diff --git a/include/kernel/fs/file.h b/include/kernel/fs/file.h
index 958d482..4fb9b4c 100644
--- a/include/kernel/fs/file.h
+++ b/include/kernel/fs/file.h
@@ -10,13 +10,16 @@
 # define FILE_OPEN_NUMBER   4
 #endif
 
-#define O_RDONLY	0x00
-#define O_WRONLY	0x01
-#define O_RDWR		0x02
+// TODO: fix me
+#ifndef __LIB_UNISTD_H__
+# define O_RDONLY	0x00
+# define O_WRONLY	0x01
+# define O_RDWR		0x02
 
-#define SEEK_SET	0
-#define SEEK_CUR	1
-#define SEEK_END	2
+# define SEEK_SET	0
+# define SEEK_CUR	1
+# define SEEK_END	2
+#endif
 
 struct file_s
 {
diff --git a/include/kernel/fs/vfs.h b/include/kernel/fs/vfs.h
index 2e9bcc2..b9bc66b 100644
--- a/include/kernel/fs/vfs.h
+++ b/include/kernel/fs/vfs.h
@@ -33,6 +33,8 @@ extern int vfs_open(FILE *file, const char *pathname, int flags);
 extern ssize_t vfs_read(FILE *file, void *buf, size_t count);
 extern ssize_t vfs_write(FILE *file, const void *buf, size_t count);
 extern off_t vfs_lseek(FILE *file, off_t offset, int whence);
+extern ssize_t vfs_pread(FILE *file, void *buf, size_t count, off_t offset);
+extern ssize_t vfs_pwrite(FILE *file, const void *buf, size_t count, off_t offset);
 extern int vfs_close(FILE *file);
 
 // Dentry opeations
diff --git a/include/kernel/memory.h b/include/kernel/memory.h
index af34990..eaa4eea 100644
--- a/include/kernel/memory.h
+++ b/include/kernel/memory.h
@@ -4,37 +4,115 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#define PM_BLOCK_SIZE	(64)
+#define PM_PAGE_SIZE	(256)
+#define PM_SIZE_TO_PAGES(size)		((size + PM_PAGE_SIZE - 1) / PM_PAGE_SIZE)
 
-struct pm_block_cache_s
+// mapping flags
+// Protection (unused)
+#define PROT_READ	0x1		/* Page can be read.  */
+#define PROT_WRITE	0x2		/* Page can be written.  */
+#define PROT_EXEC	0x4		/* Page can be executed.  */
+#define PROT_NONE	0x0		/* Page can not be accessed.  */
+
+// Mapping flags
+#define MAP_SHARED	0x01		/* Share changes.  */
+#define MAP_PRIVATE	0x02		/* Changes are private.  */
+#define MAP_ANONYMOUS	0x20		/* Don't use a file.  */
+#define MAP_ANON	MAP_ANONYMOUS	/* Don't use a file.  */
+#define MAP_FILE	0		/* Ignored.  */
+#define MAP_GROWSDOWN	0x00100		/* Stack-like segment.  */
+#define MAP_DENYWRITE	0x00800		/* ETXTBSY.  */
+#define MAP_EXECUTABLE	0x01000		/* Mark it as an executable.  */
+#define MAP_LOCKED	0x02000		/* Lock the mapping.  */
+#define MAP_NORESERVE	0x04000		/* Don't check for reservations.  */
+#define MAP_POPULATE	0x08000		/* Populate (prefault) pagetables.  */
+#define MAP_NONBLOCK	0x10000		/* Do not block on IO.  */
+#define MAP_STACK	0x20000		/* Allocation is for a stack.  */
+#define MAP_HUGETLB	0x40000		/* Create huge page mapping.  */
+#define MAP_SYNC	0x80000		/* Perform synchronous page
+					   faults for the mapping.  */
+#define MAP_FIXED_NOREPLACE 0x100000	/* MAP_FIXED but do not unmap
+					   underlying mapping.  */
+
+// Value returned when mmap value
+#define MAP_FAILED	((void*) -1)
+
+
+
+#define PM_HEAP_BLOCK_MIN	(16)
+struct pm_heap_block
 {
-	// Block status
+	uint16_t status;		/* status of the block (1=used,0=free) */
+	uint16_t size;			/* size of the block (without block header) */
+} __attribute__((packed, aligned(2)));
+
+struct pm_heap_page
+{
+	void *brk;			/* break (address of the limit area) */
+	size_t size;			/* Page size (without header) */
+	struct pm_heap_page *next;	/* Next heap page */
+	struct pm_heap_block heap;	/* Start of block informations */
+} __attribute__((packed, aligned(4)));
+
+// Real physical memory informations
+struct pm_page
+{
+	// page status
 	enum {
-		UNUSED,
-		USED
+		PAGE_USED,
+		PAGE_UNUSED
 	} status;
 
-	// Space informations.
-	uint32_t start;
-	uint32_t end;
+	// page ID
+	struct {
+		uint16_t start;
+		uint16_t end;
+	} id;
 
-	// Linked list
-	struct pm_block_cache_s *next;
+	// next page
+	struct pm_page *next;
 };
 
-struct memory_info_s
+struct memory_info
 {
 	// Cache informations.
-	struct pm_block_cache_s *cache;
-	struct pm_block_cache_s *head;
+	// @note: use delta list algorithm
+	// TODO: use AVL algo
+	struct {
+		struct pm_page *delta;
+		struct {
+			int number;
+			size_t size;
+			struct pm_page *list;
+			void *base_addr;
+		} pages;
+	} cache;
+
+	// RAM informations
+	struct {
+		void *start;
+		void *end;
+		size_t size;
+	} ram;
+
+	// Kernel heap
+	struct pm_heap_page *kheap;
+
+	// Shared pages
+//	struct {
+
+//	} shared;
 
-	// RAM informations.
-	uint32_t start;
-	uint32_t blocks;
 };
 
 // Function
 extern void *pm_alloc(size_t size);
 extern void pm_free(void *ptr);
+extern void pm_debug(void);
+
+// Page allocator
+extern void *pm_pages_alloc(int nb_pages);
+extern void pm_pages_free(void *addr);
+
 
 #endif /*__KERNEL_MEMORY_H__*/
diff --git a/include/kernel/process.h b/include/kernel/process.h
index 0c91498..bf0cec1 100644
--- a/include/kernel/process.h
+++ b/include/kernel/process.h
@@ -78,6 +78,7 @@ struct process
 			void *start;
 			size_t size;
 		} exit;
+		struct heap *heap;
 	} memory; 
 
 
diff --git a/include/kernel/syscall.h b/include/kernel/syscall.h
index d3235c4..52e3da2 100644
--- a/include/kernel/syscall.h
+++ b/include/kernel/syscall.h
@@ -20,6 +20,13 @@ extern int sys_open(const char *pathname, int flags, ...);
 extern ssize_t sys_write(int fd, const void *buf, size_t count);
 extern ssize_t sys_read(int fd, void *buf, size_t count);
 extern off_t sys_lseek(int fd, off_t offset, int whence);
+extern ssize_t sys_pwrite(int fd, const void *buf, size_t count, off_t offset);
+extern ssize_t sys_pread(int fd, void *buf, size_t count, off_t offset);
 extern int sys_close(int fd);
 
+// Memory
+extern void *sys_mmap(void *addr, size_t length,
+			int prot, int flags, int fd, off_t offset);
+extern int sys_munmap(void *addr, size_t length);
+
 #endif /*__SYSCALL_H__*/
diff --git a/include/kernel/util/unistd_32.h b/include/kernel/util/unistd_32.h
index 93784df..383ef1c 100644
--- a/include/kernel/util/unistd_32.h
+++ b/include/kernel/util/unistd_32.h
@@ -2,7 +2,7 @@
 # define __KERNEL_UNISTD_32_H__
 
 // Define the number of syscall
-#define __NR_MAX		14
+#define __NR_MAX		18
 
 // Kernel Test
 #define __NR_test_syscall	0
@@ -23,5 +23,11 @@
 #define __NR_open 		11
 #define __NR_close 		12
 #define __NR_lseek 		13
+#define __NR_pread 		14
+#define __NR_pwrite		15
+
+// Memory
+#define __NR_mmap		16
+#define __NR_munmap		17
 
 #endif /*__KERNEL_UNISTD_32_H__*/
diff --git a/include/lib/stdio.h b/include/lib/stdio.h
index 89d1440..520ea7c 100644
--- a/include/lib/stdio.h
+++ b/include/lib/stdio.h
@@ -7,6 +7,7 @@
 
 /* *printf() familly - formatted output conversion. */
 extern int printf(const char *restrict format, ...);
+extern int dprintf(int fd, const char *restrict format, ...);
 extern int sprintf(char *restrict str, const char *restrict format, ...);
 extern int snprintf(char *restrict str, size_t size, const char *restrict format, ...);
 
diff --git a/include/lib/unistd.h b/include/lib/unistd.h
index 2858743..895d440 100644
--- a/include/lib/unistd.h
+++ b/include/lib/unistd.h
@@ -9,9 +9,9 @@
 #include <kernel/util/unistd_32.h>
 
 // TODO: move me
-#define STDOUT_FILENO	0
-#define STDERR_FILENO	1
-#define STDIN_FILENO	2
+#define STDIN_FILENO	0
+#define STDOUT_FILENO	1
+#define STDERR_FILENO	2
 
 //TODO: move me
 #define WNOHANG		0
@@ -31,10 +31,23 @@ extern pid_t waitpid(pid_t pid, int *wstatus, int options);
 extern pid_t fexecve(const char *pathname);
 
 // File syscall
-#define O_DIRECT	0
+// TODO: move me 
+// FIXME: find real value
+#ifndef __FILE_H__
+# define O_DIRECT	0
+# define O_DIRECTORY	1
+# define O_RDONLY	2
+# define O_WRONLY	4
+# define O_RDWR 	8
+
+# define SEEK_SET	0
+# define SEEK_CUR	1
+# define SEEK_END	2
+#endif
 extern int open(const char *pathname, int flags, ...);
 extern ssize_t write(int fd, const void *buf, size_t count);
 extern ssize_t read(int fd, void *buf, size_t count);
+extern off_t lseek(int fd, off_t offset, int whence);
 extern int close(int fd);
 
 #endif /*__LIB_UNISTD_H__*/
diff --git a/src/kernel/bootstrap/start.c b/src/kernel/bootstrap/start.c
index 9cc662a..57d77d2 100644
--- a/src/kernel/bootstrap/start.c
+++ b/src/kernel/bootstrap/start.c
@@ -109,9 +109,6 @@ int start(void)
 	if (current_mpu != MPU_SH7305)
 		return (0);
 
-	// Execute constructor.
-	section_execute(&bctors, &ectors);
-
 	// Load UBC / VBR space.
 	memcpy(&bubc_ram, &bubc_rom, (size_t)&subc);
 	memcpy(&bvhex_ram, &bvhex_rom, (size_t)&svhex);
@@ -121,6 +118,10 @@ int start(void)
 	// before switching the VBR.
 	rom_explore(&brom, (int32_t)&srom);
 
+	// TODO: load driver on-the-fly
+	extern void screen_driver_load(void);
+	screen_driver_load();
+
 	// Start early terminal device
 	// This device is used by the kernel to display
 	// some logs on screen
@@ -129,6 +130,9 @@ int start(void)
 	earlyterm_clear();
 	earlyterm_write("Kernel initialisation...\n");
 
+	// Execute constructor.
+	section_execute(&bctors, &ectors);
+
 
 
 	// Save Casio's hardware context and set
diff --git a/src/kernel/devices/tty/operations/write.c b/src/kernel/devices/tty/operations/write.c
index 5d2a939..ecb3f61 100644
--- a/src/kernel/devices/tty/operations/write.c
+++ b/src/kernel/devices/tty/operations/write.c
@@ -7,9 +7,8 @@
 static void tty_vertical_update(struct tty_s *tty)
 {
 	// Get next line.
-	if (tty->cursor.y + 1 < tty->cursor.max.y)
-		tty->cursor.y = tty->cursor.y + 1;
-	else
+	tty->cursor.y = tty->cursor.y + 1;
+	if (tty->cursor.y >= tty->cursor.max.y)
 		tty->cursor.y = 0;
 
 	// Wipe new line.
@@ -75,6 +74,7 @@ static ssize_t tty_buffer_update(struct tty_s *tty, const uint8_t *buffer, size_
 		// Check new line char.
 		if (buffer[i] == '\n')
 		{
+			tty->buffers.output[tty->cursor.y][tty->cursor.x] = '\n';
 			tty->cursor.x = 0;
 			tty_vertical_update(tty);
 			continue;
@@ -97,6 +97,8 @@ static ssize_t tty_buffer_update(struct tty_s *tty, const uint8_t *buffer, size_
 		tty->buffers.output[tty->cursor.y][tty->cursor.x] = buffer[i];
 		tty_horizontal_update(tty);
 	}
+
+	tty->buffers.output[tty->cursor.y][tty->cursor.x] = '\0';
 	return (i);
 }
 
@@ -129,17 +131,24 @@ static void tty_display(struct tty_s *tty)
 			break;
 	}
 
+	//TODO
+	//TODO Display only the new char !
+	//TODO Use scroll drawing function to avoid draw time !
+	//TODO
+
 	// clear screen
 	dclear(&tty->disp);
 
 	// Display "on-screen" string lines.
 	y = -1;
-	while (++y <= line)
+	while (++y <= line && y < tty->winsize.ws_row)
 	{
 		// Display line
 		line_len = -1;
-		while (tty->buffers.output[start][++line_len] != '\0')
-			dascii(&tty->disp, line_len, y, tty->buffers.output[start][line_len]);
+		while (tty->buffers.output[start][++line_len] != '\0') {
+			if (tty->buffers.output[start][line_len] != '\n')
+				dascii(&tty->disp, line_len, y, tty->buffers.output[start][line_len]);
+		}
 
 		// Update row index
 		if (++start >= tty->cursor.max.y)
diff --git a/src/kernel/drivers/screen/constructor.c b/src/kernel/drivers/screen/constructor.c
index 48461dd..02d6611 100644
--- a/src/kernel/drivers/screen/constructor.c
+++ b/src/kernel/drivers/screen/constructor.c
@@ -8,7 +8,7 @@ extern void t6k11_lcd_driver(void *vram);
 void (*screen_update)(void *vram);
 
 __attribute__((constructor))
-static void screen_constructor(void)
+void screen_driver_load(void)
 {
 	// Check T6K11 variant which appear during
 	// the OS >= 03.00.0000
diff --git a/src/kernel/fs/gladfs/initialize.c b/src/kernel/fs/gladfs/initialize.c
index 6b6cd92..342d95c 100644
--- a/src/kernel/fs/gladfs/initialize.c
+++ b/src/kernel/fs/gladfs/initialize.c
@@ -1,4 +1,5 @@
 #include <kernel/fs/gladfs.h>
+#include <kernel/util/atomic.h>
 #include <kernel/fs/filesystem.h>
 #include <kernel/memory.h>
 
@@ -46,15 +47,22 @@ struct gladfs_superblock_s gladfs_superblock;
 // Contructor for the superBlock
 void gladfs_initialize(void)
 {
+	// Start atomic operations
+	atomic_start();
+
 	// initilaize ROOT inode
 	gladfs_superblock.root_inode = NULL;
 
 	// Initialize device informations
-	gladfs_superblock.block_size = PM_BLOCK_SIZE;
+	// FIXME: find better page size
+	gladfs_superblock.block_size = 64;
 
 	// Iniitlaize superblock openrations
 	gladfs_superblock.super_op.alloc_inode = &gladfs_alloc_inode;
 	gladfs_superblock.super_op.destroy_inode = &gladfs_destroy_inode;
 	gladfs_superblock.super_op.alloc_fragdata = &gladfs_alloc_fragdata;
 	gladfs_superblock.super_op.destroy_fragdata = &gladfs_destroy_fragdata;
+
+	// Stop atomic operations
+	atomic_stop();
 }
diff --git a/src/kernel/fs/smemfs/file/read.c b/src/kernel/fs/smemfs/file/read.c
index 320ce5e..2cba3d8 100644
--- a/src/kernel/fs/smemfs/file/read.c
+++ b/src/kernel/fs/smemfs/file/read.c
@@ -69,6 +69,9 @@ ssize_t smemfs_read(void *inode, void *buf, size_t count, off_t pos)
 		earlyterm_write("* pos = %#x\n", pos);
 		earlyterm_write("* frag magic   = 0x%x\n", fragment->magic);
 		earlyterm_write("* frag info    = 0x%x\n", fragment->info);
+		DBG_WAIT;
+		DBG_WAIT;
+		DBG_WAIT;
 		return (-1);
 	}
 
diff --git a/src/kernel/fs/smemfs/initialize.c b/src/kernel/fs/smemfs/initialize.c
index 6b6ad10..7662ab8 100644
--- a/src/kernel/fs/smemfs/initialize.c
+++ b/src/kernel/fs/smemfs/initialize.c
@@ -1,6 +1,7 @@
 #include <kernel/fs/smemfs.h>
 #include <kernel/fs/filesystem.h>
 #include <kernel/devices/earlyterm.h>
+#include <kernel/util/atomic.h>
 
 // Kernel FS block
 struct file_system_type smemfs_filesystem =
@@ -44,25 +45,31 @@ struct smemfs_superblock_s smemfs_superblock;
 
 void smemfs_initialize(void)
 {
+	// Start atomic operations
+	atomic_start();
+
 	// Get / check Casio SMEM sector table
 	// @note:
 	// 	Casio SMEM sector table start
 	// always (?) at 0xa0270000 (tested with OS 1.00.0000).
 	// TODO: return error !!
 	smemfs_superblock.sector_table = (void *)0xa0270000;
-	if (smemfs_superblock.sector_table->magic_start != 0x4200)
+	if (smemfs_superblock.sector_table->magic_start != CASIO_SMEM_BLOCK_ENTRY_MAGIC)
 	{
 		earlyterm_clear();
 		earlyterm_write("SMEMFS: Casio sector table error !");
 		earlyterm_write("Wait manual reset...");
+		atomic_stop();
 		while (1){ __asm__ volatile ("sleep"); }
 	}
 
-	// Casio SMEM inode table start always at the end of the sector table.
-	// Normaly start at 0xa0270320 but not always (?)
-	// TODO: return error !!
+	// Try to find Casio SMEM inode table start always at the end of
+	// the sector table. Normaly start at 0xa0270320 but not always (?)
 	int i = -1;
 	while (smemfs_superblock.sector_table[++i].magic_start == CASIO_SMEM_BLOCK_ENTRY_MAGIC);
+
+	// Get the inode table
+	// TODO: return error !!
 	smemfs_superblock.inode_table = (void *)&smemfs_superblock.sector_table[i];
 	if ((smemfs_superblock.inode_table->info != 0x51 &&
 			smemfs_superblock.inode_table->info != 0x01) ||
@@ -72,6 +79,10 @@ void smemfs_initialize(void)
 		earlyterm_clear();
 		earlyterm_write("SMEMFS: Casio inode table error !");
 		earlyterm_write("Wait manual reset...");
+		atomic_stop();
 		while (1){ __asm__ volatile ("sleep"); }
 	}
+
+	// Stop atomic operations
+	atomic_stop();
 }
diff --git a/src/kernel/fs/syscall/pread.c b/src/kernel/fs/syscall/pread.c
new file mode 100644
index 0000000..5d5e2ed
--- /dev/null
+++ b/src/kernel/fs/syscall/pread.c
@@ -0,0 +1,22 @@
+#include <kernel/fs/vfs.h>
+#include <kernel/process.h>
+
+ssize_t sys_pread(int fd, void *buf, size_t count, off_t offset)
+{
+	extern struct process *process_current;
+
+	// Check fd
+	if (fd < 0 || fd - 3 >= PROCESS_NB_OPEN_FILE)
+		return (-1);
+
+	// Check virtual file (TTY) and open it if needed
+	if (fd < 3) {
+		if (process_current->tty.private == NULL &&
+			vfs_open(&process_current->tty, "/dev/tty", O_RDWR) != 0)
+			return (-1);
+		return (vfs_pread(&process_current->tty, buf, count, offset));
+	}
+
+	// call VFS read primitive
+	return (vfs_pread(&process_current->opfile[fd - 3].file, buf, count, offset));
+}
diff --git a/src/kernel/fs/syscall/pwrite.c b/src/kernel/fs/syscall/pwrite.c
new file mode 100644
index 0000000..be6b841
--- /dev/null
+++ b/src/kernel/fs/syscall/pwrite.c
@@ -0,0 +1,22 @@
+#include <kernel/fs/vfs.h>
+#include <kernel/process.h>
+
+ssize_t sys_pwrite(int fd, const void *buf, size_t count, off_t offset)
+{
+	extern struct process *process_current;
+
+	// Check fd
+	if (fd < 0 || fd - 3 >= PROCESS_NB_OPEN_FILE)
+		return (-1);
+
+	// Check virtual file (TTY) and open it if needed
+	if (fd < 3) {
+		if (process_current->tty.private == NULL &&
+			vfs_open(&process_current->tty, "/dev/tty", O_RDWR) != 0)
+			return (-1);
+		return (vfs_pwrite(&process_current->tty, buf, count, offset));
+	}
+
+	// call VFS read primitive
+	return (vfs_pwrite(&process_current->opfile[fd].file, buf, count, offset));
+}
diff --git a/src/kernel/fs/syscall/write.c b/src/kernel/fs/syscall/write.c
index 8071b6d..be86d4e 100644
--- a/src/kernel/fs/syscall/write.c
+++ b/src/kernel/fs/syscall/write.c
@@ -17,6 +17,6 @@ ssize_t sys_write(int fd, const void *buf, size_t count)
 		return (vfs_write(&process_current->tty, buf, count));
 	}
 
-	// call VFS read primitive
+	// call VFS write primitive
 	return (vfs_write(&process_current->opfile[fd].file, buf, count));
 }
diff --git a/src/kernel/fs/vfs/dentry/resolve.c b/src/kernel/fs/vfs/dentry/resolve.c
index c830d0a..e7fed01 100644
--- a/src/kernel/fs/vfs/dentry/resolve.c
+++ b/src/kernel/fs/vfs/dentry/resolve.c
@@ -39,7 +39,7 @@ struct dentry *vfs_dentry_resolve(const char *path, int mode)
 	// Check VFS validity
 	if (vfs_root_node == NULL)
 	{
-		earlyterm_write("VFS root  error !\n");
+		earlyterm_write("VFS root error !\n");
 		DBG_WAIT;
 		return (NULL);
 	}
diff --git a/src/kernel/fs/vfs/file/close.c b/src/kernel/fs/vfs/file/close.c
index 4016ce8..f4981b8 100644
--- a/src/kernel/fs/vfs/file/close.c
+++ b/src/kernel/fs/vfs/file/close.c
@@ -9,6 +9,6 @@ int vfs_close(FILE *file)
 	//TODO: call close primitive for device !
 
 	// Update internal dentry counter
-	((struct dentry*)file->private)->counter += 1;
+	((struct dentry*)file->private)->counter -= 1;
 	return (0);
 }
diff --git a/src/kernel/fs/vfs/file/open.c b/src/kernel/fs/vfs/file/open.c
index 4adbd9d..0c87065 100644
--- a/src/kernel/fs/vfs/file/open.c
+++ b/src/kernel/fs/vfs/file/open.c
@@ -14,8 +14,8 @@ int vfs_open(FILE *file, char const *pathname, int flags)
 	dentry = vfs_dentry_resolve(pathname, 0);
 	if (dentry == NULL)
 	{
-		earlyterm_write("VFS_open() error !");
-		earlyterm_write("* path error '%s'", pathname);
+		earlyterm_write("VFS_open() error !\n");
+		earlyterm_write("* path error '%s'\n", pathname);
 		DBG_WAIT;
 		return (-1);
 	}
@@ -23,7 +23,7 @@ int vfs_open(FILE *file, char const *pathname, int flags)
 	// Check directory.
 	if ((dentry->mode & __S_IFDIR) != 0)
 	{
-		earlyterm_write("VFS_open(): file type error '%s'", pathname);
+		earlyterm_write("VFS_open(): file type error '%s'\n", pathname);
 		DBG_WAIT;
 		return (-2);
 	}
diff --git a/src/kernel/fs/vfs/file/pread.c b/src/kernel/fs/vfs/file/pread.c
new file mode 100644
index 0000000..46213fa
--- /dev/null
+++ b/src/kernel/fs/vfs/file/pread.c
@@ -0,0 +1,22 @@
+#include <kernel/fs/vfs.h>
+#include <kernel/devices/earlyterm.h>
+#include <lib/string.h>
+
+ssize_t vfs_pread(FILE *file, void *buf, size_t count, off_t offset)
+{
+	//TODO: Check permission !!
+
+	// Check error
+	if (file == NULL || buf == NULL)
+		return (-1);
+
+	// Get / check file's informations
+	if (file->private == NULL ||
+			file->file_op == NULL ||
+			file->file_op->read == NULL)
+		return (-1);
+
+	// Check error
+	// Read with FS specifique primitive and return the numbe of reading bytes.
+	return (file->file_op->read(((struct dentry*)file->private)->inode, buf, count, offset));
+}
diff --git a/src/kernel/fs/vfs/file/pwrite.c b/src/kernel/fs/vfs/file/pwrite.c
new file mode 100644
index 0000000..204a254
--- /dev/null
+++ b/src/kernel/fs/vfs/file/pwrite.c
@@ -0,0 +1,19 @@
+#include <kernel/fs/vfs.h>
+
+ssize_t vfs_pwrite(FILE *file, const void *buf, size_t count, off_t offset)
+{
+	//TODO: Check permission !!
+
+	// Check error
+	if (file == NULL || buf == NULL)
+		return (-1);
+
+	// Get / check file's informations
+	if (file->private == NULL ||
+			file->file_op == NULL ||
+			file->file_op->write == NULL)
+		return (-1);
+
+	// Writa with FS specifique primitive and return the numbe of reading bytes.
+	return (file->file_op->write(((struct dentry*)file->private)->inode, buf, count, offset));
+}
diff --git a/src/kernel/fs/vfs/file/read.c b/src/kernel/fs/vfs/file/read.c
index 907712b..cf1ca57 100644
--- a/src/kernel/fs/vfs/file/read.c
+++ b/src/kernel/fs/vfs/file/read.c
@@ -1,6 +1,5 @@
 #include <kernel/fs/vfs.h>
 #include <kernel/devices/earlyterm.h>
-#include <lib/string.h>
 
 ssize_t vfs_read(FILE *file, void *buf, size_t count)
 {
@@ -15,9 +14,12 @@ ssize_t vfs_read(FILE *file, void *buf, size_t count)
 			file->file_op == NULL ||
 			file->file_op->read == NULL)
 		return (-1);
+
+	// Check error
+	if (file->cursor == 0xffffffff)
+		earlyterm_write("pos = %#x\n", file->cursor);
 	
 	// Read with FS specifique primitive and return the numbe of reading bytes.
-	memset(buf, 0x00, count);
 	ssize_t read = file->file_op->read(((struct dentry*)file->private)->inode, buf, count, file->cursor);
 	if (read > 0)
 		file->cursor = file->cursor + read;
diff --git a/src/kernel/fs/vfs/inode/mkdir.c b/src/kernel/fs/vfs/inode/mkdir.c
index 2c73925..5dc7140 100644
--- a/src/kernel/fs/vfs/inode/mkdir.c
+++ b/src/kernel/fs/vfs/inode/mkdir.c
@@ -1,6 +1,7 @@
 #include <kernel/fs/vfs.h>
 #include <kernel/memory.h>
 #include <kernel/fs/stat.h>
+#include <kernel/util/atomic.h>
 #include <lib/string.h>
 
 /* vfs_mkdir() - Attempts to create a directory named pathname */
@@ -15,23 +16,31 @@ int vfs_mkdir(const char *pathname, mode_t mode)
 	name = strrchr(pathname, '/');
 	name = (name == NULL) ? (void *)pathname : &name[1];
 
+	// Start atomic operations
+	atomic_start();
+
 	// Get parent dentry
 	parent_dentry = vfs_dentry_resolve(pathname, VFS_DENTRY_RESOLVE_FLAG_PATHNAME);
 	
 	// Check parent dentry and FS primitives
-	if (parent_dentry == NULL || parent_dentry->dentry_op.inode_op->mkdir == NULL)
+	if (parent_dentry == NULL || parent_dentry->dentry_op.inode_op->mkdir == NULL) {
+		atomic_stop();
 		return (-1);
+	}
 
 	// Try to create new dentry
 	folder = vfs_dentry_alloc(name, mode | __S_IFDIR);
-	if (folder == NULL)
+	if (folder == NULL) {
+		atomic_stop();
 		return (-2);
+	}
 
 	// Try to request new folder
 	folder->inode = parent_dentry->dentry_op.inode_op->mkdir(parent_dentry->inode, name, mode);
 	if (folder->inode == NULL)
 	{
 		vfs_dentry_free(folder);
+		atomic_stop();
 		return (-3);
 	}
 
@@ -43,5 +52,6 @@ int vfs_mkdir(const char *pathname, mode_t mode)
 	folder->parent = parent_dentry;
 	folder->next = parent_dentry->child;
 	parent_dentry->child = folder;
+	atomic_stop();
 	return (0);
 }
diff --git a/src/kernel/fs/vfs/inode/mknod.c b/src/kernel/fs/vfs/inode/mknod.c
index ddd25a8..a3c9db7 100644
--- a/src/kernel/fs/vfs/inode/mknod.c
+++ b/src/kernel/fs/vfs/inode/mknod.c
@@ -1,5 +1,6 @@
 #include <kernel/fs/vfs.h>
 #include <kernel/fs/stat.h>
+#include <kernel/util/atomic.h>
 #include <lib/string.h>
 
 /* gevice_get() - Find internal device */
@@ -34,10 +35,15 @@ int vfs_mknod(const char *pathname, mode_t mode, dev_t dev)
 	if (dev == 0)
 		return (-2);
 
+	// Start atomic operations
+	atomic_start();
+
 	// Get parent dentry
 	parent_dentry = vfs_dentry_resolve(pathname, VFS_DENTRY_RESOLVE_FLAG_PATHNAME);
-	if (parent_dentry == NULL)
+	if (parent_dentry == NULL) {
+		atomic_stop();
 		return (-1);
+	}
 
 	// Get folder name
 	name = strrchr(pathname, '/');
@@ -46,30 +52,25 @@ int vfs_mknod(const char *pathname, mode_t mode, dev_t dev)
 	// Try to find the device
 	// TODO: handle othe file (mode) !!!
 	device = device_get(dev_get_major(dev));
-	if (device == NULL)
+	if (device == NULL) {
+		atomic_stop();
 		return (-2);
+	}
 
 	// Tru to create empty node
 	file = vfs_dentry_alloc(name, mode | __S_IFCHR);
-	if (file == NULL)
+	if (file == NULL) {
+		atomic_stop();
 		return (-3);
+	}
 
 
 	// Try to open device
 	file->inode = device->open(dev_get_major(dev), dev_get_minor(dev));
-	if (file->inode == NULL)
+	if (file->inode == NULL) {
+		atomic_stop();
 		return (-4);
-
-	// Debug !
-	/*kvram_clear();
-	printk(0, 0, "New mknod device !");
-	printk(0, 1, "dentry: %p$", file);
-	printk(0, 2, "inode: %p$", file->inode);
-	printk(0, 3, "name: %s$", file->name);
-	printk(0, 4, "dev->file_op: %p$", &device->file_op);
-	kvram_display();
-	DBG_WAIT;
-	DBG_WAIT;*/
+	}
 
 	// Set file operations
 	file->dentry_op.file_op = &device->file_op;
@@ -78,5 +79,6 @@ int vfs_mknod(const char *pathname, mode_t mode, dev_t dev)
 	file->parent = parent_dentry;
 	file->next = parent_dentry->child;
 	parent_dentry->child = file;
+	atomic_stop();
 	return (0);
 }
diff --git a/src/kernel/fs/vfs/register.c b/src/kernel/fs/vfs/register.c
index 618669f..a60ece3 100644
--- a/src/kernel/fs/vfs/register.c
+++ b/src/kernel/fs/vfs/register.c
@@ -1,4 +1,5 @@
 #include <kernel/fs/vfs.h>
+#include <kernel/util/atomic.h>
 
 // Internal cache for registered FS
 struct file_system_type *fs_list = NULL;
@@ -6,6 +7,9 @@ struct file_system_type *fs_list = NULL;
 // vfs_register_filesystem() -  Register a new FS into kernel supported FS list
 int vfs_register_filesystem(struct file_system_type *new)
 {
+	// Start atomic operations
+	atomic_start();
+
 	// Check error.
 	// TODO: check FS validity
 	if (new == NULL)
@@ -14,5 +18,8 @@ int vfs_register_filesystem(struct file_system_type *new)
 	// Register new FS.
 	new->next = fs_list;
 	fs_list = new;
+
+	// Stop atomic operations
+	atomic_stop();
 	return (0);
 }
diff --git a/src/kernel/fs/vfs/superblock/mount.c b/src/kernel/fs/vfs/superblock/mount.c
index 671d5f1..15b9427 100644
--- a/src/kernel/fs/vfs/superblock/mount.c
+++ b/src/kernel/fs/vfs/superblock/mount.c
@@ -2,6 +2,7 @@
 #include <kernel/memory.h>
 #include <kernel/fs/stat.h>
 #include <kernel/devices/earlyterm.h>
+#include <kernel/util/atomic.h>
 #include <lib/string.h>
 
 // Internal informations
@@ -39,22 +40,31 @@ int vfs_mount(const char *source, const char *target,
 	if (filesystemtype == NULL)
 		return (-1);
 
+	// Start operations
+	atomic_start();
+
 	// Get file system informations
 	struct file_system_type *filesystem = filesystem_get(filesystemtype);
-	if (filesystem == NULL)
+	if (filesystem == NULL) {
+		atomic_stop();
 		return (-1);
+	}
 
 	// Check ROOT mount.
 	if (target == NULL && mountflags == (unsigned long)VFS_MOUNT_ROOT)
 	{
 		// Check VFS root
-		if (vfs_root_node != NULL)
+		if (vfs_root_node != NULL) {
+			atomic_stop();
 			return (-4);
+		}
 
 		// Alloc root mnt
 		vfs_root_node = vfs_dentry_alloc("/", __S_IFDIR);
-		if (vfs_root_node == NULL)
+		if (vfs_root_node == NULL) {
+			atomic_stop();
 			return (-1);
+		}
 		
 		// Try to mount the FS.
 		// TODO: add possibility to return to main menu
@@ -64,33 +74,42 @@ int vfs_mount(const char *source, const char *target,
 			earlyterm_clear();
 			earlyterm_write("VFS: Unable to mount ROOT inode !");
 			earlyterm_write("Wait manual reset...");
+			atomic_stop();
 			while (1) { __asm__ volatile ("sleep"); }
 		}
 
 		// Get File System primitives
 		vfs_root_node->dentry_op.file_op = &filesystem->file_operations;
 		vfs_root_node->dentry_op.inode_op = &filesystem->inode_operations;
+		atomic_stop();
 		return (0);
 	}
 
 	// Get target inode informations
 	struct dentry *mnt = vfs_dentry_resolve(target, VFS_DENTRY_RESOLVE_FLAG_FULL_PATH);
-	if (mnt == NULL)
+	if (mnt == NULL) {
+		atomic_stop();
 		return (-1);
+	}
 
 	// Check directory validity
-	if ((mnt->mode & __S_IFDIR) == 0)
+	if ((mnt->mode & __S_IFDIR) == 0) {
+		atomic_stop();
 		return (-2);
+	}
 
 	// Try to mount the directory
 	void *inode = filesystem->filesystem_operations.mount();
-	if (inode == NULL)
+	if (inode == NULL) {
+		atomic_stop();
 		return (-3);
+	}
 
 	// Init mount point: set new FS specific primitives
 	// TODO: set new FS flags
 	mnt->mnt.inode = inode;
 	mnt->mnt.file_op = &filesystem->file_operations;
 	mnt->mnt.inode_op = &filesystem->inode_operations;
+	atomic_stop();
 	return (0);
 }
diff --git a/src/kernel/loader/entry.c b/src/kernel/loader/entry.c
index 57e41ee..7caf463 100644
--- a/src/kernel/loader/entry.c
+++ b/src/kernel/loader/entry.c
@@ -66,5 +66,6 @@ int loader(struct process *process, const char *path)
 		DBG_WAIT;
 		return (-4);
 	}
+	vfs_close(&file);
 	return (0);
 }
diff --git a/src/kernel/loader/header.c b/src/kernel/loader/header.c
index a790a09..db76a80 100644
--- a/src/kernel/loader/header.c
+++ b/src/kernel/loader/header.c
@@ -5,7 +5,7 @@
 int loader_get_header(FILE *file, Elf32_Ehdr *header)
 {
 	// Read ELF header.
-	if (vfs_read(file, header, sizeof(Elf32_Ehdr)) != sizeof(Elf32_Ehdr))
+	if (vfs_pread(file, header, sizeof(Elf32_Ehdr), 0) != sizeof(Elf32_Ehdr))
 		return (-1);
 
 	// Check magic number
diff --git a/src/kernel/loader/image.c b/src/kernel/loader/image.c
index adc761a..a25d92b 100644
--- a/src/kernel/loader/image.c
+++ b/src/kernel/loader/image.c
@@ -8,6 +8,7 @@ int loader_load_image(struct process *process, FILE *file, Elf32_Ehdr *header)
 {
 	Elf32_Phdr program;
 	void *paddress;
+	off_t offset;
 	uint16_t i;
 
 	// Walk one time to get program size and
@@ -17,8 +18,8 @@ int loader_load_image(struct process *process, FILE *file, Elf32_Ehdr *header)
 	while (++i < header->e_phnum)
 	{
 		// Read programme header.
-		vfs_lseek(file, header->e_phoff + (sizeof(Elf32_Phdr) * i), SEEK_SET);
-		if (vfs_read(file, &program, sizeof(Elf32_Phdr)) != sizeof(Elf32_Phdr))
+		offset = header->e_phoff + (i * sizeof(Elf32_Phdr));
+		if (vfs_pread(file, &program, sizeof(Elf32_Phdr), offset) != sizeof(Elf32_Phdr))
 			return (-1);
 
 		// Check programe type.
@@ -29,10 +30,11 @@ int loader_load_image(struct process *process, FILE *file, Elf32_Ehdr *header)
 		process->memory.program.size = process->memory.program.size + program.p_memsz;
 	}
 
-	// Allocate programe space into
-	// physical memory.
-	process->memory.program.start = (void *)pm_alloc(process->memory.program.size);
-	if (process->memory.program.start == 0x00000000)
+	// Allocate programe space into physical memory.
+	// @note: we use page allocator to avoid kernel
+	// heap grow up
+	process->memory.program.start = pm_pages_alloc(PM_SIZE_TO_PAGES(process->memory.program.size));
+	if (process->memory.program.start == NULL)
 		return (-3);
 
 	// Now, load all program section into
@@ -41,8 +43,8 @@ int loader_load_image(struct process *process, FILE *file, Elf32_Ehdr *header)
 	while (++i < header->e_phnum)
 	{
 		// Read programme header.
-		vfs_lseek(file, header->e_phoff + (sizeof(Elf32_Phdr) * i), SEEK_SET);
-		vfs_read(file, &program, sizeof(Elf32_Phdr));
+		offset = header->e_phoff + (i * sizeof(Elf32_Phdr));
+		vfs_pread(file, &program, sizeof(Elf32_Phdr), offset);
 
 		// Generate physical address
 		paddress = program.p_vaddr + process->memory.program.start;
@@ -52,8 +54,7 @@ int loader_load_image(struct process *process, FILE *file, Elf32_Ehdr *header)
 		memset(paddress, 0, program.p_memsz);
 
 		// Dump the program. 
-		vfs_lseek(file, program.p_offset, SEEK_SET);
-		vfs_read(file, paddress, program.p_filesz);
+		vfs_pread(file, paddress, program.p_filesz, program.p_offset);
 	}
 
 	// Generate program entry address
diff --git a/src/kernel/loader/reloc_sym.c b/src/kernel/loader/reloc_sym.c
index 10aa203..585df11 100644
--- a/src/kernel/loader/reloc_sym.c
+++ b/src/kernel/loader/reloc_sym.c
@@ -7,16 +7,18 @@ static char *get_shstrtab(FILE *file, Elf32_Ehdr *header)
 {
 	Elf32_Shdr shdr;
 	char *shstrtab;
+	off_t offset;
 
 	// Get sections string header tables
-	vfs_lseek(file, header->e_shoff + (header->e_shstrndx * sizeof(Elf32_Shdr)), SEEK_SET);
-	if (vfs_read(file, &shdr, sizeof(Elf32_Shdr)) != sizeof(Elf32_Shdr))
+	offset = header->e_shoff + (header->e_shstrndx * sizeof(Elf32_Shdr));
+	if (vfs_pread(file, &shdr, sizeof(Elf32_Shdr), offset) != sizeof(Elf32_Shdr))
 	{
 		earlyterm_write("relo_sym: shdr size\n");
 		return (NULL);
 	}
 
 	// Allocate dump area
+	earlyterm_write("Try to alloc strtab (%do)\n", shdr.sh_size);
 	shstrtab = (char*)pm_alloc(shdr.sh_size);
 	if (shstrtab == NULL)
 	{
@@ -25,8 +27,7 @@ static char *get_shstrtab(FILE *file, Elf32_Ehdr *header)
 	}
 
 	// Get string tables
-	vfs_lseek(file, shdr.sh_offset, SEEK_SET);
-	if (vfs_read(file, shstrtab, shdr.sh_size) != (ssize_t)shdr.sh_size)
+	if (vfs_pread(file, shstrtab, shdr.sh_size, shdr.sh_offset) != (ssize_t)shdr.sh_size)
 	{
 		earlyterm_write("relo_sym: shstrtab size error\n");
 		pm_free(shstrtab);
@@ -39,14 +40,15 @@ static int reloc_section(struct process *process, FILE *file, Elf32_Shdr *shdr)
 {
 	Elf32_Rela rela;
 	uint32_t *prog;
+	off_t offset;
 
 	// List symbols
 	prog = (void*)process->memory.program.start;
 	for (uint32_t i = 0 ; i < shdr->sh_size / shdr->sh_entsize ; ++i)
 	{
 		// Get relocatable entry
-		vfs_lseek(file, shdr->sh_offset + (i * sizeof(Elf32_Rela)), SEEK_SET);
-		if (vfs_read(file, &rela, sizeof(Elf32_Rela)) != sizeof(Elf32_Rela))
+		offset = shdr->sh_offset + (i * sizeof(Elf32_Rela));
+		if (vfs_pread(file, &rela, sizeof(Elf32_Rela), offset) != sizeof(Elf32_Rela))
 		{
 			earlyterm_write("relo_sym: reloc section size error\n");
 			return (-1);
@@ -64,6 +66,7 @@ int loader_reloc_sym(struct process *process, FILE *file, Elf32_Ehdr *header)
 {
 	Elf32_Shdr shdr;
 	char *shstrtab;
+	off_t offset;
 
 	// DEBUG
 	earlyterm_write("e_shoff    = %d\n", header->e_shoff);
@@ -71,7 +74,6 @@ int loader_reloc_sym(struct process *process, FILE *file, Elf32_Ehdr *header)
 	earlyterm_write("e_shstrndx = %d\n", header->e_shstrndx);
 	//DBG_WAIT;
 
-
 	// Get the shstrtab
 	shstrtab = get_shstrtab(file, header);
 	if (shstrtab == NULL)
@@ -81,13 +83,13 @@ int loader_reloc_sym(struct process *process, FILE *file, Elf32_Ehdr *header)
 	for (int i = 1 ; i < header->e_shnum ; ++i)
 	{
 		// Get next section header
-		vfs_lseek(file, header->e_shoff + (i * sizeof(Elf32_Shdr)), SEEK_SET);
-		if (vfs_read(file, &shdr, sizeof(Elf32_Shdr)) != sizeof(Elf32_Shdr))
+		offset = header->e_shoff + (i * sizeof(Elf32_Shdr));
+		if (vfs_pread(file, &shdr, sizeof(Elf32_Shdr), offset) != sizeof(Elf32_Shdr))
 		{
 			earlyterm_write("loader_reloc_sym: section header\n");
 			earlyterm_write("loader_reloc_sym: shoff = %#x\n", header->e_shoff);
 			earlyterm_write("loader_reloc_sym: shnum = %#x\n", header->e_shnum);
-			earlyterm_write("loader_reloc_sym: off = %#x\n", header->e_shoff + (i * sizeof(Elf32_Shdr)));
+			earlyterm_write("loader_reloc_sym: off = %#x\n", offset);
 			return (-2);
 		}
 
@@ -101,9 +103,5 @@ int loader_reloc_sym(struct process *process, FILE *file, Elf32_Ehdr *header)
 			return (-3);
 	}
 	pm_free(shstrtab);
-	//earlyterm_write("start = %p\n", process->memory.program.start);
-	//DBG_WAIT;
-	//DBG_WAIT;
-	//DBG_WAIT;
 	return (0);
 }
diff --git a/src/kernel/memory/heap/alloc.c b/src/kernel/memory/heap/alloc.c
new file mode 100644
index 0000000..f00774a
--- /dev/null
+++ b/src/kernel/memory/heap/alloc.c
@@ -0,0 +1,127 @@
+#include <kernel/memory.h>
+#include <kernel/util/atomic.h>
+#include <kernel/devices/earlyterm.h>
+
+static void *pm_block_split(struct pm_heap_block *block, size_t size)
+{
+	size_t rest_size;
+	void *ret;
+	
+	// Check size
+	if (block->size < size)
+		return (NULL);
+
+	// Change current block status
+	block->status = 1;
+
+	// Check if we can not split
+	rest_size = block->size - (size + sizeof(struct pm_heap_block));
+	if (rest_size < PM_HEAP_BLOCK_MIN)
+		return (&block[1]);
+
+	// Update current block size and get the
+	// returned value
+	block->size = size;
+	ret = &block[1];
+
+	// Initialize seconde block
+	block = (void *)&block[1] + block->size;
+	block->status = 0;
+	block->size = rest_size;
+	return (ret);
+}
+
+static void *new_pages(struct pm_heap_page **page, size_t size)
+{
+	int nb_page;
+
+	// calculate the number of page
+	nb_page = (size + sizeof(struct pm_heap_page) + PM_PAGE_SIZE - 1) / PM_PAGE_SIZE;
+
+	// Create new page
+	//earlyterm_write("Try to get %d page(s)...", nb_page);
+	//DBG_WAIT;
+	*page = pm_pages_alloc(nb_page);
+	if (*page == NULL)
+		return (NULL);
+	//earlyterm_write("OK!\n", nb_page);
+
+	// Initialize new page
+	(*page)->next = NULL;
+	(*page)->size = (nb_page * PM_PAGE_SIZE) - sizeof(struct pm_heap_page);
+	(*page)->brk = (void*)(*page) + (nb_page * PM_PAGE_SIZE); 
+
+	// Initialize first block
+	(*page)->heap.status = 0;
+	(*page)->heap.size = (*page)->size;
+	return (pm_block_split(&(*page)->heap, size));
+}
+
+static void *pm_heap_alloc(struct pm_heap_page *page, size_t size)
+{
+	struct pm_heap_block *block;
+	size_t rest_size;
+	void *ret;
+
+	// Walk into the page and check each block x_x
+	block = &page->heap;
+	rest_size = page->size;
+	while ((void*)block < page->brk && rest_size > size)
+	{
+		// Check if the block is used or not
+		if (block->status == 0)
+		{
+			// Try to split the area
+			ret = pm_block_split(block, size);
+			if (ret != NULL)
+				return (ret);
+		}
+
+		// Update space rest and get new block
+		rest_size = rest_size - (block->size + sizeof(struct pm_heap_block));
+		block = (void*)&block[1] + block->size;
+	}
+	return (NULL);
+}
+
+// Kernel malloc wrapper
+void *pm_alloc(size_t size)
+{
+	extern struct memory_info pmemory;
+	struct pm_heap_page **page;
+	void *ret;
+
+	// Force 4-align
+	size = (size + 3) >> 2 << 2;
+
+	// start atomic operations
+	atomic_start();
+
+	// Walk into each pages x_x
+	page = &pmemory.kheap;
+	while (*page != NULL)
+	{
+		// Check "page" size
+		if ((*page)->size < size) {
+			page = &(*page)->next;
+			continue;
+		}
+
+		// Try to find free space in the page
+		ret = pm_heap_alloc(*page, size);
+		if (ret != NULL) {
+			atomic_stop();
+			return (ret);
+		}
+
+		// Get next page
+		page = &(*page)->next;
+	}
+
+	// Try to allocate new pages
+	ret = new_pages(page, size);
+
+	// stop atomic operations
+	atomic_stop();
+	return (ret);
+}
diff --git a/src/kernel/memory/heap/debug.c b/src/kernel/memory/heap/debug.c
new file mode 100644
index 0000000..1ccc2b3
--- /dev/null
+++ b/src/kernel/memory/heap/debug.c
@@ -0,0 +1,23 @@
+#include <kernel/memory.h>
+#include <kernel/devices/earlyterm.h>
+
+void pm_debug(void)
+{
+	extern struct memory_info pmemory;
+	struct pm_heap_block *block;
+	struct pm_heap_page *page;
+
+	page = pmemory.kheap;
+	while (page != NULL)
+	{
+		earlyterm_write("page = %p, %do\n", page, page->size);
+		DBG_WAIT;
+		block = &page->heap;
+		while ((void*)block < page->brk) {
+			earlyterm_write("* [%d] - %p, %do\n", block->status, block, block->size);
+			DBG_WAIT;
+			block = (void*)&block[1] + block->size;
+		}
+		page = page->next;
+	}
+}
diff --git a/src/kernel/memory/heap/free.c b/src/kernel/memory/heap/free.c
new file mode 100644
index 0000000..edaad7c
--- /dev/null
+++ b/src/kernel/memory/heap/free.c
@@ -0,0 +1,96 @@
+#include <kernel/memory.h>
+#include <kernel/util/atomic.h>
+#include <kernel/devices/earlyterm.h>
+
+static void pm_block_backmerge(struct pm_heap_block **block,
+		struct pm_heap_block *parent)
+{
+	// Check back-merge possibility
+	if (parent == NULL || parent->status != 0)
+		return;
+
+	// Absorb current block
+	parent->size += (*block)->size + sizeof(struct pm_heap_block);
+
+	// Switch current block
+	*block = parent;
+}
+
+static void pm_block_frontmerge(struct pm_heap_block *block, void *brk)
+{
+	struct pm_heap_block *block_front;
+
+	// Check front-merge possibility
+	block_front = (void*)&block[1] + block->size;
+	if ((void*)block_front >= brk || block_front->status != 0)
+		return;
+
+	// Absorb front block
+	block->size += block_front->size + sizeof(struct pm_heap_block);
+}
+
+static int pm_block_free(struct pm_heap_page *page, void *ptr)
+{
+	struct pm_heap_block *block_parent;
+	struct pm_heap_block *block;
+
+	block_parent = NULL;
+	block = &page->heap;
+	while ((void*)block < page->brk)
+	{
+		// check block validity
+		if ((void*)&block[1] != ptr)
+		{
+			block_parent = block;
+			block = (void*)&block[1] + block->size;
+			continue;
+		}
+
+		// Try back-merge / front merge
+		pm_block_backmerge(&block, block_parent);
+		pm_block_frontmerge(block, page->brk);
+
+		// Update block status
+		block->status = 0;
+		return (0);
+	}
+	return (-1);
+}
+
+void pm_free(void *ptr)
+{
+	extern struct memory_info pmemory;
+	struct pm_heap_page *page;
+
+	// Start atomic operations
+	atomic_start();
+
+	// Try to find the page
+	page = pmemory.kheap;
+	while (page != NULL)
+	{
+		// If is the page is found
+		if (ptr > (void*)page && ptr < page->brk)
+		{
+			// Check if the block is not found
+			if (pm_block_free(page, ptr) != 0)
+				break;
+
+			// Stop atomic operations and return
+			atomic_stop();
+			return;
+		}
+		// Get the next page
+		page = page->next;
+	}
+	
+	// No block found, display error.
+	earlyterm_write(
+		"pm_free: Warning, you try to free unused"
+		" or allocated memory (%p)", ptr
+	);
+	DBG_WAIT;
+
+	// Stop atomic operations
+	atomic_stop();
+}
diff --git a/src/kernel/memory/initialize.c b/src/kernel/memory/initialize.c
index d00721e..0dce692 100644
--- a/src/kernel/memory/initialize.c
+++ b/src/kernel/memory/initialize.c
@@ -1,58 +1,67 @@
 #include <kernel/memory.h>
+#include <kernel/devices/earlyterm.h>
 
 // Internal data.
-struct memory_info_s pmemory;
+struct memory_info pmemory;
 
 __attribute__((constructor(101)))
 void memory_init(void)
 {
 	extern uint32_t ram_start;
-	uint32_t ram_end;
-	uint32_t ram_size;
+	extern uint32_t srom;
 
-	// TODO: determine RAM's end.
-	ram_end = 0x88080000;
-	ram_size = ram_end - (uint32_t)&ram_start;
+	// Initialize RAM informations
+	// TODO determine RAM's size
+	pmemory.ram.end = (void *)0x88080000;
+	pmemory.ram.start = (void *)(((uintptr_t)&ram_start + 3) >> 2 << 2);
+	pmemory.ram.size = pmemory.ram.end - pmemory.ram.start;
 
-	// DEBUG
-	/*dclear();
-	dprint(0, 0, "RAM diagnostic");
-	dprint(0, 1, "start = %p", &ram_start);
-	dprint(0, 2, "end   = %p", ram_end);
-	dprint(0, 3, "size  = %dko", ram_size / 1024);
-	dupdate();*/
-	//for (int i = 0 ; i < 9000000 ; i = i + 1);
-
-	// Get the number of block available
-	// and calculate the real numer of block with
-	// the cache.
-	// TODO: check if RAM can be used ? (block == 0)
-	// @note: try to avoid too long search part.
-	pmemory.cache = (void*)&ram_start;
-	pmemory.blocks = (ram_size / PM_BLOCK_SIZE) >> 1;
-	ram_end = ram_end - (PM_BLOCK_SIZE * pmemory.blocks);
-	while ((uint32_t)&pmemory.cache[pmemory.blocks] < ram_end - PM_BLOCK_SIZE)
+	// Generate cache part
+	pmemory.cache.delta = NULL;
+	pmemory.cache.pages.number = 0;
+	pmemory.cache.pages.size = PM_PAGE_SIZE;
+	pmemory.cache.pages.list = pmemory.ram.start;
+	pmemory.cache.pages.base_addr = pmemory.ram.end;
+	while ((void *)&pmemory.cache.pages.list[pmemory.cache.pages.number] <
+				pmemory.cache.pages.base_addr - PM_PAGE_SIZE)
 	{
-		pmemory.blocks = pmemory.blocks + 1;
-		ram_end = ram_end - PM_BLOCK_SIZE;
+		pmemory.cache.pages.base_addr -= PM_PAGE_SIZE;
+		pmemory.cache.pages.number += 1;
 	}
 
-	// Get "real" physical memory start
-	pmemory.start = ram_end;
+	// Initialize kernel heap
+	pmemory.kheap = NULL;
 
-	// DEBUG
-	/*dclear();
-	dprint(0, 0, "Cache diagnostic");
-	dprint(0, 1, "Bloks = %d (%do)", pmemory.blocks, PM_BLOCK_SIZE);
-	dprint(0, 2, "Start = %p", pmemory.cache);
-	dprint(0, 3, "PRAM  = %p", pmemory.start);
-	dupdate();
-	for (int i = 0 ; i < 9000000 ; i = i + 1);*/
-
-	// Initialize cache
-	for (uint32_t i = 0 ; i < pmemory.blocks ; i = i + 1)
+	// Debug
+/*	earlyterm_write("kernel    = %do -> %dko\n", &srom, (uint32_t)&srom / 1024);
+	earlyterm_write("ram start = %p\n", pmemory.ram.start);
+	earlyterm_write("ram end   = %p\n", pmemory.ram.end);
+	earlyterm_write("ram size  = %do -> %dko\n", pmemory.ram.size, pmemory.ram.size / 1024);
+	earlyterm_write("page size = %do -> %#xo\n", pmemory.cache.pages.size, pmemory.cache.pages.size);
+	earlyterm_write("page num  = %d\n", pmemory.cache.pages.number);
+	earlyterm_write("real RAM  = %d -> %dko\n", pmemory.cache.pages.number * PM_PAGE_SIZE, (pmemory.cache.pages.number * PM_PAGE_SIZE) / 1024);
+*/
+	// Initialize cache page list
+	for (int i = 0 ; i < pmemory.cache.pages.number ; i = i + 1)
 	{
-		pmemory.cache[i].status = UNUSED;
-		pmemory.cache[i].next = NULL;
+		pmemory.cache.pages.list[i].status = PAGE_UNUSED;
+		pmemory.cache.pages.list[i].next = NULL;
 	}
+
+	// TEST part
+/*	void *test0 = pm_alloc(16);
+	void *test1 = pm_alloc(128);
+	void *test2 = pm_alloc(80);
+	earlyterm_write("test0 = %p\n", test0);
+	earlyterm_write("test1 = %p\n", test1);
+	earlyterm_write("test2 = %p\n", test2);
+	pm_free(test2);
+	pm_free(test0);
+	pm_heap_debug();
+	DBG_WAIT;
+	pm_free(test1);
+	pm_debug();
+	pm_free((void*)0xa0000000);
+	DBG_WAIT;
+	while (1);*/
 }
diff --git a/src/kernel/memory/page/alloc.c b/src/kernel/memory/page/alloc.c
new file mode 100644
index 0000000..c3048fd
--- /dev/null
+++ b/src/kernel/memory/page/alloc.c
@@ -0,0 +1,91 @@
+#include <kernel/memory.h>
+#include <kernel/util/atomic.h>
+
+static struct pm_page *page_alloc(void)
+{
+	extern struct memory_info pmemory;
+	int i;
+
+	i = -1;
+	while (++i < pmemory.cache.pages.number)
+	{
+		// Check if the block are used
+		if (pmemory.cache.pages.list[i].status == PAGE_USED)
+			continue;
+
+		// Initialize block and return address
+		pmemory.cache.pages.list[i].status = PAGE_USED;
+		pmemory.cache.pages.list[i].next = NULL;
+		return (&pmemory.cache.pages.list[i]);
+	}
+	return (NULL);
+}
+
+void *pm_pages_alloc(int nb_page)
+{
+	extern struct memory_info pmemory;
+	uint16_t page_entry_id;
+	struct pm_page **head;
+	struct pm_page *new;
+
+	// Check obvious error.
+	if (nb_page == 0 || nb_page >= pmemory.cache.pages.number)
+		return (NULL);
+
+	// start atomic operations
+	atomic_start();
+
+	// Find block entry.
+	page_entry_id = 0;
+	head = &pmemory.cache.delta;
+	while (*head != NULL)
+	{
+		// Check is it'is the last allocated object.
+		if ((*head)->next == NULL)
+		{
+			// Check potential memory available.
+			if ((*head)->id.end + nb_page >= pmemory.cache.pages.number) {
+				atomic_stop();
+				return (NULL);
+			}
+			
+			// Get cache entry.
+			page_entry_id = (*head)->id.end;
+			head = &(*head)->next;
+			break;
+		}
+
+		// Calculate the gap between current allocated object
+		// and the next object and see if we can split the area
+		if ((*head)->next->id.start - (*head)->id.end >= nb_page)
+		{
+			page_entry_id = (*head)->id.end;
+			head = &(*head)->next;
+			break;
+		}
+
+		// Get next allocated block.
+		head = &(*head)->next;
+	}
+
+	// Setup new allocated block
+	new = page_alloc();
+	if (new == NULL) {
+		atomic_stop();
+		return (NULL);
+	}
+
+	// Initialize new block
+	new->id.start = page_entry_id;
+	new->id.end = page_entry_id + nb_page;
+
+	// Insert new block.
+	new->next = *head;
+	*head = new;
+
+	// stop atomic operations
+	atomic_stop();
+
+	// Generate physical memory address
+	return ((void*)((page_entry_id * PM_PAGE_SIZE) + pmemory.cache.pages.base_addr));
+}
diff --git a/src/kernel/memory/pm_free.c b/src/kernel/memory/page/free.c
similarity index 60%
rename from src/kernel/memory/pm_free.c
rename to src/kernel/memory/page/free.c
index 026aab1..d9df400 100644
--- a/src/kernel/memory/pm_free.c
+++ b/src/kernel/memory/page/free.c
@@ -1,21 +1,22 @@
 #include <kernel/memory.h>
+#include <kernel/util/atomic.h>
 #include <kernel/devices/earlyterm.h>
 
-void pm_free(void *ptr)
+void pm_pages_free(void *ptr)
 {
-	extern struct memory_info_s pmemory;
-	struct pm_block_cache_s **head;
-	uint32_t block_entry;
+	extern struct memory_info pmemory;
+	uint16_t page_entry_id;
+	struct pm_page **head;
 	uint32_t sptr;
 
 	// Save address for error message.
 	sptr = (uint32_t)ptr;
 
 	// Get the "real" physical space.
-	ptr = (void*)(ptr - pmemory.start);
+	ptr = (void*)(ptr - pmemory.cache.pages.base_addr);
 
 	// Check misaligned pointer.
-	if (((uint32_t)ptr % PM_BLOCK_SIZE) != 0)
+	if (((uint32_t)ptr % PM_PAGE_SIZE) != 0)
 	{
 		earlyterm_write(
 			"pm_free: Warning, you try to free misaligned"
@@ -26,23 +27,27 @@ void pm_free(void *ptr)
 	}
 
 	// Get block entry.
-	block_entry = (uint32_t)ptr / PM_BLOCK_SIZE;
+	page_entry_id = (uint32_t)ptr / PM_PAGE_SIZE;
+
+	// Start atomic operations
+	atomic_start();
 
 	// Walk into "head" cache and try to find 
 	// the allocated block.
-	head = &pmemory.head;
+	head = &pmemory.cache.delta;
 	while (*head != NULL)
 	{
 		// Check the allocated block.
-		if ((*head)->start != block_entry)
+		if ((*head)->id.start != page_entry_id)
 		{
 			head = &(*head)->next;
 			continue;
 		}
 
 		// Free the block and return
-		(*head)->status = UNUSED;
+		(*head)->status = PAGE_UNUSED;
 		*head = (*head)->next;
+		atomic_stop();
 		return;
 	}
 
@@ -52,4 +57,7 @@ void pm_free(void *ptr)
 		"allocated memory (%p)", sptr
 	);
 	DBG_WAIT;
+
+	// Stop atomic operations
+	atomic_stop();
 }
diff --git a/src/kernel/memory/pm_alloc.c b/src/kernel/memory/pm_alloc.c
deleted file mode 100644
index 718db32..0000000
--- a/src/kernel/memory/pm_alloc.c
+++ /dev/null
@@ -1,85 +0,0 @@
-#include <kernel/memory.h>
-
-static struct pm_block_cache_s *block_alloc(void)
-{
-	extern struct memory_info_s pmemory;
-	uint32_t i;
-
-	i = -1;
-	while (++i < pmemory.blocks)
-	{
-		// Check if the block are used
-		if (pmemory.cache[i].status == USED)
-			continue;
-
-		// Initialize block and return address
-		pmemory.cache[i].status = USED;
-		pmemory.cache[i].next = NULL;
-		return (&pmemory.cache[i]);
-	}
-	return (NULL);
-}
-
-void *pm_alloc(size_t size)
-{
-	extern struct memory_info_s pmemory;
-	struct pm_block_cache_s **head;
-	struct pm_block_cache_s *block;
-	uint32_t block_entry;
-	uint32_t nb_blocks;
-
-	// Check obvious error.
-	if (size == 0)
-		return (NULL);
-
-	// Get the number of blocks we need.
-	nb_blocks = (size + PM_BLOCK_SIZE - 1) / PM_BLOCK_SIZE;
-
-	// Find block entry.
-	block_entry = 0;
-	head = &pmemory.head;
-	while (*head != NULL)
-	{
-		// Check is it is the last allocated
-		// object.
-		if ((*head)->next == NULL)
-		{
-			// Check memory space.
-			if ((*head)->end + 1 + nb_blocks >= pmemory.blocks)
-				return (NULL);
-			
-			// Get cache entry.
-			block_entry = (*head)->end + 1;
-			head = &(*head)->next;
-			break;
-		}
-
-		// Calculate the gap between current
-		// allocated object and the next object.
-		if (((*head)->next->start) - ((*head)->end + 1) >= nb_blocks)
-		{
-			block_entry = (*head)->end + 1;
-			head = &(*head)->next;
-			break;
-		}
-
-		// Get next allocated block.
-		head = &(*head)->next;
-	}
-
-	// Setup new allocated block
-	block = block_alloc();
-	if (block == NULL)
-		return (NULL);
-
-	// Initialize new block
-	block->start = block_entry;
-	block->end = block_entry + nb_blocks - 1;
-
-	// Insert new block.
-	block->next = *head;
-	*head = block;
-
-	// Generate physical memory address
-	return ((void*)((block_entry * PM_BLOCK_SIZE) + pmemory.start));
-}
diff --git a/src/kernel/memory/syscall/sys_mmap.c b/src/kernel/memory/syscall/sys_mmap.c
new file mode 100644
index 0000000..8c05aea
--- /dev/null
+++ b/src/kernel/memory/syscall/sys_mmap.c
@@ -0,0 +1,44 @@
+#include <kernel/memory.h>
+#include <kernel/syscall.h>
+#include <kernel/devices/earlyterm.h>
+#include <kernel/fs/vfs.h>
+
+//TODO: udpate me !!
+//TODO: handle flags !!
+void *sys_mmap(void *addr, size_t length,
+		int prot, int flags, int fd, off_t offset)
+{
+	extern struct process *process_current;
+
+	// Check process error
+	if (process_current == NULL)
+		return (MAP_FAILED);
+
+	// @note: we can not handle user-request for
+	// the address, because we can not use the
+	// virtual memory
+	if (addr != NULL)
+		return (MAP_FAILED);
+
+	// @note: we can not handle protactions for
+	// the pages because we can not use the
+	// virtual memory
+	(void)prot;
+
+	//TODO: handle flags !!!
+	(void)flags;
+	
+	// Calculated the number of pages needed
+	int nb_pages = (length + PM_PAGE_SIZE - 1) / PM_PAGE_SIZE;
+
+	// Try to get all pages needed
+	//void *area = pm_get_pages(nb_pages);
+	//if (area == NULL)
+		return (MAP_FAILED);
+
+	// Check if we must copy the file content into
+	// new area.
+	//if (fd >= 0)
+	//	sys_pread(fd, area, length, offset);
+	//return (area);
+}
diff --git a/src/kernel/scheduler/process/create.c b/src/kernel/scheduler/process/create.c
index 5f6c5a0..9b9c71a 100644
--- a/src/kernel/scheduler/process/create.c
+++ b/src/kernel/scheduler/process/create.c
@@ -21,8 +21,8 @@ struct process *process_create(void)
 
 	// Initialize user stack
 	process->memory.stack.size.user = PROCESS_USER_STACK_SIZE;
-	process->memory.stack.user = (void *)pm_alloc(process->memory.stack.size.user);
-	if (process->memory.stack.user == 0x00000000)
+	process->memory.stack.user = pm_pages_alloc(PM_SIZE_TO_PAGES(process->memory.stack.size.user));
+	if (process->memory.stack.user == NULL)
 	{
 		earlyterm_write("proc_error: user stack error !");
 		DBG_WAIT;
@@ -33,8 +33,8 @@ struct process *process_create(void)
 
 	// Initialize kernel stack
 	process->memory.stack.size.kernel = PROCESS_KERNEL_STACK_SIZE;
-	process->memory.stack.kernel = (void *)pm_alloc(process->memory.stack.size.kernel);
-	if (process->memory.stack.kernel == 0x00000000)
+	process->memory.stack.kernel = pm_pages_alloc(PM_SIZE_TO_PAGES(process->memory.stack.size.kernel));
+	if (process->memory.stack.kernel == NULL)
 	{
 		earlyterm_write("proc_error: kernel stack error !");
 		DBG_WAIT;
@@ -45,6 +45,7 @@ struct process *process_create(void)
 	process->stack.kernel = process->memory.stack.kernel + process->memory.stack.size.kernel;
 
 	// initialize "exit" part.
+	// TODO: generate errno global address
 	uint8_t callexit[8] = {
 		0b01100100, 0b00000011,	// mov r0, r4
 		0b11000011, __NR_exit,	// trapa #__NR_exit
@@ -52,8 +53,8 @@ struct process *process_create(void)
 		0b00000000, 0b00001001	// nop
 	};
 	process->memory.exit.size = 8;
-	process->memory.exit.start = (void *)pm_alloc(process->memory.exit.size);
-	if (process->memory.exit.start == 0x00000000)
+	process->memory.exit.start = pm_pages_alloc(PM_SIZE_TO_PAGES(process->memory.exit.size));
+	if (process->memory.exit.start == NULL)
 	{
 		pm_free(process->memory.stack.user);
 		pm_free(process->memory.stack.kernel);
@@ -61,9 +62,10 @@ struct process *process_create(void)
 		return (NULL);
 	}
 	process->context.pr = (uint32_t)process->memory.exit.start;
-	memcpy((void *)process->memory.exit.start, callexit, 6);
+	memcpy(process->memory.exit.start, callexit, 6);
 
 	// Initialize context.
+	// TODO:arguments
 	for (int i = 0 ; i < 15 ; i = i + 1)
 		process->context.reg[i] = 0x00000000;
 
diff --git a/src/kernel/scheduler/syscall/sys_exit.c b/src/kernel/scheduler/syscall/sys_exit.c
index a71affc..131f185 100644
--- a/src/kernel/scheduler/syscall/sys_exit.c
+++ b/src/kernel/scheduler/syscall/sys_exit.c
@@ -18,13 +18,14 @@ void sys_exit(int status)
 	atomic_start();
 
 	// Generate stat_loc
+	// TODO: signal
 	process_current->__stat_loc = __W_EXITCODE(status, 0); 
 
 	// Frre'd all allocated space
-	pm_free(process_current->memory.stack.user);
-	pm_free(process_current->memory.stack.kernel);
-	pm_free(process_current->memory.program.start);
-	pm_free(process_current->memory.exit.start);
+	pm_pages_free(process_current->memory.stack.user);
+	pm_pages_free(process_current->memory.stack.kernel);
+	pm_pages_free(process_current->memory.program.start);
+	pm_pages_free(process_current->memory.exit.start);
 
 	// Change process state
 	process_current->status = PROC_ZOMBIE;
diff --git a/src/kernel/syscall/handler.c b/src/kernel/syscall/handler.c
index e377dbc..999b811 100644
--- a/src/kernel/syscall/handler.c
+++ b/src/kernel/syscall/handler.c
@@ -33,6 +33,12 @@ static const void *sys_handler[__NR_MAX] = {
 	sys_open,		// open
 	sys_close,		// close
 	sys_lseek,		// lseek
+	sys_pread,		// pread
+	sys_pwrite,		// pwrite
+
+	// Memory
+	sys_mmap,		// mmap
+	NULL//sys_munmap		// munmap
 };
 
 void *sys_get_handler(int sysno)
diff --git a/src/kernel/vhex.ld b/src/kernel/vhex.ld
index 086afc9..ddd264a 100644
--- a/src/kernel/vhex.ld
+++ b/src/kernel/vhex.ld
@@ -94,7 +94,7 @@ SECTIONS
 	
 		*(.data)
 
-		_ram_start = ALIGN(1024);
+		_ram_start = ALIGN(4);
 	} > ram AT> rom : data
 	_sdata = SIZEOF(.data);
 
diff --git a/src/user/shell/shell.ld b/src/user/shell/shell.ld
index c69940b..d0505b5 100644
--- a/src/user/shell/shell.ld
+++ b/src/user/shell/shell.ld
@@ -8,7 +8,7 @@ ENTRY(_main)
 MEMORY
 {
 	/* virtual memory, read-write segment */
-	userram (WX) : o = 0x00000000, l = 256k
+	userram (rwx) : o = 0x00000000, l = 256k
 }
 
 SECTIONS
diff --git a/src/user/shell/util/strtotab.c b/src/user/shell/util/strtotab.c
new file mode 100644
index 0000000..dc8a419
--- /dev/null
+++ b/src/user/shell/util/strtotab.c
@@ -0,0 +1,146 @@
+/*# include <lib/stdlib.h>
+# include <lib/stdio.h>
+# include <lib/string.h>
+
+// Internal prototypes.
+extern int strtotab(int *argc, char ***argv, char const *str);
+extern void strtotab_quit(int *argc, char ***argv);
+
+//
+// parser_get_word()
+// Get the word at the current cursor location.
+//
+static ssize_t parser_get_word(char ***tab, size_t *tab_pos,
+char const *str, int *counter)
+{
+	ssize_t i;
+
+	i = -1;
+	while (str[++i] != '\0' && str[i] != '\n' && str[i] != ' ' && str[i] != '\t');
+	if (*tab != NULL){
+		(*tab)[*tab_pos] = (char*)malloc(i + 1);
+		if ((*tab)[*tab_pos] == NULL)
+			return (-1);
+		memset((*tab)[*tab_pos], 0, i + 1);
+		strncpy((*tab)[(*tab_pos)++], str, i);
+	}
+	(*counter)++;
+	return (i);
+}
+
+//
+// parser_get_inibitor()
+// This function will get the content of an inhibitor (and check if the
+// inhibitor characteres are alone or not).
+//
+static ssize_t parser_get_inibitor(char ***tab, size_t *tab_pos,
+char const *str, int *counter)
+{
+	ssize_t i;
+
+	i = 0;
+	while (str[++i] != '\0' && str[i] != '\"');
+	if (str[i] != '\"')
+		return (0);
+	if (*tab != NULL){
+		(*tab)[*tab_pos] = (char*)malloc(i + 1);
+		if ((*tab)[*tab_pos] == NULL)
+			return (-1);
+		memset((*tab)[*tab_pos], 0, i + 1);
+		strncpy((*tab)[(*tab_pos)++], str + 1, i - 1);
+	}
+	(*counter)++;
+	return (i + 1);
+}
+
+//
+// parser_setup_arg()
+// This function removes useless spaces, tabs and handle '\"' inhibitor.
+// Return the number of word(s) stored in "str".
+//
+static int parser_entry(char ***tab, char const *str)
+{
+	size_t tab_pos;
+	ssize_t size;
+	int counter;
+
+	str--;
+	counter = 0;
+	tab_pos = 0;
+	while (*(++str) != '\0' && *str != '\n'){
+		if (*str == '\"'){
+			size = parser_get_inibitor(tab, &tab_pos, str, &counter);
+			if (size < 0)
+				return (-1);
+			str += size;
+		}
+		if (*str != ' ' && *str != '\t'){
+			size = parser_get_word(tab, &tab_pos, str, &counter) - 1;
+			if (size < 0)
+				return (-1);
+			str += size;
+		}
+	}
+	return (counter);
+}
+
+//
+// strtotab()
+// Generate word table and indicated the number of word find in the string.
+//
+int strtotab(int *argc, char ***argv, char const *str)
+{
+	int i;
+
+	// Check memory fault.
+	if (argc == NULL || argv == NULL || str == NULL)
+		return (EFAULT);
+
+	// Get the number of word.
+	*argv = NULL;
+	*argc = parser_entry(argv, str);
+	if (*argc <= 0)
+		return (EINVAL);
+
+	// Alloc tab.
+	*argv = (char **)malloc(sizeof(char *) * (*argc + 1));
+	if (*argv == NULL)
+		return (ENOMEM);
+	i = *argc;
+	while (--i >= 0)
+		(*argv)[i] = NULL;
+
+	// Get word.
+	if (parser_entry(argv, str) != *argc){
+		strtotab_quit(argc, argv);
+		return (ENOMEM);
+	}
+	(*argv)[*argc] = NULL;
+	return (0);
+}
+
+//
+// strtotab() 
+// Free all allocated memory generated by "strtotab()"
+//
+void strtotab_quit(int *argc, char ***argv)
+{
+	// Check error
+	if (argc == NULL || argv == NULL)
+		return;
+
+	// Check useless actions
+	if (*argv == NULL) {
+		*argc = 0;
+		return;
+	}
+
+	// Free all list
+	while (--(*argc) >= 0)
+		free((*argv)[*argc]);
+	free(*argv);
+
+	// Secure
+	*argv = NULL;
+	*argc = 0;
+}*/
diff --git a/src/user/test/test.c b/src/user/test/test.c
index bda9a3f..4b5550c 100644
--- a/src/user/test/test.c
+++ b/src/user/test/test.c
@@ -1,11 +1,60 @@
 #include <lib/stdio.h>
 #include <lib/unistd.h>
 
+/*static int tree(const char *pathname)
+{
+	struct dirent dir;
+	int ret;
+	int fd;
+
+	// Open directory
+	fd = open(pathname, O_RDONLY | O_DIRECTORY);
+	if (fd < 0) {
+		dprintf(STDERR_FILENO, "tree: Cannot open directory '%s'\n", pathname);
+		return (2);
+	}
+
+	ret = 0;
+	while (1)
+	{
+		// Get dirent
+		read = sys_getdents(fd, &dir, sizeof(struct dirent));
+		if (read <= 0)
+			return ((read == 0) ? 0 : 84);
+
+
+	}
+
+	return (0);
+}*/
+
 int main(void)
 {
-	setpgid(0, 12);
-	printf("%-6d%-6d%-6d\n", getppid(), getpid(), getpgid());
-	printf("child proc fini...try to exit\n");
-	for(int i = 0 ; i < 3000000 ; ++i);
-	return (84);
+	char c[1024];
+	int ret;
+	int fd;
+
+	fd = open("/mnt/casio/VHEX/text.txt", O_RDONLY);
+	if (fd < 0) {
+		dprintf(STDERR_FILENO, "unable to open test file\n");
+		return (84);
+	}
+
+	while (1)
+	{
+		ret = read(fd, c, 1024);
+		if (ret <= 0)
+			break;
+		write(STDOUT_FILENO, c, ret);
+	}
+	return (0);
 }
+
+
+
+//	setpgid(0, 12);
+//	printf("%-6d%-6d%-6d\n", getppid(), getpid(), getpgid());
+//	printf("child proc fini...try to exit\n");
+//	for(int i = 0 ; i < 3000000 ; ++i);
+//	return (84);
+//}