KERNEL: Implementing VMM & cleaning up

Folders now are alll lower case

Started working on the implementation of the Virtual memory manager. Implemented allocate and free page funtionality for as far as I can atm.

Implemented the

.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 +1,10 @@
-build
+build
+CON
+.vscode
+isodir/
+root/
+*.iso
+*.img
+*.sym
+
+

Makefile

@@ -3,11 +3,11 @@ EMULATOR = qemu-system-i386
 AS = ${HOME}/opt/cross/bin/i686-elf-as
 CC = ${HOME}/opt/cross/bin/i686-elf-gcc
 CPP = ${HOME}/opt/cross/bin/i686-elf-g++ 
-CFLAGS =  -ffreestanding -O2 -Wall -Wextra
+CFLAGS =  -ffreestanding -Og -ggdb  -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)/kterm.o $(BUILD_DIR)/kernel.o $(BUILD_DIR)/memory.o  $(BUILD_DIR)/paging.o	$(BUILD_DIR)/pit.o 	$(BUILD_DIR)/time.o	$(BUILD_DIR)/keyboard.o	 $(BUILD_DIR)/io.o 	$(BUILD_DIR)/gdtc.o $(BUILD_DIR)/idt.o $(BUILD_DIR)/pic.o $(BUILD_DIR)/sv-terminal.o $(BUILD_DIR)/string.o  $(BUILD_DIR)/prekernel.o $(BUILD_DIR)/cpu.o
 
-SRC_DIR = src
+SRC_DIR = source
 BUILD_DIR = build
 
 CRTBEGIN_OBJ = $(shell $(CC) $(CFLAGS) -print-file-name=crtbegin.o)
@@ -19,17 +19,30 @@ OBJ_LINK_LIST = $(CRTI_OBJ) $(CRTBEGIN_OBJ) $(OFILES) $(CRTEND_OBJ) $(CRTN_OBJ)
 INTERNAL_OBJS = $(CRTI_OBJ) $(OFILES) $(CRTN_OBJ)
 
 
-all: clean build
+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 source/grub.cfg root/boot/grub/grub.cfg
+	grub-mkrescue -o build/barinkOS.iso root
+	
+run: all
+	$(EMULATOR) -cdrom build/barinkOS.iso -serial stdio -vga std -display gtk -m 2G -cpu core2duo
+
+debug: all
+	objcopy --only-keep-debug build/myos.bin kernel.sym
+	$(EMULATOR) -cdrom build/barinkOS.iso -serial stdio -vga std -display gtk -m 2G -cpu core2duo -s -d int
 
 build_kernel: $(OBJ_LINK_LIST)
-	
-	$(CC) -T $(SRC_DIR)/kernel/arch/i386/linker.ld -o $(BUILD_DIR)/myos.bin \
-	 -ffreestanding -O2 -nostdlib $(OBJ_LINK_LIST) -lgcc
+	$(CC) -T $(SRC_DIR)/kernel//linker.ld -o $(BUILD_DIR)/myos.bin \
+	 -ffreestanding -ggdb -Og -nostdlib $(OBJ_LINK_LIST) -lgcc
 
 build_x86_64: 
 	$(AS) $(SRC_DIR)/cgc/x86_64/crti.s -o $(BUILD_DIR)/crti_64.o
@@ -42,18 +55,57 @@ $(BUILD_DIR)/kernel.o:
 	$(CPP) -c $(SRC_DIR)/kernel/kernel.cpp -o $(BUILD_DIR)/kernel.o $(CFLAGS) -fno-exceptions -fno-rtti
 
 $(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/terminal/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/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)/idt.o:
+	$(CPP) -c $(SRC_DIR)/kernel/interrupts/idt/idt.cpp -o $(BUILD_DIR)/idt.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+$(BUILD_DIR)/gdtc.o:
+	$(CPP) -c $(SRC_DIR)/kernel/memory/gdt/gdtc.cpp -o $(BUILD_DIR)/gdtc.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+
+$(BUILD_DIR)/pic.o:
+	$(CPP) -c $(SRC_DIR)/kernel/drivers/pic/pic.cpp -o $(BUILD_DIR)/pic.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+$(BUILD_DIR)/string.o:
+	$(CC) -c $(SRC_DIR)/kernel/lib/string.c  -o $(BUILD_DIR)/string.o $(CFLAGS) -std=gnu99
+
+
+$(BUILD_DIR)/pit.o:
+	$(CPP) -c $(SRC_DIR)/kernel/drivers/pit/pit.cpp  -o $(BUILD_DIR)/pit.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+
+$(BUILD_DIR)/keyboard.o:
+	$(CPP) -c $(SRC_DIR)/kernel/drivers/ps-2/keyboard.cpp  -o $(BUILD_DIR)/keyboard.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+
+$(BUILD_DIR)/time.o:
+	$(CPP) -c $(SRC_DIR)/kernel/time.cpp  -o $(BUILD_DIR)/time.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+$(BUILD_DIR)/sv-terminal.o:
+	$(CPP) -c $(SRC_DIR)/kernel/supervisorterminal/superVisorTerminal.cpp  -o $(BUILD_DIR)/sv-terminal.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+$(BUILD_DIR)/memory.o:
+	$(CPP) -c $(SRC_DIR)/kernel/memory/PhysicalMemoryManager.cpp  -o $(BUILD_DIR)/memory.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+$(BUILD_DIR)/paging.o:
+	$(CPP) -c $(SRC_DIR)/kernel/memory/VirtualMemoryManager.cpp -o $(BUILD_DIR)/paging.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+$(BUILD_DIR)/prekernel.o:
+	$(CPP) -c $(SRC_DIR)/kernel/prekernel/prekernel.cpp -o $(BUILD_DIR)/prekernel.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+$(BUILD_DIR)/cpu.o:
+	$(CPP) -c $(SRC_DIR)/kernel/cpu.cpp -o $(BUILD_DIR)/cpu.o $(CFLAGS) -fno-exceptions -fno-rtti

README.md

@@ -10,14 +10,22 @@ ________________________
 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.
+
+![Page faulting](screenshots/PageFault.png) \
+Enabled paging and am getting page faults!
+
+
 ________________________
 
 ### The goal
-Writing a hobby operating system to better understand the basic building blocks of any operating system.
-
-
-
-
+Writing a hobby operating system to better understand the basic building blocks of any operating system.Initially I'd like for my 
+operating system to be able to run bash.
 
 ________________________
 ### Operating System Technical specs/details
@@ -26,8 +34,8 @@ 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) \

TODO.md

@@ -1,40 +0,0 @@
-# TODO list 
-## Start planning
-<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/> Output to serial port \
-<input type="checkbox" /> Move to protected mode \
-<input type="checkbox" /> 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" /> 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)
-
-## Other features I am thinking of:
-<input type="checkbox" /> PCI support \
-<input type="checkbox" /> ATA PIO Mode support \
-<input type="checkbox" /> USTAR Filesystem ( For its simplicity this is very likely the first filesystem the OS is going to support) \
-<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" /> 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" /> RPC - for interprocess communication \
-<input type="checkbox" /> Sync primitives  - Semaphores, Mutexes, spinlocks et al. \
-<input type="checkbox" /> Basic Terminal \
-<input type="checkbox" /> Extend hardware recognition ( CPU codename, memory, ATA harddisk, RAW diskSpace, CPU speed through SMBIOS et al. ) \
-<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 \

features.md

@@ -0,0 +1,43 @@
+# TODO list 
+## Basics
+<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" checked/> Printing values/numbers to the screen \
+<input type="checkbox" checked/> Basic Terminal \
+<input type="checkbox" checked/> Extend Multiboot implementation \
+<input type="checkbox" checked/> Output to serial port \
+<input type="checkbox" checked/> Move to protected mode \
+<input type="checkbox" checked/> Enabel CMOS clock \
+<input type="checkbox" checked/> Time measurement (PIC &| PIT) \
+<input type="checkbox" /> Detect CPU speed \
+<input type="checkbox" checked/> Interrupt / exception system (API) \
+<input type="checkbox" checked/> PCI support \
+<input type="checkbox" checked/> ATA PIO Mode support \
+<input type="checkbox" checked/> FAT Filesystem \
+<input type="checkbox" /> Virtual filesystem \
+<input type="checkbox" checked/> Keyboard support ( P/S2 Keyboard) \
+<input type="checkbox" checked/> Physical memory management \
+<input type="checkbox" />  Paging \
+<input type="checkbox" /> Virtual memory management \
+<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)
+
+<input type="checkbox" /> Hardware Management system
+
+<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" /> RPC - for interprocess communication \
+<input type="checkbox" /> Sync primitives  - Semaphores, Mutexes, spinlocks et al. \
+
+<input type="checkbox" /> ACPI support  \
+<input type="checkbox" /> ATAPI support \
+
+## Optional 
+<input type="checkbox" /> Basic Window server/client \
+<input type="checkbox" /> EXT2 Filesystem 
+<input type="checkbox" /> USTAR Filesystem \

scripts/dev-setup/install.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+cmake -DLLVM_ENABLE_PROJECTS="clang-tools-extra"  -DCMAKE_BUILD_TYPE=Release -G "Unix Makefiles" ../llvm

scripts/hooks/pre-commit.hook.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+
+# Run clang-tidy 
+

source/grub.cfg

@@ -0,0 +1,9 @@
+menuentry "BarinkOS" {
+    multiboot /boot/myos.bin
+}
+
+menuentry "BarinkOS Tests" {
+    multiboot /boot/myos.bin
+}
+
+

source/kernel/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 uint32_t bitmap_first_unset( uint32_t* map , int map_size)
+{
+    for ( int i = 0 ; i < map_size ; i ++ )
+    {
+        // a bit or more is set within this byte!
+        if( (map[i] & 0xFFFFFFFF) > 0 ){
+
+            // which bit is set? 
+            for(int j = 0 ; j < 32 ; j++){
+                if ( (map[i] & (0x00000001 << j)) > 0)
+                {
+                    printf("Found bit: byte 0x%x , bit 0x%x\n", i , j);
+                    return (i*32)+j;
+                }
+            }
+
+        
+        }
+
+
+    }
+
+    return -1;
+    
+}

source/kernel/boot/boot.s

@@ -0,0 +1,112 @@
+.include "./source/kernel/boot/multiboot.s"
+/*
+*	Allocate initial stack
+*/
+.section .bootstrap_stack, "aw", @nobits
+stack_bottom:
+.skip 16384 # 16 KiB
+stack_top:
+
+/*
+* Preallocate a couple pages to get us bootstrapped 
+* Being carefull to not use any address the bootloader might 
+* be using for its multiboot structures
+*/
+.section .bss, "aw", @nobits
+	.align 4096
+.globl boot_page_directory
+boot_page_directory:
+	.skip 4096
+.globl boot_page_table
+boot_page_table:
+	.skip 4096
+.globl multiboot_page_table
+multiboot_page_table:
+	.skip 4096
+# More page tables may be required
+
+# Entry point
+.section .multiboot.text, "a"
+.global _start
+.type _start, @function 
+_start:
+
+	/* push the pointer to the Multiboot information structure*/
+	pushl %ebx
+
+	/* push the magic value */
+	pushl %eax
+	call prekernelSetup
+
+	# Get physical address of the boot_page_table
+	movl $(boot_page_table - 0xC0000000), %edi
+	# Map address 0
+	movl $0, %esi
+1:	
+	cmpl $(_kernel_end - 0xC0000000), %esi
+	jge 3f
+
+	# Map physical address as "present and writable"
+	movl %esi, %edx
+	orl $0x003, %edx
+	movl %edx, (%edi)
+
+2: # Size of page is 4096 bytes
+	addl $4096, %esi
+	# Size of entries in boot_page_table is 4 bytes
+	addl $4, %edi 
+	# Loop to the next entry if we haven't finished.
+	loop 1b
+
+3:	# Map VGA video memory to 0xC03FF00 as "present, writable"
+	movl $(0x000B8000 | 0x003), boot_page_table - 0xC0000000 + 1023 * 4
+
+	# Map the page table to both virtual addresss 0x00000000 and 0xC0000000
+	movl $(boot_page_table - 0xC0000000 + 0x003), boot_page_directory - 0xC0000000 + 0
+	movl $(boot_page_table - 0xC0000000 + 0x003), boot_page_directory - 0xC0000000 + 768 * 4
+
+	# Set cr3 to the address of the boot_page_directory
+	movl $(boot_page_directory - 0xC0000000), %ecx
+	movl %ecx, %cr3
+
+	# Enable paging and the write-protect bit
+	movl %cr0, %ecx
+	orl $0x80010000, %ecx
+	movl %ecx, %cr0
+
+	# Jump to higher half with an absolute jump
+	lea 4f, %ecx
+	jmp *%ecx
+
+.section .text
+4:
+	# At this point, paging is fully set up and enabled
+isPaging:
+	# Unmap the identity mapping as it is now unnecessary  
+	movl $0, boot_page_directory + 0
+	
+	# Reload cr3 to force tlb flush 
+	movl %cr3, %ecx
+	movl %ecx, %cr3
+
+	/*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 
+
+	call early_main
+
+	cli
+1:	hlt
+	jmp 1b
+
+
+.include "./source/kernel/memory/gdt/gdt.s"
+.include "./source/kernel/irs_table.s"
+.include "./source/kernel/irq_table.s"
+.include "./source/kernel/interrupts/idt/idt.s"
+
+

source/kernel/boot/multiboot.s

@@ -0,0 +1,15 @@
+/*
+ * 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.data, "aw"
+.align 4
+.long MAGIC
+.long FLAGS
+.long CHECKSUM
+ 

source/kernel/cpu.cpp

@@ -0,0 +1,39 @@
+#include "cpu.h"
+
+
+uint32_t GetEFLAGS()
+{
+    uint32_t EFLAGS = 0;
+    asm volatile ("pushfl;" "movl 4(%%esp), %%edx" : "=d"(EFLAGS));
+    return EFLAGS;
+}
+
+
+uint32_t GetCR0()
+{   
+    uint32_t cr0_value;
+    asm volatile ("movl %%cr0, %%edx" : "=d"(cr0_value));
+    return cr0_value;
+
+}
+
+
+uint32_t GetCR2(){
+    uint32_t cr2_value;
+    __asm__ volatile("movl %%cr2, %%edx": "=d"(cr2_value));
+    return cr2_value;
+}
+
+
+uint32_t GetCR3(){
+    uint32_t cr3_value;
+    __asm__ volatile("movl %%cr3, %%edx": "=d"(cr3_value));
+    return cr3_value;
+}
+
+
+uint32_t GetCR4(){
+    uint32_t cr4_value;
+    __asm__ volatile("movl %%cr4, %%edx": "=d"(cr4_value));
+    return cr4_value;
+}

source/kernel/cpu.h

@@ -0,0 +1,74 @@
+#pragma once
+#include <stdint.h>
+
+/*
+Based on Intel specifications.
+
+C++ interface for the cpu.s assembly file.
+
+©Nigel Barink - 2022 
+*/
+
+/*
+*       EFLAGS FUNCTIONS
+*/
+
+uint32_t GetEFLAGS();
+
+
+
+/*
+*       CONTROL_REGISTER_0 FUNCTIONS
+*/
+uint32_t GetCR0();
+
+/*
+ struct CR0_Register  {
+        uint8_t PE :1; // Protection Mode Enabled 0
+        uint8_t MP :1; // Monitor co-processor 1
+        uint8_t EM :1; // Emulation 2
+        uint8_t TS :1; // Task switched 3
+        uint8_t ET :1; // Extension Type 4
+        uint8_t NE :1; // Numeric error 5
+        uint16_t Reserved :10; // 6,7,8,9,10,11,12,13,14,15
+        uint8_t WP :1; // Write Protect 16
+        uint8_t Reserved :1; // 17
+        uint8_t AM :1; // Alligment Task 18
+        uint16_t Reserved :10; // 19,20,21,22,23,24,25,26,27,28
+        uint8_t NW :1; // Not-write through 29
+        uint8_t CD :1; // Cache disable 30
+        uint8_t PG :1; // Paging 31
+    };*/
+
+
+
+#define GET_PE_BIT(CONTROL_REGISTER_0) (CONTROL_REGISTER_0&0x1)
+#define GET_MP_BIT(CONTROL_REGISTER_0) (CONTROL_REGISTER_0&0x2)
+#define GET_EM_BIT(CONTROL_REGISTER_0) (CONTROL_REGISTER_0&0x3)
+#define GET_TS_BIT(CONTROL_REGISTER_0) (CONTROL_REGISTER_0&0x4)
+#define GET_ET_BIT(CONTROL_REGISTER_0) (CONTROL_REGISTER_0&0x5)
+#define GET_NE_BIT(CONTROL_REGISTER_0) (CONTROL_REGISTER_0&0x6)
+
+
+#define GET_PG_BIT(CONTROL_REGISTER_0) (CONTROL_REGISTER_0>>31)
+
+/*
+*       CONTROL_REGISTER_4 FUNCTIONS
+*/
+
+uint32_t GetCR4();
+
+#define GET_PSE_BIT(CONTROL_REGISTER_4) (CONTROL_REGISTER_4&0x4)
+#define GET_PAE_BIT(CONTROL_REGISTER_4) (CONTROL_REGISTER_4&0x5)
+
+/*
+*       CONTROL_REGISTER_2 FUNCTIONS
+*/
+
+uint32_t GetCR2();
+
+/*
+*       CONTROL_REGISTER_3 FUNCTIONS
+*/
+
+uint32_t GetCR3();

source/kernel/definitions.h

@@ -0,0 +1,9 @@
+#pragma once 
+/**
+ * Kernel definitions
+ */
+
+#define __DEBUG__ false
+#define KERNEL_VERSION 0
+
+#define ARCHITECTURE "I386"

source/kernel/drivers/cmos/cmos.cpp

@@ -0,0 +1,38 @@
+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
+      
+   }
+}

source/kernel/drivers/pci/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);
+        }
+    }
+
+}

source/kernel/drivers/pci/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 );

source/kernel/drivers/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);
+
+}

source/kernel/drivers/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 );

source/kernel/drivers/pit/pit.cpp

@@ -0,0 +1,54 @@
+#include "pit.h"
+
+uint32_t pit_tick = 0;
+
+
+void pit_initialise()
+{
+    asm volatile("CLI");
+
+#ifdef __VERBOSE__
+    printf("Init PIT!\n");
+#endif
+    // clear mask for IRQ 0 
+    uint8_t value = inb(0x21) & ~(1<< 0);
+    outb(0x21, value);
+
+    io_wait();
+
+    const int freq = 500;
+
+    uint32_t divisor = 1193180 / freq;
+
+    outb(PIT_COMMAND, 0x36);
+
+    uint8_t l = (uint8_t) (divisor & 0xFF);
+    uint8_t h = (uint8_t) ( (divisor>>8) & 0xff);
+
+    outb(PIT_DATA_0, l);
+    outb(PIT_DATA_0,h);
+
+
+    asm volatile("STI");
+}
+
+
+void get_pit_count()
+{
+    asm volatile ("CLI");
+
+    outb(PIT_COMMAND, 0);
+    uint16_t count = inb(PIT_DATA_0);
+    count |= inb(PIT_DATA_0) << 8;
+
+    printf("PIT count: 0x%x\n", count); 
+
+    asm volatile("STI");   
+
+}
+
+void set_pit_count()
+{
+
+}
+

source/kernel/drivers/pit/pit.h

@@ -0,0 +1,19 @@
+#pragma once 
+#include <stdint.h>
+#include "../../io.h"
+#include "../../terminal/kterm.h"
+#define PIT_DATA_0 0x40
+#define PIT_DATA_1 0x41
+#define PIT_DATA_2 0x42
+#define PIT_COMMAND 0x43
+
+
+extern uint32_t pit_tick;
+
+
+void pit_initialise();
+
+
+void get_pit_count();
+
+void set_pit_count();

source/kernel/drivers/ps-2/keyboard.cpp

@@ -0,0 +1,51 @@
+#include "keyboard.h"
+
+KeyPressInfo keyPress {};
+
+void KeyHandled(){
+    keyPress.ScanCode= 0x00;
+    keyPress.PressedModifiers = 0x00;
+}
+
+
+char getASCIIKey(){
+    char keyPressed;
+    // Wait until a key is pressed  
+    while(keyPress.ScanCode == 0x00) {
+        asm volatile ("NOP");
+    }
+
+    
+    // Translate keycode to ascii 
+    // Probably a lookup table might be handy 
+    // Until 0x37
+     const char* ASCIILookUp =
+      "\01234567890-=\0\0QWERTYUIOP[]\0\0ASDFGHJKL;\'`\0\\ZXCVBNM,./\0"; 
+     
+     uint8_t ASCII_Index = keyPress.ScanCode - 3  ;
+     //printf("ASCII_INDEX: %x\n", ASCII_Index);
+     keyPressed = ASCIILookUp[ASCII_Index];
+
+    KeyHandled();
+
+    return keyPressed;
+}
+
+
+
+uint8_t getKey(){
+    // Wait until a key is pressed 
+    while(keyPress.ScanCode == 0x00){
+        asm volatile ("NOP");
+    }
+    
+    if( keyPress.ScanCode > 0x37){
+        keyPress.ScanCode = 0x00;
+        return 0;
+    }
+
+    uint8_t ScanCode = keyPress.ScanCode;
+   // KeyHandled();
+
+    return  ScanCode ;
+}

source/kernel/drivers/ps-2/keyboard.h

@@ -0,0 +1,34 @@
+#pragma once
+#include <stdint.h>
+#include "../../terminal/kterm.h"
+enum ScanCodeSet {
+    None            =   0,
+    ScanCodeSet1    =   1,
+    ScanCodeSet2    =   2,
+    ScanCodeSet3    =   3,
+};
+
+enum Modifiers {
+    LSHIFT  =   1,
+    RSHIFT  =   2,
+
+    LCTRL   =   3,
+    RCTRL   =   4,
+
+    LALT    =   5,
+    RALT    =   6
+};
+
+struct KeyPressInfo{ 
+    uint8_t PressedModifiers;
+    uint8_t ScanCode;
+};
+
+
+
+extern KeyPressInfo keyPress;
+
+void KeyHandled();
+
+char getASCIIKey();
+uint8_t getKey();

source/kernel/drivers/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);
+    }*/

source/kernel/filesystem/FAT/FAT16.h

@@ -0,0 +1,8 @@
+#pragma once
+#include "../../vfs/File.h"
+
+
+class FAT16 : File  {
+public:
+    
+};

source/kernel/interrupts/idt/idt.cpp

@@ -0,0 +1,395 @@
+#include "idt.h"
+#include "../../drivers/pit/pit.h"
+#include "../../drivers/ps-2/keyboard.h"
+#include "../../cpu.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) {
+     uint32_t FaultingAddress;
+        //printf("(IRS) Interrupt number: %d \r", regs.int_no);
+        switch (regs.int_no)
+        {
+        case 0:
+            // Divide Error #DE
+            printf("#DE\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp);
+        break;
+        
+        case 1:
+            // Debug Exception #DB
+            printf("#DB\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp);
+        break;
+
+        case 2:
+            // NMI Interrupt 
+            printf("#NMI\n");
+        break;
+        
+        case 3:
+            // Breakpoint Exception #BP
+            printf("#BP\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp);
+        break;
+        
+        case 4:
+            // Overflow Exception #OF
+            printf("#OF\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp);
+        break;
+        
+        case 5:
+            // BOUND Range Exceeded Exception #BR
+            printf("#BR\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp);
+        break;
+        
+        case 6:
+            // Invalid OpCode Exception #UD 
+            printf("#UD\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp);
+        break;
+        
+        case 7:
+            // Device Not Available Exception  #NM
+            printf("#NM\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp);
+        break;
+        
+        case 8:
+            // Double Fault Exception #DF
+            printf("#DF\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp);
+        break;
+
+        case 9:
+            // Coprocessor Segment Overrun
+            printf("Coprocessor Segment overrun!\n");
+        break;
+        
+        case 10:
+            // Invalid TSS Exception #TS
+            printf("#TS\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp);
+        break;
+
+        case 11:
+            // Segment Not Present #NP
+            printf("#NP\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp);
+        break;
+        
+        case 12:
+            // Stack Fault Exception #SS
+            printf("#SS\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp);
+        break;
+        
+        case 13:
+            // General Protection Exception #GP
+            printf("#GP\n");
+
+            printf("Accessing memory caused a general protectuion exception.\n");
+            
+            printf("Fault due to entry at index: %d", (regs.err_code >> 3 & 0xFFF ) );
+
+            if(regs.err_code & 0x3 >> 1 == 0   ){
+                printf("* Index references GDT");
+            }
+            if(regs.err_code & 0x3 >> 1 == 1  ){
+                printf("* Index references IDT");
+            }
+
+            if(regs.err_code & 0x3 >> 1 == 2   ){
+                printf("* Index references LDT");
+            }
+
+            if(regs.err_code & 0x3 >> 1 == 4  ){
+                printf("* Index references IDT");
+            }
+
+            if( regs.err_code & 0x1)
+            {
+                printf("* Originated externally!");
+            }
+
+            __asm__("cli;" "1: hlt;" "jmp 1b;");
+
+        break;
+        
+        case 14:
+            // Page Fault Exception #PF
+            printf("#PF\n");
+
+            FaultingAddress = GetCR2();
+            printf("Accessing the linear address 0x%x resulted in a page fault!\n\n", FaultingAddress);
+        
+            // Error code of 32 bits are on the stack
+            // CR2 register contains the 32-bit linear virtual address that generated the exception
+            // See Intel Software Developers manual Volume 3A Part 1 page 236 for more info
+            #define PF_ERR_PRESENT_BIT 0x1
+            #define PF_ERR_WRITE_BIT 0x2
+            #define PF_ERR_USER_BIT 0x3
+            #define PF_ERR_RESERVERD_WRITE_BIT 0x4
+            #define PF_ERR_INSTRUCTION_FETCH_BIT 0x5
+            #define PF_ERR_PROTECTION_KEY_BIT 0x6
+            #define PF_ERR_SHADOW_STACK_BIT 0x7
+            #define PF_ERR_SOFTWARE_GUARD_EXTENSION_BIT 0xE
+
+            printf("REASON: \n\n");
+
+         
+            if (regs.err_code & PF_ERR_PRESENT_BIT ){
+                printf("* Page protection violation!\n");
+            } else{
+                printf("* Page not-present!\n");
+            }
+
+            if(regs.err_code & PF_ERR_WRITE_BIT){
+                printf("* Write access violation!\n");
+            } else{
+                printf("* Read access violation!\n");
+            }
+
+            if(regs.err_code & PF_ERR_USER_BIT){
+                printf("* Violation from user-space (CPL=3)\n");
+            }
+
+            if(regs.err_code & PF_ERR_INSTRUCTION_FETCH_BIT){
+                printf("* Caused by an instruction fetch. \n");
+            }
+
+            /*
+                Check the error code to figure out what happened here
+            */
+            __asm__("cli;" "1: hlt;" "jmp 1b;");
+
+
+            
+    
+        break;
+        
+        case 16:
+            // x87 FPU Floating-point Error #MF
+            printf("#MF\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp);
+        break;
+        
+        case 17:
+            // Alignment Check Exception #AC
+            printf("#AC\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp); 
+        break;
+        
+        case 18:
+            // Machine-Check Exception #MC
+            printf("#MC\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp); 
+        break;
+        
+        case 19:
+            // SIMD Floating-point Exception #XM
+            printf("#XM\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp); 
+        break;
+        
+        case 20:
+             // Virtualization Exception #VE
+            printf("#VE\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp); 
+        break;
+        
+        case 21:
+             // Control Protection Exception #CP
+            printf("#CP\n");
+            printf("EIP: 0x%x\n", regs.eip);
+            printf("EAX: 0x%x\n", regs.eax);
+            printf("EBP: 0x%x\n", regs.ebp); 
+        break;
+
+        default:
+            // PANIC!!!
+            break;
+        }
+
+      
+        
+}
+
+void irq_handler (registers regs) {
+
+    
+
+    switch (regs.int_no) {
+    case 0:
+            pit_tick++;
+        break;
+    case 1:
+        // Keyboard interrupt !!
+
+        int scan;
+        int i;/*register*/
+
+        // Read scancode 
+        scan = inb(0x60);
+        
+        // Send ack message!
+        i = inb(0x61);
+        outb(0x61, i|0x80);
+        outb(0x61, i);
+
+        // NOTE: check for special scan codes 
+        // e.g. modifiers etc..
+        if( scan < 0x37){
+            //printf("Read from IO: 0x%x\n", scan);
+            keyPress.ScanCode = scan ;
+            //printf( "[From Interrupt] Scancode: %x\n", keyPress.ScanCode);
+
+        }
+
+        
+        break;    
+    case 12:
+        // PS2 Mouse interrupt 
+        printf("Mouse event triggered!");
+        //int event = inb(0x60);
+        break;
+
+    default:
+        printf("Interrupt happened!");
+        printf("Received INT: 0x%x\n", regs.int_no);
+        break;
+    }        
+
+    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;
+
+#ifdef __VERBOSE__
+    printf("Init IDT\n");
+#endif
+
+    // 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);
+
+    // clear mask for IRQ 12
+    uint8_t value = inb(0x21) & ~(1<< 12);
+    outb(0x21, value);
+
+
+
+    // pic IRQ Table
+    set_id_entry(32, (uint32_t)irq0, 0x08, 0x8E);
+    set_id_entry(33, (uint32_t)irq1, 0x08, 0x8E); // PS2 Keyboard
+    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); // PS2 Mouse
+    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);
+}

source/kernel/interrupts/idt/idt.h

@@ -0,0 +1,77 @@
+#pragma once
+
+#include <stdint.h>
+#include <stddef.h>
+#include "../../drivers/vga/colors.h"
+#include "../../drivers/pic/pic.h"
+
+#include "../../terminal/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 ();
+
+
+
+
+}

source/kernel/interrupts/idt/idt.s

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

source/kernel/interrupts/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					

source/kernel/io.cpp

@@ -1,23 +1,28 @@
 #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;
 }
 
 
-void outb_p(unsigned char , unsigned short ){
+void b_p(unsigned char , unsigned short ){
 
 }
 void outw(unsigned short , unsigned short ){
@@ -56,4 +61,12 @@ void outsw(unsigned short , const void *,
 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:" );
+}

source/kernel/io.h

@@ -40,4 +40,5 @@ void outsb(unsigned short port, const void *addr,
 void outsw(unsigned short port, const void *addr,
         unsigned long count);
 void outsl(unsigned short port, const void *addr,
-        unsigned long count);
+        unsigned long count);
+void io_wait();

source/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

source/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

source/kernel/kernel.cpp

@@ -0,0 +1,122 @@
+#include "kernel.h"
+extern "C" void early_main()
+{
+    kterm_init();
+    initGDT();
+
+
+    init_serial();
+    print_serial("Hello Higher half kernel!\n");
+ 
+    init_idt();
+    // Enable interrupts
+    asm volatile("STI");
+
+    /*
+     * Show a little banner for cuteness
+     */
+    printf("|===    BarinkOS       ===|\n");
+    printf("Kernel End Addr: 0x%x\n" , &kernel_end );
+
+    uint32_t PageDirectoryEntryIndex = ((uint32_t)&kernel_end + KERNEL_BASE_ADDR ) >> 22 ;
+
+    uint32_t PageTableEntryIndex = (((uint32_t)&kernel_end + KERNEL_BASE_ADDR) >> 12) & 0x1FFF;
+    
+    printf("Kernel End PDE: %d, PTE: %d\n" , PageDirectoryEntryIndex, PageTableEntryIndex);
+
+    uint32_t BootInfoStruct = BootInfoBlock_pptr + 0xC0000000;
+    printf("Addr BootInfostruct: 0x%x\n", BootInfoStruct);
+
+    uint32_t PageDirectoryEntryIndex2 = (BootInfoStruct  ) >> 2 ;
+
+    uint32_t PageTableEntryIndex2 = (BootInfoStruct >> 12) & 0x1FFF;
+
+    printf("PDE: 0x%x, PTE: 0x%x\n",  PageDirectoryEntryIndex2 , PageTableEntryIndex2 );
+
+    BootInfoBlock* BootInfo = (BootInfoBlock*) ( BootInfoBlock_pptr + 0xC0000000 );
+
+
+    printf("Size of BootInfoBlock: %d bytes\n", sizeof(BootInfoBlock));
+    printf("Bootloader information:\n");
+    if( BootInfo->ValidELFHeader )
+    {
+        printf("- Valid ELF Header is available!\n");
+    }
+
+    if(BootInfo->EnabledVBE)
+    {
+        printf("- VBE graphics mode is available!\n");
+    }
+
+    if(BootInfo->ValidSymbolTable)
+    {
+        printf("- Valid Symbol Table available at 0x%x.\n Tab Size: %d, str Size: %d\n", BootInfo->SymbolTableAddr, BootInfo->SymbolTabSize, BootInfo->SymbolStrSize);
+    }
+
+    if(BootInfo->PhysicalMemoryMapAvailable)
+    {
+        printf("- Physical Memory Map available!\n");
+        printf("MemoryInfoheap size : %d bytes\n", BootInfo->map_size);
+        // Print the memory regions 
+        MemoryInfoBlock* currentBlock = (MemoryInfoBlock*) ((uint32_t)BootInfo->MemoryMap + KERNEL_BASE_ADDR) ;
+
+        printf( "Starting address: 0x%x\n", currentBlock);
+        while( (uint32_t)currentBlock->next != 0x0 )
+        {
+            printf("CurrentBlock: 0x%x \n", (uint32_t ) currentBlock );
+            if(IS_AVAILABLE_MEM(currentBlock->type)){
+                //printf("AVAILABLE RAM\n");
+            }
+            else if(IS_ACPI_MEM(currentBlock->type)){
+                //printf("ACPI MEMORY\n");   
+            }
+            else if(IS_RESERVED_MEM(currentBlock->type)){
+               // printf("RESERVED MEMORY\n");
+            }
+            else if(IS_NVS_MEMORY(currentBlock->type)){
+               // printf("NVS MEMORY \n");
+            }
+            else if(IS_BADRAM_MEMORY(currentBlock->type)){
+               // printf("BADRAM MEMORY \n");
+            }
+            else {
+              //  printf("(TYPE 0x%x )TYPE NOT SPECIFIED\n", currentBlock->type);
+            }
+
+            currentBlock = (MemoryInfoBlock*) ((uint32_t)currentBlock->next + KERNEL_BASE_ADDR );
+          
+        }
+
+        printf("Starting physical memory management setup\n");
+        // Setup PhysicalMemoryManagement
+        SetupPhysicalMemoryManager(BootInfo);
+     
+    }
+    printf("Enable Protected mode and jump to kernel main\n");
+	asm volatile("mov %cr0, %eax ");
+    asm volatile("or $1, %eax");
+    asm volatile("mov %eax, %cr0"); // re-enable protected mode ? 
+    kernel_main();
+    
+}
+
+void PhysicalMemoryAllocatorTest(){
+    #ifdef UNIT_TESTS
+        // Small test!
+        void* block = allocate_block();
+        void* block2 = allocate_block();
+        printf("Allocated addresss 1: 0x%x 2: 0x%x\n", (uint32_t)block ,(uint32_t)block2);
+        free_block(block);
+        free_block(block2);
+        void* block3 = allocate_block();
+        printf("Allocated addresss 3: 0x%x\n", (uint32_t)block3);
+        free_block(block3);
+    #endif
+}
+
+
+extern "C" void kernel_main () {
+    pit_initialise();
+
+    startSuperVisorTerminal();
+}   

source/kernel/kernel.h

@@ -0,0 +1,38 @@
+#pragma once
+extern "C" 
+{
+   #include "lib/string.h" 
+}
+#include "definitions.h"
+
+#include "drivers/vga/VBE.h"
+#include "terminal/kterm.h"
+
+#include "memory/PhysicalMemoryManager.h"
+#include "memory/VirtualMemoryManager.h"
+
+#include "memory/gdt/gdtc.h"
+#include "interrupts/idt/idt.h"
+
+#include "drivers/pit/pit.h"
+#include "io.h"
+#include "cpu.h"
+#include "serial.h"
+
+#include "time.h"
+#include "supervisorterminal/superVisorTerminal.h"
+#include "prekernel/bootstructure.h"
+
+#define CHECK_FLAG(flag, bit) ( flag & (1 << bit ))
+#define PANIC(message) {return;} 
+
+void map_multiboot_info_structure(unsigned long addr);
+
+extern "C" void kernel_main ();
+
+
+extern "C" uint32_t boot_page_directory;
+extern "C" uint32_t multiboot_page_table;
+
+
+const uint32_t KERNEL_BASE_ADDR = 0xC0000000;

source/kernel/lib/mem.h

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

source/kernel/lib/string.c

@@ -0,0 +1,28 @@
+#include "string.h"
+
+size_t strlen(const char* str) {
+    size_t len = 0;
+    while(str[len]){
+        len++;
+    }
+    return len;
+}
+
+
+
+int strncmp ( const char* str1, const char* str2, size_t num ){
+    for( int i = 0; i < num ; i++){
+        
+        if( str1[i] < str2[i]){
+            return -1;
+        } 
+
+        if( str1[i] > str2[i] ){
+            return 1;
+        }
+
+
+    }
+
+    return 0;
+}

source/kernel/lib/string.h

@@ -0,0 +1,6 @@
+#pragma once
+#include <stddef.h>
+size_t strlen(const char* str);
+
+
+int strncmp ( const char* str1, const char* str2, size_t num );

source/kernel/linker.ld

@@ -0,0 +1,46 @@
+ENTRY(_start)
+ 
+/* Tell where the various sections of the object files will be put in the final
+   kernel image. */
+SECTIONS
+{
+	. = 0x00100000;  /* place code at 1MB mark*/
+ 
+	_kernel_start	= .;
+	kernel_begin	= .; /*  For legacy reasons */
+
+
+	.multiboot.data : {
+		*(.multiboot.data)
+	}
+
+	.multiboot.text : {
+		*(multiboot.text)
+		*prekernel.o(.text)
+	}
+
+	. += 0xC0000000; /* Addresses in the following code need to be above the 3Gb mark */
+
+
+	.text ALIGN (4K) : AT (ADDR (.text) - 0xC0000000)
+	{
+		*(.text)
+	}
+	.rodata ALIGN (4K) : AT (ADDR (.rodata) - 0xC0000000)
+	{
+		*(.rodata)
+	}
+	.data ALIGN (4K) : AT (ADDR (.data) - 0xC0000000)
+	{
+		*(.data)
+	}
+	.bss ALIGN (4K) : AT (ADDR (.bss) - 0xC0000000)
+	{
+		*(COMMON)
+		*(.bss)
+		*(.bootstrap_stack)
+	}
+	_kernel_end = .;
+	kernel_end = .; /* For legacy reasons */
+}
+

source/kernel/memory/KernelHeap.cpp

@@ -0,0 +1,52 @@
+#include "KernelHeap.h"
+
+// Size of heap meta data is 5 bytes 
+struct heap_block{
+    uint8_t Used;
+    uint32_t Size;
+}
+
+uint32_t heap_size;
+heap_block* start ;
+
+void* malloc(size_t size)
+{
+    printf("Received request for %d bytes of memory", size);
+    heap_block* current = start;
+
+    // look for a free block
+    while(current <  start + heap_size)
+    {
+        if(current->size >= size && current->Used == false )
+        {
+            // We found a spot 
+            // Set the spot to in-use 
+            current->Used = false;
+            // return the free address 
+            // NOTE: added an offset from the initial address to accomodate for 
+            // meta-data.
+            return current + sizeof(heap_block);
+
+        }
+
+        current += current->Size + sizeof(heap_block);
+    }   
+
+    // If we are here we need more memory so we should 
+    // probably ask the VMM for more 
+    // TODO: ask for more memory | Extend kernel heap
+    
+}
+
+void free(void* addr)
+{
+    // clear the free boolean that corresponds to this adddress
+    // This should be fairly simple
+    heap_block* allocatedBlock = addr - sizeof(heap_block);
+    allocate_block->Used = false;
+}
+
+void initHeap()
+{
+    
+}

source/kernel/memory/KernelHeap.h

@@ -0,0 +1,9 @@
+#pragma once 
+#include <stdint.h>
+
+
+void initHeap();
+
+void* malloc (size_t size );
+void free(void* addr);
+

source/kernel/memory/PhysicalMemoryManager.cpp

@@ -0,0 +1,143 @@
+#include "./PhysicalMemoryManager.h"
+
+PhysicalMemoryManagerInfoBlock* PMMInfoBlock;
+extern uint32_t* boot_page_directory;
+extern uint32_t* boot_page_table;
+
+const uint32_t KERNEL_OFFSET = 0xC0000000;
+void SetupPhysicalMemoryManager( BootInfoBlock* Bootinfo) {
+    // NOTE: Physical memory map will override the boot info for now!
+    PMMInfoBlock = (PhysicalMemoryManagerInfoBlock*) (&BootInfoBlock_pptr + KERNEL_OFFSET );
+    printf("Setting up physical memory infoblock (0x%x) \n", (uint32_t)&PMMInfoBlock);
+    /*
+        Every byte contains 8 pages
+        A page is 4096 kib 
+        Every block (1 bit) represent an page 
+    */
+
+    // Calculate the maximum number of blocks
+    printf("Maxblocks at address(0x%x)\n" , (uint32_t)&(PMMInfoBlock->max_blocks));
+
+    int maximum_blocks = (uint32_t)Bootinfo->MemorySize / BLOCK_SIZE / 8;
+    printf("Set bitmap block maximum: %d\n", maximum_blocks);
+    PMMInfoBlock->max_blocks = maximum_blocks;
+
+    printf("Set used blocks to zero\n");
+    PMMInfoBlock->used_blocks = 0;
+    
+    printf("Determine memory bit map address");
+    // put the map after the gdt
+    PMMInfoBlock->memoryBitMap = (uint32_t*) ( 0xC010b100) ;
+    
+    printf("Maximum num blocks: %d \n",PMMInfoBlock->max_blocks);
+    //Size of memory map 
+    uint32_t memMap_size = PMMInfoBlock->max_blocks / 8;
+    printf("Memory map size: %d\n", memMap_size);
+    printf("Address of memory map 0x%x\n", PMMInfoBlock->memoryBitMap);
+    // Set all places in memory as free
+    memset(PMMInfoBlock->memoryBitMap, 0xFF, memMap_size  ); 
+
+    // Loop over memory map and allocate physical locations 
+    // that are already in use 
+    MemoryInfoBlock* currentBlock = (MemoryInfoBlock*) ((uint32_t)Bootinfo->MemoryMap + KERNEL_OFFSET) ;
+    printf("Starting address: 0x%x\n", currentBlock);
+    while( (uint32_t) currentBlock->next != 0x0)
+    {
+        if(IS_AVAILABLE_MEM(currentBlock->type)){
+            printf("skip!\n");
+        } else {   
+            printf("allocate region 0x%x of size 0x%x\n" , currentBlock->Base_addr, currentBlock->Memory_Size);       
+            allocate_region((uint32_t) currentBlock->Base_addr, currentBlock->Memory_Size);
+        }
+
+        currentBlock = (MemoryInfoBlock*) ((uint32_t)currentBlock->next + KERNEL_OFFSET );
+    }
+
+    uint32_t kernel_size = ((uint32_t)&kernel_end - (uint32_t)&kernel_begin ) - KERNEL_OFFSET;
+
+    printf("kernel size in memory: 0x%x\n", kernel_size);
+    allocate_region((uint32_t)&kernel_begin, kernel_size);
+
+    printf("allocate BIOS region\n");
+    allocate_region (0x0000000, 0x00100000);
+}
+
+// NOTE: This can only give blocks of 4kb at a time!
+//         We might at some point want to allocate multiple blocks at once.
+void* allocate_block() {
+    uint8_t blocks_available = PMMInfoBlock->max_blocks - PMMInfoBlock->used_blocks;
+    // Are there any blocks available?
+    if( blocks_available <= 0)
+    {
+        printf("No blocks available. Blocks Delta: 0x%x\n", blocks_available);
+        return 0;
+    }
+
+    // Find 1 free block somewhere
+    int free_block_index = bitmap_first_unset(PMMInfoBlock->memoryBitMap, PMMInfoBlock->max_blocks / 8 );
+
+    if(free_block_index == -1)
+    {
+        printf("Could not find a good block!\n");
+        // Could not find a block
+        return (void*)0xFFFF;
+    }
+
+    if(free_block_index == 0)
+        printf("Somethings wrong!!!\n");
+
+    // Set the block to be used!
+    bitmap_unset(PMMInfoBlock->memoryBitMap, free_block_index);
+    // Increase the used_block count!
+    PMMInfoBlock->used_blocks++;
+    printf("used blocks: 0x%x\n", PMMInfoBlock->used_blocks);
+    // return the pointer to the physical address
+    return (void*) (BLOCK_SIZE * free_block_index);
+}
+
+void free_block(void* p) {
+    // If it is a null pointer we don't need to do anything.
+    if(p==0) {
+        return;
+    }
+    // calculate the index into the bitmap
+    int index  = ((uint32_t) p) / BLOCK_SIZE;
+    
+    // set the block to be free
+    bitmap_set(PMMInfoBlock->memoryBitMap, index);
+    PMMInfoBlock->used_blocks--;
+    printf("used blocks: 0x%x, after free\n", PMMInfoBlock->used_blocks);
+
+}
+
+void allocate_region(uint32_t startAddress, uint32_t size) {
+    // every bit should be 4KiB 
+    // every byte is 8*4KiB = 32KiB
+    
+    int NumberOfBlocksToAllocate = ( size / 1024) / 4  / 8 + 1;
+    int startBlock = (startAddress / 1024) / 4 / 8 ;
+    
+
+    for( int i = 0; i < NumberOfBlocksToAllocate; i++)
+    {
+        bitmap_unset(PMMInfoBlock->memoryBitMap, startBlock+ i);
+        PMMInfoBlock->used_blocks++;
+    }
+
+
+}
+
+void deallocate_region(uint32_t  StartAddress , uint32_t size ) {
+    // reverse of what happened in allocate_region
+
+    int NumberOfBlocks = (size / 1024) / 4 / 8 + 1;
+    int startBlock = (StartAddress / 1024) / 4 / 8;
+
+    for(int i = 0; i < NumberOfBlocks; i++)
+    {
+        bitmap_set(PMMInfoBlock->memoryBitMap, startBlock + i);
+        PMMInfoBlock->used_blocks --;
+    }
+}
+
+

source/kernel/memory/PhysicalMemoryManager.h

@@ -0,0 +1,26 @@
+#pragma once
+#include <stddef.h>
+#include "../prekernel/bootstructure.h"
+#include "../terminal/kterm.h"
+#include "../lib/mem.h"
+#include "../bitmap.h"
+
+// Asumming i386 for now!
+#define BLOCK_SIZE 4092 
+
+#define IS_ALIGNED(addr, align) !((addr) & ~((align) - 1))
+#define ALIGN(addr, align) (((addr) & ~((align) - 1 )) + (align))
+
+struct PhysicalMemoryManagerInfoBlock
+{
+    uint32_t* memoryBitMap;
+    uint32_t pmmap_size;
+    uint32_t max_blocks;
+    int used_blocks;
+};
+
+void SetupPhysicalMemoryManager(BootInfoBlock* memory);
+void free_block(void* ptr);
+void* allocate_block();
+void allocate_region(uint32_t, uint32_t);
+void deallocate_region(uint32_t   , uint32_t );

source/kernel/memory/VirtualMemoryManager.cpp

@@ -0,0 +1,73 @@
+#include "VirtualMemoryManager.h"
+extern uint32_t boot_page_directory[1024] ;
+extern uint32_t boot_page_table[1024];
+void AllocatePage(uint32_t vaddr)
+{
+    uint32_t page_aligned_address = ALIGN(vaddr, 4096);
+
+    // allocate a page at  virtual address
+    int PageDirectoryEntryIndex = vaddr >> 22;
+    int PageTableEntryIndex = (vaddr >> 12) & 0x1FFF;
+
+    printf("Allocation happening at PDE: %d PTE: %d\n", PageDirectoryEntryIndex, PageTableEntryIndex);
+
+    // check if the page directory entry is marked as present 
+    if (boot_page_directory[PageDirectoryEntryIndex] & 0x1 ) {
+
+        uint32_t* page_table = (uint32_t*)((boot_page_directory[PageDirectoryEntryIndex]) & 0xFFFFE000 + 0xC0000000);
+
+        // check if the page table entry is marked as present 
+        if ( page_table[PageTableEntryIndex] & 0x1 )
+        {   
+            // Map the entry to a physical page
+            page_table[PageTableEntryIndex] = (uint32_t)(allocate_block() + 0x3);
+        } else{
+            // mark page as present
+            page_table[PageTableEntryIndex] =   0x3;
+        }
+
+    } else {
+        // mark the page table as present and allocate a physical block for it
+        boot_page_directory[PageDirectoryEntryIndex] = (uint32_t)(allocate_block() + 0x3);
+    }
+
+
+}
+
+void FreePage(uint32_t vaddr )
+{
+    uint32_t page_aligned_address = ALIGN(vaddr, 4096);
+
+    // allocate a page at  virtual address
+    int PageDirectoryEntryIndex = vaddr >> 22;
+    int PageTableEntryIndex = (vaddr >> 12) & 0x1FFF;
+
+    uint32_t* pageTable = (uint32_t*)(boot_page_directory[PageDirectoryEntryIndex] & 0xFFFFE000 + 0xC0000000);
+
+
+    void* physicalAddressToFree = (void*)(pageTable[PageTableEntryIndex] & 0xFFFFE000 + 0xC0000000);
+    free_block(physicalAddressToFree);
+
+    pageTable[PageTableEntryIndex] = 0x0;
+
+
+}
+
+void Map (  uint32_t vaddr, uint32_t paddr)
+{
+    uint32_t page_aligned_address = ALIGN(vaddr, 4096);
+
+    // allocate a page at  virtual address
+    int PageDirectoryEntryIndex = vaddr >> 22;
+    int PageTableEntryIndex = (vaddr >> 12) & 0x1FFF;
+}
+
+void Unmap(uint32_t vaddr)
+{
+    // NOTE: I will implement lazy unmapping for now 
+    uint32_t page_aligned_address = ALIGN(vaddr, 4096);
+
+    // allocate a page at  virtual address
+    int PageDirectoryEntryIndex = vaddr >> 22;
+    int PageTableEntryIndex = (vaddr >> 12) & 0x1FFF;
+}

source/kernel/memory/VirtualMemoryManager.h

@@ -0,0 +1,10 @@
+#pragma once 
+#include "PhysicalMemoryManager.h"
+#include "../terminal/kterm.h"
+#include "../cpu.h"
+
+void AllocatePage(uint32_t v_addr );
+void FreePage(uint32_t v_addr);
+
+void Map(uint32_t p_addr, uint32_t v_addr);
+void Unmap (uint32_t v_addr);

source/kernel/memory/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
+		
+	
+

source/kernel/memory/gdt/gdtc.cpp

@@ -0,0 +1,58 @@
+#include "gdtc.h"
+#include "../../terminal/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(){
+
+#ifdef __VERBOSE__
+      printf("Init GDT!\n");
+#endif
+      // 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("GDT at address 0x%x, with an size of 0x%x bytes\n" , (unsigned int)GlobalDescriptorTable, sizeof(GlobalDescriptorTable));
+
+      LoadGlobalDescriptorTable();
+
+}

source/kernel/memory/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();

source/kernel/prekernel/bootstructure.h

@@ -0,0 +1,45 @@
+#pragma once 
+#include <stddef.h>
+#include <stdint.h>
+
+extern "C" const uint32_t kernel_begin;
+extern "C" const uint32_t kernel_end;
+
+#define IS_AVAILABLE_MEM(MEM_TYPE) MEM_TYPE & 0x1
+#define IS_ACPI_MEM(MEM_TYPE) MEM_TYPE & 0x2
+#define IS_RESERVED_MEM(MEM_TYPE) MEM_TYPE & 0x4
+#define IS_NVS_MEMORY(MEM_TYPE) MEM_TYPE & 0x8
+#define IS_BADRAM_MEMORY(MEM_TYPE) MEM_TYPE & 0x10
+           
+struct MemoryInfoBlock {
+    uint32_t Base_addr ;
+    uint32_t Memory_Size;
+    MemoryInfoBlock* next;
+    uint8_t  type;
+
+};
+struct BootInfoBlock {
+    bool MapIsInvalid;
+    uint32_t bootDeviceID ;
+
+    uint32_t GrubModuleCount;
+
+    bool ValidSymbolTable;
+    uint32_t SymbolTableAddr;
+    uint32_t SymbolTabSize;
+    uint32_t SymbolStrSize;
+
+    bool ValidELFHeader;
+
+    bool EnabledVBE;
+
+    bool PhysicalMemoryMapAvailable;
+    MemoryInfoBlock* MemoryMap;
+    uint32_t map_size;
+    uint32_t MemorySize ;
+
+};
+
+// TODO Put the BootInfoBlock 1MB above the kernel.
+const uint32_t BootInfoBlock_pptr = (uint32_t)&kernel_end - 0xC0000000 + 0x1;
+const uint32_t MemoryMapHeap_pptr = BootInfoBlock_pptr + sizeof(BootInfoBlock);

source/kernel/prekernel/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 */

source/kernel/prekernel/prekernel.cpp

@@ -0,0 +1,120 @@
+#include <stdint.h>
+#include <stddef.h>
+#include "multiboot.h"
+#include "bootstructure.h"
+#define CHECK_FLAG(flags, bit) ((flags) & (1 <<(bit)))
+
+
+extern "C" void prekernelSetup  ( unsigned long magic, multiboot_info_t* mbi) {
+  
+  // Create the bootInfoBlock at its location
+  BootInfoBlock* BIB = (BootInfoBlock*) BootInfoBlock_pptr;
+
+  /*
+   * Check Multiboot magic number
+   */ 
+  if (magic != MULTIBOOT_BOOTLOADER_MAGIC)
+  {
+        BIB->MapIsInvalid = true;
+        // crash
+        return;
+  } else{
+        BIB->MapIsInvalid = false;
+  }
+
+  /* is boot device valid ? */
+  if (CHECK_FLAG (mbi->flags, 1))
+  {
+        BIB->bootDeviceID = mbi->boot_device;
+  } else{
+        BIB->bootDeviceID = 0x11111111;
+  }
+
+  /* Are mods_* valid? */
+  if(CHECK_FLAG ( mbi->flags, 3)){
+      multiboot_module_t *mod;
+      uint32_t i;
+
+      BIB->GrubModuleCount = mbi->mods_count;
+
+
+      for(i = 0, mod = (multiboot_module_t *) mbi->mods_addr; i < mbi->mods_count; i++ , mod++){
+                
+      }
+  }
+
+  /* Is the symbol table of a.out valid? */
+  if (CHECK_FLAG(mbi->flags, 4))
+  {
+          BIB->ValidSymbolTable = true;
+          multiboot_aout_symbol_table_t *multiboot_aout_sym = &(mbi->u.aout_sym);
+
+  } else{
+          BIB->ValidSymbolTable = false;
+  }
+
+  /* Is the section header table of ELF valid? */
+  if (CHECK_FLAG(mbi->flags, 5))
+  {
+          BIB->ValidELFHeader = true;
+          multiboot_elf_section_header_table_t *multiboot_elf_sec = &(mbi->u.elf_sec);
+
+  }else{
+          BIB->ValidELFHeader = false;
+  }
+/*
+If we got a memory map from our bootloader we 
+should be parsing it to find out the memory regions available.
+*/
+if (CHECK_FLAG(mbi->flags, 6))
+{  
+        BIB->PhysicalMemoryMapAvailable = true;
+        BIB->MemoryMap = (MemoryInfoBlock*) MemoryMapHeap_pptr;
+        multiboot_memory_map_t *mmap = (multiboot_memory_map_t*) (mbi->mmap_addr) ;
+        auto MemoryMapEnd =  mbi->mmap_addr + mbi->mmap_length;
+        
+        auto CurrentInfoBlock = BIB->MemoryMap;
+      
+        uint32_t RAM_size = 0;
+
+        while((unsigned long) mmap < MemoryMapEnd){
+                BIB->map_size += sizeof(MemoryInfoBlock);
+                CurrentInfoBlock->Base_addr = mmap->addr;
+                CurrentInfoBlock->Memory_Size = mmap->len;
+                
+
+                if(mmap->type == MULTIBOOT_MEMORY_AVAILABLE)
+                        CurrentInfoBlock->type |= 0x1;
+                        RAM_size += mmap->len;
+                if(mmap->type == MULTIBOOT_MEMORY_ACPI_RECLAIMABLE)
+                        CurrentInfoBlock->type |= 0x2;
+                if(mmap->type == MULTIBOOT_MEMORY_RESERVED)
+                        CurrentInfoBlock->type |= 0x4;
+                if(mmap->type == MULTIBOOT_MEMORY_NVS)
+                        CurrentInfoBlock->type |= 0x8;
+                if(mmap->type == MULTIBOOT_MEMORY_BADRAM)
+                        CurrentInfoBlock->type |= 0x10;
+                
+
+                // continue to the next block
+                mmap = (multiboot_memory_map_t *) ((unsigned long) mmap + mmap->size + sizeof(mmap->size));
+              
+              CurrentInfoBlock->next = (MemoryInfoBlock*) ((uint32_t)CurrentInfoBlock) + sizeof(MemoryInfoBlock);
+              CurrentInfoBlock = CurrentInfoBlock->next;
+
+        }
+
+        CurrentInfoBlock->next = (MemoryInfoBlock*) 0x0;
+        BIB->MemorySize = RAM_size;
+} else
+{
+        BIB->PhysicalMemoryMapAvailable = false;
+}
+    
+  /* Draw diagonal blue line */
+  if (CHECK_FLAG (mbi->flags, 12)){
+          BIB->EnabledVBE = true;
+  } else{
+          BIB->EnabledVBE;
+  }
+}

source/kernel/serial.h

@@ -1,36 +1,14 @@
-#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();
-};
-
-
-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");
-}
+#pragma once
 
+#include "terminal/kterm.h"
+#include "io.h"
 #define PORT 0x3f8 
 static int init_serial() {
+
+#ifdef __VERBOSE__
+   printf("Init Serial\n");
+#endif
+   
    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
@@ -52,7 +30,6 @@ static int init_serial() {
    return 0;
 }
 
-
 int is_transmit_empty() {
    return inb(PORT + 5) & 0x20;
 }
@@ -73,6 +50,11 @@ char read_serial() {
    return inb(PORT);
 }
 
+void print_serial(const char* string ){
+    for(size_t i = 0; i < strlen(string); i ++){
+        write_serial(string[i]);
+    }
+}
 
 void test_serial(){
         /** Serial test **/
@@ -91,46 +73,3 @@ void test_serial(){
 
         kterm_writestring("\n");
 }
-
-
-extern "C" {
-    void kernel_main (void) {
-        /** initialize terminal interface */ 
-        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");
-        }
-    
-
-        /** Test objective cpp **/
-        kterm_writestring("Testing C++ object support\n");
-        auto testObject = Test();
-        testObject.printMe();
-
-        /** Setup the MMU **/
-        kterm_writestring("Starting MMU...\n");
-        auto mmu = MMU();
-        mmu.enable();
-        kterm_writestring("MMU enabled!\n");
-
-        
-
-
-        /** 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();
-
-    
-    }   
-}

source/kernel/supervisorterminal/superVisorTerminal.cpp

@@ -0,0 +1,72 @@
+#include "superVisorTerminal.h"
+
+void startSuperVisorTerminal(){
+    while (true){
+           
+           printf("SUPERVISOR:>$ " );
+            int characterCount = 0;
+            char command[10] = "";
+         
+            // NOTE: lets just show a kernel prompt                
+            uint8_t ScanCode = getKey();
+            while( ScanCode  != 0x1C )
+            {
+                char character = getASCIIKey();
+                kterm_put(character );
+                // wHAT THE HELL
+
+                if( characterCount  < 10 ){
+                    command[characterCount] = character;  
+                    characterCount++;
+                }
+
+                ScanCode = getKey(); 
+            }
+            printf("\n");
+            KeyHandled();
+         
+
+            if ( strncmp("DATE", command , characterCount ) == 0 )
+            {
+                 read_rtc();
+                 printf("======= Time & Date ==========\n");
+                 printf("   - Date:     %02d-%02d-%02d\n",day, month, year);
+                 printf("   - Time:     %02d:%02d:%02d\n" , hour, minute, second);
+                 printf("   - Ticks:    %09d\n", pit_tick);            
+            }
+            else if( strncmp ("MEMORY" , command , characterCount) == 0 )
+            {
+                // Show memory layout
+                printf("========= Memory ==========\n");
+                printf("Not Available!\n");
+                printf("Kernel MemoryMap:\n");
+                printf("Frames used: -- \n");   
+                printf("Available Memory:-- \n");
+                printf("Reserved Memory: -- bytes\n");
+            }
+            else if(strncmp("TEST", command, characterCount) == 0)
+            {
+                // TEST #DE exception
+               asm volatile ("MOV $4, %AX ;  MOV $0, %BX ; DIV %BX"); // IRS 0
+            }
+            else if (strncmp("VERSION", command , characterCount) == 0)
+            {
+                // Show version information 
+                printf("========= Version ========\n");
+                printf("Kernel v%d\n", 0);
+
+            }
+            else if(strncmp("CLEAR", command, characterCount) == 0)
+            {
+                kterm_init();
+                printf("|===    BarinkOS       ===|\n");
+            }
+            else
+            {
+                printf("Unknown command\n");
+            }
+
+
+            delay(1000);
+        }   
+}

source/kernel/supervisorterminal/superVisorTerminal.h

@@ -0,0 +1,8 @@
+#pragma once 
+#include "../terminal/kterm.h"
+#include "../time.h"
+#include "../drivers/pit/pit.h"
+#include "../drivers/ps-2/keyboard.h"
+#include "../memory/PhysicalMemoryManager.h"
+
+void startSuperVisorTerminal();

source/kernel/terminal/kterm.cpp

@@ -0,0 +1,232 @@
+#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*) 0xC03FF000;
+    
+    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));
+}
+
+
+static 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, ...) {
+    
+    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;
+            }
+        }
+    }
+}

source/kernel/terminal/kterm.h

@@ -0,0 +1,45 @@
+#pragma once 
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+
+#include "../drivers/vga/colors.h"
+#include "../io.h"
+
+extern "C"{
+    #include "../lib/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);
+
+
+void printf ( const char *format, ...);
+
+//static void itoa (char *buf, int base, int d);
+
+#define KernelTag "[Kernel]: "
+#define AS_KERNEL() (  kterm_setcolor(VGA_COLOR_LIGHT_BLUE),\
+                       kterm_write(KernelTag, 10 ), \
+                       kterm_resetcolor())
+
+

source/kernel/time.cpp

@@ -0,0 +1,111 @@
+#include "time.h"
+
+// Set by ACPI table parsing code if possible
+int century_register = 0x00;     
+unsigned char second;
+unsigned char minute;
+unsigned char hour;
+unsigned char day;
+unsigned char month;
+unsigned int year;
+ 
+
+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 delay(int t){
+    volatile int i,j;
+    for(i=0;i<t;i++)
+        for(j=0;j<25000;j++)
+            asm("NOP");
+}

source/kernel/time.h

@@ -0,0 +1,23 @@
+#pragma once 
+#include "io.h"
+#define CURRENT_YEAR        2021
+ 
+                           
+extern int century_register;     
+extern unsigned char second;
+extern unsigned char minute;
+extern unsigned char hour;
+extern unsigned char day;
+extern unsigned char month;
+extern unsigned int year;
+
+ 
+enum {
+      cmos_address = 0x70,
+      cmos_data    = 0x71
+};
+ 
+int get_update_in_progress_flag();
+unsigned char get_RTC_register();
+void read_rtc();
+void delay(int t);

source/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);
+
+
+}

source/kernel/timer.h

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

src/kernel/MMU.cpp

@@ -1,35 +0,0 @@
-#include "MMU.h"
-
-
-
-void MMU::enable(){
-
-    //set each entry to not present
-    int i;
-    for(i = 0; i < 1024; i++)
-    {
-        // This sets the following flags to the pages:
-        //   Supervisor: Only kernel-mode can access them
-        //   Write Enabled: It can be both read from and written to
-        //   Not Present: The page table is not present
-        this->page_directory[i] = 0x00000002;
-    }
-
-    // holds the physical address where we want to start mapping these pages to.
-    // in this case, we want to map these pages to the very beginning of memory.
-
-    //we will fill all 1024 entries in the table, mapping 4 megabytes
-    for(unsigned int i = 0; i < 1024; i++)
-    {
-    // As the address is page aligned, it will always leave 12 bits zeroed.
-    // Those bits are used by the attributes ;)
-    first_page_table[i] = (i * 0x1000) | 3; // attributes: supervisor level, read/write, present.
-    }
-
-    // attributes: supervisor level, read/write, present
-    this->page_directory[0] = ((unsigned int)first_page_table) | 3;
-
-
-    loadPageDirectory(this->page_directory);
-    enablePaging();
-}

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/linker.ld

@@ -1,43 +0,0 @@
-/* The bootloader will look at this image and start execution at the symbol
-   designated as the entry point. */
-ENTRY(_start)
- 
-/* Tell where the various sections of the object files will be put in the final
-   kernel image. */
-SECTIONS
-{
-	/* Begin putting sections at 1 MiB, a conventional place for kernels to be
-	   loaded at by the bootloader. */
-	. = 1M;
- 
-	/* 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. */
-	.text BLOCK(4K) : ALIGN(4K)
-	{
-		*(.multiboot)
-		*(.text)
-	}
- 
-	/* Read-only data. */
-	.rodata BLOCK(4K) : ALIGN(4K)
-	{
-		*(.rodata)
-	}
- 
-	/* Read-write data (initialized) */
-	.data BLOCK(4K) : ALIGN(4K)
-	{
-		*(.data)
-	}
- 
-	/* Read-write data (uninitialized) and stack */
-	.bss BLOCK(4K) : ALIGN(4K)
-	{
-		*(COMMON)
-		*(.bss)
-	}
- 
-	/* 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. */
-}

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/kernel.h

@@ -1,7 +0,0 @@
-#pragma once 
-extern "C" {
-#include "../libc/include/string.h"
-#include "arch/i386/tty/kterm.h"
-}
-#include "MMU.h"
-#include "io.h"

src/libc/include/string.h

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

todo.md

@@ -0,0 +1,21 @@
+# TODO list
+
+![Todo image](https://camo.githubusercontent.com/c43d969d9d071c8342e9a69cdd6acb433c541f431127738974ce22290c46f2b8/68747470733a2f2f692e696d6775722e636f6d2f4f764d5a4273392e6a7067)
+
+
+This list keeps me focused and organised so I don't forget what
+needs to be done. It is a expansion on the features markdown file which describes the features. Here I put things I need to remember 
+to do on a more in depth level.
+
+## --
+[ ] Setup paging  \
+[ ] HELP command   
+[ ] Setup a proper HEAP \
+[ ] Setup a proper Stack \
+[ ] Setup KMalloc and KFree \
+[ ] Merge Functioning Feature branches into sandboxKernelDev \
+[ ] Remove merged feature branches \
+[ ] Merge sandboxKernelDev with dev \
+[ ] Remove sandboxKernelDev branch \
+[ ] Implement proper virtual filesystem 
+