diff --git a/core/elf.c b/core/elf.c
index 0e481c3..94a2478 100644
--- a/core/elf.c
+++ b/core/elf.c
@@ -17,7 +17,7 @@
 uaddr_t loadElfProg(const char *prog, struct process *proc)
 {
     int i;
-    uaddr_t lastUserAddr = 0;
+    uaddr_t lastUserAddr  = 0;
     struct uAddrSpace *as = processGetAddrSpace(proc);
 
 /* e_ident value */
diff --git a/core/fs.c b/core/fs.c
index 290b8c5..845c255 100644
--- a/core/fs.c
+++ b/core/fs.c
@@ -1,13 +1,27 @@
 #include "fs.h"
+#include "list.h"
+#include "stddef.h"
+
+// List of all fs supported (e.g. EXT4, FAT32 ...)
+struct file_system *fsList = NULL;
+
+
+int fsRegister(struct file_system *fs){
+    list_add_tail(fsList, fs);
+
+    return 0;
+}
 
 int fsInodeUnref(struct inode *inode)
 {
+    //TODO
     (void)inode;
     return 0;
 };
 
 int fsInodeRef(struct inode *inode)
 {
+    //TODO
     (void)inode;
     return 0;
 };
diff --git a/core/fs.h b/core/fs.h
index aa70ed1..c9bf70f 100644
--- a/core/fs.h
+++ b/core/fs.h
@@ -1,7 +1,139 @@
 #pragma once
+#include "fsEntry.h"
+#include "process.h"
+#include "stdint.h"
+#include <stddef.h>
+#include <stdint.h>
+
+#define FS_NAME_MAXLEN 32
+
+// Forward declaration
+struct file_system;
+struct file_system_instance;
+struct fs_stat;
+struct file;
+
+typedef enum {
+    FS_INODE_REGULAR_FILE = 0x01,
+    FS_INODE_DIRECTORY    = 0x02,
+    FS_INODE_SYMLINK      = 0x04,
+    FS_INODE_DEVICE_CHAR  = 0x08,
+    FS_INODE_DEVICE_BLOCK = 0x10
+} fs_inode_type_t;
+
+struct inode_operation {
+};
+
+struct inode { // inode_operation
+    struct file_system_instance *fs;
+
+    uint64_t location;
+    size_t ondiskRef;
+    size_t inmemRef;
+    fs_inode_type_t type;
+
+#define FS_READABLE 00400
+#define FS_WRITABLE 00200
+#define FS_EXECUTABLE 00100
+    uint32_t mode;
+
+    bool_t dirty;
+    struct inode_operation *ops;
+
+    union {
+        struct inode_dir_ops *opsDir;
+
+        struct inode_dir_symlink *opsSymlink;
+    };
+
+    int (*destructor)(struct inode *this);
+    int (*new_opened_file)(struct inode *this, const struct process *owner,
+                           uint32_t open_flags, struct file **result_of);
+    int (*close_opened_file)(struct inode *this, struct file *of);
+    void *custom;
+
+    struct inode *prev_dirty, *next_dirty;
+};
+
+struct file_system_instance_ops { // super_operations
+    // From the inode location, instantiace a struct inode
+    int (*getInodeFromDevice)(struct file_system_instance *this, uint64_t storage_location,
+                              struct inode **result);
+
+    int (*allocateNewInode)(struct file_system_instance *this, fs_inode_type_t type,
+                            const struct process *creator, uint32_t access_rights,
+                            uint32_t open_creat_flags, struct inode **result);
+
+    int (*statfs)(struct file_system_instance *this, struct fs_stat *result);
+};
+
+struct file_system_instance {
+
+    struct file_system *fsType; // this instance is of this type of file_system
+    struct inode *device; // device (like block one) could have a disk associated
+
+#define FS_MOUNT_SYNC (1 << 0)
+#define FS_MOUNT_READONLY (1 << 1)
+#define FS_MOUNT_NOEXEC (1 << 2)
+    uint32_t flags;
+
+    struct fsEntry *root; // root fsEntry for this fs instance
+    struct indoe *dirtyNodes; // list of inodes that are out of sync
+    void *custom; // custom
+    const struct file_system_instance_ops *ops;
 
 
-struct inode {//TODO
-              };
+    struct file_system_instance *prev, *next;
+};
+
+struct file_system {
+    char name[FS_NAME_MAXLEN];
+    struct file_system_instance *instances;
+    void *custom;
+
+    int (*mount)(struct file_system *this, struct inode *device, const char *args,
+                 struct file_system_instance **mounted_fs);
+
+    int (*umount)(struct file_system *this, struct file_system_instance *mounted_fs);
+
+    struct file_system *prev, *next;
+};
+
+struct file_operations{
+};
+
+struct file {
+    const struct process *owner;
+
+    struct fs_entry *direntry;
+    uint ref;
+    int64_t position;
+
+#define O_ACCMODE	   0003
+#define O_RDONLY	     00
+#define O_WRONLY	     01
+#define O_RDWR		     02
+
+#define O_CREAT 0100  /* Not fcntl.  */
+#define O_EXCL 0200   /* Not fcntl.  */
+#define O_NOCTTY 0400 /* Not fcntl.  */
+#define O_TRUNC 01000 /* Not fcntl.  */
+#define O_APPEND 02000
+#define O_DIRECTORY 0200000 /* Must be a directory.  */ 
+#define O_NOFOLLOW 0400000 /* Do not follow links.  */
+#define O_SYNC 04010000
+#define O_CLOEXEC 02000000 /* Set close_on_exec.  */
+
+    uint32_t flags;
+    const struct file_operations	*ops;
+
+    int (*duplicate)(struct file *this, const struct process *for_owner,
+                     struct file **result);
+
+    void *custom;
+};
+
+int fsRegister(struct file_system *fs);
+
 int fsInodeUnref(struct inode *inode);
 int fsInodeRef(struct inode *inode);
diff --git a/core/main.c b/core/main.c
index 24312a5..0786309 100644
--- a/core/main.c
+++ b/core/main.c
@@ -7,7 +7,6 @@
 #include "gdt.h"
 #include "idt.h"
 #include "interrupt.h"
-#include "io.h"
 #include "irq.h"
 #include "kernel.h"
 #include "keyboard.h"
@@ -20,7 +19,6 @@
 #include "process.h"
 #include "serial.h"
 #include "stack.h"
-#include "stdarg.h"
 #include "swintr.h"
 #include "thread.h"
 #ifdef RUN_TEST
@@ -42,7 +40,6 @@ void idleThread(void *arg)
     }
 }
 
-
 #define FILE_HEADER_SIZE   16
 #define FILE_MAX_SIZE   64 // In nb of sectors
 void loadUserSpace()
@@ -54,7 +51,7 @@ void loadUserSpace()
         return;
     }
 
-    char *buf = malloc(FILE_MAX_SIZE * DISK_SECTOR_SIZE);
+    char *buf = (char *)malloc(FILE_MAX_SIZE * DISK_SECTOR_SIZE);
     if (buf == NULL) {
         printf("ENOMEM\n");
         return;