diff --git a/kernel/trunk/docs/sysfuncr.txt b/kernel/trunk/docs/sysfuncr.txt
index ac50580ef1..d3be6b0f31 100644
--- a/kernel/trunk/docs/sysfuncr.txt
+++ b/kernel/trunk/docs/sysfuncr.txt
@@ -1794,6 +1794,23 @@ dd 1675
   * При создании процесса/потока текущая папка наследуется от
     родителя.
 
+---- Подфункция 3 - установить доп. системную директорию для ядра ----
+Параметры:
+  * eax = 30 - номер функции
+  * ebx = 3 - номер подфункции
+  * ecx = указатель на блок данных:
+          sysdir_name     rb 64
+          sysdir_path     rb 64
+Пример:  
+dir_name1       db 'addappl',0
+                rb 64-8
+dir_path1       db 'HD0/1',0
+                rb 64-6
+Возвращаемое значение:
+  * функция не возвращает значения
+Замечания:
+  * Функция может быть вызвана только 1 раз за 1 сессию работы ОС.
+
 ======================================================================
 ========= Функция 34 - узнать кому принадлежит точка экрана. =========
 ======================================================================
diff --git a/kernel/trunk/docs/sysfuncs.txt b/kernel/trunk/docs/sysfuncs.txt
index 24c14f53e8..8218b8a96f 100644
--- a/kernel/trunk/docs/sysfuncs.txt
+++ b/kernel/trunk/docs/sysfuncs.txt
@@ -1776,6 +1776,23 @@ Remarks:
   * At process/thread creation the current folder will be inherited
     from the parent.
 
+--- Subfunction 3 - install the add.system directory for the kernel --
+Parameters:
+  * eax = 30 - function number
+  * ebx = 3 - subfunction number
+  * ecx = pointer to a block of data:
+          sysdir_name     rb 64
+          sysdir_path     rb 64
+For example:  
+dir_name1       db 'addappl',0
+                rb 64-8
+dir_path1       db 'HD0/1',0
+                rb 64-6
+Returned value:
+  * function does not return value
+Remarks:
+  * The function can be called only 1 time for 1 session of the OS.
+
 ======================================================================
 ========= Function 34 - who owner the pixel on the screen. ===========
 ======================================================================
diff --git a/kernel/trunk/fs/fs_lfn.inc b/kernel/trunk/fs/fs_lfn.inc
index 61d5265005..213613204c 100644
--- a/kernel/trunk/fs/fs_lfn.inc
+++ b/kernel/trunk/fs/fs_lfn.inc
@@ -934,6 +934,12 @@ biosdisk_enum_root:
         ret
 
 process_replace_file_name:
+; in
+; esi - path with filename(f.70)
+;
+; out
+; ebp - full filename
+
         mov     ebp, [full_file_name_table]
         mov     edi, [full_file_name_table.size]
         dec     edi
@@ -975,6 +981,10 @@ process_replace_file_name:
 .ret:
         ret
 
+uglobal
+lock_flag_for_f30_3 rb 1
+endg
+        
 sys_current_directory:
 ;       mov     esi, [current_slot]
 ;       mov     esi, [esi+APPDATA.cur_dir]
@@ -988,7 +998,42 @@ sys_current_directory:
         jz      .set
         dec     ebx
         jz      .get
+        dec     ebx
+        jz      .mount_additional_directory
         ret
+
+.mount_additional_directory:
+; sysfunction 30.2: [for app] eax=30,ebx=3,ecx->dir name+dir path (128)
+; for our code: nothing
+
+; check lock of the function
+        cmp     [lock_flag_for_f30_3], 1
+        je      @f
+        
+        mov     esi, ecx
+        mov     edi, sysdir_name1
+; copying fake directory name
+        mov     ecx, 63
+        cld
+        rep     movsb
+; terminator of name, in case if we get the inlet trash
+        inc     esi
+        xor     eax, eax
+        stosb
+; copying real directory path for mounting
+        mov     ecx, 63
+        rep     movsb
+; terminator of name, in case if we get the inlet trash
+        xor     eax, eax
+        stosb
+; increase the pointer of inputs for procedure "process_replace_file_name"        
+        mov     [full_file_name_table.size], 2
+; block the ability to call f.30.3 because for one session is necessary
+; for us only once
+        mov     [lock_flag_for_f30_3], 1
+@@:
+        ret
+        
 .get:
 ; sysfunction 30.2: [for app] eax=30,ebx=2,ecx->buffer,edx=len
 ; for our code: ebx->buffer,ecx=len
diff --git a/kernel/trunk/fs/parse_fn.inc b/kernel/trunk/fs/parse_fn.inc
index b959e053ed..f25dea6edf 100644
--- a/kernel/trunk/fs/parse_fn.inc
+++ b/kernel/trunk/fs/parse_fn.inc
@@ -32,6 +32,17 @@ uglobal
 ; Parser_params will initialize: sysdir_name = "sys", sysdir_path = <sysdir>
 sysdir_name     rb      64
 sysdir_path     rb      64
+sysdir_name1    rb      64
+sysdir_path1    rb      64
+
+; for example:
+;dir_name1      db 'addappl',0
+;               rb 64-8
+;dir_path1      db 'HD0/1',0
+;               rb 64-6
+endg
+
+uglobal
 tmp_file_name_table dd  ?
 endg