diff --git a/apps/Makefile b/apps/Makefile
index 308b541..d372c9e 100644
--- a/apps/Makefile
+++ b/apps/Makefile
@@ -1,10 +1,10 @@
 default: Makefile
 	make -r -C libs
 	make -r -C init
-	make -r -C base_service
+	make -r -C shell
 
 clean:
 	rm ../isodir/apps/*
 	make -r -C libs clean
 	make -r -C init clean
-	make -r -C base_service clean
\ No newline at end of file
+	make -r -C shell clean
\ No newline at end of file
diff --git a/apps/base_service/service.c b/apps/base_service/service.c
deleted file mode 100644
index 0233207..0000000
--- a/apps/base_service/service.c
+++ /dev/null
@@ -1,6 +0,0 @@
-#include "../include/stdio.h"
-
-int main(){
-    while (1);
-    return 0;
-}
\ No newline at end of file
diff --git a/apps/include/syscall.h b/apps/include/syscall.h
index bbdc2a1..58326ed 100644
--- a/apps/include/syscall.h
+++ b/apps/include/syscall.h
@@ -7,6 +7,7 @@
 #define SYSCALL_MALLOC 4
 #define SYSCALL_FREE 5
 #define SYSCALL_EXIT 6
+#define SYSCALL_G_CLEAN 7
 
 #include <stdint.h>
 #include <stddef.h>
@@ -17,5 +18,6 @@ char syscall_getc();
 void* syscall_malloc(size_t size);
 void syscall_free(void *ptr);
 void syscall_exit(int code);
+void syscall_g_clean();
 
 #endif
diff --git a/apps/init/init.c b/apps/init/init.c
index 5baf018..35e9af4 100644
--- a/apps/init/init.c
+++ b/apps/init/init.c
@@ -1,9 +1,5 @@
 #include "../include/stdio.h"
 
-void hlt(){
-    while (1);
-}
-
 int main(){
     printf("User application %d\n",12);
     return -1;
diff --git a/apps/libs/syscall.c b/apps/libs/syscall.c
index 80bf9d8..07b5a09 100644
--- a/apps/libs/syscall.c
+++ b/apps/libs/syscall.c
@@ -39,6 +39,10 @@ void syscall_exit(int code){
     uint32_t rets;
     uint32_t __arg1 = (uint32_t)(code);
     register uint32_t ebx asm("ebx")  = __arg1;
-    asm volatile("int $31\n\t" : "=a"(rets) : "0"(SYSCALL_EXIT), "r"(ebx)  : "memory", "cc");
-    return rets;
+    asm volatile("int $31\n\t" : "=a"(rets) : "0"(SYSCALL_EXIT), "r"(ebx)  : "memory", "cc");\
+}
+
+void syscall_g_clean(){
+    uint32_t rets;
+    asm volatile("int $31\n\t" : "=a"(rets) : "0"(SYSCALL_G_CLEAN) : "memory", "cc");
 }
\ No newline at end of file
diff --git a/apps/base_service/Makefile b/apps/shell/Makefile
similarity index 67%
rename from apps/base_service/Makefile
rename to apps/shell/Makefile
index 0ec2c6d..ae03727 100644
--- a/apps/base_service/Makefile
+++ b/apps/shell/Makefile
@@ -1,8 +1,8 @@
-OBJS_PACK = out/service.obj
+OBJS_PACK = out/shell.obj
 include ../def.mk
 
 default: $(OBJS_PACK)
-	$(LINK) $(OBJS_PACK) $(BASIC_LIB_C) -o ../../isodir/apps/service.bin
+	$(LINK) $(OBJS_PACK) $(BASIC_LIB_C) -o ../../isodir/apps/shell.bin
 out/%.obj : %.c Makefile
 	$(C) -c $*.c -o out/$*.obj
 out/%.obj : %.cpp Makefile
diff --git a/apps/shell/shell.c b/apps/shell/shell.c
new file mode 100644
index 0000000..5c79966
--- /dev/null
+++ b/apps/shell/shell.c
@@ -0,0 +1,11 @@
+#include <stdio.h>
+#include "../include/syscall.h"
+
+int main(){
+    syscall_g_clean();
+    printf("CoolPotOS UserShell v0.0.1\n");
+    while (1){
+
+    }
+    return 0;
+}
\ No newline at end of file
diff --git a/src/fs/fat.c b/src/fs/fat.c
index 801e9ca..8eea678 100644
--- a/src/fs/fat.c
+++ b/src/fs/fat.c
@@ -25,6 +25,7 @@ static inline int get_fat_time(unsigned short hour, unsigned short minute) {
     time |= (minute & 0x3f) << 5;
     return time;
 }
+
 void read_fat(unsigned char *img, int *fat, unsigned char *ff, int max,
               int type) {
     if (type == 12) {
diff --git a/src/fs/vfs.c b/src/fs/vfs.c
index b9548da..7155b61 100644
--- a/src/fs/vfs.c
+++ b/src/fs/vfs.c
@@ -9,9 +9,9 @@
 #include "../include/fat.h"
 #include "../include/iso9660.h"
 
+char root_disk = 'A';
 vfs_t vfsstl[26];
 vfs_t vfsMount_Stl[26];
-vfs_t *vfs_now;
 bool hasFS;
 
 static vfs_t *drive2fs(uint8_t drive) {
@@ -24,7 +24,7 @@ static vfs_t *drive2fs(uint8_t drive) {
 }
 
 static vfs_t *ParsePath(char *result) {
-    vfs_t *vfs_result = vfs_now;
+    vfs_t *vfs_result = get_current()->vfs_now;
     if (result[1] == ':') {
         if (!(vfs_result = drive2fs(result[0]))) {
             printf("Mount Drive is not found!\n");
@@ -154,7 +154,7 @@ uint32_t vfs_filesize(char *filename) {
 
 List *vfs_listfile(char *dictpath) { // dictpath == "" 则表示当前路径
     if (strcmp(dictpath, "") == 0) {
-        return vfs_now->ListFile(vfs_now, dictpath);
+        return get_current()->vfs_now->ListFile(get_current()->vfs_now, dictpath);
     } else {
         char *new_path = kmalloc(strlen(dictpath) + 1);
         strcpy(new_path, dictpath);
@@ -188,7 +188,7 @@ bool vfs_change_path(char *dictName) {
     memcpy(buf, dictName, strlen(dictName) + 1);
     int i = 0;
     if (buf[i] == '/' || buf[i] == '\\') {
-        if (!vfs_now->cd(vfs_now, "/")) {
+        if (!get_current()->vfs_now->cd(get_current()->vfs_now, "/")) {
             kfree(r);
             return false;
         }
@@ -199,14 +199,14 @@ bool vfs_change_path(char *dictName) {
     for (;; i++) {
         if (buf[i] == '/' || buf[i] == '\\') {
             buf[i] = 0;
-            if (!vfs_now->cd(vfs_now, buf)) {
+            if (!get_current()->vfs_now->cd(get_current()->vfs_now, buf)) {
                 kfree(r);
                 return false;
             }
             buf += strlen(buf) + 1;
         }
         if (buf[i] == 0) {
-            if (!vfs_now->cd(vfs_now, buf)) {
+            if (!get_current()->vfs_now->cd(get_current()->vfs_now, buf)) {
                 kfree(r);
                 return false;
             }
@@ -329,15 +329,15 @@ vfs_file *get_cur_file(char* filename){
     return file;
 }
 
-bool vfs_change_disk(uint8_t drive) {
-    if (vfs_now != NULL) {
-        while (FindForCount(1, vfs_now->path) != NULL) {
-            kfree(FindForCount(vfs_now->path->ctl->all, vfs_now->path)->val);
-            DeleteVal(vfs_now->path->ctl->all, vfs_now->path);
+bool vfs_change_disk(struct task_struct *task,uint8_t drive) {
+    if (task->vfs_now != NULL) {
+        while (FindForCount(1, task->vfs_now->path) != NULL) {
+            kfree(FindForCount(task->vfs_now->path->ctl->all, task->vfs_now->path)->val);
+            DeleteVal(task->vfs_now->path->ctl->all, task->vfs_now->path);
         }
-        kfree(vfs_now->cache);
-        DeleteList(vfs_now->path);
-        kfree(vfs_now);
+        kfree(task->vfs_now->cache);
+        DeleteList(task->vfs_now->path);
+        kfree(task->vfs_now);
     }
 
     vfs_t *f;
@@ -345,11 +345,11 @@ bool vfs_change_disk(uint8_t drive) {
         return false; // 没有mount
     }
 
-    vfs_now = kmalloc(sizeof(vfs_t));
-    memcpy(vfs_now, f, sizeof(vfs_t));
-    f->CopyCache(vfs_now, f);
-    vfs_now->path = NewList();
-    vfs_now->cd(vfs_now, "/");
+    task->vfs_now = kmalloc(sizeof(vfs_t));
+    memcpy(task->vfs_now, f, sizeof(vfs_t));
+    f->CopyCache(task->vfs_now, f);
+    task->vfs_now->path = NewList();
+    task->vfs_now->cd(task->vfs_now, "/");
     return true;
 }
 
@@ -357,12 +357,12 @@ void vfs_getPath(char *buffer) {
     char *path;
     List *l;
     buffer[0] = 0;
-    insert_char(buffer, 0, vfs_now->drive);
+    insert_char(buffer, 0, get_current()->vfs_now->drive);
     insert_char(buffer, 1, ':');
     insert_char(buffer, 2, '\\');
     int pos = strlen(buffer);
-    for (int i = 1; FindForCount(i, vfs_now->path) != NULL; i++) {
-        l = FindForCount(i, vfs_now->path);
+    for (int i = 1; FindForCount(i, get_current()->vfs_now->path) != NULL; i++) {
+        l = FindForCount(i, get_current()->vfs_now->path);
         path = (char *)l->val;
         insert_str(buffer, path, pos);
         pos += strlen(path);
@@ -378,8 +378,8 @@ void vfs_getPath_no_drive(char *buffer) {
     buffer[0] = 0;
     int pos = strlen(buffer);
     int i;
-    for (i = 1; FindForCount(i, vfs_now->path) != NULL; i++) {
-        l = FindForCount(i, vfs_now->path);
+    for (i = 1; FindForCount(i, get_current()->vfs_now->path) != NULL; i++) {
+        l = FindForCount(i, get_current()->vfs_now->path);
         path = (char *)l->val;
         insert_char(buffer, pos, '/');
         pos++;
@@ -401,7 +401,7 @@ void init_vfs() {
         vfsMount_Stl[i].drive = 0;
         // PDEBUG("Set vfsstl[%d] & vfsMount_Stl[%d] OK.", i, i);
     }
-    vfs_now = NULL;
+    get_current()->vfs_now = NULL;
     klogf(true,"Virtual File System initialize.\n");
     Register_fat_fileSys();
     init_iso9660();
diff --git a/src/include/common.h b/src/include/common.h
index f4c8a5d..0ca613c 100644
--- a/src/include/common.h
+++ b/src/include/common.h
@@ -2,7 +2,7 @@
 #define CRASHPOWEROS_COMMON_H
 
 #define OS_NAME "CoolPotOS"
-#define OS_VERSION "v0.2.9"
+#define OS_VERSION "v0.3.0"
 
 // b 0x211972
 // b 0x20d0a6
diff --git a/src/include/syscall.h b/src/include/syscall.h
index 8c1db53..d590426 100644
--- a/src/include/syscall.h
+++ b/src/include/syscall.h
@@ -11,6 +11,7 @@
 #define SYSCALL_MALLOC 4
 #define SYSCALL_FREE 5
 #define SYSCALL_EXIT 6
+#define SYSCALL_G_CLEAN 7
 
 void syscall_install();
 
diff --git a/src/include/task.h b/src/include/task.h
index ee06294..53cf7b6 100644
--- a/src/include/task.h
+++ b/src/include/task.h
@@ -43,6 +43,7 @@ struct task_struct {
     void *stack;                  // 进程的内核栈地址
     header_t *head;               // 进程堆
     header_t *tail;
+    vfs_t *vfs_now;               // 文件路径焦点
     bool isUser;                  // 是否是用户进程
     uint32_t program_break;       // 进程堆基址
     uint32_t program_break_end;   // 进程堆尾
diff --git a/src/include/vfs.h b/src/include/vfs.h
index 4597cd0..cc50470 100644
--- a/src/include/vfs.h
+++ b/src/include/vfs.h
@@ -67,7 +67,10 @@ bool vfs_renamefile(char *filename, char *filename_of_new);
 bool vfs_attrib(char *filename, ftype type);
 bool vfs_format(uint8_t disk_number, char *FSName);
 vfs_file *vfs_fileinfo(char *filename);
-bool vfs_change_disk(uint8_t drive);
+
+#include "task.h"
+
+bool vfs_change_disk(struct task_struct *task,uint8_t drive);
 bool vfs_register_fs(vfs_t vfs);
 void init_vfs();
 vfs_file *get_cur_file(char* filename);
diff --git a/src/kernel/kernel.c b/src/kernel/kernel.c
index 3ae5ad5..2c4504f 100644
--- a/src/kernel/kernel.c
+++ b/src/kernel/kernel.c
@@ -116,7 +116,9 @@ void kernel_main(multiboot_t *multiboot) {
     }
     hasFS = false;
     if(disk_id != '0'){
-        if(vfs_change_disk(disk_id)){
+        if(vfs_change_disk(get_current(),disk_id)){
+            extern char root_disk;
+            root_disk = disk_id;
             klogf(true,"Chang default mounted disk.\n");
             hasFS = true;
         }
@@ -135,13 +137,13 @@ void kernel_main(multiboot_t *multiboot) {
 
     clock_sleep(25);
 
-    vfs_change_path("apps");
-    //klogf(user_process("service.bin","Service") != -1,"Service base process init.\n");
-    klogf(user_process("init.bin","Init") != -1,"Init base process init.\n");
+    //vfs_change_path("apps");
+    //klogf(user_process("shell.bin","Shell") != -1,"Shell process init.\n");
+    //klogf(user_process("init.bin","Init") != -1,"Init base process init.\n");
 
-    //int pid = kernel_thread(setup_shell,NULL,"CPOS-Shell");
-    //klogf(pid != -1,"Launch kernel shell.\n");
-    //kernel_thread(check_task,&pid,"CPOS-CK");
+    int pid = kernel_thread(setup_shell,NULL,"CPOS-Shell");
+    klogf(pid != -1,"Launch kernel shell.\n");
+    kernel_thread(check_task,&pid,"CPOS-CK");
 
     //panic_pane("System out of memory error!",OUT_OF_MEMORY);
 
diff --git a/src/kernel/syscall.c b/src/kernel/syscall.c
index 99cee4b..70b38e2 100644
--- a/src/kernel/syscall.c
+++ b/src/kernel/syscall.c
@@ -37,6 +37,10 @@ static void syscall_free(uint32_t ebx,uint32_t ecx,uint32_t edx,uint32_t esi,uin
     use_free(get_current(),ebx);
 }
 
+static void syscall_g_clean(uint32_t ebx,uint32_t ecx,uint32_t edx,uint32_t esi,uint32_t edi){
+     screen_clear();
+}
+
 void *sycall_handlers[MAX_SYSCALLS] = {
         [SYSCALL_PUTC] = syscall_puchar,
         [SYSCALL_PRINT] = syscall_print,
@@ -44,6 +48,7 @@ void *sycall_handlers[MAX_SYSCALLS] = {
         [SYSCALL_MALLOC] = syscall_malloc,
         [SYSCALL_FREE] = syscall_free,
         [SYSCALL_EXIT] = syscall_exit,
+        [SYSCALL_G_CLEAN] = syscall_g_clean,
 };
 
 typedef size_t (*syscall_t)(size_t, size_t, size_t, size_t, size_t);
diff --git a/src/kernel/task.c b/src/kernel/task.c
index ece4bc4..0d77e23 100644
--- a/src/kernel/task.c
+++ b/src/kernel/task.c
@@ -216,6 +216,9 @@ int32_t user_process(char *path, char *name){ // 用户进程创建
     new_task->name = name;
     new_task->isUser = 1;
 
+    extern char root_disk;
+    vfs_change_disk(new_task,root_disk);
+
     io_sti();
 
     page_switch(page);
diff --git a/src/sysapp/shell.c b/src/sysapp/shell.c
index 4775e08..c5b0601 100644
--- a/src/sysapp/shell.c
+++ b/src/sysapp/shell.c
@@ -303,7 +303,7 @@ void cmd_disk(int argc, char **argv) {
                 return;
             }
             if(have_vdisk(argv[2][0])){
-                vfs_change_disk(argv[2][0]);
+                vfs_change_disk(get_current(),argv[2][0]);
             } else printf("[DISK]: Cannot found disk.\n");
             return;
         }
@@ -386,6 +386,9 @@ void setup_shell() {
     int argc = -1;
     char *buffer[255];
 
+    extern char root_disk;
+    vfs_change_disk(get_current(),root_disk);
+
     while (1) {
         if(hasFS) vfs_getPath(buffer);
         else{