Import backup from 2003-10-30

Functions.c

@@ -1,18 +1,21 @@
 //Functions.c
 //05/07/03 Josh Holtrop
 //for HOS
+//Modified: 10/30/03
 
-
+//Writes a byte out to a port
 inline void outportb(unsigned int port, unsigned char value)		// Output a byte to a port
 {
     asm volatile ("outb %%al,%%dx"::"d" (port), "a" (value));
 };
 
+//Writes a word out to a port
 inline void outportw(unsigned int port, unsigned int value)		// Output a word to a port
 {
     asm volatile ("outw %%ax,%%dx"::"d" (port), "a" (value));
 };
 
+//Reads a byte from a port
 inline byte inportb(unsigned short port)
 {
 	unsigned char ret_val;
@@ -23,16 +26,19 @@ inline byte inportb(unsigned short port)
 	return ret_val;
 };
 
-void enable_ints()
+//Enables (SeTs) Interrupt Flag on the processor
+inline void enable_ints()
 {
 	asm("sti");
 };
 
-void disable_ints()
+//Disables (CLears) Interrupt Flag on the processor
+inline void disable_ints()
 {
 	asm("cli");
 };
 
+//Re-maps the Programmable Interrupr Controllers so IRQ0->pic1 base address, IRG8->pic2 base address
 void remap_pics(int pic1, int pic2)
 {
 	byte	a1, a2;
@@ -53,24 +59,37 @@ void remap_pics(int pic1, int pic2)
 	outportb(PIC2_DATA, a2);			//0xA1
 }
 
+//Masks interrupts on first Programmable Interrupt Controller
 inline void pic1_mask(byte mask)
 {
 	outportb(PIC1_DATA, mask);			//0x21, maskfield *OCW1*
 }
 
+//Masks interrupts on second Programmable Interrupt Controller
 inline void pic2_mask(byte mask)
 {
  	outportb(PIC2_DATA, mask);			//0xA1, maskfield *OCW1*
 }
 
+//Restarts the computer
 inline void restart()
 {
+ 	byte temp;
+	do
+	{
+		temp = inportb(0x64);
+		if (temp & 1)
+		inportb(0x60);
+	} while(temp & 2);
+
+
 	outportb (0x64, 0xfe);
 	for (;;)
 	{
 	}
 }
 
+//Halts (freezes) the computer
 inline void halt()
 {
  	asm("cli");
@@ -79,17 +98,32 @@ inline void halt()
  	;
 }
 
-inline void eoi()
+//Initializes 8253 Programmable Interrupt Timer
+inline void init_timer()
 {
-	outportb(0x20, 0x20);							//EOI
+ 	//set timer : 2e9c = 100hz
+	outportb(0x43, 0x34);
+	outportb(0x40, 0x9c); //lsb
+	outportb(0x40, 0x2e); //msb
 }
 
+//Signals an End Of Interrupt signal to the first PIC
+inline void eoi()
+{
+	outportb(0x20, 0x20);
+}
+
+//Signals an End Of Interrupt signal to both the second and first PIC unit
 inline void eoi2()
 {
  	outportb(0xA0, 0x20);
  	outportb(0x20, 0x20);
 }
 
+//Returns the size of the kernel (code & data)
+// - this does not include the bss section
+// - this should be 4kb aligned per the linker script
+// - this should be the size of kernel.bin
 inline dword kernel_size()
 {
 	return (dword)(&_bss)-(dword)(&_code);

asmfuncs.asm

@@ -7,6 +7,7 @@
 [global _write_cr3]
 [global _read_cr3]
 
+;stores the parameter to the CR0 register
 ;extern dword write_cr0(dword cr0);
 _write_cr0:
 	push	ebp
@@ -16,12 +17,13 @@ _write_cr0:
 	pop	ebp
 	ret
 
+;returns the value in the CR0 register
 ;extern dword read_cr0();
 _read_cr0:
 	mov	eax, cr0;
 	ret
 
-
+;stores the parameter to the CR3 register
 ;extern dword write_cr3(dword cr3);
 _write_cr3:
 	push	ebp
@@ -31,6 +33,7 @@ _write_cr3:
 	pop	ebp
 	ret
 
+;returns the value in the CR3 register
 ;extern dword read_cr3();
 _read_cr3:
 	mov	eax, cr3;

fdc.c

@@ -0,0 +1,9 @@
+//fdc.c
+//Author: Josh Holtrop
+//Date: 10/30/03
+
+
+inline	void	fdc_sendDOR(byte dor)
+{
+	outportb(FDC_DOR, dor);
+}

fdc.h

@@ -0,0 +1,12 @@
+//fdc.h
+//Author: Josh Holtrop
+//Date: 10/30/03
+
+
+#define FDC_DOR 0x3f2
+#define FDC_MSR 0x3f4
+
+
+inline	void	fdc_sendDOR(byte dor);
+
+

functions.h

@@ -1,6 +1,7 @@
 //functions.h
 //05/07/03 Josh Holtrop
 //for HOS
+//Modified: 10/30/03
 
 extern dword _code;
 extern dword _bss;
@@ -9,8 +10,8 @@ extern dword _end;
 inline void outportb(unsigned int port, unsigned char value);
 inline void outportw(unsigned int port, unsigned int value);
 inline byte inportb(unsigned short port);
-void enable_ints();
+inline void enable_ints();
-void disable_ints();
+inline void disable_ints();
 inline void restart();
 inline void halt();
 void remap_pics(int pic1, int pic2);
@@ -19,6 +20,7 @@ inline void pic2_mask(byte mask);
 inline void eoi();
 inline void eoi2();
 inline dword kernel_size();
+inline void init_timer();
 
 
 

gdt.inc

@@ -1,4 +1,7 @@
-
+;gdt.inc
+;Author: Josh Holtrop
+;for HOS
+;Modified: 10/30/03
 
 gdtr:
 	dw	gdt_end-gdt-1

idt.inc

@@ -1,3 +1,7 @@
+;idt.inc
+;Author: Josh Holtrop
+;for HOS
+;Modified: 10/30/03
 
 idtr:
 	dw	50*8-1		;size of idt

k_defines.h

@@ -1,5 +1,6 @@
 //k_defines.h
 //03/17/03 Josh Holtrop
+//Modified: 10/30/03
 
 #define	PIC1		0x20
 #define	PIC2		0xA0
@@ -31,9 +32,9 @@
 #define FREERAM_START	0x268000
 #define MAX_RAM		0x40000000	//1gb maximum RAM supported
 
-#define PID_KERNEL	0x02
+#define PID_KERNEL	0x02		//kernel's PID
 #define PID_VMM		0x03
-#define PID_USER	0x10000
+#define PID_USER	0x10000		//user processes' start PID
 
 typedef	unsigned char	byte;
 typedef	unsigned short	word;

kernel.asm

@@ -1,3 +1,6 @@
+;kernel.asm
+;Author: Josh Holtrop
+;Modified: 10/30/03
 
 %include "bootdef.inc"
 
@@ -10,6 +13,7 @@
 
 bits 32
 
+;This is where the kernel begins execution
 start:
 	cli				;if they weren't already off
 	mov	edi, GDT
@@ -38,6 +42,7 @@ fill_idt:
 	mov	esi, ebx
 	add	esi, edx
 	loop	fill_idt
+	mov	word	[IDT+0x30*8+4], 0xEE00	;interrupt 0x30 has user priviledges
 
 	lgdt	[gdtr]			;load gdt
 	jmp	KERNEL_CODE:newgdtcontinue
@@ -52,8 +57,9 @@ newgdtcontinue:
 	lidt	[idtr]			;load idt
 
 	call	_k_init
+haltit:
 	hlt				;halt processor when k_init is done
-	jmp	$			;shouldn't get here...	
+	jmp	haltit			;shouldn't get here...
 
 %include "gdt.inc"
 %include "idt.inc"

kernel.c

@@ -1,23 +1,24 @@
 //kernel.c
 //08/13/03 Josh Holtrop
 //Holtrop's Operating System
-//Version: 0.1.1
+//Version: 0.1.2
-//Modified: 10/23/03
+//Modified: 10/30/03
 
 #define VXR video_mode.XResolution
 #define VYR video_mode.YResolution
 
-#include "k_defines.h"
+#include "k_defines.h"		//#DEFINE's for kernel
 
-#include "lib/string.h"
+#include "lib/string.h"		//library string functions
-#include "lib/io.h"
+#include "lib/io.h"		//library input/output functions
 
-#include "functions.h"
+#include "functions.h"		//general functions
-#include "video.h"
+#include "video.h"		//video functions
-#include "mm.h"
+#include "mm.h"			//physical memory management functions
-#include "vmm.h"
+#include "vmm.h"		//virtual memory management & paging functions
-#include "keyboard.h"
+#include "keyboard.h"		//generic keyboard driver & functions
-#include "mouse.h"
+#include "mouse.h"		//generic ps/2 mouse driver & functions
+#include "fdc.h"		//Floppy Disk Controller functions
 
 void isr(dword num);
 void k_init();
@@ -26,6 +27,7 @@ extern dword read_cr0();
 extern dword write_cr3(dword cr3);
 extern dword read_cr3();
 
+#include "fdc.c"
 #include "mouse.c"
 #include "keyboard.c"
 #include "mm.c"
@@ -35,76 +37,44 @@ extern dword read_cr3();
 
 dword	timer = 0;
 
+//Main kernel initialization method
 void k_init()
 {
+		// ===== Initialization
+	fdc_sendDOR(0x0C);		//turn off floppy motor!!
 	console_cls();
 	remap_pics(0x20, 0x28);
-	//set timer : 2e9c = 100hz
+	init_timer();
-	outportb(0x43, 0x34);
-	outportb(0x40, 0x9c); //lsb
-	outportb(0x40, 0x2e); //msb
 	video_init((ModeInfoBlock *) 0x90306);
-	video_rectf(VXR*3/11, 0, VXR*4/11, VYR-1, 0x00000088);      		//test rectangles, draws "HOS"
-	video_rectf(VXR*7/11, 0, VXR*8/11, VYR-1, 0x00000088);
-	video_rectf(VXR/11, 0, VXR*2/11, VYR*2/5, 0x00000088);
-	video_rectf(VXR/11, VYR*3/5, VXR*2/11, VYR-1, 0x00000088);
-	video_rectf(VXR*5/11, VYR/5, VXR*6/11, VYR*4/5, 0x00000088);
-	video_rectf(VXR*9/11, VYR/5, VXR-1, VYR*2/5, 0x00000088);
-	video_rectf(VXR*8/11, VYR*3/5, VXR*10/11, VYR*4/5, 0x00000088);
-
-	video_vert(10, 10, 16, 0x00ffff00);		//should be yellow 'H'
-	video_horiz(13, 10, 14, 0x00ffff00);
-	video_vert(14, 10, 16, 0x00ffff00);
-	
-	video_horiz(10, 17, 21, 0x00ffff00);
-	video_vert(19, 10, 16, 0x00ffff00);
-	video_horiz(16, 17, 21, 0x00ffff00);
-	
-	int a, b;
-	for (a = 0; a < 256; a++)
-	{
-		for (b = 0; b < 256; b++)
-		{
-			video_pset(a+5, b+30, (a<<16)|(b<<8));
-			video_pset(a+270, b+30, (a<<8)|(b));
-			video_pset(a+535, b+30, (a<<16)|(b));
-
-			video_pset(a+5, b+290, (a<<16)|(b<<8)|0x000000ff);
-			video_pset(a+270, b+290, (a<<8)|(b)|0x00ff0000);
-			video_pset(a+535, b+290, (a<<16)|(b)|0x0000ff00);
-		}
-	}
-
 	mm_init();
 	vmm_init();
 	mouse_init();
-	printf("HOS 0.1.1 - Kernel Size: %d kb\n", kernel_size()/1024);
-	printf("%x\t%x\n", read_cr0(), read_cr3());
 	vmm_enable_paging();
-	printf("%x\t%x\n", read_cr0(), read_cr3());
-	printf("Memory available to OS: %d MB (Bytes: %d)\n", mm_totalmem/0x100000, mm_totalmem);
-	vmm_map1(0x45000000, 0xB8000, 0x3);
-	*((word *)0x45000002) = 0x0444;
-	vmm_mapn(0x54FFF000, 0xB7000, 0x3, 2);
-	*((word *)0x55000020) = 0x0443;
 	pic1_mask(0);			//unmask IRQ's 0-7
 	pic2_mask(0);			//unmask IRQ's 8-15
 	enable_ints();
+	kbd_resetLEDs();		//after enabling interrupts!!
+	
+	printf("HOS 0.1.2 - Kernel Size: %d kb\n", kernel_size()/1024);
+	printf("Memory available to OS: %d MB (Bytes: %d)\n", mm_totalmem/0x100000, mm_totalmem);
+
 	dword key = 0;
 	for (;;)
 	{
 		key = kbdWaitKey();
-		putc(key);
+		if (((key & 0xFF00) >> 8) != 2)	//key is not a control key
+			putc(key);
 	}
 }
 
+// main Interrupt Service Routine - handles all interrupts unless caught by kernel.asm
 void isr(dword num)
 {
 	switch(num)
 	{
 	case 0x20:         		// IRQ0 - timer interrupt
 		timer++;
-		(*(byte *)0xb8000)++;
+		(*(byte *)(0xb8000+3998))++;
 		eoi();
 		break;
 	case 0x21:  			// IRQ1 - keyboard interrupt

keyboard.c

@@ -1,28 +1,29 @@
 //Keyboard.c
 // Created: 04/17/03 Josh Holtrop
-// Modified: 09/09/03
+// Modified: 10/30/03
 //for HOS
 
 #define KBD_BUFFER_LENGTH 64
 
-byte kbdFlags = 0;
+byte kbdFlags = 0;		//holds current keyboard flags - caps/num/scroll/shift/ctrl/alt
-byte kbdAscii = 0;
+byte kbdAscii = 0;		//holds ASCII value of a key pressed
-byte kbdScan = 0;
+byte kbdScan = 0;		//holds the keyboard scan code of a key pressed
 
-dword kbdBuffer[KBD_BUFFER_LENGTH];
+dword kbdBuffer[KBD_BUFFER_LENGTH];	//a buffer for all keypresses
-int kbdBufferStart = 0;
+int kbdBufferStart = 0;			//position of next key in buffer
-int kbdBufferLen = 0;
+int kbdBufferLen = 0;			//number of keys left in the buffer
-byte kbdExt = 0;
+byte kbdExt = 0;			//# of extended key codes left to input
-byte kbdExt2 = 0;
+byte kbdExt2 = 0;                       //# of 2nd-set-extended key codes left to input
 byte ackReason = 0;		//used to record the reason why we would get an acknowledge byte (0xFA)
 
 
+//these arrays convert a keyboard scan code to an ASCII character value
                                    //nul esc            bksp tab              lctl            lsft            rsft lalt caps F1  F2  F3  F4  F5  F6  F7  F8  F9  F10 numScrlNumPad-------                                  unknown---- F11 F12 unknown....
 const byte SCAN2ASCII[128]      = "\000\0331234567890-=\010\011qwertyuiop[]\n\001asdfghjkl;'`\001\\zxcvbnm,./\001*\001 \001\001\001\001\001\001\001\001\001\001\001\001\001\001\001\001-\001\001\001+\001\001\001\001\001\002\002\002\001\001\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002";
 const byte SCAN2ASCIISHIFT[128] = "\000\033!@#$%^&*()_+\010\011QWERTYUIOP{}\n\001ASDFGHJKL:\"~\001|ZXCVBNM<>?\001*\001 \001\001\001\001\001\001\001\001\001\001\001\001\001789-456+1230.\002\002\002\001\001\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002";
 
 //====FUNCTIONS:
-
+// The Keyboard Interrupt Service Routine
 void isr_keyboard()
 {
 	kbdScan = inportb(0x60);
@@ -35,20 +36,20 @@ void isr_keyboard()
 
 	if (kbdScan == 0xFA)	//250					//ACKnowledge
 	{
+		//printf("KBD_ACK 0x%x!\n", ackReason);
 		if (ackReason == 0xED)					//reset LEDs
 		{
-			outportb(0x64, (kbdFlags & 0x07));
+			outportb(0x60, (kbdFlags & 0x07));
-			printf("KBD_ACK!");
 		}
 		ackReason = 0;
 	}
-	if (kbdScan == 224)							//extended key
+	if (kbdScan == 224)						//extended key
 	{
 		kbdExt = 1;
 		eoi();
 		return;
 	}
-	if (kbdScan == 225)
+	if (kbdScan == 225)						//2nd-set-extended key
 	{
 		kbdExt2 = 2;
 		eoi();
@@ -57,7 +58,7 @@ void isr_keyboard()
 
 //====handle control keys::
 	kbdAscii = 2;
-	switch (kbdScan)							//control keys
+	switch (kbdScan)						//control keys
 	{
 		case KBD_SCAN_LSHIFT:
 			kbdFlags |= KBD_SHIFT;
@@ -96,17 +97,17 @@ void isr_keyboard()
 		case KBD_SCAN_CAPS+KBD_SCAN_RELEASED:
 			kbdFlags ^= KBD_CAPS;
 			kbdAscii = 1;
-			kbd_resetLEDs();			//update LEDs
+			kbd_resetLEDs();				//update LEDs
 			break;
 		case KBD_SCAN_SCROLL+KBD_SCAN_RELEASED:
 			kbdFlags ^= KBD_SCROLL;
 			kbdAscii = 1;
-			kbd_resetLEDs();			//update LEDs
+			kbd_resetLEDs();				//update LEDs
 			break;
 		case KBD_SCAN_NUM+KBD_SCAN_RELEASED:
 			kbdFlags ^= KBD_NUM;
 			kbdAscii = 1;
-			kbd_resetLEDs();			//update LEDs
+			kbd_resetLEDs();				//update LEDs
 			break;
 	}
 	if (kbdAscii == 1)
@@ -170,7 +171,7 @@ void isr_keyboard()
 	}
 
 //====do something with key::
-	if ((kbdScan == 83) & ((kbdFlags & KBD_CTRL) != 0) & ((kbdFlags & KBD_ALT) != 0))
+	if ((kbdScan == 83) && (kbdFlags & KBD_CTRL) && (kbdFlags & KBD_ALT))
 	{
 		printf("Initiating reboot.");
 		restart();
@@ -196,19 +197,19 @@ void isr_keyboard()
 
 	eoi();
 
-//	if (key == 0xFA)							//ACKnowledge
-//		outportb(0x60, 0x3);
 }
 
-inline byte switchCase(byte asciiCode)
+//Switches the case of an ASCII character
+/*inline byte (byte asciiCode)
 {
 	if ((asciiCode >= 'A') & (asciiCode <= 'Z'))
 		return (asciiCode + ('a' - 'A'));
 	if ((asciiCode >= 'a') & (asciiCode <= 'z'))
 		return (asciiCode - ('a' - 'A'));
 	return asciiCode;
-}
+}*/
 
+//Gets a key from the buffer, returns 0 if no keys available, returns immediately
 dword kbdGetKey()
 {
 	if (kbdBufferLen == 0)					//buffer empty
@@ -221,6 +222,7 @@ dword kbdGetKey()
 	return retVal;
 }
 
+//Gets a key from the buffer, if no keys available, waits for one to be entered
 dword kbdWaitKey()
 {
 	for (;;)
@@ -236,10 +238,11 @@ dword kbdWaitKey()
 	return retVal;
 }
 
+//Resets the keyboard LEDs to reflect the current state of the num lock, caps lock, and scroll lock bits
 inline void kbd_resetLEDs()
 {
-	outportb(0x64, 0xED);
+	outportb(0x60, 0xED);
-	//outportb(0x64, (kbdFlags & 0x07));
+	//outportb(0x60, (kbdFlags & 0x07));
 	ackReason = 0xED;
 }
 

video.c

@@ -31,6 +31,39 @@ void video_init(ModeInfoBlock *mib)
 		else
 			video_psetp(a, 0x00FFFFFF);		
 	}
+
+	video_rectf(VXR*3/11, 0, VXR*4/11, VYR-1, 0x00000088);      		//test rectangles, draws "HOS"
+	video_rectf(VXR*7/11, 0, VXR*8/11, VYR-1, 0x00000088);
+	video_rectf(VXR/11, 0, VXR*2/11, VYR*2/5, 0x00000088);
+	video_rectf(VXR/11, VYR*3/5, VXR*2/11, VYR-1, 0x00000088);
+	video_rectf(VXR*5/11, VYR/5, VXR*6/11, VYR*4/5, 0x00000088);
+	video_rectf(VXR*9/11, VYR/5, VXR-1, VYR*2/5, 0x00000088);
+	video_rectf(VXR*8/11, VYR*3/5, VXR*10/11, VYR*4/5, 0x00000088);
+
+	video_vert(10, 10, 16, 0x00ffff00);		//should be yellow 'H'
+	video_horiz(13, 10, 14, 0x00ffff00);
+	video_vert(14, 10, 16, 0x00ffff00);
+	
+	video_horiz(10, 17, 21, 0x00ffff00);
+	video_vert(19, 10, 16, 0x00ffff00);
+	video_horiz(16, 17, 21, 0x00ffff00);
+	
+	int b;
+	for (a = 0; a < 256; a++)
+	{
+		for (b = 0; b < 256; b++)
+		{
+			video_pset(a+5, b+30, (a<<16)|(b<<8));
+			video_pset(a+270, b+30, (a<<8)|(b));
+			video_pset(a+535, b+30, (a<<16)|(b));
+
+			video_pset(a+5, b+290, (a<<16)|(b<<8)|0x000000ff);
+			video_pset(a+270, b+290, (a<<8)|(b)|0x00ff0000);
+			video_pset(a+535, b+290, (a<<16)|(b)|0x0000ff00);
+		}
+	}
+
+
 }
 
 void video_horiz(int y, int x1, int x2, dword color)

vmm.c

@@ -64,6 +64,7 @@ int	vmm_map1(dword virtual, dword physical, dword flags)
 	if (ptp->page[pte] & 0x01)
 		return 3;			// ERROR 3: page table entry already exists
 	ptp->page[pte] = physical | flags;
+	//invlpg();
 	return 0;
 }
 
@@ -76,8 +77,7 @@ int	vmm_mapn(dword virtual, dword physical, dword flags, dword n)
 	dword pa = physical;
 	for (mapped = 0; mapped < n; mapped++)
 	{
-		result = vmm_map1(va, pa, flags);
+		if (result = vmm_map1(va, pa, flags))
-		if (result != 0)
 		{
 			if (mapped > 0)
 				vmm_unmapn(virtual, mapped);
@@ -86,6 +86,8 @@ int	vmm_mapn(dword virtual, dword physical, dword flags, dword n)
 		va += 4096;
 		pa += 4096;
 	}
+	//invlpg();
+	return 0;
 }
 
 int	vmm_unmap1(dword virtual)
@@ -94,14 +96,28 @@ int	vmm_unmap1(dword virtual)
 	int pte = (virtual & 0x003FF000) >> 12;
 	if (virtual & 0x00000FFF)
 		return 1;		// ERROR 1: address not page-aligned
+	if (!(vmm_PDBR->pageTables[pde] & 0x01))
+		return 2;		// ERROR 2: page table not present
 	PageTable *ptp = (PageTable *)(vmm_PDBR->pageTables[pde] & 0xFFFFF000);
-
+	ptp->page[pte] = 0;
+	//invlpg();
+	return 0;
 }
 
 
 int	vmm_unmapn(dword virtual, dword n)
 {
-
+	int reslt;
+	int i;
+	for (i = 0; i < n; i++)
+	{
+		if (reslt = vmm_unmap1(virtual))
+			return reslt;
+		virtual += 4096;
+	}
+	vmm_walkPageTables();
+	//invlpg();
+	return 0;
 }
 
 
@@ -114,6 +130,34 @@ void	vmm_init_pagetable(dword address)
 }
 
 
+int	vmm_walkPageTables()
+{
+	int pde;
+	int pte;
+	int used_ptes;
+	PageTable *ptp;
+	for (pde = 0; pde < 1024; pde++)
+	{
+		if (vmm_PDBR->pageTables[pde] & 0x01)
+		{
+			used_ptes = 0;
+			ptp = (PageTable *)(vmm_PDBR->pageTables[pde] & 0xFFFFF000);
+			for (pte = 0; pte < 1024; pte++)
+			{
+				if (ptp->page[pte] & 0x01)	//page table entry present
+					used_ptes++;
+			}
+			if (!(used_ptes))			//no used pte's -- remove page table & page directory entry
+			{
+				mm_pfree(ptp);
+				vmm_PDBR->pageTables[pde] = 0;
+			}
+		}
+	}
+	return 0;
+}
+
+
 void	*malloc(dword bytes)
 {
 

vmm.h

@@ -22,6 +22,7 @@ int	vmm_mapn(dword virtual, dword physical, dword flags, dword n);
 int	vmm_unmap1(dword virtual);
 int	vmm_unmapn(dword virtual, dword n);
 void	vmm_init_pagetable(dword address);
+int	vmm_walkPageTables();