/* memory.h - This file is a part of NutsOS
 *
 * NutsOS
 * Copyright (C) 2013  Free Software Foundation, Inc.
 *
 * NutsOS is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * NutsOS is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with NutsOS; If not, see <http://www.gnu.org/licenses/>.
 *
 * Valentin Verdier <valentin.verdier03@gmail.com>
 */

#pragma once
#ifndef MEMORY_H
#define MEMORY_H

#include "types.h"

/* ###### Main Memory Management ###### */
#define KERNEL_SPACE_SIZE 0x10000000 /* Mémoire potentiellement utilisable par le kernel, adresse virtuelle de fin de l'espace noyau, aligné sur 4 Mo */

/* Configation dynamique */
#define KERNEL_SPACE_PT_COUNT (KERNEL_SPACE_SIZE / (PAGE_PER_PT * PAGE_SIZE))
#define KERNEL_SPACE_PAGE_COUNT (KERNEL_SPACE_PT_COUNT * PAGE_PER_PT)

#define KERNEL_PHY_SPACE_SIZE (KERNEL_PT_ADDR + (KERNEL_SPACE_PT_COUNT * PT_SIZE))
#define KERNEL_PHY_SPACE_PAGE_COUNT (KERNEL_PHY_SPACE_SIZE / PAGE_SIZE)

#define KERNEL_VM_SIZE (KERNEL_SPACE_SIZE - KERNEL_PHY_SPACE_SIZE)
#define KERNEL_VM_PAGE_COUNT (KERNEL_VM_SIZE / PAGE_SIZE)
/* ----------------------- */

/* Configation statique */
#define KERNEL_PD_ADDR 0x303000
#define KERNEL_PT_ADDR 0x304000

#define PD_SIZE 4096
#define PT_SIZE 4096
#define PAGE_SIZE 4096

#define MAX_PT_COUNT 1024
#define MAX_PAGE_COUNT 1048576

#define PAGE_OFFSET_BITS 12
#define PAGE_PER_PT 1024
/* ----------------------- */

/* Special types */
typedef T_dword T_page;
typedef T_Page* T_pageTable;
typedef T_pageTable* T_pageDir;
/* ----------------------- */

#ifdef MEMORY_PRIVATE
	T_PageDirectory kpageDir;
	T_PageTable kageTable;
	unsigned int KernPageTableMutex;
#endif

void kinitSpace();
unsigned int kaddPage(T_Page);
void kremovePage(T_Page);
T_Page kgetPage();
void* kgetPhyAddr(void*);

/* ##################################### */



/* ###### Segment Management ###### */

#define GDT_BASE 0x200000
#define SEG_DESC_SIZE 8
#define SEG_DESC_NUMBER 256

#define MAIN_KERNEL_STACK 0xA0000

#define TSS_BASE 0x201000

struct MemSegDescriptor
{
	bits16 limite0_15;
	bits16 base0_15;
	bits8 base16_23;
	bits8 acces;
	bits8 limite16_19:4;
	bits8 other:4;
	bits8 base24_31;
}__attribute__((packed));

struct GdtReg
{
	bits16 limite;
	bits32 base;
}__attribute__((packed));

struct TaskStateSegment
{
	bits16 prevTask;
	bits16 reserved_1;
	bits32 esp0;
	bits16 ss0;
	bits16 reserved_2;
	bits32 esp1;
	bits16 ss1;
	bits16 reserved_3;
	bits32 esp2;
	bits16 ss2;
	bits16 reserved_4;
	bits32 cr3;
	bits32 eip;
	bits32 eflags;
	bits32 eax;
	bits32 ecx;
	bits32 edx;
	bits32 ebx;
	bits32 esp;
	bits32 ebp;
	bits32 esi;
	bits32 edi;
	bits16 es;
	bits16 reserved_5;
	bits16 cs;
	bits16 reserved_6;
	bits16 ss;
	bits16 reserved_7;
	bits16 ds;
	bits16 reserved_8;
	bits16 fs;
	bits16 reserved_9;
	bits16 gs;
	bits16 reserved_10;
	bits16 ldtSegSelect;
	bits16 reserved_11;
	bits16 flagDebug;
	bits16 io_map;
}__attribute__((packed));

/* Special types */
typedef struct MemSegDescriptor T_GdtDesc;
typedef struct GdtReg T_GDT;
typedef struct TaskStateSegment T_TSS;
/* ----------------------- */

T_TSS *tss;

void InitGDT();
void CreateSegDescriptor(bits32, bits32, bits8, bits8, unsigned int);

/* ##################################### */



/* ###### Page Management ###### */

#ifdef MEMORY_PRIVATE
	#define PHY_PAGE_MAP_ADDR 0x203000

	#define PAGE_FREE 0
	#define PAGE_USED 1
	#define PAGE_NOT_PRESENT 4
	bits8 *PageMap;
	unsigned int PhyPageMapMutex;
#endif

#define PAGE_FLAG_PRESENT 1
#define PAGE_FLAG_RW 2
#define PAGE_FLAG_USER 4

T_Page GetPhyPage();
void ReleasePhyPage(T_Page);

/* ##################################### */



/* ###### Alloc Management ###### */

#ifdef MEMORY_PRIVATE
	#define FREE 0
	#define USED 1

	unsigned int KERNEL_HEAP_BASE;
	unsigned int KERNEL_HEAP_LIMIT;

	struct AllocAreaModel {
		T_byte state; /* 1:used 0:free */
		struct AllocAreaModel *next;
	}__attribute__((packed));

	unsigned int AllocMutex;
#endif

void* malloc(unsigned int);
void free(void*);
struct AllocAreaModel* EnlargeHeap();

/* ##################################### */



/* ###### Paging Management ###### */

T_PageDirectory CreateTaskPageDirectory();
void DestroyTaskPageDirectory(T_PageDirectory);
unsigned int AddPage(T_Page, bits32);
void RemovePage(T_Page);
unsigned int LinkPhyPage(T_Page, T_Page, bits32);
void UnlinkPhyPage(T_Page);
void* GetPhyAddr(void*);

/* ##################################### */

#endif