4_SFNM	0x10		/* Special fully nested (not) */
+
+#define PIC_EOI 0x20
+#define PIC_READ_IRR 0x0a    /* OCW3 irq ready next CMD read */
+#define PIC_READ_ISR 0x0b    /* OCW3 irq service next CMD read */
+
+extern "C"{
+
+extern void irq0 ();
+extern void irq1 ();
+extern void irq2 ();
+extern void irq3 ();
+extern void irq4 ();
+extern void irq5 ();
+extern void irq6 ();
+extern void irq7 ();
+extern void irq8 ();
+extern void irq9 ();
+extern void irq10 ();
+extern void irq11 ();
+extern void irq12 ();
+extern void irq13 ();
+extern void irq14 ();
+extern void irq15 ();
+
+void PIC_sendEOI (unsigned char irq);
+
+}
+
+
+//static uint16_t __pic_get_irq_reg(int ocw3);
+uint16_t pic_get_irr(void);
+uint16_t pic_get_isr(void);
+
+
+void PIC_remap (int offset1, int offset2 );

src/kernel/serial.h

@@ -0,0 +1,133 @@
+#pragma once
+#include "tty/kterm.h"
+#include "io.h"
+
+#define PORT 0x3f8 
+
+inline static int init_serial() {
+   outb(PORT + 1, 0x00);    // Disable all interrupts
+   outb(PORT + 3, 0x80);    // Enable DLAB (set baud rate divisor)
+   outb(PORT + 0, 0x03);    // Set divisor to 3 (lo byte) 38400 baud
+   outb(PORT + 1, 0x00);    //                  (hi byte)
+   outb(PORT + 3, 0x03);    // 8 bits, no parity, one stop bit
+   outb(PORT + 2, 0xC7);    // Enable FIFO, clear them, with 14-byte threshold
+   outb(PORT + 4, 0x0B);    // IRQs enabled, RTS/DSR set
+   outb(PORT + 4, 0x1E);    // Set in loopback mode, test the serial chip
+   outb(PORT + 0, 0xAE);    // Test serial chip (send byte 0xAE and check if serial returns same byte)
+ 
+   // Check if serial is faulty (i.e: not same byte as sent)
+   if(inb(PORT + 0) != 0xAE) {
+      return 1;
+   }
+ 
+   // If serial is not faulty set it in normal operation mode
+   // (not-loopback with IRQs enabled and OUT#1 and OUT#2 bits enabled)
+   outb(PORT + 4, 0x0F);
+   return 0;
+}
+
+inline int is_transmit_empty() {
+   return inb(PORT + 5) & 0x20;
+}
+ 
+inline void write_serial(char a) {
+   while (is_transmit_empty() == 0);
+ 
+   outb(PORT,a);
+}
+
+inline int serial_received() {
+   return inb(PORT + 5) & 1;
+}
+ 
+inline char read_serial() {
+   while (serial_received() == 0);
+ 
+   return inb(PORT);
+}
+
+inline void print_serial(const char* string ){
+    for(size_t i = 0; i < strlen(string); i ++){
+        write_serial(string[i]);
+    }
+}
+
+
+inline void printf_serial ( const char *format, ...) {
+   
+    char **arg = (char **)&format;
+    int c;
+    char buf[20];
+
+    arg++;
+    
+    while ((c = *format++) != 0){
+        if( c != '%')
+            write_serial(c);
+        else{
+            char *p, *p2;
+            int pad0 = 0, pad = 0;
+
+            c = *format++;
+            if(c =='0'){
+                pad0 = 1;
+                c = *format++;
+            }
+
+            if ( c >= '0' && c <= '9'){
+                pad = c - '0';
+                c = *format++;
+            }
+
+            switch (c)
+            {
+            case 'd':
+             
+            case 'u':
+            case 'x':
+                itoa(buf, c, *((int *) arg++));
+
+                p = buf;
+                goto string;
+                break;
+            
+            case 's':
+                p = *arg++;
+                if(!p)
+                    p = "(null)";
+                
+                string: 
+                    for (p2 = p; *p2; p2++);
+                    for (; p2 < p + pad; p2++)
+                        write_serial(pad0 ? '0': ' ');
+                    while (*p)
+                        write_serial(*p++);
+                    break;
+
+
+            default:
+                write_serial(*((int *)arg++));
+                break;
+            }
+        }
+    }
+}
+
+
+inline void test_serial(){
+        /** Serial test **/
+        kterm_writestring("Writing to COM1 serial port:");
+        init_serial();
+        write_serial('A');
+        write_serial('B');
+        write_serial('C');
+        write_serial('D');
+        write_serial('E');
+
+        char Character_received = read_serial();
+        kterm_writestring("\n");
+        kterm_writestring("received from COM 1: \n");
+        kterm_put(Character_received);
+
+        kterm_writestring("\n");
+}

src/kernel/time.h

@@ -0,0 +1,153 @@
+#define CURRENT_YEAR        2021                            // Change this each year!
+ 
+int century_register = 0x00;                                // Set by ACPI table parsing code if possible
+ 
+unsigned char second;
+unsigned char minute;
+unsigned char hour;
+unsigned char day;
+unsigned char month;
+unsigned int year;
+ 
+
+ 
+enum {
+      cmos_address = 0x70,
+      cmos_data    = 0x71
+};
+ 
+int get_update_in_progress_flag() {
+      outb(cmos_address, 0x0A);
+      return (inb(cmos_data) & 0x80);
+}
+ 
+unsigned char get_RTC_register(int reg) {
+      outb(cmos_address, reg);
+      return inb(cmos_data);
+}
+ 
+void read_rtc() {
+      unsigned char century;
+      unsigned char last_second;
+      unsigned char last_minute;
+      unsigned char last_hour;
+      unsigned char last_day;
+      unsigned char last_month;
+      unsigned char last_year;
+      unsigned char last_century;
+      unsigned char registerB;
+ 
+      // Note: This uses the "read registers until you get the same values twice in a row" technique
+      //       to avoid getting dodgy/inconsistent values due to RTC updates
+ 
+      while (get_update_in_progress_flag());                // Make sure an update isn't in progress
+      second = get_RTC_register(0x00);
+      minute = get_RTC_register(0x02);
+      hour = get_RTC_register(0x04);
+      day = get_RTC_register(0x07);
+      month = get_RTC_register(0x08);
+      year = get_RTC_register(0x09);
+      if(century_register != 0) {
+            century = get_RTC_register(century_register);
+      } else {
+            century = 21;
+      }
+ 
+      do {
+            last_second = second;
+            last_minute = minute;
+            last_hour = hour;
+            last_day = day;
+            last_month = month;
+            last_year = year;
+            last_century = century;
+ 
+            while (get_update_in_progress_flag());           // Make sure an update isn't in progress
+            second = get_RTC_register(0x00);
+            minute = get_RTC_register(0x02);
+            hour = get_RTC_register(0x04);
+            day = get_RTC_register(0x07);
+            month = get_RTC_register(0x08);
+            year = get_RTC_register(0x09);
+            if(century_register != 0) {
+                  century = get_RTC_register(century_register);
+            }
+      } while( (last_second != second) || (last_minute != minute) || (last_hour != hour) ||
+               (last_day != day) || (last_month != month) || (last_year != year) ||
+               (last_century != century) );
+ 
+      registerB = get_RTC_register(0x0B);
+ 
+      // Convert BCD to binary values if necessary
+ 
+      if (!(registerB & 0x04)) {
+            second = (second & 0x0F) + ((second / 16) * 10);
+            minute = (minute & 0x0F) + ((minute / 16) * 10);
+            hour = ( (hour & 0x0F) + (((hour & 0x70) / 16) * 10) ) | (hour & 0x80);
+            day = (day & 0x0F) + ((day / 16) * 10);
+            month = (month & 0x0F) + ((month / 16) * 10);
+            year = (year & 0x0F) + ((year / 16) * 10);
+            if(century_register != 0) {
+                  century = (century & 0x0F) + ((century / 16) * 10);
+            }
+      }
+ 
+      // Convert 12 hour clock to 24 hour clock if necessary
+ 
+      if (!(registerB & 0x02) && (hour & 0x80)) {
+            hour = ((hour & 0x7F) + 12) % 24;
+      }
+ 
+      // Calculate the full (4-digit) year
+ 
+      if(century_register != 0) {
+            year += century * 100;
+      } else {
+            year += (CURRENT_YEAR / 100) * 100;
+            if(year < CURRENT_YEAR) year += 100;
+      }
+}
+
+
+/*
+void ReadFromCMOS(unsigned char array[])
+{
+    unsigned char tvalue, index;
+
+    for (index = 0; index < 128; index++)
+    {
+        asm(
+            "cli\n\t"           // Disable interrupts
+            "mov al, index\n\t" // Move index address
+            // since the 0x80 bit of al is not set, NMI is active 
+            "out 0x70,al\n\t" // Copy address to CMOS register
+            // some kind of real delay here is probably best 
+            "in al,0x71\n\t" // Fetch 1 byte to al
+            "sti\n\t"        // Enable interrupts
+            "mov tvalue,al\n\t");
+
+        array[index] = tvalue;
+    }
+}
+*/
+
+/*
+void WriteTOCMOS(unsigned char array[])
+{
+   unsigned char index;
+ 
+   for(index = 0; index < 128; index++)
+   {
+      unsigned char tvalue = array[index];
+      
+       asm("cli\n\t"       // Clear interrupts
+         "mov al,index\n\t"    // move index address
+         "out 0x70,al\n\t"     // copy address to CMOS register
+         // some kind of real delay here is probably best 
+         "mov al,tvalue\n\t"   // move value to al
+         "out 0x71,al\n\t"   // write 1 byte to CMOS
+         "sti\n\\t"   );        // Enable interrupts
+      
+   }
+}
+*/

src/kernel/timer.cpp

@@ -0,0 +1,27 @@
+#include "timer.h"
+
+uint32_t tick = 0;
+
+
+static void timer_callback (registers_t regs ){
+    tick ++ ;
+    kterm_writestring ("tick passed!");
+}
+
+void init_timer (uint32_t frequency){
+    // register timer callback
+
+    uint32_t divisor = 1193180 / frequency;
+
+    // Send the commmand byte
+    outb(0x43, 0x36);
+
+    // Divisor has to be sent byt-wise , so will send lower then upper bytes
+    uint8_t low = (uint8_t) (divisor & 0xFF);
+    uint8_t high = (uint8_t) ((divisor >> 8) & 0xFF);
+
+    outb(0x40, low);
+    outb(0x40, high);
+
+
+}

src/kernel/timer.h

@@ -0,0 +1,6 @@
+#pragma once
+
+#include <stddef.h>
+#include <stdint.h>
+
+void init_timer (uint32_t frequency);

src/kernel/tty/kterm.cpp

@@ -0,0 +1,234 @@
+#include "kterm.h"
+
+static const size_t VGA_WIDTH = 80;
+static const size_t VGA_HEIGHT = 25;
+
+size_t kterm_row;
+size_t kterm_column;
+uint8_t kterm_color;
+uint16_t* kterm_buffer;
+
+
+static inline uint8_t vga_entry_color( enum vga_color fg, enum vga_color bg) {
+    return fg | bg << 4;
+}
+
+static inline uint16_t vga_entry (unsigned char uc, uint8_t color) {
+    return (uint16_t) uc | (uint16_t) color << 8;
+}
+
+void kterm_init () { 
+    kterm_row = 0;
+    kterm_column = 0;
+    kterm_color = vga_entry_color ( VGA_COLOR_LIGHT_GREY , VGA_COLOR_BLACK);
+    kterm_buffer = (uint16_t*) 0xB8000;
+    for (size_t y = 0; y < VGA_HEIGHT; y++ ){
+        for( size_t x = 0; x < VGA_WIDTH; x++){
+            const size_t index = y * VGA_WIDTH + x;
+            kterm_buffer[index] = vga_entry(' ', kterm_color);
+
+        }
+    }
+}
+
+
+void kterm_resetcolor(){
+     kterm_color = vga_entry_color ( VGA_COLOR_LIGHT_GREY , VGA_COLOR_BLACK);
+}
+
+void kterm_setcolor(uint8_t color){
+    kterm_color = color;
+}
+
+void kterm_putat (char c, uint8_t color, size_t x, size_t y ) {
+    const size_t index = y * VGA_WIDTH + x;
+
+    kterm_buffer[index] = vga_entry(c, color);
+
+}
+
+void enable_cursor (uint8_t start_cursor , uint8_t end_cursor ){
+    outb(0x3D4, 0x0A);
+    outb(0x3D5, (inb(0x3D5) & 0xC0) | start_cursor);
+
+    outb(0x3D4, 0x0B);
+    outb(0x3D5, (inb(0x3D5) & 0xE0) | end_cursor);
+}
+
+void disable_cursor() 
+{
+        outb(0x3D4, 0x0A);
+        outb(0x3D5, 0x20);
+}
+
+
+void update_cursor(int x, int y){
+    uint16_t pos = y * VGA_WIDTH + x;
+
+    outb(0x3D4, 0x0F);
+    outb(0x3D5, (uint8_t) (pos & 0xFF));
+    outb(0x3D4, 0x0E);
+    outb(0x3D5, (uint8_t) ((pos >> 8) & 0xFF));
+}
+
+uint16_t get_cursor_position(){
+    uint16_t pos = 0;
+    outb(0x3D4, 0x0F);
+    pos |= inb(0x3D5);
+    outb(0x3D4, 0x0E);
+    pos |= ((uint16_t) inb(0x3D5)) << 8;
+    return pos;
+}
+
+int get_cursor_x (uint16_t cursor_pos) {
+    return cursor_pos % VGA_WIDTH;
+}
+
+int get_cursor_y (uint16_t cursor_pos ) {
+    return cursor_pos / VGA_WIDTH;
+}
+
+
+
+/**
+ *  With the help from:
+ * https://whiteheadsoftware.dev/operating-systems-development-for-dummies/
+ **/ 
+void kterm_scrollup(){
+    size_t i ;
+    for(i=0; i < (VGA_WIDTH * VGA_HEIGHT - VGA_WIDTH); i++)
+        kterm_buffer[i] = kterm_buffer[i+VGA_WIDTH];
+
+    for( i=0; i< VGA_WIDTH; i++)
+        kterm_buffer[(VGA_HEIGHT -1) * VGA_WIDTH + i ] = vga_entry(' ', kterm_color); 
+
+}
+
+void kterm_put (char c) {
+    if(++kterm_column == VGA_WIDTH || c == '\n' ) {
+        update_cursor(kterm_column , kterm_row);
+        kterm_column = 0;
+        if(kterm_row == VGA_HEIGHT-1 ) {       
+            kterm_scrollup();
+        } else {
+            kterm_row ++;
+        }
+    }
+    if ( c == '\r'){
+        kterm_column = 0;
+        return;
+    }
+    
+    if(c == '\n') return;
+    kterm_putat ( c, kterm_color, kterm_column, kterm_row);
+    
+
+}
+
+void kterm_write(const char* data, size_t size) {
+    for(size_t i = 0; i < size; i++){
+        kterm_put(data[i]);
+    }
+}   
+
+void kterm_writestring(const char* data ){
+   // AS_KERNEL();
+    kterm_write(data, strlen(data));
+}
+
+
+void itoa (char *buf, int base, int d) {
+    char *p = buf;
+    char *p1, *p2;
+    unsigned long ud = d;
+    int divisor = 10;
+    if ( base == 'd' && d < 0){
+        *p++ = '-';
+        buf++;
+        ud = -d;
+    } else if (base == 'x'){
+        divisor = 16;
+    }
+
+    do { 
+        int remainder = ud % divisor;
+
+         *p++ = (remainder < 10 ) ? remainder + '0' : remainder + 'a' -10;
+    } while(ud /= divisor);
+
+    /*terminate buf*/
+    *p =0;
+    p1 = buf;
+    p2 = p -1;
+
+    while (p1 < p2)
+    {
+        char tmp = *p1;
+        *p1 = *p2;
+        *p2 = tmp;
+        p1++;
+        p2--;
+
+    }
+
+}
+
+void printf ( const char *format, ...) {
+    return;
+    char **arg = (char **)&format;
+    int c;
+    char buf[20];
+
+    arg++;
+    
+    while ((c = *format++) != 0){
+        if( c != '%')
+            kterm_put(c);
+        else{
+            char *p, *p2;
+            int pad0 = 0, pad = 0;
+
+            c = *format++;
+            if(c =='0'){
+                pad0 = 1;
+                c = *format++;
+            }
+
+            if ( c >= '0' && c <= '9'){
+                pad = c - '0';
+                c = *format++;
+            }
+
+            switch (c)
+            {
+            case 'd':
+             
+            case 'u':
+            case 'x':
+                itoa(buf, c, *((int *) arg++));
+
+                p = buf;
+                goto string;
+                break;
+            
+            case 's':
+                p = *arg++;
+                if(!p)
+                    p = "(null)";
+                
+                string: 
+                    for (p2 = p; *p2; p2++);
+                    for (; p2 < p + pad; p2++)
+                        kterm_put(pad0 ? '0': ' ');
+                    while (*p)
+                        kterm_put(*p++);
+                    break;
+
+
+            default:
+                kterm_put(*((int *)arg++));
+                break;
+            }
+        }
+    }
+}

src/kernel/tty/kterm.h

@@ -0,0 +1,45 @@
+#pragma once 
+#include <stdint.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "../vga/colors.h"
+#include "../io.h"
+
+extern "C"{
+    #include "./../../libc/include/string.h"
+}
+
+void kterm_init();
+
+/* Kernel terminal - Colour functions*/
+void kterm_resetcolor();
+void kterm_setcolor(uint8_t);
+
+/* Kernel terminal - Printing function */
+void kterm_putat(char, uint8_t, size_t, size_t);
+void kterm_put(char);
+void kterm_write(const char*, size_t);
+void kterm_writestring(const char*);
+void kterm_scrollup();
+
+
+/* Kernel terminal - Cursor functions */
+void enable_cursor (uint8_t start_cursor , uint8_t end_cursor );
+void disable_cursor();
+void update_cursor(int x, int y);
+uint16_t get_cursor_position();
+int get_cursor_x (uint16_t cursor_pos);
+int get_cursor_y (uint16_t cursor_pos);
+
+extern "C"  void itoa (char *buf, int base, int d);
+void printf ( const char *format, ...);
+
+
+#define KernelTag "[Kernel]: "
+#define AS_KERNEL() (  kterm_setcolor(VGA_COLOR_LIGHT_BLUE),\
+                       kterm_write(KernelTag, 10 ), \
+                       kterm_resetcolor())
+
+

src/kernel/vga/VBE.h

@@ -0,0 +1,41 @@
+
+#define VBE_DISPI_IOPORT_INDEX 0x01CE
+#define VBE_DISPI_IOPORT_DATA 0x01CF
+
+/* VBE index values*/
+#define VBE_DISPI_INDEX_ID              0x0
+#define VBE_DISPI_INDEX_XRES            0x1
+#define VBE_DISPI_INDEX_YRES            0x2
+#define VBE_DISPI_INDEX_BPP             0x3
+#define VBE_DISPI_INDEX_ENABLE          0x4
+#define VBE_DISPI_INDEX_BANK            0x5
+#define VBE_DISPI_INDEX_VIRT_WIDTH      0x6
+#define VBE_DISPI_INDEX_VIRT_HEIGHT     0x7
+#define VBE_DISPI_INDEX_X_OFFSET        0x8
+#define VBE_DISPI_INDEX_Y_OFFSET        0x9
+
+/* BGA Version */
+#define VBE_DISPI_ID5   0xB0C5
+#define VBE_DISPI_ID4   0xB0C3 
+#define VBE_DISPI_ID3   0xB0C2
+#define VBE_DISPI_ID2   0xB0C1
+#define VBE_DISPI_ID1   0xB0C0
+
+
+/* BGA BIT DEPTH */
+#define VBE_DISPI_BPP_4 0x04
+#define VBE_DISPI_BPP_8 0x08
+#define VBE_DISPI_BPP_15 0x0F
+#define VBE_DISPI_BPP_16 0x10
+#define VBE_DISPI_BPP_24 0x18
+#define VBE_DISPI_BPP_32 0x20
+
+
+    /*unsigned short BGAReadRegister(unsigned short IndexValue){
+        // outpw(VBE_DISPI_IOPORT_INDEX, IndexValue);
+       // return inpw (VBE_DISPI_IOPORT_DATA);
+    }
+
+    int BGAIsAvailable (){
+        return (BGAReadRegister(VBE_DISPI_INDEX_ID) == VBE_DISPI_ID5);
+    }*/

src/libc/include/mem.h

@@ -0,0 +1,8 @@
+inline void* memset (void* ptr, int value, size_t num){
+    for( int i = 0; i < num; i++ )
+    {
+        int* data  = (int*)ptr+ i;
+        *data = value;
+    }
+    return ptr;
+}

src/libc/include/string.c

@@ -0,0 +1,9 @@
+#include "string.h"
+
+size_t strlen(const char* str) {
+    size_t len = 0;
+    while(str[len]){
+        len++;
+    }
+    return len;
+}

src/libc/include/string.h

@@ -1,8 +1,3 @@
+#pragma once
 #include <stddef.h>
-size_t strlen(const char* str){
-    size_t len = 0;
-    while(str[len]){
-        len++;
-    }
-    return len;
-}
+size_t strlen(const char* str);