From 105eb7c48276615543a90d94c8af4df5d2f90883 Mon Sep 17 00:00:00 2001
From: Yann MAGNIN <yann.magnin@epitech.eu>
Date: Wed, 5 Feb 2020 21:09:39 +0100
Subject: [PATCH] Add scheduler first release + fix process stack crash

---
 Makefile                                   |  14 +-
 include/kernel/devices/timer.h             |  18 --
 include/kernel/hardware/cpg.h              |  80 ++++++++
 include/kernel/hardware/tmu.h              |  30 +--
 include/kernel/memory.h                    |   2 +-
 include/kernel/process.h                   |   3 +-
 include/kernel/scheduler.h                 |   6 +-
 include/kernel/syscall.h                   |   2 +
 include/kernel/unistd_32.h                 |   3 +-
 include/kernel/util.h                      |  20 +-
 include/lib/display.h                      |   3 +-
 include/lib/unistd.h                       |   1 +
 include/user/builtin.h                     |  12 +-
 src/kernel/bootstrap/start.c               |  14 +-
 src/kernel/devices/tty/file_op/read.c      |   3 +-
 src/kernel/fs/gladfs/filesystem/mount.c    |   2 +-
 src/kernel/fs/vfs/dentry/resolve.c         |   7 +-
 src/kernel/fs/vfs/inode/mknod.c            |   4 +-
 src/kernel/fs/vfs/superblock/mount.c       |   4 +-
 src/kernel/hardware/tmu/constructor.c      |  16 --
 src/kernel/hardware/tmu/handler.c          |  19 +-
 src/kernel/hardware/vbr/interrupt.c        |   1 -
 src/kernel/hardware/vbr/interrupt_pre.s    |  52 ++++++
 src/kernel/scheduler/context_switch.s      |   6 +-
 src/kernel/scheduler/debug.c               |  37 ++++
 src/kernel/scheduler/handler.S             | 204 +++++++++++++++++++++
 src/kernel/scheduler/process/alloc.c       |   4 +-
 src/kernel/scheduler/process/get.c         |  16 +-
 src/kernel/scheduler/process/initialize.c  |   2 +-
 src/kernel/scheduler/schedule.c            |  46 ++---
 src/kernel/scheduler/start.c               | 108 ++++++++++-
 src/kernel/scheduler/syscall/sys_exit.c    |  11 ++
 src/kernel/scheduler/syscall/sys_fexecve.c |  77 ++++++++
 src/kernel/scheduler/syscall/sys_fork.c    |  45 +++--
 src/kernel/syscall/handler.c               |  35 ++--
 src/kernel/syscall/syscall_pre.s           |   1 +
 src/kernel/util/kvram.c                    |  57 +++---
 src/kernel/util/timer.c                    |  72 +++++++-
 src/lib/display/dclr_str_area.S            |  12 ++
 src/lib/unistd/fexecve.S                   |  12 ++
 src/user/{ => shell}/Makefile              |  18 +-
 src/user/shell/builtin/proc.c              |  43 +++++
 src/user/{ => shell}/shell.ld              |   5 -
 src/user/shell/util/check_builtin.c        |  98 +++++++---
 src/user/test/Makefile                     | 106 +++++++++++
 src/user/test/test.c                       |  21 ++-
 src/user/test/test.ld                      |  65 +++++++
 src/user/test/test_asm.s                   |   4 +-
 48 files changed, 1168 insertions(+), 253 deletions(-)
 delete mode 100644 include/kernel/devices/timer.h
 create mode 100644 include/kernel/hardware/cpg.h
 delete mode 100644 src/kernel/hardware/tmu/constructor.c
 create mode 100644 src/kernel/hardware/vbr/interrupt_pre.s
 create mode 100644 src/kernel/scheduler/debug.c
 create mode 100644 src/kernel/scheduler/handler.S
 create mode 100644 src/kernel/scheduler/syscall/sys_exit.c
 create mode 100644 src/kernel/scheduler/syscall/sys_fexecve.c
 create mode 100644 src/lib/display/dclr_str_area.S
 create mode 100644 src/lib/unistd/fexecve.S
 rename src/user/{ => shell}/Makefile (77%)
 create mode 100644 src/user/shell/builtin/proc.c
 rename src/user/{ => shell}/shell.ld (89%)
 create mode 100644 src/user/test/Makefile
 create mode 100644 src/user/test/test.ld

diff --git a/Makefile b/Makefile
index dae1e50..c041356 100644
--- a/Makefile
+++ b/Makefile
@@ -7,6 +7,7 @@
 
 KERNEL	:= output/vhex.g1a
 USER	:= output/shell.elf
+TEST	:= output/test.elf
 
 
 ##---
@@ -15,11 +16,13 @@ USER	:= output/shell.elf
 all:
 	@ make --no-print-directory -C src/lib
 	@ make --no-print-directory -C src/kernel
-	@ make --no-print-directory -C src/user
+	@ make --no-print-directory -C src/user/shell
+	@ make --no-print-directory -C src/user/test
 
 install: all
 	sudo p7 send --force --no-term $(KERNEL)
-	sudo p7 send --force --directory=VHEX $(USER)
+	sudo p7 send --force --no-term --directory=VHEX $(USER)
+	sudo p7 send --force --directory=VHEX $(TEST)
 
 
 
@@ -30,12 +33,15 @@ install: all
 clean:
 	make clean --no-print-directory -C src/lib
 	make clean --no-print-directory -C src/kernel
-	make clean --no-print-directory -C src/user
+	make clean --no-print-directory -C src/user/shell
+	make clean --no-print-directory -C src/user/test
 
 fclean: clean
 	make fclean --no-print-directory -C src/lib
 	make fclean --no-print-directory -C src/kernel
-	make fclean --no-print-directory -C src/user
+	make fclean --no-print-directory -C src/user/shell
+	make fclean --no-print-directory -C src/user/test
+	rm -rf build
 
 re: fclean all
 
diff --git a/include/kernel/devices/timer.h b/include/kernel/devices/timer.h
deleted file mode 100644
index 01f0929..0000000
--- a/include/kernel/devices/timer.h
+++ /dev/null
@@ -1,18 +0,0 @@
-#ifndef __KERNEL_DEVICES_TIMER_H__
-# define __KERNEL_DEVICES_TIMER_H__
-
-#include <stddef.h>
-#include <stdint.h>
-
-// TODO: MOVE ME !!!!!!!!
-#define TIMER_NUMBER	3
-#define TIMER_UNUSED	0xff
-
-struct timer_cache_s
-{
-	void *callback;
-	volatile void *arg;
-	uint8_t status;
-};
-
-#endif /*__KERNEL_DEVICES_TIMER_H__*/
diff --git a/include/kernel/hardware/cpg.h b/include/kernel/hardware/cpg.h
new file mode 100644
index 0000000..13363e2
--- /dev/null
+++ b/include/kernel/hardware/cpg.h
@@ -0,0 +1,80 @@
+#ifndef __KERNEL_HARDWARE_CPG_H__
+# define __KERNEL_HARDWARE_CPG_H__
+
+#include <stddef.h>
+#include <stdint.h>
+#include <kernel/def/union_types.h>
+#include <kernel/def/attributes.h>
+
+struct SH7305_cpg_s
+{
+	volatile long_union(FRQCRA,		/* Casio's configuration: 0x0f212213 */
+		uint32_t KICK		: 1;	/* Kick bits */
+		uint32_t const		: 1;	/* All 0 */
+		uint32_t STC		: 6;	/* PLL circuit multiplication ratio */
+		uint32_t IFC		: 4;	/* CPU clock frequency division ratio */
+		uint32_t const		: 4;	/* All 0 */
+		uint32_t SFC		: 4;	/* S clock frequency division ratio */
+		uint32_t BFC		: 4;	/* Bus clock frequency division ration */
+		uint32_t const		: 4;	/* All 0 */
+		uint32_t PFC		: 4;	/* Peripheral clock frequency division ratio */
+	);
+	volatile uint32_t FRQCRB;		/* Undocumented (0x00000000) */
+	volatile long_union(FCLKACR,		/* Casio's configuration: 0x00000157 */
+		uint32_t const		: 16;	/* All 0 */
+		uint32_t unknown	: 16;	/* Unknown (default 0x0157) */
+	);
+	volatile long_union(FCLKBCR,		/* Casio's configuration: 0x0000003f */
+		uint32_t const		: 16;	/* All 0 */
+		uint32_t unknown	: 16;	/* Unknown (default 0x003f) */
+	);
+
+	GAPS(0x08);
+	volatile long_union(IRDACLKCR,		/* Casio's configuration: 0x0000003f */
+		uint32_t const		: 16;	/* All 0 */
+		uint32_t unknown	: 16;	/* Unknown (default 0x003f) */
+	);
+
+	GAPS(0x08);
+	volatile long_union(PLLCR,		/* Casio's configuration: 0x00005000 */
+		uint32_t const		: 16;	/* All 0 */
+		uint32_t unknown0	: 1;	/* Unknown (default 0) */
+		uint32_t PLLE		: 1;	/* PLL enable (?) */
+		uint32_t const		: 1;	/* All 0 */
+		uint32_t FLLE		: 1;	/* FLL enable (?) */
+		uint32_t const		: 8;	/* All 0 */
+		uint32_t unknown1	: 4;	/* Unknown (default 0b0000) */
+	);
+
+	GAPS(0x14);
+	volatile long_union(SPUCLKCR,		/* Casio's configuration: 0x00000103 */
+		uint32_t const		: 16;	/* All 0 */
+		uint32_t unknown	: 16;	/* Unknown (default 0x0103) */
+	);
+
+	GAPS(0x08);
+	volatile long_union(VCLKCR,		/* Casio's configuration: 0x0000003f */
+		uint32_t const		: 16;	/* All 0 */
+		uint32_t unknown	: 16;	/* Unknown (default 0x003f) */
+	);
+
+
+	GAPS(0x04);
+	volatile long_union(FLLFRQ,		/* Casio's configuration: 0x00004384 */
+		uint32_t const		: 16;	/* All 0 */
+		uint32_t SELXM		: 2;    /* FLL output division */
+		uint32_t unknown	: 3;	/* Unknown */
+		uint32_t FLF		: 11;	/* FLL Multiplication Ratio */
+
+	);
+
+	GAPS(0x0c);
+	volatile long_union(LSTATS,
+		uint32_t const		: 31;	/* All 0 */
+		uint32_t const FQRF	: 1;	/* Frequency change status */
+	);
+};
+
+
+#define SH7305_CPG	(*(volatile struct SH7305_cpg_s	*)0xa4150000)
+#endif /*__KERNEL_HARDWARE_CPG_H__*/
diff --git a/include/kernel/hardware/tmu.h b/include/kernel/hardware/tmu.h
index 895276a..7a36b6c 100644
--- a/include/kernel/hardware/tmu.h
+++ b/include/kernel/hardware/tmu.h
@@ -8,29 +8,29 @@
 
 struct timer_s
 {
-	volatile uint32_t TCOR;         /* Timer Constant register */
-	volatile uint32_t TCNT;         /* Timer Counter */
-	volatile word_union(TCR,        /* Timer Control Register */
-		uint16_t const  : 7;    /* All 0 */
-		uint16_t UNF    : 1;    /* Underflow flags */
-		uint16_t const  : 2;    /* All 0 */
-		uint16_t UNIE   : 1;    /* Underflow interrup control */
-		uint16_t const  : 2;    /* All 0 */
-		uint16_t TPSC   : 3;    /* Time prescaler */
+	volatile uint32_t TCOR;			/* Timer Constant register */
+	volatile uint32_t TCNT;			/* Timer Counter */
+	volatile word_union(TCR,		/* Timer Control Register */
+		uint16_t const  : 7;		/* All 0 */
+		uint16_t UNF    : 1;		/* Underflow flags */
+		uint16_t const  : 2;		/* All 0 */
+		uint16_t UNIE   : 1;		/* Underflow interrup control */
+		uint16_t CKREG  : 2;		/* Input Clock edge */
+		uint16_t TPSC   : 3;		/* Time prescaler */
 	);
 	GAPS(2);
 };
 
 struct __sh7305_tmu_s
 {
-	volatile byte_union(TSTR,                /* Timer Start Register */
-		uint8_t const   : 5;                /* All 0 */
-		uint8_t STR2    : 1;                /* Counter start 2 */
-		uint8_t STR1    : 1;                /* Counter start 1 */
-		uint8_t STR0    : 1;                /* Counter start 0 */
+	volatile byte_union(TSTR,		/* Timer Start Register */
+		uint8_t const   : 5;		/* All 0 */
+		uint8_t STR2    : 1;		/* Counter start 2 */
+		uint8_t STR1    : 1;		/* Counter start 1 */
+		uint8_t STR0    : 1;		/* Counter start 0 */
 	);
 	GAPS(3);
-	volatile struct timer_s TIMER[3];
+	volatile struct timer_s TIMER[3];	/* Timers */
 };
 
 #define SH7305_TMU (*(volatile struct __sh7305_tmu_s  *)0xa4490004)
diff --git a/include/kernel/memory.h b/include/kernel/memory.h
index 74eca5f..af34990 100644
--- a/include/kernel/memory.h
+++ b/include/kernel/memory.h
@@ -15,7 +15,7 @@ struct pm_block_cache_s
 	} status;
 
 	// Space informations.
-	uint16_t start;
+	uint32_t start;
 	uint32_t end;
 
 	// Linked list
diff --git a/include/kernel/process.h b/include/kernel/process.h
index bda9cf7..20c63ff 100644
--- a/include/kernel/process.h
+++ b/include/kernel/process.h
@@ -14,8 +14,6 @@
 #define PROCESS_NAME_LENGHT		(16)
 #define PROCESS_MAX			(4)
 
-#define PROC_IDLE			(0)
-
 // define process struct.
 //TODO: signal !
 struct process
@@ -93,6 +91,7 @@ struct process_stack
 // Functions.
 extern struct process *process_create(const char *name);
 extern struct process *process_get(pid_t pid);
+extern pid_t process_get_pid(struct process *process);
 extern int process_switch(pid_t pid);
 
 // Internal function.
diff --git a/include/kernel/scheduler.h b/include/kernel/scheduler.h
index 14f3547..7165d81 100644
--- a/include/kernel/scheduler.h
+++ b/include/kernel/scheduler.h
@@ -59,10 +59,10 @@ extern int sched_add_task(struct process *process);
 extern void sched_start(void);
 
 /*
-** Save current context of the current task and run the
-** next one based on internal task priority.
+** Get the current task context and the next one
+** based on internal task priority / status.
 */
-extern void sched_schedule(void);
+extern int sched_schedule(common_context_t **current, common_context_t **next);
 
 /*
 ** Internal function wich will switch current process
diff --git a/include/kernel/syscall.h b/include/kernel/syscall.h
index a63bd0e..78a861f 100644
--- a/include/kernel/syscall.h
+++ b/include/kernel/syscall.h
@@ -14,6 +14,8 @@ extern pid_t sys_fork(void);
 extern pid_t sys_getpid(void);
 extern pid_t sys_getppid(void);
 extern pid_t sys_waitpid(pid_t pid, int *wstatus, int options);
+extern pid_t sys_fexecve(const char *pathname);
+extern void sys_exit(int status);
 
 extern int sys_open(const char *pathname, int flags, ...);
 extern ssize_t sys_write(int fd, const void *buf, size_t count);
diff --git a/include/kernel/unistd_32.h b/include/kernel/unistd_32.h
index e066abd..d882e82 100644
--- a/include/kernel/unistd_32.h
+++ b/include/kernel/unistd_32.h
@@ -6,7 +6,7 @@
 
 // Process
 #define __NR_exit 		1
-#define __NR_exec 		2
+#define __NR_fexecve 		2
 #define __NR_waitpid 		3
 
 // VFS
@@ -27,6 +27,7 @@
 #define __NR_kvram_ascii	12
 #define __NR_kvram_reverse	13
 #define __NR_kvram_scroll	14
+#define __NR_kvram_clr_str_area	15
 
 //TODO: keyboard
 
diff --git a/include/kernel/util.h b/include/kernel/util.h
index 5d1dc27..33552b2 100644
--- a/include/kernel/util.h
+++ b/include/kernel/util.h
@@ -18,9 +18,9 @@ extern size_t strlen(char const *str);
 extern void kvram_clear(void);
 extern void kvram_display(void);
 extern void kvram_scroll(int lines);
-extern void kvram_reverse(int x, int y, int width, int height);
-extern void kvram_print(int x, int y, char const *str);
 extern void kvram_ascii(int x, int y, char const c);
+extern void kvram_reverse(int x, int y, int width, int height);
+extern void kvram_clr_str_area(int x, int y, int width, int height);
 
 // Kernel printf-wrapper
 extern void printk(int x, int y, char const *str, ...);
@@ -28,9 +28,21 @@ extern void printk(int x, int y, char const *str, ...);
 // Hardware specific function (do not use !)
 extern void t6k11_display(void *vram);
 
-// Timer functions.
+//---
+//	Timer functions.
+//---
+#define TIMER_NUMBER	3
+#define TIMER_UNUSED	0xff
+
+struct timer_cache_s
+{
+	void *callback;
+	volatile void *arg;
+	uint8_t status;
+};
 extern int timer_uninstall(int timer_ID);
-extern int timer_install(void *callback, void *arg, uint32_t delay_ms, uint8_t mode);
+extern int timer_install(void *callback, void *arg, uint32_t ticks, uint8_t mode);
+extern int timer_start(int timer_ID);
 
 // Debug wait
 #define DBG_WAIT for(int i = 0 ; i < 3000000 ; i++)
diff --git a/include/lib/display.h b/include/lib/display.h
index ec71229..e316599 100644
--- a/include/lib/display.h
+++ b/include/lib/display.h
@@ -6,7 +6,8 @@
 
 // Draw primtives
 extern void dclear(void);
-extern void dprint(int x, int y, char const *str);
+extern void dclr_str_area(int x, int y, int with, int height);
+extern void dprint(int x, int y, char const *str, ...);
 extern void dascii(int x, int y, char const c);
 extern void dreverse(int x, int y, int width, int height);
 extern void dscroll(int line);
diff --git a/include/lib/unistd.h b/include/lib/unistd.h
index ba72c8f..5bc4c7c 100644
--- a/include/lib/unistd.h
+++ b/include/lib/unistd.h
@@ -14,6 +14,7 @@
 #define WUNTRACED	1
 #define WCONTINUED	2
 extern pid_t waitpid(pid_t pid, int *wstatus, int options);
+extern pid_t fexecve(const char *pathname);
 
 // File syscall
 #define O_DIRECT	0
diff --git a/include/user/builtin.h b/include/user/builtin.h
index b5fce45..c8a7516 100644
--- a/include/user/builtin.h
+++ b/include/user/builtin.h
@@ -4,14 +4,6 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#define VHEX_BUILTIN(bname)				\
-	static int bname(int argc, char **argv);	\
-	__attribute__((section(".builtin")))		\
-	struct builtin_s _##bname = {			\
-		.name = #bname,				\
-		.entry = &bname				\
-	};						\
-	static int bname(int argc, char **argv)
 
 // Define builtin struct.
 struct builtin_s
@@ -20,5 +12,9 @@ struct builtin_s
 	int (*entry)(int argc, char **argv);
 };
 
+// Builtin list
+extern int builtin_proc(void);
+extern int builtin_ram(void);
+
 
 #endif /*__USER_BUILTIN_H__*/
diff --git a/src/kernel/bootstrap/start.c b/src/kernel/bootstrap/start.c
index 88d034c..2787c9a 100644
--- a/src/kernel/bootstrap/start.c
+++ b/src/kernel/bootstrap/start.c
@@ -174,9 +174,9 @@ int start(void)
 	if (vhex_process == NULL)
 	{
 		kvram_clear();
-		kvram_print(0, 0, "Vhex fatal error !");
-		kvram_print(0, 1, "First process error !");
-		kvram_print(0, 2, "Wait manual reset...");
+		printk(0, 0, "Vhex fatal error !");
+		printk(0, 1, "First process error !");
+		printk(0, 2, "Wait manual reset...");
 		kvram_display();
 		while (1) { __asm__ volatile ("sleep"); }
 	}
@@ -188,9 +188,9 @@ int start(void)
 	{
 		// Display message.
 		kvram_clear();
-		kvram_print(0, 0, "Vhex fatal error !");
-		kvram_print(0, 1, "File \"VHEX/shell.elf\" not found !");
-		kvram_print(0, 2, "Press [MENU key]...");
+		printk(0, 0, "Vhex fatal error !");
+		printk(0, 1, "File \"VHEX/shell.elf\" not found !");
+		printk(0, 2, "Press [MENU key]...");
 		kvram_display();
 
 		// Restore Casio context.
@@ -225,7 +225,7 @@ int start(void)
 
 	// normally the kernel SHOULD / CAN not arrive here.
 	kvram_clear();
-	kvram_print(0, 0, "Kernel job fini !");
+	printk(0, 0, "Kernel job fini !");
 	kvram_display();
 	while (1)
 	{
diff --git a/src/kernel/devices/tty/file_op/read.c b/src/kernel/devices/tty/file_op/read.c
index dfec176..5ebbfd9 100644
--- a/src/kernel/devices/tty/file_op/read.c
+++ b/src/kernel/devices/tty/file_op/read.c
@@ -42,7 +42,8 @@ ssize_t tty_read(void *inode, void *buffer, size_t count)
 	keyboard.saved.tty.cursor.y = tty.cursor.y;
 
 	// Initialize timer for cursor.
-	timer_fd = timer_install(&cursor_callback, &keyboard, 500, 1);
+	// FIXME: find real ticks value !!
+	timer_fd = timer_install(&cursor_callback, &keyboard, 500 * 500 * 2, 1);
 	if (timer_fd == -1)
 		return (0);
 
diff --git a/src/kernel/fs/gladfs/filesystem/mount.c b/src/kernel/fs/gladfs/filesystem/mount.c
index d2ed87d..2f425bc 100644
--- a/src/kernel/fs/gladfs/filesystem/mount.c
+++ b/src/kernel/fs/gladfs/filesystem/mount.c
@@ -19,7 +19,7 @@ void *gladfs_mount(void)
 		if (gladfs_superblock.root_inode == NULL)
 		{
 			kvram_clear();
-			kvram_print(0, 0, "GladFS: ROOT inode alloc error !");
+			printk(0, 0, "GladFS: ROOT inode alloc error !");
 			kvram_display();
 			DBG_WAIT;
 		}
diff --git a/src/kernel/fs/vfs/dentry/resolve.c b/src/kernel/fs/vfs/dentry/resolve.c
index 33b3b21..afb8fe2 100644
--- a/src/kernel/fs/vfs/dentry/resolve.c
+++ b/src/kernel/fs/vfs/dentry/resolve.c
@@ -24,7 +24,7 @@ static int get_name(int *name_lenght, const char *path, char *name)
 	return (0);
 }
 
-//TODO add '..' handling.
+//TODO: update ?
 struct dentry *vfs_dentry_resolve(const char *path, int mode)
 {
 	extern struct process *process_current;
@@ -114,7 +114,6 @@ struct dentry *vfs_dentry_resolve(const char *path, int mode)
 				printk(0, 3, "name: %s$", name);
 				kvram_display();
 				DBG_WAIT;
-				while (1);
 				return (NULL);
 			}
 		}
@@ -138,7 +137,7 @@ struct dentry *vfs_dentry_resolve(const char *path, int mode)
 
 			// Try to find first child
 			next = vfs_dentry_find_first_child(next);
-			if (next != NULL)
+			/*if (next != NULL)
 			{
 				// Debug !
 				kvram_clear();
@@ -148,7 +147,7 @@ struct dentry *vfs_dentry_resolve(const char *path, int mode)
 				printk(0, 3, "name: %s$", name);
 				kvram_display();
 				DBG_WAIT;
-			}
+			}*/
 
 			// Update name lenght to skip '/' char
 			name_lenght = name_lenght + 1; 
diff --git a/src/kernel/fs/vfs/inode/mknod.c b/src/kernel/fs/vfs/inode/mknod.c
index f3c13bf..b1c3a64 100644
--- a/src/kernel/fs/vfs/inode/mknod.c
+++ b/src/kernel/fs/vfs/inode/mknod.c
@@ -62,7 +62,7 @@ int vfs_mknod(const char *pathname, mode_t mode, dev_t dev)
 
 
 	// Debug !
-	kvram_clear();
+	/*kvram_clear();
 	printk(0, 0, "New mknod device !");
 	printk(0, 1, "dentry: %p$", file);
 	printk(0, 2, "inode: %p$", file->inode);
@@ -70,7 +70,7 @@ int vfs_mknod(const char *pathname, mode_t mode, dev_t dev)
 	printk(0, 4, "dev->file_op: %p$", &device->file_op);
 	kvram_display();
 	DBG_WAIT;
-	DBG_WAIT;
+	DBG_WAIT;*/
 
 	// Set file operations
 	file->dentry_op.file_op = &device->file_op;
diff --git a/src/kernel/fs/vfs/superblock/mount.c b/src/kernel/fs/vfs/superblock/mount.c
index a51ec1a..1c1c2c6 100644
--- a/src/kernel/fs/vfs/superblock/mount.c
+++ b/src/kernel/fs/vfs/superblock/mount.c
@@ -67,13 +67,13 @@ int vfs_mount(const char *source, const char *target,
 		vfs_root_node->dentry_op.inode_op = &filesystem->inode_operations;
 
 		// Debug !
-		kvram_clear();
+		/*kvram_clear();
 		printk(0, 0, "vfs_root_node = %p", vfs_root_node);
 		printk(0, 1, "vfs_root_node = %s$", vfs_root_node->name);
 		printk(0, 2, "vfs_root_node = %p", vfs_root_node->child);
 		printk(0, 3, "vfs_root_node = %p", vfs_root_node->next);
 		kvram_display();
-		DBG_WAIT;
+		DBG_WAIT;*/
 		return (0);
 	}
 
diff --git a/src/kernel/hardware/tmu/constructor.c b/src/kernel/hardware/tmu/constructor.c
deleted file mode 100644
index 7bab556..0000000
--- a/src/kernel/hardware/tmu/constructor.c
+++ /dev/null
@@ -1,16 +0,0 @@
-#include <kernel/hardware/tmu.h>
-#include <kernel/devices/timer.h>
-
-// Internal timer "cache".
-struct timer_cache_s timercache[TIMER_NUMBER];
-
-__attribute__((constructor))
-void timer_constructor(void)
-{
-	for (int i = 0 ; i < TIMER_NUMBER ; i = i + 1)
-	{
-		timercache[i].status = TIMER_UNUSED;
-		timercache[i].callback = NULL;
-		timercache[i].arg = NULL;
-	}
-}
diff --git a/src/kernel/hardware/tmu/handler.c b/src/kernel/hardware/tmu/handler.c
index e8126a1..3eafc74 100644
--- a/src/kernel/hardware/tmu/handler.c
+++ b/src/kernel/hardware/tmu/handler.c
@@ -1,9 +1,10 @@
 #include <kernel/hardware/tmu.h>
-#include <kernel/devices/timer.h>
+#include <kernel/util.h>
 
 void timer_handler(void)
 {
 	extern struct timer_cache_s timercache[TIMER_NUMBER];
+	static uint32_t counter = 0;
 	uint32_t intevt;
 	int timer_ID;
 
@@ -11,10 +12,18 @@ void timer_handler(void)
 	// @note: tricky way to get timer ID
 	// TODO: find better way !
 	intevt = *(uint32_t*)0xff000028;
-	timer_ID = (intevt - 0x400) >> 9;
+	timer_ID = (intevt - 0x400) / 0x20;
 
-	// Stop timer flag and clear interrupt flags.
-	SH7305_TMU.TSTR.BYTE &= ~(1 << timer_ID);
+	/*if (intevt != 0x400)
+	{
+		kvram_clear();
+		printk(0, 0, "Timer ID: %d\n", timer_ID);
+		printk(0, 1, "Interrupt: %#x\n", intevt);
+		printk(0, 2, "counter: %d\n", counter++);
+		kvram_display();
+	}*/
+
+	// Clear interrupt flags.
 	SH7305_TMU.TIMER[timer_ID].TCR.UNF = 0;
 
 	// Execute callback if possible.
@@ -24,6 +33,4 @@ void timer_handler(void)
 		((void (*)(volatile void *))timercache[timer_ID].callback)(timercache[timer_ID].arg);
 	}
 
-	// Re-start timer.
-	SH7305_TMU.TSTR.BYTE |= 1 << timer_ID;
 }
diff --git a/src/kernel/hardware/vbr/interrupt.c b/src/kernel/hardware/vbr/interrupt.c
index 8f6b50e..2b3e119 100644
--- a/src/kernel/hardware/vbr/interrupt.c
+++ b/src/kernel/hardware/vbr/interrupt.c
@@ -4,7 +4,6 @@
 extern void keysc_handler(void);
 extern void timer_handler(void);
 
-__attribute__((section(".vhex.interrupt"), interrupt_handler))
 void interrupt_handler(void)
 {
 	uint32_t intevt = *(uint32_t*)0xff000028;
diff --git a/src/kernel/hardware/vbr/interrupt_pre.s b/src/kernel/hardware/vbr/interrupt_pre.s
new file mode 100644
index 0000000..835b7e3
--- /dev/null
+++ b/src/kernel/hardware/vbr/interrupt_pre.s
@@ -0,0 +1,52 @@
+.section ".vhex.interrupt", "awx", @progbits
+
+.global	_interrupt_handler_pre
+.type	_interrupt_handler_pre, @function
+
+.extern	_sched_timer_intevt
+.extern	_sched_handler
+.extern	_interrupt_handler
+
+_interrupt_handler_pre:
+	! Due to PR register used to switch process
+	! context, we SHOULD catch scheduler timer
+	! interrupt before the interrupt handler because
+	! we need to save / restore pr register before
+	! context swtich.
+	mov.l	.sched_timer_intevt, r0		! get the precalculate scheduler timer event
+	mov.l	.intevt_register, r1		! get INTEVT register address
+	mov.l	@r0, r0				! get the scheduler event code
+	mov.l	@r1, r1				! get the interrupt event
+	cmp/eq	r0, r1				! if scheduler timer event == INTEVT...
+	bf	general_interrupt		! ...if not, jump at <general_interrupt>
+
+scheduler_interrupt:
+	mov.l	.scheduler_handler, r0		! get scheduler handler address
+	jmp	@r0				! jump into scheduler handler
+	nop					! (db) nop
+
+general_interrupt:
+	! Save critical regsiter.
+	stc.l	spc, @-r15			! save SPC register.
+	stc.l	ssr, @-r15			! save SSR register.
+	sts.l	pr, @-r15			! save pr register.
+
+	! Call interrupt handler
+	mov.l	.interrupt_handler, r0		! get interrupt handler address
+	jsr	@r0				! call interurpt handler
+	nop					! (db) nop
+
+	! Restore critical regsiter
+	lds.l	@r15+, pr			! restore PR register.
+	ldc.l	@r15+, ssr			! restore SSR regsiter.
+	ldc.l	@r15+, spc			! restore SPC regsiter.
+
+	! Return
+	rte					! exit
+	nop					! (db) nop
+
+.align 4
+.sched_timer_intevt:	.long _sched_timer_intevt
+.scheduler_handler:	.long _sched_handler
+.interrupt_handler:	.long _interrupt_handler
+.intevt_register:	.long 0xff000028
diff --git a/src/kernel/scheduler/context_switch.s b/src/kernel/scheduler/context_switch.s
index 13e9422..0108300 100644
--- a/src/kernel/scheduler/context_switch.s
+++ b/src/kernel/scheduler/context_switch.s
@@ -44,10 +44,10 @@ save_current_context:
 	! @note: current process can be NULL !
 	tst	r4, r4					! if current task == NULL...
 	bt	context_load				! ...if yes, jump at <context_switch> 
-	add	#88, r4					! get &process->context (end)
+	add	#84, r4					! get &process->context (end)
 
 	! save current context
-	sts.l	pr, @-r4				! get pr regsiter
+	!sts.l	pr, @-r4				! get pr regsiter
 	stc.l	spc, @-r4				! get spc regsiter
 	stc.l	ssr, @-r4				! get ssr regsiter
 	sts.l	mach, @-r4				! get mach regsiter
@@ -95,7 +95,7 @@ context_load:
 	lds.l	@r5+, mach				! set mach regsiter
 	ldc.l	@r5+, ssr				! set ssr regsiter
 	ldc.l	@r5+, spc				! set spc regsiter
-	lds.l	@r5+, pr				! set pr regsiter
+	!lds.l	@r5+, pr				! set pr regsiter
 
 
 	! Process switch
diff --git a/src/kernel/scheduler/debug.c b/src/kernel/scheduler/debug.c
new file mode 100644
index 0000000..2a18839
--- /dev/null
+++ b/src/kernel/scheduler/debug.c
@@ -0,0 +1,37 @@
+#include <kernel/context.h>
+#include <kernel/hardware/tmu.h>
+#include <kernel/util.h>
+
+// Test
+uint32_t counter = 0;
+
+void sched_debug(common_context_t *context_current, common_context_t *context_next)
+{
+	extern uint32_t sched_timer_id;
+	extern uint32_t sched_timer_address;
+
+	uint32_t tstr = SH7305_TMU.TSTR.BYTE;
+	uint32_t tcr = *(uint16_t*)sched_timer_address;
+	uint32_t tcor = *(uint32_t*)(sched_timer_address - 4);
+	uint32_t tcnt = *(uint32_t*)(sched_timer_address - 8);
+
+	
+	//SH7305_TMU.TSTR.STR2 = 0;
+	//SH7305_TMU.TSTR.STR1 = 0;
+	//SH7305_TMU.TSTR.STR0 = 0;
+
+	//SH7305_TMU.TIMER[0].TCR.UNF = 0;
+	//SH7305_TMU.TIMER[1].TCR.UNF = 0;
+	//SH7305_TMU.TIMER[2].TCR.UNF = 0;
+
+	kvram_clear();
+	printk(0, 0, "Scheduler_schudele !");
+	printk(0, 1, "context current = %p", context_current);
+	printk(0, 2, "context next = %p", context_next);
+	printk(0, 3, "counter = %#x", counter++);
+	printk(0, 4, "TSTR: %#x", tstr);
+	printk(0, 5, "TCOR: %#x", tcor);
+	printk(0, 6, "TCNT: %#x", tcnt);
+	printk(0, 7, "TCR:  %#x", tcr);
+	kvram_display();
+}
diff --git a/src/kernel/scheduler/handler.S b/src/kernel/scheduler/handler.S
new file mode 100644
index 0000000..d0910c0
--- /dev/null
+++ b/src/kernel/scheduler/handler.S
@@ -0,0 +1,204 @@
+.text
+
+.global	_sched_handler
+.type	_sched_handler, @function
+
+.extern _sched_timer_id
+.extern _sched_timer_address
+.extern _sched_schedule
+
+.align 2
+/*
+** @note
+** We can use only r0 - r7 register because
+** we SHOULD not modify the current process context.
+*/
+_sched_handler:
+
+
+/*
+** Stop scheduler timer and clear interrupt flags
+*/
+stop_clear_sched_timer:
+	! Clear scheduler timer interrupt
+	mov.l	.sched_timer_address, r0		! get precalculated scheduler timer address
+	mov.l	.timer_unf_field, r1			! get TIMER.TCR.UNF byte field
+	mov.l	@r0, r0					! get scheduler timer TCR register
+	mov.w	@r0, r2					! get scheduler timer TCR register
+	not	r1, r1					! get interrupt flags bit mask (to remove)
+	and	r1, r2					! clear timer interrupt flags
+	mov.w	r2, @r0					! update timer TCR
+
+	! Stop scheduler timer
+	mov.l	.sched_timer_tstr_bit, r0		! get precalculated scheduler timer ID
+	mov.l	.timer_tstr_register, r1		! get TMU0.TSTR base address
+	mov.l	@r0, r0					! get scheduler timer ID
+	mov.b	@r1, r2					! get TMU0.TSTR data
+	not	r0, r0					! get TSTR scheduler timer ID mask (to remove)
+	and	r0, r2					! stop scheduler timer
+	mov.b	r2, @r1					! update TMU0.TSTR
+
+#ifdef __SCHED_DEBUG__
+	sts.l	pr, @-r15				! save pr register
+	mov	#0, r4					! save r4 register (current context)
+	mov	#0, r5					! save r5 register (next context)
+	mov.l	.sched_debug, r0			! get sched_debug() absraction
+	jsr	@r0					! call abstraction
+	nop						! (db) nop
+	lds.l	@r15+, pr				! restore pr register
+
+	bra	restart_sched_timer
+	nop
+#endif
+
+
+/*
+** Get current and next context
+*/
+get_contexts:
+	! prologue
+	mov.l	r9, @-r15				! save r9 register
+	mov.l	r8, @-r15				! save r8 register
+	sts.l	pr, @-r15				! save pr register
+
+	! Create to context_common_t **ptr
+	add	#-4, r15				! create first context pointer
+	mov	r15, r8					! save first context pointer
+	add	#-4, r15				! create second context pointer
+	mov	r15, r9					! save second context pointer
+	add	#-4, r15				! create context pointer
+	mov.l	r15, @r8				! save context pointer
+	add	#-4, r15				! create context pointer
+	mov.l	r15, @r9				! save context pointer
+	
+	! call high level abstraction
+	mov	r8, r4					! send current contexts pointer
+	mov	r9, r5					! send next context pointer
+	mov.l	.sched_schedule, r0			! get sched_scheduler() abstraction address
+	jsr	@r0					! call sched_schedule() abstract
+	nop						! (db) nop
+
+	! Restore stack and register (epilogue)
+	mov.l	@r8, r4					! save current context
+	mov.l	@r9, r5					! save next context
+	add	#16, r15				! restore stack
+	lds.l	@r15+, pr				! restore pr register
+	mov.l	@r15+, r8				! restore r8 register
+	mov.l	@r15+, r9				! restore r9 register
+
+	! Check context error
+	tst	r0, r0					! check if returned value == 0...
+	bt	debug					! if yes, jump at <debug>
+	bra	restart_sched_timer			! jump at <restart_sched_timer>
+	nop						! (db) nop
+
+
+/*
+** Debug part, used to debug the contexts
+*/
+debug:
+#ifdef __SCHED_DEBUG__
+	sts.l	pr, @-r15				! save pr register
+	mov.l	r4, @-r15				! save r4 register (current context)
+	mov.l	r5, @-r15				! save r5 register (next context)
+	mov.l	.sched_debug, r0			! get sched_debug() absraction
+	jsr	@r0					! call abstraction
+	nop						! (db) nop
+	mov.l	@r15+, r5				! restore r5 register
+	mov.l	@r15+, r4 				! restore r4 register
+	lds.l	@r15+, pr				! restore pr register
+#endif
+
+
+
+/*
+** Context switch
+*/
+save_current_context:
+	! Check current process
+	! @note: current process can be NULL !
+	tst	r4, r4					! if current task == NULL...
+	bt	next_context_load			! ...if yes, jump at <context_switch> 
+	add	#88, r4					! get &process->context (end)
+
+	! save current context
+	sts.l	pr, @-r4				! get pr regsiter
+	stc.l	spc, @-r4				! get spc regsiter
+	stc.l	ssr, @-r4				! get ssr regsiter
+	sts.l	mach, @-r4				! get mach regsiter
+	sts.l	macl, @-r4				! get macl regsiter
+	stc.l	gbr, @-r4				! get gbr regsiter
+	mov.l	r15, @-r4				! get r15 register
+	mov.l	r14, @-r4				! get r14 regsiter
+	mov.l	r13, @-r4				! get r13 regsiter
+	mov.l	r12, @-r4				! get r12 regsiter
+	mov.l	r11, @-r4				! get r11 regsiter
+	mov.l	r10, @-r4				! get r10 regsiter
+	mov.l	r9, @-r4				! get r9 regsiter
+	mov.l	r8, @-r4				! get r8 regsiter
+	stc.l	R7_BANK, @-r4				! get "process" r7 regsiter
+	stc.l	R6_BANK, @-r4				! get "process" r6 regsiter
+	stc.l	R5_BANK, @-r4				! get "process" r5 regsiter
+	stc.l	R4_BANK, @-r4				! get "process" r4 regsiter
+	stc.l	R3_BANK, @-r4				! get "process" r3 regsiter
+	stc.l	R2_BANK, @-r4				! get "process" r2 regsiter
+	stc.l	R1_BANK, @-r4				! get "process" r1 regsiter
+	stc.l	R0_BANK, @-r4				! get "process" r0 regsiter
+
+next_context_load:
+	! Load next process
+	! @note: next process can not be NULL !
+	ldc.l	@r5+, R0_BANK				! set "process" r0 regsiter
+	ldc.l	@r5+, R1_BANK				! set "process" r1 regsiter
+	ldc.l	@r5+, R2_BANK				! set "process" r2 regsiter
+	ldc.l	@r5+, R3_BANK				! set "process" r3 regsiter
+	ldc.l	@r5+, R4_BANK				! set "process" r4 regsiter
+	ldc.l	@r5+, R5_BANK				! set "process" r5 regsiter
+	ldc.l	@r5+, R6_BANK				! set "process" r6 regsiter
+	ldc.l	@r5+, R7_BANK				! set "process" r7 regsiter
+	mov.l	@r5+, r8				! set r8 regsiter
+	mov.l	@r5+, r9				! set r9 regsiter
+	mov.l	@r5+, r10				! set r10 regsiter
+	mov.l	@r5+, r11				! set r11 regsiter
+	mov.l	@r5+, r12				! set r12 regsiter
+	mov.l	@r5+, r13				! set r13 regsiter
+	mov.l	@r5+, r14				! set r14 regsiter
+	mov.l	@r5+, r15				! set r15 register
+	ldc.l	@r5+, gbr				! set gbr regsiter
+	lds.l	@r5+, macl				! set macl regsiter
+	lds.l	@r5+, mach				! set mach regsiter
+	ldc.l	@r5+, ssr				! set ssr regsiter
+	ldc.l	@r5+, spc				! set spc regsiter
+	lds.l	@r5+, pr				! set pr regsiter
+
+
+/*
+** Restart timer
+*/
+restart_sched_timer:
+	mov.l	.sched_timer_tstr_bit, r0		! get precalculated scheduler timer ID
+	mov.l	.timer_tstr_register, r1		! get TMU0.TSTR base address
+	mov.l	@r0, r0					! get scheduler timer ID
+	mov.b	@r1, r2					! get TMU0.TSTR data
+	or	r0, r2					! start scheduler timer
+	mov.b	r2, @r1					! update TMU0.TSTR
+
+
+/*
+** Process switch
+*/
+process_switch:
+	rte						! use RTE to switch process
+	nop						! (db) nop
+
+
+.align 4
+.sched_timer_tstr_bit:	.long _sched_timer_tstr_bit
+.sched_timer_address:	.long _sched_timer_address
+.sched_schedule:	.long _sched_schedule
+.timer_tstr_register:	.long 0xa4490004
+.timer_unf_field:	.long 0x00000100
+#ifndef __SCHED_DEBUG__
+.sched_debug:		.long _sched_debug
+#endif
+.end
diff --git a/src/kernel/scheduler/process/alloc.c b/src/kernel/scheduler/process/alloc.c
index ea57666..9de6c68 100644
--- a/src/kernel/scheduler/process/alloc.c
+++ b/src/kernel/scheduler/process/alloc.c
@@ -2,14 +2,16 @@
 
 // This function SHOULD NOT be called
 // without atomic operation !!
+// TODO: dynamic allocation ?
 pid_t process_alloc(struct process **process)
 {
 	extern struct process_stack process_stack[PROCESS_MAX];
 
 	for (int i = 0 ; i < PROCESS_MAX ; i = i + 1)
 	{
-		if (process_stack[i].status == PROC_IDLE)
+		if (process_stack[i].status == PROC_UNUSED)
 		{
+			process_stack[i].status = PROC_USED;
 			*process = &process_stack[i].process;
 			return (i);
 		}
diff --git a/src/kernel/scheduler/process/get.c b/src/kernel/scheduler/process/get.c
index 03f441e..9f8e5ae 100644
--- a/src/kernel/scheduler/process/get.c
+++ b/src/kernel/scheduler/process/get.c
@@ -1,6 +1,6 @@
 #include <kernel/process.h>
 
-struct process *process_get(pid_t pid)
+struct process *process_get_proc(pid_t pid)
 {
 	extern struct process_stack process_stack[PROCESS_MAX];
 
@@ -11,3 +11,17 @@ struct process *process_get(pid_t pid)
 	// Return process.
 	return (&process_stack[pid].process);
 }
+
+pid_t process_get_pid(struct process *target)
+{
+	extern struct process_stack process_stack[PROCESS_MAX];
+	int i;
+
+	i = -1;
+	while (++i < PROCESS_MAX)
+	{
+		if (&process_stack[i].process == target)
+			return (i);
+	}
+	return (-1);
+}
diff --git a/src/kernel/scheduler/process/initialize.c b/src/kernel/scheduler/process/initialize.c
index 96d26e0..f36fa8f 100644
--- a/src/kernel/scheduler/process/initialize.c
+++ b/src/kernel/scheduler/process/initialize.c
@@ -10,6 +10,6 @@ void process_constructor(void)
 	// Set all process to idle state.
 	for (int i = 0 ; i < PROCESS_MAX ; i = i + 1)
 	{
-		process_stack[i].status = PROC_IDLE;
+		process_stack[i].status = PROC_UNUSED;
 	}
 }
diff --git a/src/kernel/scheduler/schedule.c b/src/kernel/scheduler/schedule.c
index 5da4f2d..fa618bf 100644
--- a/src/kernel/scheduler/schedule.c
+++ b/src/kernel/scheduler/schedule.c
@@ -3,26 +3,20 @@
 #include <kernel/util.h>
 
 //TODO: assembly !
-void sched_schedule(void)
+// @note: This part *SHOULD* be exeption safe !
+int sched_schedule(common_context_t **context_current, common_context_t **context_next)
 {
 	extern struct sched_task *sched_task_current;
 	extern struct sched_task *sched_task_queue;
 	struct sched_task *task_current;
 	struct sched_task *task_next;
-	common_context_t *context_current;
-	common_context_t *context_next;
 	
-	// Start atomic operation
-	atomic_start();
-
 	// Check current task
+	// TODO: check process status !!
 	if (sched_task_current == NULL)
 	{
 		task_current = NULL;
-		task_next = (sched_task_queue != NULL)
-			? sched_task_queue
-			: NULL;
-
+		task_next = (sched_task_queue != NULL) ? sched_task_queue : NULL;
 	} else {
 		task_current = sched_task_current;
 		task_next = (sched_task_current->next != NULL)
@@ -32,39 +26,23 @@ void sched_schedule(void)
 
 	// Check potantial error
 	if (task_next == NULL || task_next == sched_task_current)
-	{
-		atomic_stop();
-		return;
-	}
-
-	//TODO: check process status !!!
+		return (-1);
 	
 	// Update internal scheduler task cursor
 	sched_task_current = task_next;
 
-
 	// Get context
-	context_current =
-		(task_current != NULL)
-		? &task_current->process->context
-		: NULL;
-	context_next =
-		(task_next != NULL)
-		? &task_next->process->context
-		: NULL;
+	*context_current = (task_current != NULL) ? &task_current->process->context : NULL;
+	*context_next = &task_next->process->context;
 
 	// DEBUG !
-	kvram_clear();
+	/*kvram_clear();
 	printk(0, 0, "Scheduler_schudele !");
 	printk(0, 1, "task current = %p", task_current);
 	printk(0, 2, "task next = %p", task_next);
-	printk(0, 3, "context current = %p", context_current);
-	printk(0, 4, "context next = %p", context_next);
+	printk(0, 3, "context current = %p", *context_current);
+	printk(0, 4, "context next = %p", *context_next);
 	kvram_display();
-	DBG_WAIT;
-	printk(0, 5, "context switch !");
-	kvram_display();
-
-	// Context switch	
-	sched_context_switch(context_current, context_next);
+	DBG_WAIT;*/
+	return (0);
 }
diff --git a/src/kernel/scheduler/start.c b/src/kernel/scheduler/start.c
index b5171b9..c4d2be0 100644
--- a/src/kernel/scheduler/start.c
+++ b/src/kernel/scheduler/start.c
@@ -1,12 +1,114 @@
 #include <kernel/scheduler.h>
+#include <kernel/hardware/cpg.h>
+#include <kernel/hardware/tmu.h>
+#include <kernel/util.h>
+
+// Internal data used by the scheduler handler
+uint32_t sched_timer_id = 0;
+uint32_t sched_timer_address = 0;
+uint32_t sched_timer_intevt = 0;
+uint32_t sched_timer_tstr_bit = 0;
+
+// Internal private function
+//void sched_handler(void);
+
+//FIXME: remove me and wrap timer interrupt when occur !!
+static void scheduler_timer_callback(void)
+{
+	common_context_t *context_current;
+	common_context_t *context_next;
+
+	//TODO: quantum handling !!
+	//TODO: scheduler block / unblock options !!
+	//FIXME: Get SPC, SSR, ... !!
+	
+	// Get current context and 
+	if (sched_schedule(&context_current, &context_next) != 0)
+		return;
+
+	// Debug
+	//kvram_clear();
+	//printk(0, 0, "Scheduler_schudele !");
+	//printk(0, 1, "context current = %p", context_current);
+	//printk(0, 2, "context next = %p", context_next);
+	//kvram_display();
+	//printk(0, 3, "context switch !");
+	//kvram_display();
+	//DBG_WAIT;
+
+	// Context switch	
+	sched_context_switch(context_current, context_next);
+}
 
 void sched_start(void)
 {
 	extern struct sched_task *sched_task_queue;
 	extern struct process *process_current;
+	uint32_t fll_freq;
+	uint32_t pll_freq;
+	uint32_t cpu_freq;
+	uint32_t bus_freq;
+	uint32_t per_freq;
 
-	//TODO: get CPU frequency !
-	//TODO: setup TMU0 interrupt !
+
+	// Calculate FLL frequency (Khz)
+	// @note: RCLK = 32 768 Hz
+	fll_freq = SH7305_CPG.FLLFRQ.FLF * 32768;		// Hz
+	fll_freq = fll_freq /  (1 << SH7305_CPG.FLLFRQ.SELXM);	// Check FLL output division
+
+	// Calculate PLL frequency (Khz)
+	pll_freq = fll_freq * (SH7305_CPG.FRQCRA.STC + 1);
+
+	// Calculate CPU clock frequency !
+	cpu_freq = pll_freq / (1 << (SH7305_CPG.FRQCRA.IFC + 1));
+
+	// Calculate BUS clock frequency !
+	bus_freq = pll_freq / (1 << (SH7305_CPG.FRQCRA.BFC + 1));
+
+	// Calculate Peripheral clock frequency !
+	per_freq = pll_freq / (1 << (SH7305_CPG.FRQCRA.PFC + 1));
+	
+
+	// Debug
+	kvram_clear();
+	printk(0, 0,
+		"FLL freq: %d.%d Mhz\n"
+		"PLL freq: %d.%d Mhz\n"
+		"CPU freq: %d.%d Mhz\n"
+		"BUS freq: %d.%d Mhz\n"
+		"Per freq: %d.%d Mhz",
+		fll_freq / 1000000, (((fll_freq - ((fll_freq / 1000000)) * 1000000)) + 999) / 1000,
+		pll_freq / 1000000, (((pll_freq - ((pll_freq / 1000000)) * 1000000)) + 999) / 1000,
+		cpu_freq / 1000000, (((cpu_freq - ((cpu_freq / 1000000)) * 1000000)) + 999) / 1000,
+		bus_freq / 1000000, (((bus_freq - ((bus_freq / 1000000)) * 1000000)) + 999) / 1000,
+		per_freq / 1000000, (((per_freq - ((per_freq / 1000000)) * 1000000)) + 999) / 1000
+	);
+	kvram_display();
+	DBG_WAIT;
+
+	// Register first process ! 
 	process_current = sched_task_queue->process;
-	sched_schedule();
+
+	// Setup TMU0 (scheduler) interrupt !
+	// @note: I use Po/4 on TMU prescaler
+	// TODO: generate quantum and quantum counter for preemption !
+	uint32_t ticks = (per_freq / 4) / 16;
+	//sched_timer_id = timer_install(scheduler_timer_callback, NULL, ticks, 0);
+	sched_timer_id = timer_install(NULL, NULL, ticks, 0);
+	sched_timer_address = (uint32_t)&SH7305_TMU.TIMER[sched_timer_id].TCR; 
+	sched_timer_intevt = 0x400 + (0x20 * sched_timer_id);
+	sched_timer_tstr_bit = 1 << sched_timer_id;
+
+	// Debug
+	kvram_clear();
+	printk(0, 0, "timer ID:    %d", sched_timer_id);
+	printk(0, 1, "timer addr:  %#x", sched_timer_address);
+	printk(0, 2, "timer event: %#x", sched_timer_intevt);
+	printk(0, 3, "timer TSTR:  %#x", sched_timer_tstr_bit);
+	kvram_display();
+	DBG_WAIT;
+	
+
+	// Start scheduler timer
+	timer_start(sched_timer_id);
 }
diff --git a/src/kernel/scheduler/syscall/sys_exit.c b/src/kernel/scheduler/syscall/sys_exit.c
new file mode 100644
index 0000000..affe2a5
--- /dev/null
+++ b/src/kernel/scheduler/syscall/sys_exit.c
@@ -0,0 +1,11 @@
+#include <kernel/scheduler.h>
+#include <kernel/util.h>
+
+void sys_exit(int status)
+{
+	kvram_clear();
+	printk(0, 0, "PROCESS EXIT SYSCALL !!!!");
+	printk(0, 0, "Wait manual reset...");
+	kvram_display();
+	while (1);
+}
diff --git a/src/kernel/scheduler/syscall/sys_fexecve.c b/src/kernel/scheduler/syscall/sys_fexecve.c
new file mode 100644
index 0000000..e79095a
--- /dev/null
+++ b/src/kernel/scheduler/syscall/sys_fexecve.c
@@ -0,0 +1,77 @@
+#include <kernel/process.h>
+#include <kernel/scheduler.h>
+#include <kernel/loader.h>
+#include <kernel/atomic.h>
+#include <kernel/util.h>
+
+pid_t sys_fexecve(const char *pathname)
+{
+	struct process *proc;
+	pid_t child_pid;
+	FILE *bin;
+	int error;
+
+	// Start atomic operation
+	atomic_start();
+
+	// Try create new process
+	proc = process_create(pathname);
+	if (proc == NULL)
+	{
+		kvram_clear();
+		printk(0, 0, "sys_fexecve: alloc error !");
+		kvram_display();
+		DBG_WAIT;
+		atomic_stop();
+		return (-1);
+	}
+
+	// Try to load binary into physical memory
+	proc->context.spc = (uint32_t)loader(pathname, proc);
+	if (proc->context.spc == 0x00000000)
+	{
+		kvram_clear();
+		printk(0, 0, "sys_fexecve: loader error !");
+		kvram_display();
+		DBG_WAIT;
+		process_free(proc);
+		atomic_stop();
+		return (-1);
+	}
+
+	// Debug
+	kvram_clear();
+	printk(0, 0, "New proc loaded !");
+	kvram_display();
+	DBG_WAIT;
+
+	// Add new process into task queue
+	error = sched_add_task(proc);
+	if (error != 0)
+	{
+		kvram_clear();
+		printk(0, 0, "sys_fexecve: scheduler error !");
+		kvram_display();
+		DBG_WAIT;
+		process_free(proc);
+		atomic_stop();
+		return (-1);
+	}
+
+	// Debug
+	printk(0, 1, "New proc sched added !");
+	kvram_display();
+	DBG_WAIT;
+
+	// Get child process PID
+	child_pid = process_get_pid(proc);
+
+	// Debug
+	printk(0, 2, "New proc PID = %#x !", child_pid);
+	kvram_display();
+	DBG_WAIT;
+
+	// Stop atomic operations
+	atomic_stop();
+	return (child_pid);
+}
diff --git a/src/kernel/scheduler/syscall/sys_fork.c b/src/kernel/scheduler/syscall/sys_fork.c
index 16ee9a3..16f9167 100644
--- a/src/kernel/scheduler/syscall/sys_fork.c
+++ b/src/kernel/scheduler/syscall/sys_fork.c
@@ -2,20 +2,41 @@
 
 pid_t sys_fork(void)
 {
-	extern process_t *process_current;
-	process_t **process_new;
-	pid_t process_pid;
+	extern struct process *process_current;
+	struct process *process_new;
+	pid_t process_new_pid;
+
+	// Check error
+	if (process_current == NULL)
+		return (-1);
 
 	// Get the new process slot.
-	process_new = &process_current->child;
-	while (*process_new != NULL)
-		process_new = &(*process_new)->next;
-
-	// Try to find new sheduler place.
-	process_pid = process_alloc(&(*process_new));
-	if (*process_new == NULL)
+	new_pid = process_alloc(&process_new);
+	if (new_pid != 0)
 		return (-1);
-	
-	// Initialize context.
+
+	// Try to create user stack
+	process_new->memory.stack.size.user = process_current->;
+	process_new->memory.stack.user = (uint32_t)pm_alloc(process_new->memory.stack.size.user);
+	if (process_new->memory.stack.user == 0x00000000)
+	{
+		process_free(process_new);
+		return (-1);
+	}
+
+	// Try to create kernel stack
+	process_new->memory.stack.size.kernel = process_current->memory.stack.size.kernel;
+	process_new->memory.stack.kernel = (uint32_t)pm_alloc(process_new->memory.stack.size.kernel);
+	if (process_new->memory.stack.kernel == 0x00000000)
+	{
+		pm_free(process_new->memory.stack.user);
+		process_free(process_new);
+		return (-1);
+	}
+
+
+	//TODO: dump stack data
+	//TODO: dump code data
+	//TODO: Initialize context.
 	return (-1);
 }*/
diff --git a/src/kernel/syscall/handler.c b/src/kernel/syscall/handler.c
index c5b7261..19651e5 100644
--- a/src/kernel/syscall/handler.c
+++ b/src/kernel/syscall/handler.c
@@ -12,35 +12,36 @@ static void sys_test(uint32_t a, uint32_t b, uint32_t c, uint32_t d)
 	DBG_WAIT;
 }
 
-static const void *sys_handler[15] = {
+static const void *sys_handler[16] = {
 	// Kernel Test
-	sys_test,	//restart
+	sys_test,		// test
 
 	// Process
-	NULL,		//exit
-	sys_waitpid,	//waitpid
-	NULL,		//exec
+	sys_exit,		// exit
+	sys_fexecve,		// fexecve
+	sys_waitpid,		// waitpid
 
 	// VFS
-	sys_read,	//read
-	sys_write,	//write
-	sys_open,	//open
-	sys_close,	//close
-	sys_lseek,	//lseek
+	sys_read,		// read
+	sys_write,		// write
+	sys_open,		// open
+	sys_close,		// close
+	sys_lseek,		// lseek
 
 	// Display
-	kvram_display,	//kvram_display
-	kvram_clear,	//kvram_clear
-	kvram_print,	//kvram_print
-	kvram_ascii,	//kvram_ascii
-	kvram_reverse,	//kvram_reverse
-	kvram_scroll	//kvram_scroll
+	kvram_display,		// kvram_display
+	kvram_clear,		// kvram_clear
+	printk,			// printk
+	kvram_ascii,		// kvram_ascii
+	kvram_reverse,		// kvram_reverse
+	kvram_scroll,		// kvram_scroll
+	kvram_clr_str_area	// kvram_clr_str_area
 };
 
 void *sys_get_handler(int sysno)
 {
 	// Check sysno validity
-	if (sysno < 0 || sysno >= 14)
+	if (sysno < 0 || sysno >= 16)
 		return (0);
 
 	// DEBUG
diff --git a/src/kernel/syscall/syscall_pre.s b/src/kernel/syscall/syscall_pre.s
index 5c04542..af4dfab 100644
--- a/src/kernel/syscall/syscall_pre.s
+++ b/src/kernel/syscall/syscall_pre.s
@@ -31,6 +31,7 @@ _syscall_pre:
 	! Switch register bank and allow interrupt
 	! @note: user context has been saved
 	! during the `exception_handler_pre`
+	! TODO: do not allow interrupt ?
 	mov.l	.sr_mask, r1		! get SR mask for BL and IMASK
 	and	r1, r0			! set SR.BL = 0, SR.RB = 0 and SR.IMASK = 0b0000
 	ldc	r0, sr			! update SR regsiter
diff --git a/src/kernel/util/kvram.c b/src/kernel/util/kvram.c
index f5db090..30b4c3a 100644
--- a/src/kernel/util/kvram.c
+++ b/src/kernel/util/kvram.c
@@ -133,42 +133,49 @@ void kvram_reverse(int x, int y, int width, int height)
 	atomic_stop();
 }
 
-/* kvram_print() - Print string on Video RAM */
-void kvram_print(int x, int y, char const *str)
+/* kvram_clr_str_area() - Clear area based on kernel font size on Video RAM */
+//FIXME: secure
+void kvram_clr_str_area(int x, int y, int width, int height)
 {
-	int default_pos_x;
-	int starting_x;
-	int i;
+	uint32_t vram_offset_y;
+	int cur_x;
+	int cur_y;
 
 	// Initialize part
-	i = -1;
-	starting_x = x;
 	x = x * (KERNEL_FONT_REAL_WIDTH + 1);
 	y = y * (KERNEL_FONT_REAL_HEIGHT + 1);
-	default_pos_x = x;
+	width = width * (KERNEL_FONT_REAL_WIDTH + 1);
+	height = height * (KERNEL_FONT_REAL_HEIGHT + 1);
 
-	// Walk into string and display character by character
-	while (str[++i] != '\0')
+	// Get VRAM offset
+	vram_offset_y = y << 2;
+
+	//DEbug
+	/*kvram_clear();
+	printk(0, 0, "kvram_clr_str_area debug !");
+	printk(0, 1, "x = %d", x);
+	printk(0, 2, "y = %d", y);
+	printk(0, 3, "width = %d", width);
+	printk(0, 4, "height = %d", height);
+	kvram_display();
+	DBG_WAIT;*/
+
+	// Clear area, pixel per pixel x____x
+	// TODO: update me !!!!
+	cur_y = -1;
+	while (++cur_y < height)
 	{
-		// New line
-		if (str[i] == '\n')
+		cur_x = -1;
+		while (++cur_x < width)
 		{
-			y = y + KERNEL_FONT_REAL_HEIGHT + 1;
-			x = default_pos_x;
-			continue;
-		}
-		// Horizontal tab
-		if (str[i] == '\t')
-		{
-			x = x / (KERNEL_FONT_REAL_WIDTH + 1);
-			x = (x + (4 - ((x - starting_x) & 3))) * (KERNEL_FONT_REAL_WIDTH + 1);
-			continue;
+			vram[((x + cur_x) >> 5) + vram_offset_y] &=
+				~(0x80000000 >> ((x + cur_x) & 31));
 		}
 
-		// Default, display character
-		font_draw(x, y, str[i]);
-		x = x + KERNEL_FONT_REAL_WIDTH + 1;
+		// update internal counter
+		vram_offset_y = vram_offset_y + 4;
 	}
+
 }
 
 /* kvram_ascii() - Draw ASCII character into Video RAM */
diff --git a/src/kernel/util/timer.c b/src/kernel/util/timer.c
index 4cb127f..15f0682 100644
--- a/src/kernel/util/timer.c
+++ b/src/kernel/util/timer.c
@@ -1,10 +1,39 @@
 #include <kernel/util.h>
 #include <kernel/hardware/tmu.h>
-#include <kernel/devices/timer.h>
 #include <kernel/atomic.h>
 
-//TODO: update !
-int timer_install(void *callback, void *arg, uint32_t delay_ms, uint8_t mode)
+// Internal timer "cache".
+struct timer_cache_s timercache[TIMER_NUMBER];
+
+__attribute__((constructor))
+void timer_constructor(void)
+{
+	// Initialise internal cache
+	for (int i = 0 ; i < TIMER_NUMBER ; i = i + 1)
+	{
+		timercache[i].status = TIMER_UNUSED;
+		timercache[i].callback = NULL;
+		timercache[i].arg = NULL;
+	}
+
+	// Configure TMU
+	SH7305_TMU.TSTR.STR0 = 0;			// Stop timer 0
+	SH7305_TMU.TSTR.STR1 = 0;			// Stop timer 1
+	SH7305_TMU.TSTR.STR2 = 0;			// Stop timer 2
+
+	// Configure TMU timers
+	for (int i = 0 ; i < 3 ; ++i)
+	{
+		SH7305_TMU.TIMER[i].TCOR = 0xffffffff;	// Reset timer constant register
+		SH7305_TMU.TIMER[i].TCNT = 0xffffffff;	// Reset timer counter
+		SH7305_TMU.TIMER[i].TCR.UNF = 0;	// Clear interrupt flags
+		SH7305_TMU.TIMER[i].TCR.UNIE = 0;	// Disable timerinterrupt
+		SH7305_TMU.TIMER[i].TCR.CKREG = 0b00;	// Count on rising edge
+		SH7305_TMU.TIMER[i].TCR.TPSC = 0b000;	// Select P/4 prescaler
+	}
+}
+
+int timer_install(void *callback, void *arg, uint32_t ticks, uint8_t mode)
 {
 	extern struct timer_cache_s timercache[TIMER_NUMBER];
 	int timer_ID;
@@ -20,6 +49,12 @@ int timer_install(void *callback, void *arg, uint32_t delay_ms, uint8_t mode)
 	if (timer_ID >= TIMER_NUMBER)
 		return (-1);
 
+	// Debug !!
+	/*kvram_clear();
+	printk(0, 0, "Timer find: %d\n", timer_ID);
+	printk(0, 1, "TMU = %p\n", &SH7305_TMU.TIMER[timer_ID]);
+	kvram_display();
+	DBG_WAIT;*/
 
 	// Initialise internal timer data.
 	timercache[timer_ID].callback = callback;
@@ -29,12 +64,11 @@ int timer_install(void *callback, void *arg, uint32_t delay_ms, uint8_t mode)
 	// Initialise hardware module.
 	SH7305_TMU.TSTR.BYTE &= ~(1 << timer_ID);	// Stop timer.
 
-	// Convert delay in millisecond into timer tick.
-	// TODO !!
-	SH7305_TMU.TIMER[timer_ID].TCOR = delay_ms * 2000;
-	SH7305_TMU.TIMER[timer_ID].TCNT = delay_ms * 2000;
-	SH7305_TMU.TIMER[timer_ID].TCR.TPSC = 0b000;	// TODO use appropriate divisor !
+	// Setup Timer
+	SH7305_TMU.TIMER[timer_ID].TCOR = ticks;
+	SH7305_TMU.TIMER[timer_ID].TCNT = ticks;
 
+	// Configure timer
 	SH7305_TMU.TIMER[timer_ID].TCR.UNF = 0;		// Clear interrupt flag.
 	SH7305_TMU.TIMER[timer_ID].TCR.UNIE = 1;	// Enable interrupt.
 	
@@ -48,7 +82,6 @@ int timer_install(void *callback, void *arg, uint32_t delay_ms, uint8_t mode)
 	return (timer_ID);
 }
 
-//TODO: update !
 int timer_uninstall(int timer_ID)
 {
 	extern struct timer_cache_s timercache[TIMER_NUMBER];
@@ -71,6 +104,27 @@ int timer_uninstall(int timer_ID)
 
 	// Free'd timer cache.
 	timercache[timer_ID].status = TIMER_UNUSED;
+	timercache[timer_ID].callback = NULL;
+	timercache[timer_ID].arg = NULL;
+
+	// Stop atomic operation and return.
+	atomic_stop();
+	return (0);
+}
+
+int timer_start(int timer_ID)
+{
+	extern struct timer_cache_s timercache[TIMER_NUMBER];
+
+	// Check bad ID
+	if (timer_ID < 0 || timer_ID >= TIMER_NUMBER)
+		return (-1);
+
+	// Start Atomic operation.
+	atomic_start();
+
+	// Start hardware timer.
+	SH7305_TMU.TSTR.BYTE |= 1 << timer_ID;
 
 	// Stop atomic operation and return.
 	atomic_stop();
diff --git a/src/lib/display/dclr_str_area.S b/src/lib/display/dclr_str_area.S
new file mode 100644
index 0000000..b62c747
--- /dev/null
+++ b/src/lib/display/dclr_str_area.S
@@ -0,0 +1,12 @@
+.text
+.global	_dclr_str_area
+.type	_dclr_str_area, @function
+
+#include "kernel/unistd_32.h"
+
+.align 2
+_dclr_str_area:
+	trapa	#__NR_kvram_clr_str_area
+	rts
+	nop
+.end
diff --git a/src/lib/unistd/fexecve.S b/src/lib/unistd/fexecve.S
new file mode 100644
index 0000000..e70296d
--- /dev/null
+++ b/src/lib/unistd/fexecve.S
@@ -0,0 +1,12 @@
+.text
+.global	_fexecve
+.type	_fexecve, @function
+
+#include "kernel/unistd_32.h"
+
+.align 2
+_fexecve:
+	trapa	#__NR_fexecve
+	rts
+	nop
+.end
diff --git a/src/user/Makefile b/src/user/shell/Makefile
similarity index 77%
rename from src/user/Makefile
rename to src/user/shell/Makefile
index f0dd72b..6a4fdf8 100644
--- a/src/user/Makefile
+++ b/src/user/shell/Makefile
@@ -3,16 +3,16 @@
 ##	Project: Vhex - On-calc debugger
 ##	Author: yann.magnin@epitech.eu
 ## ---
-include ../../global.mk
+include ../../../global.mk
 
 ##---
 ##	Static variables
 ##--
-HEADER		:= -I../../include -I../../include/user
-LIBS		:= -L../lib/ -l_unistd -l_stdio -l_string -l_display
-BUILD		:= ../../build/user
-DEBUG		:= ../../debug
-OUTPUT		:= ../../output
+HEADER		:= -I../../../include -I../../../include/user
+LIBS		:= -L../../lib/ -l_unistd -l_stdio -l_string -l_display
+BUILD		:= ../../../build/user/shell
+DEBUG		:= ../../../debug
+OUTPUT		:= ../../../output
 
 NAME		:= shell
 EXEC		:= $(OUTPUT)/$(NAME).elf
@@ -26,7 +26,7 @@ MEMORY_MAP	:= $(DEBUG)/$(NAME).map
 ##	Automated variables
 ##---
 SRC		:=
-DIRECTORY	:= $(shell find shell -not -path "*/\.*" -type d)
+DIRECTORY	:= $(shell find . -not -path "*/\.*" -type d)
 # Get all source files
 $(foreach path,$(DIRECTORY),$(eval		\
 	SRC	+= $(wildcard $(path)/*.c)	\
@@ -34,7 +34,7 @@ $(foreach path,$(DIRECTORY),$(eval		\
 			$(wildcard $(path)/*.s)	\
 ))
 # Geneate all object files
-OBJ	:= $(patsubst %,$(BUILD)/%.o,$(subst /,_,$(subst src/,,$(basename $(SRC)))))
+OBJ	:= $(patsubst ._%,$(BUILD)/%.o,$(subst /,_,$(subst src/,,$(basename $(SRC)))))
 
 
 
@@ -75,7 +75,7 @@ sec:
 ##	  Automated rules
 ##---
 define rule-src
-$(patsubst %,$(BUILD)/%.o,$(subst /,_,$(subst src/,,$(basename $1)))): $1
+$(patsubst ._%,$(BUILD)/%.o,$(subst /,_,$(subst src/,,$(basename $1)))): $1
 	@ printf "compiling $(white)$$<$(nocolor)..."
 	@ $(CC) -fPIC $(CFLAGS) -o $$@ -c $$< $(HEADER) -lgcc
 	@ printf "$(green)[ok]$(nocolor)\n"
diff --git a/src/user/shell/builtin/proc.c b/src/user/shell/builtin/proc.c
new file mode 100644
index 0000000..6f48ac4
--- /dev/null
+++ b/src/user/shell/builtin/proc.c
@@ -0,0 +1,43 @@
+#include <lib/unistd.h>
+#include <lib/display.h>
+#include <builtin.h>
+
+int builtin_proc(void)
+{
+	pid_t child;
+
+	// Debug
+	dclear();
+	dprint(0, 0, "Proc builtin !");
+	dupdate();
+	for (int i = 0 ; i < 3000000 ; i++);
+
+	// Try to create first child
+	/*child = fork();
+	if (child == -1)
+	{
+		dprint(0, 1, "fork() fail !");
+		dupdate();
+		for (int i = 0 ; i < 3000000 ; i++);
+		return (0);
+	}
+
+	// Check parent
+	if (child_pid != 0)
+	{
+		int counter = 0;
+		while (1)
+		{
+			dprint(0, 1, "parent: %d", counter++);
+			for (int i = 0 ; i < 3000000 ; i++);
+		}
+	} else {
+		int counter = 0;
+		while (1)
+		{
+			dprint(0, 2, "child: %d", counter++);
+			for (int i = 0 ; i < 9000000 ; i++);
+		}
+	}*/
+	return (0);
+}
diff --git a/src/user/shell.ld b/src/user/shell/shell.ld
similarity index 89%
rename from src/user/shell.ld
rename to src/user/shell/shell.ld
index a605e6a..7729fdd 100644
--- a/src/user/shell.ld
+++ b/src/user/shell/shell.ld
@@ -27,11 +27,6 @@ SECTIONS
 	.rodata : {
 		*(.rodata);
 		*(.rodata.*);
-
-		/* Builtin */
-		_bbuiltin_section = ALIGN(4) ;
-		*(.builtin);
-		_ebuiltin_section = . ;
 	}
 
 	.data ALIGN(4) : {
diff --git a/src/user/shell/util/check_builtin.c b/src/user/shell/util/check_builtin.c
index a5b51b5..b3cf2b9 100644
--- a/src/user/shell/util/check_builtin.c
+++ b/src/user/shell/util/check_builtin.c
@@ -1,48 +1,88 @@
 #include "util.h"
 #include "builtin.h"
 #include <lib/string.h>
+#include <lib/display.h>
+#include <lib/unistd.h>
+
+// Internal builtin list
+// FIXME: due to PIE binary format, we can not
+// FIXME: use address of builtin_proc !!
+/*struct builtin_s list[1] = {
+	{
+		.name = "proc",
+		.entry = (void*)&builtin_proc
+	},
+	//{
+	//	.name = "ram",
+	//	.entry = (void *)&builtin_ram
+	//}
+};*/
+
 
 //TODO: use agc, argv.
 int check_builtin(char *cmd)
 {
-	extern uint32_t bbuiltin_section;
-	extern uint32_t ebuiltin_section;
-	struct builtin_s *list;
-	int wstatus;
-	//pid_t pid;
-	int i;
 
-	i = -1;
-	list = (void*)&bbuiltin_section;
-	while ((uint32_t)&list[++i] < (uint32_t)&ebuiltin_section)
+	// Process test
+	dclear();
+	dprint(0, 0, "Process Load Test !");
+
+	// Load process test
+	pid_t pid = fexecve("/mnt/smemfs/VHEX/test.elf");
+	if (pid < 0)
+	{
+		dprint(0, 1, "Process error !");
+		dupdate();
+		for(int i = 0 ; i < 3000000 ; ++i);
+		return (-1);
+	}
+
+	int counter = 0;
+	dclear();
+	dprint(0, 0, "Process Test !");;
+	while (1)
+	{
+		dclr_str_area(0, 1, 20, 1);
+		dprint(0, 1, "P process: %d", counter);
+		dupdate();
+		counter = counter + 1;
+		for (int i = 0 ; i < 30000 ; ++i);
+	}
+
+	//int wstatus;
+	//pid_t pid;
+	//int i;
+
+	// Try to find builtin
+/*	for (int i = 0 ; i < 1 ; i++)
 	{
 		if (strcmp(list[i].name, cmd) != 0)
 			continue;
-		
+
 		// Execute builtin
 		list[i].entry(0, NULL);
 		return (0);
-	}
+	}*/
 	return (-1);
-		// Create subprocess
-		//pid = fork();
-		//if (pid < 0)
-		//	return (1);
-	
-		// If we are the child execute
-		// the builtins.
-		//if (pid == 0)
-//		//{
-//			dclear();
-//			dprint(0, 0, "Child process !!");
-//			dprint(0, 1, "PID  = %d", getpid());
-//			dprint(0, 2, "PPID = %d", getppid());
-//			dupdate();
+	// Create subprocess
+	//pid = fork();
+	//if (pid < 0)
+	//	return (1);
+
+	// If we are the child execute
+	// the builtins.
+	//if (pid == 0)
+	//		//{
+	//			dclear();
+	//			dprint(0, 0, "Child process !!");
+	//			dprint(0, 1, "PID  = %d", getpid());
+	//			dprint(0, 2, "PPID = %d", getppid());
+	//			dupdate();
 
 	//	} else {
 	//		waitpid(pid, &wstatus, WCONTINUED);
-			//TODO: signal handling.
+	//TODO: signal handling.
 	//	}
-//	}
-//	return (1);
-}
+	//	}
+	//	return (1);
+	}
diff --git a/src/user/test/Makefile b/src/user/test/Makefile
new file mode 100644
index 0000000..9391e6f
--- /dev/null
+++ b/src/user/test/Makefile
@@ -0,0 +1,106 @@
+#!/usr/bin/make -f
+## ---
+##	Project: Vhex - On-calc debugger
+##	Author: yann.magnin@epitech.eu
+## ---
+include ../../../global.mk
+
+##---
+##	Static variables
+##--
+HEADER		:= -I../../../include -I../../../include/user
+LIBS		:= -L../../lib/ -l_unistd -l_stdio -l_string -l_display
+BUILD		:= ../../../build/user/test
+DEBUG		:= ../../../debug
+OUTPUT		:= ../../../output
+
+NAME		:= test
+EXEC		:= $(OUTPUT)/$(NAME).elf
+LDFLAG		:= -T $(NAME).ld
+MEMORY_MAP	:= $(DEBUG)/$(NAME).map
+
+
+
+
+##---
+##	Automated variables
+##---
+SRC		:=
+DIRECTORY	:= $(shell find . -not -path "*/\.*" -type d)
+# Get all source files
+$(foreach path,$(DIRECTORY),$(eval		\
+	SRC	+= $(wildcard $(path)/*.c)	\
+			$(wildcard $(path)/*.S)	\
+			$(wildcard $(path)/*.s)	\
+))
+# Geneate all object files
+OBJ	:= $(patsubst ._%,$(BUILD)/%.o,$(subst /,_,$(subst src/,,$(basename $(SRC)))))
+
+
+
+
+##---
+##	General rules
+##---
+all: | $(BUILD) $(DEBUG) $(EXEC)
+
+$(EXEC): $(OBJ)
+	$(CC) -fPIC -Wl,-M $(LDFLAG) $(CFLAGS) -o $(DEBUG)/$(NAME).elf.big $(OBJ) $(HEADER) $(LIBS) -lgcc > $(MEMORY_MAP)
+	$(OBJCOPY) -S $(DEBUG)/$(NAME).elf.big $@
+	rm -f $(DEBUG)/$(NAME).elf.big
+
+$(BUILD) $(DEBUG):
+	@ printf "Create $(blue)$@$(nocolor) directory\n"
+	@ mkdir -p $@
+
+install: $(EXEC)
+	sudo p7 send --force -d VHEX $^
+
+check:
+	@ echo 'src: $(SRC)'
+	@ echo 'obj: $(OBJ)'
+	@ echo 'directory: $(DIRECTORY)'
+
+asm:
+	@ $(OBJDUMP) -D $(EXEC) | less
+
+map:
+	@ cat $(MEMORY_MAP) | less
+
+sec:
+	@ $(OBJDUMP) -h $(EXEC)
+
+
+##---
+##	  Automated rules
+##---
+define rule-src
+$(patsubst ._%,$(BUILD)/%.o,$(subst /,_,$(subst src/,,$(basename $1)))): $1
+	@ printf "compiling $(white)$$<$(nocolor)..."
+	@ $(CC) -fPIC $(CFLAGS) -o $$@ -c $$< $(HEADER) -lgcc
+	@ printf "$(green)[ok]$(nocolor)\n"
+endef
+
+$(foreach source,$(SRC),$(eval		\
+	$(call rule-src,$(source)))	\
+)
+
+
+
+
+##---
+##	Cleaning rules
+##---
+clean:
+	rm -rf $(BUILD)
+	rm -rf $(DEBUG)
+
+fclean: clean
+	rm -f $(EXEC)
+
+re: fclean all
+
+
+
+
+.PHONY: re fclean clean all install
diff --git a/src/user/test/test.c b/src/user/test/test.c
index b844fc8..7ba5a73 100644
--- a/src/user/test/test.c
+++ b/src/user/test/test.c
@@ -1,8 +1,19 @@
-/*#include <kernel/syscall.h>
+#include <lib/display.h>
 
-void test(void)
+int main(void)
 {
-	uint8_t *vram;
+	uint32_t counter = 0;
+	while (1)
+	{
+		// Display data
+		dclr_str_area(0, 2, 20, 1);
+		dprint(0, 2, "C process: %d", counter);
+		dupdate();
 
-	vram = casio_Bdisp_GetVRAM();
-}*/
+		// Update counter and "wait"
+		counter = counter + 1;
+		if (counter >= 100)
+			counter = 0;
+		for (int i = 0 ; i < 300000 ; ++i);
+	}
+}
diff --git a/src/user/test/test.ld b/src/user/test/test.ld
new file mode 100644
index 0000000..7729fdd
--- /dev/null
+++ b/src/user/test/test.ld
@@ -0,0 +1,65 @@
+OUTPUT_ARCH(sh3)
+OUTPUT_FORMAT(elf32-sh)
+ENTRY(_main)
+
+/*
+** Linker script for user executables.
+*/
+MEMORY
+{
+	/* virtual memory, read-write segment */
+	userram (WX) : o = 0x00000000, l = 256k
+}
+
+PHDRS
+{
+	text PT_LOAD ;
+	data PT_LOAD ;
+}
+
+SECTIONS
+{
+	.text : {
+		*(.text);
+		*(.text.*);
+	} : text
+
+	.rodata : {
+		*(.rodata);
+		*(.rodata.*);
+	}
+
+	.data ALIGN(4) : {
+		*(.plt);
+		*(.data);
+		*(.data.*);
+
+		/* bss section included to avoid missaligned segment */
+		*(.bss);
+		*(.bss.*);
+		*(COMMON);
+	} : data
+
+
+	.relocgot : {
+		BRELOC_GOT = . ;
+		*(.got.plt)
+		*(.got)
+		ERELOC_GOT = . ;
+	}
+
+	/* unwanted section */
+	/DISCARD/ : {
+		*(.debug_info)
+		*(.debug_abbrev)
+		*(.debug_loc)
+		*(.debug_aranges)
+		*(.debug_ranges)
+		*(.debug_line)
+		*(.debug_str)
+		*(.jcr)
+		*(.eh_frame_hdr)
+		*(.eh_frame)
+		*(.comment)
+	}
+}
diff --git a/src/user/test/test_asm.s b/src/user/test/test_asm.s
index c2e79e9..ee21ea3 100644
--- a/src/user/test/test_asm.s
+++ b/src/user/test/test_asm.s
@@ -1,4 +1,4 @@
-.global	_test
+/*.global	_test
 .type	_test, @function
 
 .align 2
@@ -20,4 +20,4 @@ _test:
 .align 4
 .syscall_entry:	.long 0xa0010070
 .syscall_vram:	.long 0x00000135
-.end
+.end*/