diff --git a/README.md b/README.md
index fe72259..c16cad4 100644
--- a/README.md
+++ b/README.md
@@ -63,7 +63,7 @@ Compilation:
 
 Nom | Paquet | Version
 --- | --- | ---
-gcc | gcc | 5.4.0 20160609
+gcc | gcc | *>7.0*
 GNU Make | make | 4.1
 Outils divers | binutils | 2.26-8
 
@@ -222,16 +222,16 @@ Pour l'instant quelques commandes seulement sont disponibles:
 * affichage de chaîne de caractères (prinfs,sprintf,vsprintf) avec type (bin,hexa,octal,float,double,string,char),
 * mode protégé limité à 4Go de mémoire vive (32 bits),
 * gestion avancée de la mémoire (vmalloc).
+* chargeur ELF32,
+* espace utilisateur et appels systèmes,
+* liste d'API automatiquement mise à jour,
 
 #### En cours
 
-* espace utilisateur et appels systèmes,
 * ordonnanceur de tâche (par TSS),
-* liste d'API automatiquement mise à jour,
 
 #### A faire
 
-* chargeur ELF32,
 * pilote IDE/ATA (PIO mode),
 * fonctions affichage image PNG,
 * double buffering,
diff --git a/include/process.h b/include/process.h
index 62667b2..600da91 100644
--- a/include/process.h
+++ b/include/process.h
@@ -185,7 +185,6 @@ typedef struct process
 pid_t     getcurrentpid(void);
 pid_t     getparentpid(void);
 pid_t     getfreepid(void);
-void      usepid(pid_t pid);
 tid_t	getcurrenttid(void);
 tid_t	maketid(pid_t pid, u32 number);
 
diff --git a/include/timer.h b/include/timer.h
index 94b33d4..ba48eae 100644
--- a/include/timer.h
+++ b/include/timer.h
@@ -1,4 +1,7 @@
 /*******************************************************************************/
 /* COS2000 - Compatible Operating System - LGPL v3 - Hordé Nicolas             */
 /*                                                                             */
-void    timer(void);
+
+#include "interrupts.h"
+
+__attribute__ ((noreturn)) void timer_handler(regs *dump);
diff --git a/lib/gdt.c b/lib/gdt.c
index 08ee743..233e1c4 100644
--- a/lib/gdt.c
+++ b/lib/gdt.c
@@ -30,7 +30,7 @@ void initgdt(u32 offset)
 
 	tss0.trapflag = 0x00;
 	tss0.iomap = 0x00;
-	tss0.esp0 = 0x00;
+	tss0.esp0 = 0x6000;
 	tss0.ss0 = SEL_TSS;
 
 	makegdtdes(&tss0, 0x67, SEG_PRESENT | SEG_CODE | SEG_RING3 | SEG_ACCESSED, 0x00, &gdt[7]);	/* descripteur de tss */
diff --git a/lib/handlers.c b/lib/handlers.c
index f32db15..c866a98 100644
--- a/lib/handlers.c
+++ b/lib/handlers.c
@@ -14,9 +14,65 @@
 /******************************************************************************/
 /* Déclenché lors de l'appel d'une interruption */
 
-__attribute__((interrupt)) void interruption(exception_stack_noerror *caller)
+__attribute__ ((noreturn)) void interruption_handler(regs *dump)
 {
-	print("Appel d'une interruption\r\n");
+	u32 interruption=dump->eip;
+	exception_stack_noerror *caller = (exception_stack_noerror*) ((u32*)dump->esp+1);
+	bool noerror,user;
+	if (caller->cs==SEL_KERNEL_CODE || caller->cs==SEL_USER_CODE)
+	{
+		noerror=true;
+		dump->eip = caller->eip;
+		dump->cs = caller->cs;
+		dump->eflags = caller->eflags;
+		if (dump->cs==SEL_KERNEL_CODE)
+		{
+			dump->esp = (u32) caller + sizeof(exception_stack_noerror);
+			user=false;
+		}
+		else
+		{
+			dump->esp = (u32) ((exception_stack_noerror_user*) caller)->esp;
+			dump->ss = (u32) ((exception_stack_noerror_user*) caller)->ss;
+			user=true;
+		}
+	}
+	else
+	{
+		noerror=false;
+		dump->eip = ((exception_stack*)caller)->eip;
+		dump->cs = ((exception_stack*)caller)->cs;
+		if (dump->cs==SEL_KERNEL_CODE)
+		{
+			dump->esp = (u32) caller + sizeof(exception_stack);
+			user=false;
+		}
+		else
+		{
+			dump->esp = (u32) ((exception_stack_user*) caller)->esp;
+			dump->ss = (u32) ((exception_stack_user*) caller)->ss;
+			user=true;
+		}
+	}
+	switch (interruption)
+	{
+		case 20:
+			show_lightcpu(dump);
+			break;
+		default:
+			print("Appel d'une interruption\r\n");
+	}
+	if (dump->cs==SEL_KERNEL_CODE)
+		{
+			setESP(dump);
+			restcpu_kernel();
+		}
+		else
+		{
+			setESP(dump);
+			restcpu_user();
+			iret();
+		}
 }
 
 /******************************************************************************/
@@ -178,7 +234,8 @@ __attribute__ ((noreturn)) void exception_handler(regs *dump)
 /* Les IRQ par défaut */
 
 __attribute__((interrupt)) void irq0(exception_stack_noerror *caller)
-{	print("irq 0");
+{	
+	print("irq 0");
 	irqendmaster();
 }
 
@@ -267,8 +324,6 @@ __attribute__((interrupt)) void irq13(exception_stack_noerror *caller)
 	print("irq 13");
 	irqendslave();
 	irqendmaster();
-	popad();
-	popf();
 }
 
 __attribute__((interrupt)) void irq14(exception_stack_noerror *caller)
diff --git a/lib/handlers_asm.S b/lib/handlers_asm.S
index 58efa91..a297e57 100644
--- a/lib/handlers_asm.S
+++ b/lib/handlers_asm.S
@@ -12,7 +12,46 @@ pushl %esp
 pushf 
 pushl %cs
 pushl $\num
-jmp dumpcpu
+jmp exception_suite
+.endm
+
+.macro  semidumpcpu
+pushl %ds
+pushl %es
+pushl %fs
+pushl %gs
+pushl %eax
+pushl %ebx
+pushl %ecx
+pushl %edx
+pushl %esi
+pushl %edi
+pushl %ebp
+mov %cr0, %eax 
+pushl %eax
+mov %cr2, %eax 
+pushl %eax
+mov %cr3, %eax 
+pushl %eax
+mov %cr4, %eax 
+pushl %eax 
+mov %dr0, %eax 
+pushl %eax
+mov %dr1, %eax 
+pushl %eax
+mov %dr2, %eax 
+pushl %eax
+mov %dr3, %eax 
+pushl %eax
+mov %dr6, %eax 
+pushl %eax
+mov %dr7, %eax 
+pushl %eax
+mov $0xC0000080, %ecx 
+rdmsr 
+pushl %edx 
+pushl %eax
+pushl %esp
 .endm
 
 exception 0
@@ -35,6 +74,10 @@ exception 16
 exception 17
 exception 18
 
+exception_suite:
+semidumpcpu
+call exception_handler
+
 .global wrapper_sysenter
 wrapper_sysenter:
 pushl %ss
@@ -42,79 +85,25 @@ pushl %esp
 pushf 
 pushl %cs
 pushl $0x00
-pushl %ds
-pushl %es
-pushl %fs
-pushl %gs
-pushl %eax
-pushl %ebx
-pushl %ecx
-pushl %edx
-pushl %esi
-pushl %edi
-pushl %ebp
-mov %cr0, %eax 
-pushl %eax
-mov %cr2, %eax 
-pushl %eax
-mov %cr3, %eax 
-pushl %eax
-mov %cr4, %eax 
-pushl %eax 
-mov %dr0, %eax 
-pushl %eax
-mov %dr1, %eax 
-pushl %eax
-mov %dr2, %eax 
-pushl %eax
-mov %dr3, %eax 
-pushl %eax
-mov %dr6, %eax 
-pushl %eax
-mov %dr7, %eax 
-pushl %eax
-mov $0xC0000080, %ecx 
-rdmsr 
-pushl %edx 
-pushl %eax
-pushl %esp
+semidumpcpu
 call sysenter_handler
 
-dumpcpu:
-pushl %ds
-pushl %es
-pushl %fs
-pushl %gs
-pushl %eax
-pushl %ebx
-pushl %ecx
-pushl %edx
-pushl %esi
-pushl %edi
-pushl %ebp
-mov %cr0, %eax 
-pushl %eax
-mov %cr2, %eax 
-pushl %eax
-mov %cr3, %eax 
-pushl %eax
-mov %cr4, %eax 
-pushl %eax 
-mov %dr0, %eax 
-pushl %eax
-mov %dr1, %eax 
-pushl %eax
-mov %dr2, %eax 
-pushl %eax
-mov %dr3, %eax 
-pushl %eax
-mov %dr6, %eax 
-pushl %eax
-mov %dr7, %eax 
-pushl %eax
-mov $0xC0000080, %ecx 
-rdmsr 
-pushl %edx 
-pushl %eax
+.global wrapper_interruption
+wrapper_interruption:
+pushl %ss
 pushl %esp
-call exception_handler
+pushf 
+pushl %cs
+pushl $0x00
+semidumpcpu
+call interruption_handler
+
+.global wrapper_timer
+wrapper_timer:
+pushl %ss
+pushl %esp
+pushf 
+pushl %cs
+pushl $0x00
+semidumpcpu
+call timer_handler
diff --git a/lib/interrupts.c b/lib/interrupts.c
index 0c811a3..7839ade 100644
--- a/lib/interrupts.c
+++ b/lib/interrupts.c
@@ -41,6 +41,7 @@ extern wrapper_exception15;
 extern wrapper_exception16;
 extern wrapper_exception17;
 extern wrapper_exception18;
+extern wrapper_interruption;
 /******************************************************************************/
 /* Initialise la reprise après erreur */
 
@@ -208,7 +209,7 @@ void initidt(void)
 	       ENTRY_PRESENT | ENTRY_RING0 | INTGATE, 18);
 	for (i = 19; i < 32; i++)
 	{
-		putidt((u32) interruption, SEL_KERNEL_CODE,
+		putidt((u32) &wrapper_interruption, SEL_KERNEL_CODE,
 		       ENTRY_PRESENT | ENTRY_RING3 | TRAPGATE, i);
 	}
 	putidt((u32) irq0, SEL_KERNEL_CODE,
@@ -229,7 +230,7 @@ void initidt(void)
 	       ENTRY_PRESENT | ENTRY_RING0 | INTGATE, 39);
 	for (i = 40; i < 96; i++)
 	{
-		putidt((u32) interruption, SEL_KERNEL_CODE,
+		putidt((u32) &wrapper_interruption, SEL_KERNEL_CODE,
 		       ENTRY_PRESENT | ENTRY_RING3 | TRAPGATE, i);
 	}
 	putidt((u32) irq8, SEL_KERNEL_CODE,
@@ -250,7 +251,7 @@ void initidt(void)
 	       ENTRY_PRESENT | ENTRY_RING0 | INTGATE, 103);
 	for (i = 104; i < IDT_SIZE; i++)
 	{
-		putidt((u32) interruption, SEL_KERNEL_CODE,
+		putidt((u32) &wrapper_interruption, SEL_KERNEL_CODE,
 		       ENTRY_PRESENT | ENTRY_RING0 | TRAPGATE, i);
 	}
 	/* initialise le registre idt */
diff --git a/lib/keyboard.c b/lib/keyboard.c
index a8ee520..19460a0 100644
--- a/lib/keyboard.c
+++ b/lib/keyboard.c
@@ -364,7 +364,6 @@ unsigned convert(u32 keypressed)
 __attribute__((interrupt)) void keyboard_handler(exception_stack_noerror *caller)
 {
 	u8      scancode, ascii;
-	cli();
 	while ((inb(0x64) & 1) == 0);
 	scancode = inb(0x60);
 	ascii = convert(scancode);
diff --git a/lib/makefile b/lib/makefile
index d3fd2b9..68e0cd6 100755
--- a/lib/makefile
+++ b/lib/makefile
@@ -22,13 +22,13 @@ libs.o:$(OBJS) $(OBJASM)
 		$(ASM) $^
 
 handlers.o:handlers.c
-		$(CC)  -mno-sse $^
+		$(CC) -mgeneral-regs-only $^
 
 keyboard.o:keyboard.c
-		$(CC)  -mno-sse $^
+		$(CC) -mgeneral-regs-only $^
 
 mouse.o:mouse.c
-		$(CC)  -mno-sse $^
+		$(CC) -mgeneral-regs-only $^
 
 syscall.o:syscall.c
 		$(CC) -fomit-frame-pointer $^
diff --git a/lib/process.c b/lib/process.c
index 916c4a5..c552d6e 100644
--- a/lib/process.c
+++ b/lib/process.c
@@ -95,6 +95,8 @@ u32 loadelf(u8 * src, pid_t pid)
 	header = (elf32 *) src;
 	program = (elf32p *) (src + header->e_phoff);
 	code = iself(src);
+	process *aprocess=findprocess(pid);
+	if (aprocess==NULL) return NULL;
 	if (code != 0)
 	{
 		printf("Erreur de chargement ELF, %s !\r\n",
@@ -119,13 +121,13 @@ u32 loadelf(u8 * src, pid_t pid)
 			}
 			if (program->p_flags == PF_X + PF_R)
 			{
-				processes[(u32)pid].exec_low = (u8 *) v_begin;
-				processes[(u32)pid].exec_high = (u8 *) v_end;
+				aprocess->exec_low = (u8 *) v_begin;
+				aprocess->exec_high = (u8 *) v_end;
 			}
 			if (program->p_flags == PF_W + PF_R)
 			{
-				processes[(u32)pid].bss_low = (u8 *) v_begin;
-				processes[(u32)pid].bss_high = (u8 *) v_end;
+				aprocess->bss_low = (u8 *) v_begin;
+				aprocess->bss_high = (u8 *) v_end;
 			}
 			memcpy((u8 *) (src + program->p_offset),
 			       (u8 *) v_begin, program->p_filesz, 0);
@@ -144,19 +146,21 @@ u32 loadelf(u8 * src, pid_t pid)
 
 void initprocesses(void)
 {
-	u32     i = 1;
+	u32     i = 0;
 	processes = (process *) vmalloc(sizeof(process) * MAXNUMPROCESS);
 	while (i < MAXNUMPROCESS)
 	{
 		processes[i].pid = NULL;
 		processes[i++].status = PROCESS_STATUS_FREE;
 	}
-	createtask(0,getinitretry(),true);
-	processes[0].result = 0;
-	processes[0].status = PROCESS_STATUS_READY;
-	processes[0].iskernel = true;
-	current = maketid(0,0);
-	lastpid = NULL;
+	pid_t pid=getfreepid();
+	process *aprocess=findprocess(pid);
+	if (aprocess==NULL) return NULL;
+	aprocess->pid = pid;
+	aprocess->result = 0;
+	aprocess->status = PROCESS_STATUS_READY;
+	aprocess->iskernel = true;
+	current=createtask(pid,getinitretry(),true);
 }
 
 /*******************************************************************************/
@@ -166,8 +170,8 @@ pid_t getfreepid(void)
 {
 	u32     i = lastpid;
 	u32     parsed = 0;
-	while (processes[++i].status != PROCESS_STATUS_FREE
-	       && ++parsed < MAXNUMPROCESS)
+	while (processes[i++].status != PROCESS_STATUS_FREE
+	       && parsed++ < MAXNUMPROCESS)
 	{
 		if (i >= MAXNUMPROCESS)
 			i = 0;
@@ -177,6 +181,7 @@ pid_t getfreepid(void)
 		printf("PANIC: plus d'emplacement disponible pour un novueau processus\n");
 		return NULL;
 	}
+	lastpid=i;
 	return (pid_t)i;
 }
 
@@ -185,15 +190,15 @@ pid_t getfreepid(void)
 
 tid_t getfreeptid(pid_t pid)
 {
-	tid_t new;
-	new.pid=pid;
-	task_t *task_head= &processes[(u32)pid].task_head;
+	process *aprocess=findprocess(pid);
+	if (aprocess==NULL) return maketid(0,0);
+	u32 number=0;
 	task *next;
-	TAILQ_FOREACH(next, task_head, tailq)
-		if (next->tid.number>new.number)
-			new.number=next->tid.number;
-	next->tid.number++;
-	return new;
+	TAILQ_FOREACH(next, &aprocess->task_head, tailq)
+		if (next->tid.number>number)
+			number=next->tid.number;
+	number++;
+	return maketid(pid,number);
 }
 
 /*******************************************************************************/
@@ -228,7 +233,10 @@ tid_t	maketid(pid_t pid, u32 number)
 
 process* findprocess(pid_t pid)
 {
-	return &processes[(u32)pid];
+	if ((u32)pid>0)
+		return &processes[(u32)pid-1];
+	else
+		return NULL;
 }
 
 /*******************************************************************************/
@@ -236,15 +244,7 @@ process* findprocess(pid_t pid)
 
 process* findcurrentprocess(void)
 {
-	return &processes[(u32)getcurrentpid()];
-}
-
-/*******************************************************************************/
-/* Determine le dernier PID occupé */
-
-void usepid(pid_t pid)
-{
-	lastpid = pid;
+	return &processes[(u32)getcurrentpid()-1];
 }
 
 /*******************************************************************************/
@@ -254,7 +254,9 @@ void switchtask(tid_t tid)
 {
 	tid_t previous = current;
 	task *atask = findtask(tid);
+	if (atask==NULL) return;
 	process *aprocess=findprocess(tid.pid);
+	if (aprocess==NULL) return;
 	if (!aprocess->iskernel)
 		setTSS(atask->kernel_stack.ss0, atask->kernel_stack.esp0);
 	else
@@ -273,9 +275,10 @@ void switchtask(tid_t tid)
 
 task* findtask(tid_t tid)
 {
-	task_t *task_head= &processes[(u32)tid.pid].task_head;
+	process *aprocess=findprocess(tid.pid);
+	if (aprocess==NULL) return NULL;
 	task *next;
-	TAILQ_FOREACH(next, task_head, tailq)
+	TAILQ_FOREACH(next, &aprocess->task_head, tailq)
 		if (next->tid.number==tid.number)
 			return next;
 }
@@ -296,7 +299,9 @@ void deletetask(tid_t tid)
 {
 	stoptask(tid);
 	process* aprocess=findprocess(tid.pid);
+	if (aprocess==NULL) return;
 	task *atask=findtask(tid);
+	if (atask==NULL) return;
 	TAILQ_REMOVE(&aprocess->task_head, atask, tailq);
 	vfree(atask);
 }
@@ -307,6 +312,7 @@ void deletetask(tid_t tid)
 void runtask(tid_t tid)
 {
 	task *atask=findtask(tid);
+	if (atask==NULL) return;
 	if (atask->status == TASK_STATUS_READY)
 	{
 		atask->status = TASK_STATUS_RUN;
@@ -322,6 +328,7 @@ tid_t createtask(pid_t pid,u8 *entry, bool kerneltask)
 	tid_t tid;
 	tid.pid=pid;
 	process* aprocess=findprocess(pid);
+	if (aprocess==NULL) return maketid(0,0);
 	task *new = (task *) vmalloc(sizeof(task));
 	TAILQ_INSERT_TAIL(&aprocess->task_head, new, tailq);
 	page *astack = virtual_page_getfree();
@@ -355,7 +362,6 @@ tid_t createtask(pid_t pid,u8 *entry, bool kerneltask)
 	}
 	new->tid=getfreeptid(pid);
 	new->dump.eip = aprocess->entry;
-	new->status=TASK_STATUS_READY;
 	new->dump.eax = 0;
 	new->dump.ecx = 0;
 	new->dump.edx = 0;
@@ -372,8 +378,9 @@ tid_t createtask(pid_t pid,u8 *entry, bool kerneltask)
 
 void stoptask(tid_t tid)
 {
-	task *current=findtask(tid);
-	current->status=TASK_STATUS_STOP;
+	task *atask=findtask(tid);
+	if (atask==NULL) return;
+	atask->status=TASK_STATUS_STOP;
 }
 
 /*******************************************************************************/
@@ -384,18 +391,24 @@ pid_t createprocess(u8 *src, bool kerneltask)
 	tid_t previous = current;
 	current.pid = getfreepid();
 	current.number = 0;
-	usepid(current.pid);
 	process* new=findcurrentprocess();
+	if (new==NULL) return NULL;
 	new->pid = current.pid;
 	new->pdd = virtual_pd_create();
 	TAILQ_INIT(&new->page_head);
+	TAILQ_INIT(&new->task_head);
 	new->iskernel=kerneltask;
 	setCR3(new->pdd->addr->paddr);
 	new->entry = loadelf(src, new->pid);
 	createtask(new->pid,new->entry, new->iskernel);
 	current = previous;
 	process* old=findcurrentprocess();
-	setCR3(old->pdd->addr->paddr);
+	if (old==NULL) return NULL;
+	u32 cr3=KERNEL_PD_ADDR;
+	if (old->pdd!=NULL)
+		cr3=old->pdd->addr->paddr;
+	setCR3(cr3);
+	new->status=PROCESS_STATUS_READY;
 	return new->pid;
 }
 
@@ -406,6 +419,7 @@ void deleteprocess(pid_t pid)
 {
 	stopprocess(pid);
 	process* aprocess=findprocess(pid);
+	if (aprocess==NULL) return;
 	task *next;
 	TAILQ_FOREACH(next, &aprocess->task_head, tailq)
 		deletetask(next->tid);
@@ -419,11 +433,13 @@ void deleteprocess(pid_t pid)
 void runprocess(pid_t pid)
 {
 	process* aprocess=findprocess(pid);
+	if (aprocess==NULL) return;
 	if (aprocess->status == PROCESS_STATUS_READY)
 	{
 		aprocess->status = PROCESS_STATUS_RUN;
-		tid_t tid=maketid(pid,0);
+		tid_t tid=maketid(pid,1);
 		task *atask=findtask(tid);
+		if (atask==NULL) return;
 		atask->status=TASK_STATUS_RUN;
 		switchtask(tid);
 	}
@@ -435,6 +451,7 @@ void runprocess(pid_t pid)
 void stopprocess(pid_t pid)
 {
 	process* aprocess=findprocess(pid);
+	if (aprocess==NULL) return;
 	if (aprocess->status == PROCESS_STATUS_RUN)
 	{
 		aprocess->status = PROCESS_STATUS_READY;
diff --git a/lib/scheduler.c b/lib/scheduler.c
new file mode 100644
index 0000000..459f72b
--- /dev/null
+++ b/lib/scheduler.c
@@ -0,0 +1,98 @@
+/*******************************************************************************/
+/* COS2000 - Compatible Operating System - LGPL v3 - Hordé Nicolas             */
+/*                                                                             */
+#include "interrupts.h"
+#include "types.h"
+#include "asm.h"
+#include "memory.h"
+#include "timer.h"
+#include "vga.h"
+#include "gdt.h"
+
+static u8 curs[4] = { "-\\|/" };
+
+static u8 curspos = 0;
+
+static u32 time = 0;
+
+/******************************************************************************/
+/* Récupère la valeur du timer */
+/* SYSCALL 
+{
+"ID":4, 
+"NAME":"getticks",
+"LIBRARY":"libsys",
+"INTERNALNAME":"gettimer",
+"DESCRIPTION":"Return the internal value of the timer",
+"ARGS": [],
+"RETURN":"u32"
+}
+END */
+
+u32 gettimer(void)
+{
+	return time;
+}
+
+/******************************************************************************/
+/* Handler d'interruption du timer IRQ 0 */
+
+__attribute__ ((noreturn)) void timer_handler(regs *dump)
+{
+	u32 interruption=dump->eip;
+	exception_stack_noerror *caller = (exception_stack_noerror*) ((u32*)dump->esp+1);
+	bool noerror,user;
+	if (caller->cs==SEL_KERNEL_CODE || caller->cs==SEL_USER_CODE)
+	{
+		noerror=true;
+		dump->eip = caller->eip;
+		dump->cs = caller->cs;
+		dump->eflags = caller->eflags;
+		if (dump->cs==SEL_KERNEL_CODE)
+		{
+			dump->esp = (u32) caller + sizeof(exception_stack_noerror);
+			user=false;
+		}
+		else
+		{
+			dump->esp = (u32) ((exception_stack_noerror_user*) caller)->esp;
+			dump->ss = (u32) ((exception_stack_noerror_user*) caller)->ss;
+			user=true;
+		}
+	}
+	else
+	{
+		noerror=false;
+		dump->eip = ((exception_stack*)caller)->eip;
+		dump->cs = ((exception_stack*)caller)->cs;
+		if (dump->cs==SEL_KERNEL_CODE)
+		{
+			dump->esp = (u32) caller + sizeof(exception_stack);
+			user=false;
+		}
+		else
+		{
+			dump->esp = (u32) ((exception_stack_user*) caller)->esp;
+			dump->ss = (u32) ((exception_stack_user*) caller)->ss;
+			user=true;
+		}
+	}
+	showchar(0, 0, curs[curspos], 7);
+	curspos = (curspos + 1) & 0x3;
+	time++;
+	irqendmaster();
+	if (dump->cs==SEL_KERNEL_CODE)
+		{
+			setESP(dump);
+			restcpu_kernel();
+		}
+		else
+		{
+			setESP(dump);
+			restcpu_user();
+			iret();
+		}
+}
+
+
+/*******************************************************************************/
diff --git a/lib/timer.c b/lib/timer.c
deleted file mode 100644
index c594e52..0000000
--- a/lib/timer.c
+++ /dev/null
@@ -1,55 +0,0 @@
-/*******************************************************************************/
-/* COS2000 - Compatible Operating System - LGPL v3 - Hordé Nicolas             */
-/*                                                                             */
-#include "interrupts.h"
-#include "types.h"
-#include "asm.h"
-#include "memory.h"
-#include "timer.h"
-#include "vga.h"
-
-static u8 curs[4] = { "-\\|/" };
-
-static u8 curspos = 0;
-
-static u32 time = 0;
-
-/******************************************************************************/
-/* Récupère la valeur du timer */
-/* SYSCALL 
-{
-"ID":4, 
-"NAME":"getticks",
-"LIBRARY":"libsys",
-"INTERNALNAME":"gettimer",
-"DESCRIPTION":"Return the internal value of the timer",
-"ARGS": [],
-"RETURN":"u32"
-}
-END */
-
-u32 gettimer(void)
-{
-	return time;
-}
-
-/******************************************************************************/
-/* Handler d'interruption de la souris IRQ 0 */
-
-void timer(void)
-{
-	cli();
-	pushf();
-	pushad();
-	showchar(0, 0, curs[curspos], 7);
-	curspos = (curspos + 1) & 0x3;
-	time++;
-	irqendmaster();
-	popad();
-	popf();
-	sti();
-	leave();
-	iret();
-}
-
-/*******************************************************************************/
diff --git a/system/system.c b/system/system.c
index dab3c5e..060f23c 100644
--- a/system/system.c
+++ b/system/system.c
@@ -25,6 +25,8 @@ static u8 errormsg[] =
 	"\033[150C\033[8D\033[37m\033[1m[\033[31mERREUR\033[37m]\033[0m";
 static u8 key = 0;
 
+extern wrapper_timer;
+
 void ok()
 {
 	print(okmsg);
@@ -78,20 +80,20 @@ int main(u32 magic, u32 addr)
 	sti();
 	ok();
 
-	print(" -Installation de l'horloge systeme (IRQ 0)");
-	setidt((u32) timer, SEL_KERNEL_CODE,
+	print(" -Installation de l'ordonnanceur et horloge systeme (IRQ 0)");
+	setidt((u32) &wrapper_timer, SEL_KERNEL_CODE,
 	       ENTRY_PRESENT | ENTRY_RING0 | INTGATE, 32);
 	enableirq(0);
 	ok();
 
 	print(" -Installation du pilote clavier (IRQ 1)");
-	setidt((u32) keyboard_handler, SEL_KERNEL_CODE,
+	setidt((u32) &keyboard_handler, SEL_KERNEL_CODE,
 	       ENTRY_PRESENT | ENTRY_RING0 | INTGATE, 33);
 	enableirq(1);
 	ok();
 
 	print(" -Installation du pilote souris (IRQ12+IRQ2)");
-	setidt((u32) mouse_handler, SEL_KERNEL_CODE,
+	setidt((u32) &mouse_handler, SEL_KERNEL_CODE,
 	       ENTRY_PRESENT | ENTRY_RING0 | INTGATE, 100);
 	enableirq(2);
 	enableirq(12);