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

Makefile

@@ -5,7 +5,7 @@ CC = ${HOME}/opt/cross/bin/i686-elf-gcc
 CPP = ${HOME}/opt/cross/bin/i686-elf-g++ 
 CFLAGS =  -ffreestanding -Og -ggdb  -Wall -Wextra
 
-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  $(BUILD_DIR)/prekernel.o
+OFILES =$(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 = source
 BUILD_DIR = build
@@ -55,10 +55,10 @@ $(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:
-	$(CPP) -c $(SRC_DIR)/kernel/Terminal/kterm.cpp  -o $(BUILD_DIR)/kterm.o $(CFLAGS) -fno-exceptions -fno-rtti
+	$(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/Boot/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/crti.s -o $(BUILD_DIR)/crti.o
@@ -71,38 +71,41 @@ $(BUILD_DIR)/io.o:
 
 
 $(BUILD_DIR)/idt.o:
-	$(CPP) -c $(SRC_DIR)/kernel/Interrupts/idt/idt.cpp -o $(BUILD_DIR)/idt.o $(CFLAGS) -fno-exceptions -fno-rtti
+	$(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
+	$(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
+	$(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
+	$(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
+	$(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
+	$(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
+	$(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
+	$(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
+	$(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
+	$(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

source/kernel/Memory/MBIMMap/MBI_MMap.cpp

@@ -1,44 +0,0 @@
-#include "MBI_MMap.h"
-
-/*
-void mapMultibootMemoryMap( MemoryInfo* memInfo , multiboot_info_t *mbt) {
-
-    printf("mmap_addr = 0x%x, mmap_length = 0x%x\n", (unsigned) mbt->mmap_addr , (unsigned) mbt->mmap_length );
-
-
-    multiboot_memory_map_t *mmap = (multiboot_memory_map_t*) mbt->mmap_addr;
-
-    for (;  (unsigned long) mmap <  mbt->mmap_addr + mbt->mmap_length;  mmap = (multiboot_memory_map_t *) ((unsigned long) mmap + mmap->size + sizeof(mmap->size))){
-
-        if ( mmap->type == MULTIBOOT_MEMORY_AVAILABLE){
-    
-            memInfo->TotalMemory +=  mmap->len;   
-        } else {
-            memInfo->ReservedMemory += mmap->len;
-        }
-        
-        print_Multiboot_memory_Map(mmap);
-            
-    }
-}
-
-
-*/
-/**
- * @brief Debug Verbose functions
- * 
- * @param mmap 
- */
-/*
-void print_Multiboot_memory_Map(multiboot_memory_map_t* mmap) {
-    printf(
-        "size = 0x%x, base_addr = 0x%x%08x, length = 0x%x%08x, type = 0x%x\n",
-        (unsigned) mmap->size,
-        (unsigned) (mmap->addr >> 32),
-        (unsigned) (mmap->addr & 0xffffffff),
-        (unsigned) (mmap->len >> 32),
-        (unsigned) (mmap->len & 0xffffffff),
-        (unsigned) mmap->type
-    );
-}
-*/

source/kernel/Memory/MBIMMap/MBI_MMap.h

@@ -1,18 +0,0 @@
-#pragma once 
-#include <stddef.h>
-//#include "../../multiboot.h"
-#include "../memoryinfo.h"
-
-void initialise_available_regions(uint32_t memoryMapAddr, uint32_t memoryMapLastAddr, uint32_t* memoryBitMap, int* used_blocks);
-
-/*
-void mapMultibootMemoryMap( MemoryInfo* memInfo , multiboot_info_t *mbt);
-*/
-/**
- * @brief Debug Verbose Functions
- * 
- * @param mmap 
- */
-/*
-void print_Multiboot_memory_Map(multiboot_memory_map_t* mmap);
-*/

source/kernel/Memory/VirtualMemoryManager.cpp

@@ -1,24 +0,0 @@
-#include "VirtualMemoryManager.h"
-
-extern "C" void loadPageDirectory (uint32_t* addr );
-extern "C" void enablePaging();
-
-void AllocatePage(uint32_t vaddr)
-{
-
-}
-
-void FreePage(uint32_t vaddr )
-{
-
-}
-
-void Map (  uint32_t vaddr, uint32_t paddr)
-{
-
-}
-
-void Unmap(uint32_t vaddr)
-{
-    // NOTE: I will implement lazy unmapping for now 
-}

source/kernel/Memory/memoryinfo.h

@@ -1,20 +0,0 @@
-#pragma once
-#include <stdint.h>
-#include <stddef.h>
-
-struct MemoryArea{
-    void* StartAddress;
-    size_t Size;
-    unsigned int type;
-    MemoryArea* Next;
-
-}__attribute__((packed));
-
-struct MemoryInfo {
-    uint32_t TotalMemory;
-    uint32_t ReservedMemory;
-    MemoryArea* MemoryRegionList;
-}__attribute__((packed));
-
-
-

source/kernel/Memory/paging.definitions.h

@@ -1,56 +0,0 @@
-#pragma once
-#include <stdint.h>
-/*
-    This file contains some handy definitions for different types 
-    that have to do with paging in atleast 32 bit and maybe sometime in the future
-    also 64 bit mode.
-*/
-
-#define MAX_DIRECTORY_ENTRIES 1024
-#define MAX_PAGE_TABLE_ENTRIES 1024
-#define MAX_PAGES 1024
-
-#define PHYSICAL_ADDRESS uint32_t 
-#define VIRTUAL_ADDRESS uint32_t
-
-#define PageDirectoryEntry uint32_t
-#define PageTableEntry uint32_t
-
-
-#define KERNEL_VRT_MEMORY_BEGIN 0xC0000000
-#define KERNEL_VRT_MEMORY_END   0xCFFFFFFF
-#define PAGE_SIZE  4096;
-
-
-// NOTE: FIXME: I am fairly certain these masks are off by one!
-
-#define PD32_PRESENT_MASK                   (0x1 << 0)
-#define PD32_READ_WRITE_MASK                (0x1 << 1)
-#define PD32_SUPERVISOR_MASK                (0x1 << 2)
-#define PD32_WRITE_THROUGH_MASK             (0x1 << 3)
-#define PD32_CACHE_DISABLE_MASK             (0x1 << 4)
-#define PD32_ACCESSED_MASK                  (0x1 << 5)
-#define PD32_AVAILABLE_1_4KB_MASK           (0x1 << 6)
-#define PD32_DISABLE_4MB_MASK               (0x1 << 6)
-#define PD32_PAGE_SIZE_MASK                 (0x1 << 7)
-#define PD32_GLOBAL_4MB_MASK                (0x1 << 8)
-#define PD32_AVAILABLE_2_4MB_MASK           ( 14 << 9)
-#define PD32_AVAILABLE_2_4KB_MASK           ( 15 << 8)
-#define PD32_ADDRESS_4KB_MASK               (0x8FFFF << 12)
-#define PD32_PAGE_ATTRIBUTE_TABLE_4MB_MASK  (0x1 << 12)
-#define PD32_HIGH_HALF_ADDRESS_4MB_MASK     (0x7F<< 13)
-#define PD32_RESERVED_4MB_MASK              (0x1 << 21)
-#define PD32_LOWER_HALF_ADDRESS_4MB_MASK    (0x1FF << 22)
-
-#define PT32_PRESENT_MASK                   (0x1 << 0)
-#define PT32_READ_WRITE_MASK                (0x1 << 1)
-#define PT32_SUPERVISOR_MASK                (0x1 << 2)
-#define PT32_WRITE_THROUGH_MASK             (0x1 << 3)
-#define PT32_CACHE_DISABLE_MASK             (0x1 << 4)
-#define PT32_ACCESSED_MASK                  (0x1 << 5)
-#define PT32_DIRTY_MASK                     (0x1 << 6)
-#define PT32_PAGE_ATTRIBUTE_TABLE_MASK      (0x1 << 7)
-#define PT32_GLOBAL_MASK                    (0x1 << 8)
-#define PT32_AVAILABLE_MASK                 (0x7 << 9)
-#define PT32_CACHE_DISABLE_MASK             (0x7FFFF << 12)
-

source/kernel/Memory/paging.s

@@ -1,44 +0,0 @@
-# NOTE: I wish this wasn't AT&T Syntax its horrible
-# REMINDER: INSTRUCTION FROM_REGISTER, TO_REGISTER
-.globl enablePaging
-enablePaging:
-	# Create a new call frame 
-	push %ebp
-	mov %esp, %ebp
-
-	# Set the PG bit of CR0
-	mov %cr0, %eax
-	or $0x80000000, %eax
-	mov %eax, %cr0
-
-	# Restore to the previous call frame 
-	mov %ebp, %esp
-	pop %ebp
-	ret
-
-.globl loadPageDirectory
-loadPageDirectory:
-	push %ebp
-	mov %esp, %ebp
-
-	/* NOTE: We should probably check if paging is already enabled.
-		Changing the CR3 register whilst paging is enabled might 
-		result in unwanted behaviour (in the worst case) or cause a 
-		fault (in the best case).
-	*/
-
-	mov 8(%esp), %eax # Move the first argument in the eax register
-
-	mov %eax, %cr3  # Move the value of eax into the CR3 register
-
-	/*
-		Moving the value of the argument  passed to this function 
-		into the CR3 register will allow the MMU to access the paging 
-		structure we setup in memory once we enable paging
-	*/
-
-	mov %ebp, %esp
-	pop %ebp
-	ret
-
-

source/kernel/SuperVisorTerminal/superVisorTerminal.h

@@ -1,9 +0,0 @@
-#pragma once 
-#include "../Terminal/kterm.h"
-#include "../time.h"
-#include "../Drivers/PIT/pit.h"
-#include "../Drivers/PS-2/keyboard.h"
-#include "../Memory/PhysicalMemoryManager.h"
-#include "../bootinfo.h"
-
-void startSuperVisorTerminal(BootInfo * );

source/kernel/boot/boot.s

@@ -1,4 +1,4 @@
-.include "./source/kernel/Boot/Multiboot.S"
+.include "./source/kernel/boot/multiboot.s"
 /*
 *	Allocate initial stack
 */
@@ -17,6 +17,7 @@ stack_top:
 .globl boot_page_directory
 boot_page_directory:
 	.skip 4096
+.globl boot_page_table
 boot_page_table:
 	.skip 4096
 .globl multiboot_page_table
@@ -60,15 +61,6 @@ _start:
 3:	# Map VGA video memory to 0xC03FF00 as "present, writable"
 	movl $(0x000B8000 | 0x003), boot_page_table - 0xC0000000 + 1023 * 4
 
-	# IMPORTANT NOTE FROM WIKI.OSDEV.ORG/HIGHER_HALF_X86_BARE_BONES
-
-	# The page table is used at both page directory entry 0 (virtually from 0x0
-	# to 0x3FFFFF) (thus identity mapping the kernel) and page directory entry
-	# 768 (virtually from 0xC0000000 to 0xC03FFFFF) (thus mapping it in the
-	# higher half). The kernel is identity mapped because enabling paging does
-	# not change the next instruction, which continues to be physical. The CPU
-	# would instead page fault if there was no identity mapping.\
-	
 	# 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
@@ -112,11 +104,9 @@ isPaging:
 	jmp 1b
 
 
-.include "./source/kernel/Memory/GDT/gdt.s"
+.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"
-.include "./source/kernel/Memory/paging.s"
-.include "./source/kernel/cpu.s"
+.include "./source/kernel/interrupts/idt/idt.s"
 
 

source/kernel/bootinfo.h

@@ -1,8 +0,0 @@
-#pragma once
-#include "Memory/memoryinfo.h"
-
-struct BootInfo{
-    const char* BootStructureID = "BarinkOS";
-    MemoryInfo* memory;
-
-}; 

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

@@ -1,4 +1,5 @@
 #pragma once
+#include <stdint.h>
 
 /*
 Based on Intel specifications.
@@ -8,19 +9,18 @@ C++ interface for the cpu.s assembly file.
 ©Nigel Barink - 2022 
 */
 
-
 /*
 *       EFLAGS FUNCTIONS
 */
 
-extern "C" uint32_t GetEFLAGS();
+uint32_t GetEFLAGS();
 
 
 
 /*
 *       CONTROL_REGISTER_0 FUNCTIONS
 */
-extern "C" uint32_t GetCR0();
+uint32_t GetCR0();
 
 /*
  struct CR0_Register  {
@@ -56,7 +56,7 @@ extern "C" uint32_t GetCR0();
 *       CONTROL_REGISTER_4 FUNCTIONS
 */
 
-extern "C" uint32_t GetCR4();
+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)
@@ -65,10 +65,10 @@ extern "C" uint32_t GetCR4();
 *       CONTROL_REGISTER_2 FUNCTIONS
 */
 
-extern "C" uint32_t GetCR2();
+uint32_t GetCR2();
 
 /*
 *       CONTROL_REGISTER_3 FUNCTIONS
 */
 
-extern "C" uint32_t GetCR3();
+uint32_t GetCR3();

source/kernel/cpu.s

@@ -1,63 +0,0 @@
-# Basic cpu functions 
-.globl GetCR0
-GetCR0:
-	push %ebp # save the base pointer on the stack
-	mov %esp, %ebp  # Set the base pointer to the current stack pointer 
-
-	xor %eax, %eax # Clear EAX to make sure no weird stuff is going on
-	mov %cr0, %eax # Copy the value of the CR0 register into EAX
-
-	mov %ebp, %esp # restore the base pointer 
-	pop %ebp
-	ret
-
-.globl GetCR4
-GetCR4:
-	push %ebp
-	mov %esp, %ebp
-
-	xor %eax, %eax
-	mov %cr4, %eax 
-
-	mov %ebp, %esp 
-	pop %ebp
-	ret
-
-
-
-.globl GetEFLAGS
-GetEFLAGS:
-	push %ebp 
-	mov %esp, %ebp
-
-	xor %eax, %eax 
-	pushfl # Push the EFLAGS register content onto the stack, should be pushfd but GAS apparently doesn't agree
-	mov 4(%esp) , %eax
-
-	mov %ebp, %esp
-	pop %ebp
-	ret
-
-.globl GetCR2
-GetCR2:
-	push %ebp
-	mov %esp, %ebp
-
-	xor %eax, %eax
-	mov %cr2, %eax
-	
-	mov %ebp, %esp
-	pop %ebp
-	ret
-	
-.globl GetCR3
-GetCR3:
-	push %ebp
-	mov %esp, %ebp
-
-	xor %eax, %eax
-	mov %cr3, %eax
-	
-	mov %ebp, %esp
-	pop %ebp
-	ret

source/kernel/drivers/pit/pit.cpp

@@ -1,5 +1,5 @@
 #include "pit.h"
-#include "../../Terminal/kterm.h"
+
 uint32_t pit_tick = 0;
 
 

source/kernel/drivers/pit/pit.h

@@ -1,6 +1,7 @@
 #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

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

@@ -1,6 +1,6 @@
 #pragma once
 #include <stdint.h>
-#include "../../Terminal/kterm.h"
+#include "../../terminal/kterm.h"
 enum ScanCodeSet {
     None            =   0,
     ScanCodeSet1    =   1,

source/kernel/interrupts/idt/idt.cpp

@@ -1,6 +1,6 @@
 #include "idt.h"
-#include "../../Drivers/PIT/pit.h"
-#include "../../Drivers/PS-2/keyboard.h"
+#include "../../drivers/pit/pit.h"
+#include "../../drivers/ps-2/keyboard.h"
 #include "../../cpu.h"
 IDT_entry idt_table[256];
 IDT_ptr idt_ptr;

source/kernel/interrupts/idt/idt.h

@@ -1,11 +1,11 @@
 #pragma once
 
-#include "stdint.h"
-#include "stddef.h"
-#include "../../Drivers/VGA/colors.h"
-#include "../../Drivers/PIC/pic.h"
+#include <stdint.h>
+#include <stddef.h>
+#include "../../drivers/vga/colors.h"
+#include "../../drivers/pic/pic.h"
 
-#include "../../Terminal/kterm.h"
+#include "../../terminal/kterm.h"
 
 
 extern "C" {

source/kernel/kernel.cpp

@@ -1,11 +1,6 @@
 #include "kernel.h"
 extern "C" void early_main()
 {
-    /*
-     * Initialize terminal interface 
-     */ 
-
-
     kterm_init();
     initGDT();
 
@@ -21,7 +16,7 @@ extern "C" void early_main()
      * Show a little banner for cuteness
      */
     printf("|===    BarinkOS       ===|\n");
-    printf("Kernel End Addr: 0x%x\n" , &kernel_end + KERNEL_BASE_ADDR);
+    printf("Kernel End Addr: 0x%x\n" , &kernel_end );
 
     uint32_t PageDirectoryEntryIndex = ((uint32_t)&kernel_end + KERNEL_BASE_ADDR ) >> 22 ;
 
@@ -68,6 +63,7 @@ extern "C" void early_main()
         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");
             }
@@ -91,10 +87,22 @@ extern "C" void early_main()
           
         }
 
+        printf("Starting physical memory management setup\n");
         // Setup PhysicalMemoryManagement
         SetupPhysicalMemoryManager(BootInfo);
-        // Small test!
      
+    }
+    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);
@@ -103,55 +111,6 @@ extern "C" void early_main()
         void* block3 = allocate_block();
         printf("Allocated addresss 3: 0x%x\n", (uint32_t)block3);
         free_block(block3);
-    }
-    
-	asm volatile("mov %cr0, %eax ");
-    asm volatile("or $1, %eax");
-    asm volatile("mov %eax, %cr0"); // re-enable protected mode ? 
-    kernel_main();
-    
-}
-
-
-void map_multiboot_info_structure(unsigned long addr){
-    // map the multiboot structure into virtual memory 
-    // so we can gather the necessary data from it.
-
-    uint32_t pageDirectoryIndex = (addr )  >> 22;
-    printf("pageDirectoryIndex: %d\n", pageDirectoryIndex);
-
-    uint32_t pageTableIndex = (addr  >> 12)  & 0x1FFF;
-    printf("PagTableIndex: %d\n", pageTableIndex);
-
-
-    printf("boot_page_directory addr: 0x%x\n", &boot_page_directory);
-    printf("boot_page_table addr: 0x%x\n", &multiboot_page_table);
-
-    uint32_t* current_page_directory = &boot_page_directory;
-    uint32_t* needed_page_table = &multiboot_page_table - KERNEL_BASE_ADDR;
-    // set the page tabel reference;
-    current_page_directory[pageDirectoryIndex]  = (uint32_t)&multiboot_page_table - KERNEL_BASE_ADDR + 0x003;
-
-    // set the page reference;
-    needed_page_table[ pageTableIndex ] = addr | 0x003;
-
-
-    // Reload CR3 to force a flush
-    asm("movl %cr3, %ecx;" "movl %ecx, %cr3" );
-}
-
-void PhysicalMemoryAllocatorTest(){
-
-#ifdef UNIT_TESTS
-       // test alloc_block
-        uint8_t* memory = (uint8_t*) memAlloc.allocate_block();
-        printf("Got a new pointer: 0x%x\n", memory);
-
-        uint8_t* memory2 = (uint8_t*) memAlloc.allocate_block();
-        printf("Got a new pointer: 0x%x\n", memory2);
-
-        memAlloc.free_block((void*) memory);
-        uint8_t* newBlockPlse = (uint8_t*) memAlloc.allocate_block();
     #endif
 }
 
@@ -159,10 +118,5 @@ void PhysicalMemoryAllocatorTest(){
 extern "C" void kernel_main () {
     pit_initialise();
 
-    // Create a dummy BootInfo object
-    // TODO: This should be done properly or the dependency should
-    //          be removed from the SuperVisorTerminal.
-    BootInfo* bootinfo = {};
-
-    startSuperVisorTerminal(bootinfo);
+    startSuperVisorTerminal();
 }   

source/kernel/kernel.h

@@ -1,30 +1,27 @@
 #pragma once
 extern "C" 
 {
-   #include "Lib/string.h" 
+   #include "lib/string.h" 
 }
 #include "definitions.h"
 
-#include "Drivers/VGA/VBE.h"
-#include "Terminal/kterm.h"
+#include "drivers/vga/VBE.h"
+#include "terminal/kterm.h"
 
-#include "bootinfo.h"
+#include "memory/PhysicalMemoryManager.h"
+#include "memory/VirtualMemoryManager.h"
 
-#include "Memory/PhysicalMemoryManager.h"
-#include "Memory/memoryinfo.h"
-#include "Memory/VirtualMemoryManager.h"
+#include "memory/gdt/gdtc.h"
+#include "interrupts/idt/idt.h"
 
-#include "Memory/GDT/gdtc.h"
-#include "Interrupts/idt/idt.h"
-
-#include "Drivers/PIT/pit.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"
+#include "supervisorterminal/superVisorTerminal.h"
+#include "prekernel/bootstructure.h"
 
 #define CHECK_FLAG(flag, bit) ( flag & (1 << bit ))
 #define PANIC(message) {return;} 

source/kernel/memory/KernelHeap.cpp

@@ -14,6 +14,7 @@ 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 )
@@ -33,7 +34,7 @@ void* malloc(size_t size)
 
     // If we are here we need more memory so we should 
     // probably ask the VMM for more 
-    // TODO: ask for more memory
+    // TODO: ask for more memory | Extend kernel heap
     
 }
 

source/kernel/memory/PhysicalMemoryManager.cpp

@@ -1,30 +1,34 @@
 #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) {
-
-    PMMInfoBlock = (PhysicalMemoryManagerInfoBlock*) ((uint32_t)MemoryMapHeap_pptr + Bootinfo->map_size + 0xC0000000);
-
+    // 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
-    PMMInfoBlock->max_blocks =Bootinfo->MemorySize / BLOCK_SIZE / 8;
+
+    // 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) ;
     
-    // // Page in the address space please 
-    // uint32_t PDEI =  0xC020a000 >> 22;
-    // uint32_t PTEI = (0xC020a000 >> 12) & 0x1FFF;
-    // printf("PDEI: %d, PTEI: %d\n", PDEI, PTEI);
-
-    
     printf("Maximum num blocks: %d \n",PMMInfoBlock->max_blocks);
     //Size of memory map 
     uint32_t memMap_size = PMMInfoBlock->max_blocks / 8;
@@ -54,7 +58,7 @@ void SetupPhysicalMemoryManager( BootInfoBlock* Bootinfo) {
     printf("kernel size in memory: 0x%x\n", kernel_size);
     allocate_region((uint32_t)&kernel_begin, kernel_size);
 
-    printf("allocate BIOS region");
+    printf("allocate BIOS region\n");
     allocate_region (0x0000000, 0x00100000);
 }
 

source/kernel/memory/PhysicalMemoryManager.h

@@ -1,8 +1,8 @@
 #pragma once
 #include <stddef.h>
-#include "../PreKernel/bootstructure.h"
-#include "../Terminal/kterm.h"
-#include "../Lib/mem.h"
+#include "../prekernel/bootstructure.h"
+#include "../terminal/kterm.h"
+#include "../lib/mem.h"
 #include "../bitmap.h"
 
 // Asumming i386 for now!
@@ -14,8 +14,8 @@
 struct PhysicalMemoryManagerInfoBlock
 {
     uint32_t* memoryBitMap;
-    size_t pmmap_size;
-    size_t max_blocks;
+    uint32_t pmmap_size;
+    uint32_t max_blocks;
     int used_blocks;
 };
 

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

@@ -1,6 +1,6 @@
 #pragma once 
 #include "PhysicalMemoryManager.h"
-#include "../Terminal/kterm.h"
+#include "../terminal/kterm.h"
 #include "../cpu.h"
 
 void AllocatePage(uint32_t v_addr );

source/kernel/memory/gdt/gdtc.cpp

@@ -1,5 +1,5 @@
 #include "gdtc.h"
-#include "../../Terminal/kterm.h"
+#include "../../terminal/kterm.h"
 
 #define NULL_SEGMENT          0
 #define KERNEL_CODE_SEGMENT   1

source/kernel/prekernel/prekernel.cpp

@@ -16,6 +16,7 @@ extern "C" void prekernelSetup  ( unsigned long magic, multiboot_info_t* mbi) {
   if (magic != MULTIBOOT_BOOTLOADER_MAGIC)
   {
         BIB->MapIsInvalid = true;
+        // crash
         return;
   } else{
         BIB->MapIsInvalid = false;

source/kernel/serial.h

@@ -1,6 +1,6 @@
 #pragma once
 
-#include "Terminal/kterm.h"
+#include "terminal/kterm.h"
 #include "io.h"
 #define PORT 0x3f8 
 static int init_serial() {

source/kernel/supervisorterminal/superVisorTerminal.cpp

@@ -1,6 +1,6 @@
 #include "superVisorTerminal.h"
 
-void startSuperVisorTerminal(BootInfo* bootinfo){
+void startSuperVisorTerminal(){
     while (true){
            
            printf("SUPERVISOR:>$ " );
@@ -38,22 +38,11 @@ void startSuperVisorTerminal(BootInfo* bootinfo){
             {
                 // Show memory layout
                 printf("========= Memory ==========\n");
+                printf("Not Available!\n");
                 printf("Kernel MemoryMap:\n");
-                //printf("kernel: 0x%x - 0x%x\n", &kernel_begin , &kernel_end);         
-                printf("Frames used: 0x%x blocks of 4 KiB\n", 0);  
-                const int bytesInGiB = 1073741824;
-                int64_t bytesLeft = (bootinfo->memory->TotalMemory % bytesInGiB) / bytesInGiB;
-                int64_t effectiveNumberOfGib = bootinfo->memory->TotalMemory / bytesInGiB;
-
-                int64_t GiBs = effectiveNumberOfGib + bytesLeft;  
-
-                printf("Available Memory: %d bytes, %d GiB\n",  bootinfo->memory->TotalMemory, GiBs );
-                printf("Reserved Memory: %d bytes\n",  bootinfo->memory->ReservedMemory);
-
-                //printf("\n\n");
-                //PrintPhysicalMemoryAllocation(  );
-
-
+                printf("Frames used: -- \n");   
+                printf("Available Memory:-- \n");
+                printf("Reserved Memory: -- bytes\n");
             }
             else if(strncmp("TEST", command, characterCount) == 0)
             {

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.h

@@ -3,11 +3,11 @@
 #include <stddef.h>
 #include <stdbool.h>
 
-#include "../Drivers/VGA/colors.h"
+#include "../drivers/vga/colors.h"
 #include "../io.h"
 
 extern "C"{
-    #include "../Lib/string.h"
+    #include "../lib/string.h"
 }
 
 void kterm_init();