 6  
-----------------------------------------------------------------

 室  ࠡ  ⨧筮 ०. ।⢠
   ᯮ짮  ।饭 
ﭨ ६ 믮塞 . ਬ, 
믮   ࠭  祩   
㣮 .

 ࠧࠡ⪥ ணࠬ 堭    
 ⨭ ணࠬ 訡.  ணࠬ 믮
 뫪  ⨬    
, 堭   ஢  ᮡ⨥ 
ᮮ  .

 ⥬, ।祭   짮⥫ 堭
  ।࠭ ⥬  ணࠬ ᡮ,
뢠 묨 訡  ணࠬ.  ᡮ 
ணࠬ ⢨  ࠭ ⠪ ࠧ  
࠭祭  . 樮 ⥬  ⮬ 
 饭  襭  ⥩,  
ॣ஢ ᪮ ᮮ饭  訡  ᤥ
 ⮬᪮ ⠭ ணࠬ.

  ਬ  ᥣ⠬  ࠭栬 . 
 ॣ  । ஢ ਢ஢
⥪饩 믮塞 ணࠬ ( ஢ 뢠 ⥪騬
஢ ਢ஢,  CPL).  ६ ࠭樨
  㯠  ᥣ  ࠭ 믮 ஢ઠ
CPL.

  몫祭 堭  ᯥ樠쭮 ࠢ饣
ॣ   ०  ।ᬮ७,   䥪 
, 稢 ஢ ਢ஢ 0 ( 訩
஢ ਢ஢) ᥬ ᥫࠬ ᥣ⮢,
ਯࠬ ᥣ⮢  ⠬ ࠭筮 ⠡.

6.1    ஢ ᥣ⮢
-----------------------------------------------------------------

堭   ࠭ ﭨ ࠢ쭮
ࠡ饩 ணࠬ  㣨 믮塞 ணࠬ  
.  ।⠢ ᮡ 業 ᢮⢮  ࠧࠡ⪥
ணࠬ த⮢, ᪮  ᯥ稢 ࠭ 
    । ࠧࠡ⪨ ணࠬ
ᯥ祭 (樮 ⥬, ⫠稪).  ᡮ 
ਪ ணࠬ   ࠢ ࠭
ணࠬ ᯥ祭, 饥 뤠 ᪨
ᮮ饭,  ⫠稪   ந "ᬥ"
 ᮤন   ॣ஢ ᡮ ணࠬ. 
⥬, ᯫ ⮢ ணࠬ ᯥ祭,
       
樨஢ ⠭⥫ 楤  ⥬.

 뫪   ஫  窨 ७
㤮⢮७  ஢ઠ.  ஢ન 믮 
砫 横 饭  ;  襭 
। 砫 横 㯠    
᪫祭. ᪮ ஢ન  믮 ࠫ쭮 
࠭樥 ,     ࠪ⨪
த⢨ ⥬.   ஢ப:

     1. ஢ઠ ⨯
     2. ஢ઠ ࠭
     3. ࠭祭 㥬 
     4. ࠭祭 祪 室  楤
     5. ࠭祭  

襭    樨 ᪫祭. 堭
᪫祭 ᠭ   9.    ᠭ 襭
 , 騥  樨 ᪫祭.

6.2  ਯ ᥣ  
-----------------------------------------------------------------

 㭪 6-1   ਯ ᥣ, ᯮ㥬
堭 . ⤥     
믮塞  㭪.

ࠬ    ਯ   ᮧ. 
楫, ਪ ணࠬ⠬  ࠬ  
ॡ.


               ਯ ᥣ 

                       2 1 1 1 1 1 1 1 1 1 1
31                     0 9 8 7 6 5 4 3 2 1 0 9 8 7            0
----------------------------------------------------------------
|               | | | | |       | | D | | | | | |              |
| BASE  31:24   | | | | |LIMIT  | | P |1|0|E|W|A|  BASE 23:16  | +4
|               | | | | |19:16  | | L | | | | | |              |
|--------------------------------------------------------------|
|       ᥣ 15:00      |    ࠭ ᥣ 15:00    | +0
----------------------------------------------------------------

               ਯ ᥣ 

                       2 1 1 1 1 1 1 1 1 1 1
31                     0 9 8 7 6 5 4 3 2 1 0 9 8 7            0
----------------------------------------------------------------
|               | | | | |       | | D | | | | | |              |
| BASE  31:24   | | | | |LIMIT  | | P |1|1|C|R|A|  BASE 23:16  | +4
|               | | | | |19:16  | | L | | | | | |              |
|--------------------------------------------------------------|
|       ᥣ 15:00      |    ࠭ ᥣ 15:00    | +0
----------------------------------------------------------------


A          ந襫
C         ଭ
DPL       ஢ ਢ஢ ਯ
E         ७ 
R         㯭  ⥭
LIMIT     ࠭ ᥣ
W         㯭  

     㭮 6-1.  ਯ, ᯮ㥬  
                         ( 1  2)


               ਯ ⥬ ᥣ

                       2 1 1 1 1 1 1 1 1 1 1
31                     0 9 8 7 6 5 4 3 2 1 0 9 8 7            0
----------------------------------------------------------------
|               | | | | |       | | D | |       |              |
| BASE  31:24   | | | | |LIMIT  | | P |0|    |  BASE 23:16  | +4
|               | | | | |19:16  | | L | |       |              |
|--------------------------------------------------------------|
|       ᥣ 15:00      |    ࠭ ᥣ 15:00    | +0
----------------------------------------------------------------


DPL       ஢ ਢ஢ ਯ
LIMIT     ࠭ ᥣ

     㭮 6-2.  ਯ, ᯮ㥬  
                         ( 2  2)

 ணࠬ 㦠  ᥣ ॣ ᥫ
ᥣ,  ⮬᪨ 㦠 㤠  
⮣ ᥣ  ଠ   .  
 ᥣ⭮ ॣ ࠭  , ࠭, ⨯
 ஢ ਢ஢.  ⮬,  
ଠ १⭮ 室  ᥣ⭮ ॣ, 
᫥騥 ஢ન   ⮣ ॣ  
믮  ⥫  ६   .

6.2.1  ஢ઠ ⨯
-----------------------------------------------------------------

 ਯ஢  ᥣ⮢    ਪ
ணࠬ,  i486  ਯ  ⥬
ᥣ⮢  .   , ᯮ㥬 
࣠樨 믮  ( 7), ⠪ ᪫祭 
뢠 ( 9).   6-1 ᫥  ⨯,
।  ⥬ ᥣ⮢  . ⬥⨬,  
 ਯ । ᥣ: ਯ  ᮤঠ
窨 室  楤.

  ਯ஢ ᥣ⮢      ᥡ
,  ஡ ।騥 祭 ᥣ (.
㭮 6-1):

-  "㯭  "  ਯ ᥣ 
  ࠢ  믮   ணࠬ  
  ᥣ.

-  "㯭  ⥭" ਯ 믮塞 ᥣ
    믮 ⥭ ணࠬ  
  ᥣ (ਬ  㯠  ⠭⠬, ᠭ
  ।⢥   ). 㯭  ⥭
  믮塞 ᥣ   ⠭  ᯮᮡ:

     1.   ॣ CS, ᯮ 䨪 ८।
        ᥣ CS.
     2.   㧪 ᥫ   ਯ 
        ॣ ᥣ  (DS, ES, FS  GS).

          6-1.  ⥬ ᥣ⮢  

-----------------------------------------------------------------
                                  ᠭ
-----------------------------------------------------------------
      0         ࢨ
      1         㯭 ᥣ ﭨ  (TSS) 80286
      2         LDT
      3          ᥣ ﭨ  (TSS) 80286
      4          맮
      5          
      6          뢠 80286
      7          襪 80286
      8         ࢨ
      9         㯭 TSS  i486
     10         ࢨ
     11          TSS  i486
     12          맮  i486
     13         ࢨ
     14          뢠  i486
     15            i486
-----------------------------------------------------------------

஢ઠ ⨯  ᯮ짮  । ணࠬ
訡,   ⪥ ᯮ짮 ᥣ⮢ ᯮᮡ, 
ࠧ㬥訬 ணࠬ⮬.  ᬠਢ
ଠ  ⨯    :

     1.  ᥫ  ਯ 㦠  ᥣ
        ॣ.  ᥣ ॣ  ᮤঠ
        ⮫쪮  ⨯ ਯ஢; ਬ:

        -  CS   㦥 ⮫쪮 ᥫ஬
          믮塞 ᥣ.

        -  믮塞 ᥣ⮢,  騥
          "㯭묨  ⥭",    㦥 
          ॣ ᥣ⮢ .

        -  ॣ SS   㦥 ⮫쪮 ᥫ
          ᥣ⮢ , "㯭  ".

     2.  ᥣ  ᯮ짮 
        ⮫쪮 묨, ।।묨 ᯮᮡ;
        ਬ:

        -     믮  
          믮塞 ᥣ.

        -     믮   ᥣ
          , ᫨    ⠭  "㯥 
          ".

        -     믮 ⥭
          믮塞 ᥣ, ᫨    ⠭ 
          "㯥  ⥭".

6.2.2  ஢ઠ ࠭
-----------------------------------------------------------------

 ࠭ ਯ ᥣ   ணࠬ 믮
  ᥣ. 饥 祭 ࠭  
⠭  G ( ࠭樨).  ᥣ⮢  ࠭
⠪    E ( ࠢ ७ ᥣ). 
⢥  E 砥   ⮢    뫪
 ਯࠬ ᥣ⮢ .

       G 饭, ࠭ ᥣ ࠢ 祭
20-ࠧ來  ࠭ ਯ.  ⮬ 砥 ࠭
     0  0FFFFFH (2**20-1,  1
). ᫨  G ⠭,   㬭 祭
 ࠭  ⠡ 樥 2**12.  ⮬ 砥
࠭ 㤥     0FFFH (2**12-1,  4K),
 0FFFFFFFFH (2**32-1,  4 ).⬥⨬,  
ᯮ짮 ⠪ ⠡஢, ஢ઠ ࠭ 
 12 ⮢   믮;   G ⠭,
 ࠭ ᥣ ࠢ 0, ⨬ 祭 ᬥ饭 
ᥣ     0  4095.

  ⨯ ᥣ⮢,  ᪫祭 ᥣ⮢, 塞
 (.. ⥪ ᥣ⮢), 祭 ࠭  
 ࠧ ᥣ  .  
᪫祭 饩     ᫥ 砥:

     - ⪠ 㯠     , ॢ饬
       ࠭ ᥣ.
     - ⪠ 㯠  ᫮   , ॢ饬
       ࠭ ᥣ - 1.
     - ⪠ 㯠   ᫮   ,
       ॢ饬 ࠭ ᥣ - 3.

      ᥣ⮢,  , ࠭ 㦨  ⮩
 㭪樨 ஢ન,   .  ⮬ 砥
 ⨬ 祭  ।  (࠭+1)
 2** 32-1.   ७   ᨬ
ࠧ  祭 ࠭, ࠢ 0.

஫ ࠭  ⫠ ⠪ ணࠬ 訡,
 ୮ ᫥  ᨢ  ⨬
㪠⥫.  訡 । ࠧ ,  ⮫쪮 
ந諨, ⮬ 䨪 맢襩  稭
⢥ 頥.  ⠪ ஫ ࠭ 㪠
訡   ᫥⢨ ࠧ襭  ⥩ 
 㣨 ,   ⢮  㦨, 
 ந ᡮ  ᯮ祭 ⠪ ࠧ 㫥,  ⠪
ᮡ⨥  㯨  , 祬 䠪᪠ 맢
 訡.   ஢ ⠪ 訡  ᮮ
  筨.

        ஢થ ࠭ ᥣ⮢  ⠪
஢ઠ ࠭ ⠡ ਯ஢.  GDTR  IDTR
ᮤঠ 16-ࠧ來 祭 ࠭.  ᯮ
஬   ணࠬ  롮 ਯ ᥣ
 , 饩   ⠡. ࠭ ⠡
ਯ஢  ᫥ ⨬  ⮩
⠡. ᪮  ਯ   ᥬ ⮢,
⠡, ᮤঠ  N ਯ஢,   祭
࠭, ࠢ 8N-1.

ਯ    㫥 祭.  ⭮ 
ࢮ ਯ  ⠡ GDT,   ᯮ. 
 ਯ   㦥  ᥣ ॣ, 
⪠ 뫪     ⮣ ਯ ਢ 
樨 ᪫祭 饩 .

6.2.3  ஢ ਢ஢
-----------------------------------------------------------------

     堭  ᯮ  ஢ ਢ஢,
㬥㥬  0  3.   , ⥬  ஢
ਢ஢.  㤮⢮७   ஢ப
 ᪫祭 饩    ⪥
ணࠬ 㯠  ᥣ  訬 ஢
ਢ஢ (..  訬 ᫮, 騬 ஢),
祬   ᥣ.

  ⬥ 堭   ࠢ饣 ॣ
  ०  ।ᬮ७, ⮣  䥪 
⨣ ⥬ ᢮ ᥬ ஢ ਢ஢
祭 0. ( PE ॣ CR0   ࠧ騬 ⮬
ᮡ⢥  堭 ;  ᯮ  祭
"饭 ०", ० 믮 ணࠬ,  ஬
㯭   32-ࠧ來 ⥪  
楫. ᫨ 饭 ० 몫祭,   ࠡ⠥ 
० "ॠ ᮢ",   ॠ 
饣  ᮪ த⢨  襭
 8086).

஢ ਢ஢  ᯮ짮  襭
 樮 ⥬.  砥 ᢮
樮 ⥬ 襣 ஢ ਢ஢ 
⠭ 饭  ᡮ  砥 訡  㣨
ணࠬ.  ⠪ ணࠬ ᡮ 樮 ⥬
  ᣥ஢ ᮮ⢥騥 ᪨
ᮮ饭   믮 ⠭⥫ 楤.

騩 ஢ ਢ஢   ⠭ 
㣨 ⥩ ணࠬ ᯥ祭, ⠪  ணࠬ,
ࠢ騥 ਩묨 ன⢠,  뢠
ࠩࠬ ன.  ᡮ  ࠩ ன⢠
樮 ⥬    뤠
᪮ ᮮ饭, ⮬   
樮 ⥬   ᡮ ࠩ஢ ன.
, ࠩ ன⢠  ࠡ   ਩
㤮, ਬ  ᪮.  ਪ ணࠬ
  ਢ  ࠧ襭  ४਩  ᪥,
⮬    ࠩ ன  ᡮ
ਪ ணࠬ. ࠩ ன   ஢
ਢ஢ ஬,  樮 ⥬ 
ਪ묨 ணࠬ. ਪ ணࠬ ᢠ
ᠬ  ஢ ਢ஢.

 㭪 6-2 ,   ஢ ਢ஢
  ஢  ⢥  . ࠫ쭮
  ᮤন ᥣ,   室 
 ணࠬ ᯥ祭, 筮  樮 ⥬.
稥  ᯮ    ணࠬ
ᯥ祭.

஢ ਢ஢ ࠭  ᫥ 
:

     -    ᥣ⭮ ॣ CS ᮤঠ ⥪騩
       ஢ ਢ஢ (CPL).  ஢
       ਢ஢ 믮塞  ⥪騩 
       ணࠬ. 訥   ॣ SS ⠪ ᮤঠ
        CPL. 筮 CPL ࠢ ஢ ਢ஢
        ᥣ,  ண ந室 롮ઠ 
       ணࠬ. CPL   । ࠢ
        ᥣ  㣨 ஢ ਢ஢.

     - ਯ ᥣ ᮤঠ , ஥ 뢠
       ஢ ਢ஢ ਯ (DPL). DPL
       ।⠢ ᮡ ஢ ਢ஢
       ਬ⥫쭮  ᥣ.

     -  ᥣ ᮤঠ , ஥ 뢠
       襭 ஢ ਢ஢ (RPL) RPL
       ।⠢ ᮡ ஢ ਢ஢ 楤,
       ᮧ襩  ᥫ. ᫨ RPL  訩 ஢
       ਢ஢, 祬 CPL,   頥 CPL. 
        ਢ஢ ணࠬ ਭ ᥫ
       ᥣ   ਢ஢ ணࠬ, RPL
       뢠     訬 ஢
       ਢ஢.

஢ ਢ஢ ஢,  ᥫ
ਯ 㦠  ᥣ ॣ. ஢ન,
ᯮ㥬  㯠  , ⫨  ஢ப 
। 믮  믮塞묨 ᥣ⠬;
᫥⥫쭮,   ⨯ 㯠, ᬠਢ 
᫥ ࠧ  ⤥쭮.


                         
                             **
                         *        *
                             **
                    *    *        *    *
                             **
                  *   *   *      *   *    *

           *   *   *     * *     *   *   *
樮 -----------> *      *
⥬       *   *   *  *஢ 0*  *  *  *
                          *      *
               *   *   *     * *     *  *   *
ᯮ⥫ --------> ஢ 1
।⢠                 *         *
樮      *   *       **       *   *
⥬ (ࠩ ------> ஢ 2
ன  ..)   *    *         *     *
                              **
ਪ ணࠬ----> ஢ 3
                         *         *
                              **

                   㭮 6-2.  

6.3  ࠭祭 㯠  
-----------------------------------------------------------------

 樨 ࠭   ᥫ ᥣ  
 㦥  ॣ ᥣ  (ॣ DS, ES, FS, GS
 SS).  ஢ ஢ ਢ஢
ᥣ⮢. ஢ઠ 믮  㧪 ᥫ ᥣ.
   㭪 6-3,  ஢થ ਢ஢
⮣ ⨯   ࠧ ஢ ਢ஢.

 ஢塞 ஢ ਢ஢:

1. CPL (⥪騩 ஢ ਢ஢ ணࠬ). 
   ࠭     ॣ CS.
2. DPL (஢ ਢ஢ ਯ) ਯ
   ᥣ, ᮤঠ饣 ࠭.
3. RPL (஢ ਢ஢ 筨 ) 
   ᥫ, ᯮ㥬   ᥣ, ᮤঠ饣
   ࠭.  ஢ ࠭    
   ᥣ⭮ ॣ, ᯮ㥬  㯠  ࠭
   (ॣ SS, DS, ES, FS  GS). ᫨ ࠭ 室 
   ⥪ ᥣ,  RPL  CPL ᮢ.

               ਯ ᥣ, ᮤঠ饣 ࠭

                                   1 1
31                                 4 3           7            0
----------------------------------------------------------------
|               | | | | |       | | D | | | | | |              |
|               | | | | |       | | P | | | | | |              | +4
|               | | | | |       | | L | | | | | |              |
|--------------------------------------------------------------|
|                               |   |__________________        | +0
-------------------------------------------------------|--------
                                                       |
                騩  ᥣ ॣ     |
                                                       |
--------------------                                   |
|            | CPL |------------------------------     |
--------------------                              |    |
                 ᥣ, ᮤঠ饣    |    |
--------------------               ࠭        |    |
|            | RPL |-------------------------     |    |
--------------------                         |    |    |
                                             |    |    |
                                             \/   \/   \/
                                         ---------------------
                                         |      ஢ઠ     |
                                         |ਢ஢|
                                         ---------------------
CPL       騩 ஢ ਢ஢
DPL       ஢ ਢ஢ ਯ
RPL       襭 ஢ ਢ஢

 㭮 6-3. ஢ઠ ਢ஢  㯥  

  㦠 ᥣ ॣ ⮫쪮 ᫨ DPL
ᥣ  ⠪   訩 ஢ ਢ஢
(訩  ਢ஢), 祬  
ਢ஢ CPL  RPL ᥫ.

㥬       CPL. ᫨
CPL ࠢ 0,  ᥣ   ஢ ਢ஢
㯭;  CPL ࠢ 1,  㯭 ⮫쪮 ᥣ 
 ஢ﬨ ਢ஢  1  3;   CPL ࠢ 3,
 㯭 ⮫쪮 ᥣ   ஢ ਢ஢
3.

     ᥣ
-----------------------------------------------------------------

  ⥫ ࠭    ᥣ;
ਬ,   ,   ࠭  .  ᥣ
 ᪠ ࠭ ⠬ ⠭,  믮 
 ᥣ, ।  ⢥  ᥣ,
⨬, ᫨  ⮬  ᭮ ࠭⢥  ⮡ࠦ
ᥣ .  ᫥騥 ᯮᮡ 㯠   
 ᥣ:

1. 㧪  ॣ ᥣ  ᥫ ଭ,
   㯭  ⥭ 믮塞 ᥣ.

2. 㧪  ॣ ᥣ  ᥫ ଭ,
   㯭  ⥭ 믮塞 ᥣ.

3. ᯮ짮 䨪 ८। ᥣ  ⥭ 
   㯭  ⥭ 믮塞 ᥣ, ᥫ
   ண 㦥 㦥  ॣ CS.

  1 ਬ   ࠢ 㯠,    ᥣ
. 砩 2 ⨬ ᥣ, ᪮ ஢
ਢ஢  ᥣ  ⠭ ⮬
ଭ ⠪ ,   CPL, ᨬ   DPL. 砩
3 ⠪ ⨬ ᥣ, ᪮ DPL  ᥣ,
࠭   ॣ CS, ᮢ  CPL.

6.4  ࠭祭 । ࠢ
-----------------------------------------------------------------

  i486 । ࠢ 믮  JMP,
CALL, RET, INT  IRET,  ⠪ 堭 ᪫祭 
뢠. ᪫祭  뢠 -  ᮡ 砨  
ᬠਢ   9.     㦤 ⮫쪮
 JMP, CALL  RET.

""   JMP, CALL  RET । ࠢ 
। ᮤঠ饣   ᥣ,  ᫥⥫쭮,
 ⮫쪮 ஢ન ࠭ 室.  ஢,
⮡  祭  JMP, CALL  RET  室 
࠭ ⥪饣 ᥣ . ࠭   ॣ
CS, ⮬ ஢ઠ ࠭   室  ॡ
⥫  ६.

࠭ "쭨"   JMP  CALL 뫠  㣨
ᥣ, ⮬  믮 ஢
ਢ஢.   ᯮᮡ 뫪   JMP
 CALL  㣨 ᥣ:

1. ࠭ 롨ࠥ ਯ 㣮 믮塞 ᥣ.

2. ࠭ 롨ࠥ ਯ  맮.  ଠ
   । ࠢ  ᯮ짮 
   ᬠਢ   7.

   㭪 6-4,  ࠧ ஢
ਢ஢ 뢠 ஢ ਢ஢
। ࠢ  ᯮ짮  맮:

1. CPL (⥪騩 ஢ ਢ஢).

2. DPL ਯ  ᥣ 祭 室.

筮 CPL ࠢ DPL ᥣ, 믮塞 ஬ 
⥪騩 . CPL  , ,  (.. 
ਢ஢), 祬 DPL, ᫨ ⥪騩  ᥣ
 ଭ ᥣ⮬ (ଭ 㪠뢠  
 ᥣ⭮ ਯ). ଭ ᥣ 믮 
஢ ਢ஢ 뢠饩 楤.  
६  CPL  ॣ CS;  祭  
⫨  祭 DPL  ᥣ⭮ ਯ ⥪饣
 ᥣ.



               ਯ  ᥣ 祭 室

                                 1 1 1 1 1 1
31                               5 4 3 2 1 0 9 8 7            0
----------------------------------------------------------------
|               | | | | |       | | D |      |              |
|               | | | | |       | | P | | | | | |              | +4
|               | | | | |       | | L |1|1|C|R|A|              |
|--------------------------------------------------------------|
|                               |   |      |___________        |
|                               |   |_____________     |       | +0
--------------------------------------------------|----|--------
                                                  |    |
            騩  ᥣ ॣ    |    |
                                                  |    |
--------------------                              |    |
|            | CPL |--------------------------    |    |
--------------------                         |    |    |
                                             |    |    |
                                             \/   \/   \/
                                         ---------------------
                                         |      ஢ઠ     |
                                         |ਢ஢|
                                         ---------------------
C          ଭ
CPL       騩 ஢ ਢ஢
DPL       ஢ ਢ஢ ਯ

     㭮 6-4. ஢ઠ ਢ஢  ।
                   ࠢ  

 ࠧ蠥 । ࠢ  JMP  CALL
  㣮 ᥣ ⮫쪮  ⮬ 砥, ᫨ 믮
᫥騥 ࠢ ਢ஢:

- DPL ᥣ ࠢ ⥪饬 CPL.

-   ଭ  ᥣ⮬,   DPL
   (ਢ஢ ), 祬 ⥪騩 CPL.

ଭ ᥣ ᯮ  ⠪ ணࠬ, 
⥪ ⥬᪨ 㭪権   
ࠡ稪 뢠,  ন ਪ
ணࠬ,   ॡ 㯠  饭 ⥬
।⢠.  । ࠢ ଭ ᥣ CPL 
,  ᫨ ᥫ, ᯮ짮  樨
ᥣ,  㣮 RPL.  ⢥ ᫮,  CPL
  ⫨  DPL ⥪饣  ᥣ.

設⢮  ᥣ⮢  -ଭ묨.  ⠪
ᥣ⮢ ࠢ  ।   ⮫쪮 
㣨  ᥣ⠬, 騬   ஢
ਢ஢. ,  뢠 室 ।
ࠢ ᥣ⠬  訬 ஢ﬨ ਢ஢. 
믮    CALL, ᯮ饩 ਯ
 맮,  ᬠਢ   7.  JMP
   । ࠢ -ଭ ᥣ⠬,
DPL   ࠢ CPL.

6.5   ਯ
-----------------------------------------------------------------

 ᯥ祭   । ࠢ 
믮塞묨 ᥣ⠬  ࠧ묨 ஢ﬨ ਢ஢
 i486 ᯮ  ਯ. 
 ⨯  ਯ஢:

-  맮

-  誨

-  뢠

-  

  ᯮ  ४祭   뢠 
 7.   9 ,   襪  뢠
ᯮ  ࠡ⪨ ᪫祭  뢠.  
 ᬠਢ ⮫쪮  맮.  맮
।⠢ ᮡ   饭 ।
ࠢ.  ᯮ  । ࠢ 
ࠧ묨 ஢ﬨ ਢ஢.  ᯮ짮
室 ⮫쪮  ⥬,     ஢
ਢ஢.  㭮 6-5  ଠ  맮.

 맮   ᭮ 㭪樨:

1. । 窨 室  楤.

2.  ஢ ਢ஢, ॡ㥬  室 
   楤.


                   32-⮢  맮

31                          6 5 4 3 2 1 0 9 8 7 6 5 4 3       3
----------------------------------------------------------------
|                            | | D | | | | | | | | | |稪  |
| 饭  ᥣ  31:16 |P| P |0|1|1|0|0|0|0|0|0|  |+4
|                            | | L | | | | | | | | | |᫮     |
|                            | |   | | | | | | | | | |         |
----------------------------------------------------------------
|    ᥣ        |     饭  ᥣ 15:00   |+0
----------------------------------------------------------------

DPL    ஢ ਢ஢ ਯ
P      ⢨ ᥣ

                   㭮 6-5.   맮

ਯ  맮 ᯮ  CALL  JUMP
ᯮ  ᯮᮡ,   ਯ 
ᥣ⮢.  ⭠  ᯮ,  ᥫ
ᥣ 祭 뫠   ਯ,
믮  । ᮤন  맮.
ਯ  맮  室  GDT   LDT,  
 ⠡ ਯ஢ 뢠 (IDT).

   饭   ࠧ 㪠⥫  
室  楤.  맮 ࠭,   ।
ࠢ 㣨 ᥣ⠬  ந室  ࠢ 窨
室 楤,   㤠-  । 楤 (, 
 㦥,  । ). ࠭  ।
ࠢ   ᥫ஬ ᥣ  ᬥ饭 
ᥣ 窨 室  楤.  ⮣ ᥫ
ᥣ 㪠뢠   ᥫ,  ᬥ饭 
ᯮ.  ଠ 樨   㭪 6-6.


|<----------------  祭 --------------->|

15           0     31                              0
---------------    ----------------------------------
|     |    |    饭  ᥣ         |
---------------    ----------------------------------
         \                         |
          \                        \/
           \                  ᯮ
            \
             \
              \            ਯ஢
               \   ----------------------------------
                \  |        |       |       |       |
                 \ |--------------------------------|
                  \|                |               |
                   |--------------------------------|
  -----------------|    饭    |  DPL  |稪| ਯ
  |                |--------------------------------| 
  |      ----------|        |  饭     |
  |      |         |--------------------------------|
  |      |         |        |       |       |       |
  |      |         |--------------------------------|
  |      |         |                |               |
  |      |-----    |--------------------------------|
  |            \   |        |       |       |       |
  |             \  |--------------------------------|
  |              \ |                |               |
  |               \|--------------------------------| ਯ
  |                |    |       |  DPL  |   | 
-----              |--------------------------------| ᥣ
| + |<------------ |            |               |
-----              |--------------------------------|
  |                |        |       |       |       |
  |                |--------------------------------|
  \/               |                |               |
窠 室        ----------------------------------
 楤

              㭮 6-6. 堭  맮

   㭪 6-7,  ஢ન ⨬ ।
ࠢ १  맮 ᯮ  ࠧ
஢ ਢ஢.

஢ ਢ஢, ஢塞  । ࠢ
१  맮, :

1. CPL (⥪騩 ஢ ਢ஢).

2. RPL (஢ ਢ஢ 筨 ) ᥫ
   ᥣ,   ᯮ짮    맮.

3. DPL (஢ ਢ஢ ਯ) ਯ
   .

4. DPL ਯ ᥣ  ᥣ 祭
   室.

 DPL ਯ  ।,   ஢
ਢ஢  ᯮ짮  . 
 ᥣ  ᮤঠ ᪮쪮 ࠧ 楤,
।祭  ᯮ짮  ࠧ ஢
ਢ஢. , 樮 ⥬  
 㦭 楤, ᯮ㥬  ਪ묨
ணࠬ, ⠪  ᠬ 樮 ⥬, ਬ,
ணࠬ /뢮 ᨬ, ⮣  㣨 㦥
楤   ।祭 ⮫쪮  ᯮ짮 
樮 ⥬, ਬ, ணࠬ 樠樨
ࠩ஢ ன.

  ᯮ짮  । ࠢ   
ਢ஢ ஢, ⠪     ஢
ਢ஢ (  ᫥ 砥  ᯮ짮 
易⥫쭮).  । ࠢ   ਢ஢
஢   ᯮ짮 ⮫쪮  CALL. 
JMP  ᯮ짮  ⮫쪮  । ࠢ 
 ᥣ  ⥬  ஢ ਢ஢, 
ଭ  ᥣ  ⥬    ᮪ ஢
ਢ஢.

  室 JMP  ଭ ᥣ 
㤮⢮ ᫥騥  ࠢ ਢ஢ (
⨢ 砥  ᪫祭 饩 ):

MAX(CPL,RPL) <= DPL 
DPL  ᥣ 祭 = CPL

  CALL (  室 JMP  ଭ
ᥣ)  㤮⢮ ᫥騥  ࠢ
ਢ஢ ( ⨢ 砥  ᪫祭
饩 ):

MAX(CPL,RPL) <= DPL 
DPL  ᥣ 祭 <= CPL

6.5.1  ४祭 ⥪
-----------------------------------------------------------------

 맮 楤  ਢ஢ ஢ 믮
᫥饥:

1.  CPL.

2. । ࠢ (믮).

3. ந室 ४祭 ⥪.


                맮


31                               15              7            0
----------------------------------------------------------------
|                               | | D |         |     |        |
|                               | | P |         |     |        | +4
|                               | | L |         |     |        |
|--------------------------------------------------------------|
|                               |   |__________________        | +0
-------------------------------------------------------|--------
                                                       |
                                                       |
               ਯ ᥣ  祭     |
                                                       |
                                                       |
31                               15              7     |      0
-------------------------------------------------------|--------
|               | | | | |       | | D |         |      |       |
|               | | | | |       | | P |         |      |       | +4
|               | | | | |       | | L |         |      |       |
|------------------------------------------------------|-------|
|                               |   |_______________   |       | +0
----------------------------------------------------|--|--------
                                                    |  |
                騩 ॣ  ᥣ   |  |
                                                    |  |
--------------------                                |  |
|            | CPL |-----------------------------   |  |
--------------------                            |   |  |
                  맮           |   |  |
--------------------                            |   |  |
|            | RPL |-------------------------   |   |  |
--------------------                         |  |   |  |
                                             |  |   |  |
                                             \/ \/  \/ \/
                                         ---------------------
                                         |      ஢ઠ     |
                                         |ਢ஢|
                                         ---------------------
CPL       騩 ஢ ਢ஢
DPL       ஢ ਢ஢ ਯ
RPL       襭 ஢ ਢ஢

         㭮 6-7. ஢ઠ ਢ஢ 
          । ࠢ    맮

७   (஢ ਢ஢ 0, 1  2)
 ᢮ ᮡ⢥ ⥪  ਥ 맮  
ਢ஢ ஢. ᫨ ⥪  뫠 ᯥ
뢠 楤,  ⥪  ᫨誮 ,  
१ 筮 ࠧ ⥪  ந ᡮ
뢠 楤. ⮬ ᯥ稢  
ਢ஢ ணࠬ  ᡮ ᫥⢨ 
ਢ஢ ணࠬ ⥬ ᮧ  ⥪ 
맮  ਢ஢묨 楤ࠬ 
ਢ஢.   ⥪, ࠬ 맮
  ண ⥪  ,  祭 ॣ஢
࠭, ᫥ 祣 த 筮 믮
맢 楤.    ⮩ 楤 ᮤন
࠭ ॣ஢ ⠭  室 ⥪. 
ᠭ 堭 ४祭  ਢ   7.

 室   ᮧ  ⥪  
ᥣ ﭨ  (TSS),    㭪 6-8.
   ᮡ⢥ TSS. TSS ᮤন 室
㪠⥫ ⥪  ७  . 樮
⥬ ⢥砥  ᮧ  TSS  樠
ᮮ⢥  㪠⥫ ⥪. 室 㪠⥫ ⥪
⮨  ᥫ ᥣ  室 祭 ॣ ESP
(室 ᬥ饭  ᥣ). 室 㪠⥫ ⥪
।⠢ ᮡ 祭, ।祭 ᪫⥫쭮 
⥭.      ६ 믮 . 
㪠⥫ ⥪ ᯮ ⮫쪮  ᮧ  ⥪
 믮 맮 楤   ᮪ ஢
ਢ஢.    맢 楤 
⥪ 祧.  ᫥饬 맮 楤 ந室
ᮧ  ⥪  ᯮ짮  ⮣ 室
㪠⥫ ⥪.


          32-ࠧ來 ᥣ ﭨ 
31                                                 0
----------------------------------------------------
|                                                  | 64
|                                                  |
|                                                  |
|                                                  |
|                                                  |
|--------------------------------------------------|
|                         |         SS2            | 18
|--------------------------------------------------|
|                        ESP2                      | 14
|--------------------------------------------------|
|                         |         SS1            | 10
|--------------------------------------------------|
|                        ESP1                      | 0C
|--------------------------------------------------|
|                         |         SS0            | 8
|--------------------------------------------------|
|                        ESP0                      | 4
|--------------------------------------------------|
|                         |         SS2            | 0
----------------------------------------------------

ਬ砭:   ਢ  ⭠筮 ଠ

     㭮 6-8. 室 㪠⥫ ⥪  TSS

 ᯮ짮  맮   ஢
ਢ஢  ⥪ ᮧ 㧪  
TSS.  ᯮ DPL  ᥣ 祭
( CPL)  롮 室 㪠⥫ ⥪  ஢
ਢ஢ 0, 1  2.

DPL  ⥪ ᥣ   ࠢ  CPL: 
⨢ 砥  ᪫祭 ᡮ  ⥪.
⢥⢥  ᮧ ⥪  ਯ஢ ⥪
ᥣ   ᯮ㥬 ஢ ਢ஢ 
 樮 ⥬. ⥪   㯭 
⥭/,      ᮮ⢥ ᥣ
ਯ஢.   ᮤঠ 筮 ,  
 ࠭, ⮡ ⠬   ᮤন ॣ஢
SS  ESP,  , ࠬ  ६ ६,
ॡ㥬  ࠡ 뢠 楤.

   맮  ।  ஢ ਢ஢,
ࠬ   楤   ⥪. ⥬ 
ࠬ    ⥪.   ⨬ ࠬࠬ 
뢠 楤 ந室  ⥬  ᠬ,  
 ࠬ 室   ४祭 ⥪.  稪
 맮 ᮮ頥 , ᪮쪮  ᫮ ( 31)
 ஢  ⥪ 뢠饩 楤  ⥪
뢠 楤. ᫨  稪 ࠢ 0,  ஢
ࠬ஢  ந室.

᫨ ॡ ।  뢠 楤  31 
᫮ ,    ࠬ஢  ᤥ 㪠⥫ 
 ,  ࠭   祭 ॣ஢ SS 
ESP  ᯮ짮  㯠  ࠬࠬ  ன
 ⥪.

 ६ 맮 楤  㣨 ஢ ਢ஢
 믮 ᫥騥 易  ⥪ ⢨:

1. ஢ ⥪ 뢠 楤, ⮡ 㡥, 
    筮   ⮣, ⮡ ࠭ ࠬ 
   ࠭塞 祭 ॣ஢;  ⨢ 砥
    ᪫祭 ९ ⥪.

2. ஥ ᮤন ॣ஢ SS  ESP 頥  ⥪
   뢠 楤     ᫮ (16-ࠧ來
   ॣ SS  㫥  32 ⮢;  
   㫥 襥 ᫮ १ࢨ஢ Intel  ७
   짮;   ᯮ짮).

3. ࠬ   ⥪ 뢠饩 ணࠬ  ⥪
   뢠 ணࠬ.

4.   ⥪ 頥 㪠⥫ , 室饩 ᫥
    CALL (஥ ᮤন ॣ஢ CS  IP).
   ন ॣ஢ SS  ESP ᫥ 맮 㪠뢠  
   㪠⥫    ⥪.

 㭪 6-9   ⥪ ,  ६  ᫥
ᯥ譮 맮    楤ࠬ  ࠧ묨 ஢ﬨ
ਢ஢.

TSS   㪠⥫ ⥪  ⥪  ஢
ਢ஢ 3, ᪮ 楤  ஢
ਢ஢ 3    맢 楤ன  
  ஢. ⥪  ஢ ਢ஢ 3
।࠭ ᮤন ॣ஢ SS  EIP, 
࠭  ⥪ ਢ஢ ஢, 맢 
஢ 3.


   ⥪          ⥪            ⥪
   맮           ᫥ 맮,        ᫥ 
                       

                      ----------------
|             |       |  SS    |     |             |
|-------------|       |--------------|     |-------------|
|             |       |  ESP   |     |             |<-ESP
|-------------|       |--------------|     |-------------|
| ࠬ 1  |       | ࠬ 1   |     |             |
|-------------|       |--------------|     |-------------|
| ࠬ 2  |       | ࠬ 2   |     |             |
|-------------|       |--------------|     |-------------|
| ࠬ 3  |<-ESP  | ࠬ 3   |     |             |
|-------------|       |--------------|     |-------------|
|             |       |  CS    |     |             |
|-------------|       |--------------|     |-------------|
                      |  EIP   |<-ESP
                      |--------------|
                      |              |
                      |--------------|

         㭮 6-9.  ⥪  맮 楤
               㣨 ஢ ਢ஢

맮, ᯮ騩  맮,  ஢ 祭 ᫮,
㥬   ⥪. 맢 楤  ஢
⨬  ࠬ.  ᫥ ࠧ 㦤
ᯮ짮  ARPL, VERR, VERW, LSL  LAR  ஢ન
祭 㪠⥫.

6.5.2    楤
-----------------------------------------------------------------

""   RET 믮 । ࠢ ⮫쪮
 । ⥪饣  ᥣ,  ᫥⥫쭮,  
믮 ⮫쪮 ஫ ࠭. 饭  ,
᫥饩 ᫥  맮 CALL,   ⥪ 
頥  ॣ EIP.  ஫, ⮡ 
ᬥ饭  ॢ室 ࠭ ⥪饣  ᥣ.

"" ଠ  RET   , 饭
 ⥪ ।饩  CALL.  ଠ ᫮ 㪠⥫
 ᥣ ⮢७, ᪮   ᣥ஢
 CALL  INT.   ,  믮
஢ ਢ஢ ᫥⢨  ⮣, 
⥪ 楤  㪠⥫   ᬮ ࠢ쭮
ࠡ ⥪. RPL ᥫ  ᥣ, 祭 
⥪  ,   ஢
ਢ஢ 뢠饩 楤.

  㣮 ᥣ   ஢
ਢ஢,  ⮫쪮  ஭   ஢.
  RET 砥 ࠭ 祭 CS, RPL
ண ᫥  CPL (..   ਢ஢
஢), ந室  १ ஢ ਢ஢.
 த  믮 ᫥騥 蠣:

1. 믮 ஢ન,    6-2  ॣ CS,
   EIP, SS  ESP 㦠  ।騬 祭ﬨ, 
   뫨 ࠭  ⥪.

2. ஥ ᮤন ॣ஢ SS  ESP ( 設 ⥪饣
   ⥪) ࠨ  ࠧ  ,   
   RET. 饥 祭 ESP  ஢  ࠭
   ⥪ ᥣ. ᫨ 祭 ESP 室   ࠭,
     䠪  ᯮ ஬  ᫥饩
   ⥪ 樨. (ন ॣ஢ SS  ESP 
   頥 楤  ࠭; 筮  祭 
   ,   ࠭  TSS).

3. ஢ ᮤন ᥣ ॣ஢ DS, ES, FS  GS.
   ᫨     ॣ஢ 뫠  ᥣ, DPL
   ண   CPL ( ଭ 
   ᥣ), ᥣ ॣ 㦠  ᥫ஬
   (=0, TI=0).   RET  ⠪  
   ᮮ頥  ᪫祭;   ᫥騥 뫪 
      ᥣ⭮ ॣ, ᮤয饣 ⮩
   ᥫ, 맮 ᪫祭 饩 .   
    ਢ஢    
   ਢ஢ ᥣ⠬ ।⢮ ᥫ஢,
   ⠢  ᥣ ॣ  ਢ஢
   楤ன.

       6-2. ஢ન    楤ࠬ
              ࠧ묨 ஢ﬨ ਢ஢

------------------------------------------------------------------
| ஢ન |                   ᮡ 樨 |  訡|
------------------------------------------------------------------
|設 ⥪                                         |
| । ࠭ ᥣ                                     |
|⥪                            ⥪                 0         |
|                                                                |
| 設 ⥪+7                                 |
| । ࠭ ᥣ                                     |
|⥪                            ⥪                 0         |
|                                                                |
|RPL  ᥣ                                   |
| ॢ CPL                           CS |
|                                                                |
|  ᥣ                                      |
|                     CS |
|                                                                |
|ਯ  ᥣ                                    |
|    ।                                 |
|࠭ ⠡ ਯ஢                   CS |
|                                                                |
|ਯ ᥣ                                     |
| ⭮                                      |
|ᥣ                                       CS |
|                                                                |
|⢨  ᥣ                          |
|                                 CS |
|                                                                |
|DPL -ଭ                                      |
|ᥣ                                      |
|ࠢ RPL ᥫ                                     |
|ᥣ ,  DPL                                     |
|ଭ  ᥣ                                   |
|                                        |
| ࠢ RPL ᥫ                                 |
|ᥣ                               CS |
|                                                                |
|ESP+N+15*   室                                    |
| । ࠭ ᥣ                                     |
|⥪                              ⥪        CS |
|                                                                |
| ᥣ  ESP+N+12*                                   |
|                             CS |
|                                                                |
|ਯ ᥣ  ESP+N+12*                                 |
| 室  ।                                    |
|࠭ ⠡ ਯ஢                   CS |
|                                                                |
|ਯ ⥪ ᥣ                                   |
|  㯥                                         |
|⥭/                                  CS |
|                                                                |
| ⢮ ⥪                                  |
|ᥣ                            ⥪        CS |
|                                                                |
|DPL ண ⥪ ᥣ                                  |
|  ࠢ RPL ண                                   |
| ᥣ                              CS |
|                                                                |
| ண ⥪                                      |
|ᥣ   RPL,                                      |
|ࠢ DPL ண ⥪                                    |
|ᥣ                                       CS ᥣ|
------------------------------------------------------------------

* N -  祭 ।⢥ ࠭,  
   RET.

6.6  , १ࢨ஢  ࠡ 樮 ⥬
-----------------------------------------------------------------

,   ⢮  堭  
  騥 ࠪ⨪ ந⥫쭮 ⥬,
 믮 ⮫쪮  ஢७묨 楤ࠬ.
 i486    ⠪ :

1. ਢ஢  - , ᯮ㥬 
   ࠢ ⥬.

2. ⢨⥫  - , ᯮ㥬  /
   뢮  ⢨, 易  /뢮.

6.6.1  ਢ஢ 
-----------------------------------------------------------------

,  뢠 ﭨ  ।⢠  ⥬,
  믮 ⮫쪮  CPL ࠢ 0 (訩 ஢
ਢ஢). ᫨ -    믮
 CPL  ࠢ 0,  ᪫祭 饩 . 
᫮   室:

CLTS               -  䫠 ४祭 
HLT                - 믮 ⠭ 
LGDT               - 㧨 ॣ GDT
LIDT               - 㧨 ॣ IDT
LLDT               - 㧨 ॣ LDT
LMSW               - 㧨 ᫮ ﭨ 設
LTR                - 㧨 ॣ 
MOV / CR0       - 뫪  ࠢ騬 ॣ஬ 0
MOV / DRn       - 뫪  ⫠ ॣ஬ n
MOV / TRn       - 뫪  ⮢ ॣ஬ n

6.6.2  ⢨⥫ 
-----------------------------------------------------------------

, ࠡ騥  /뢮,   饭묨,
  ⠪    믮   
஢ ਢ஢,  ࠢ 0 (. 믮  
  ਢ஢ ஢). 堭 
権 /뢮 ஡ ᠭ   8.

6.6   ஢ન ⮢୮ 㪠⥫
-----------------------------------------------------------------

஢ઠ ⮢୮ 㪠⥫ 室  ঠ
஢ ࠧ ஢ ਢ஢.  ⮨
 ᫥ 蠣:

1. ஢ઠ ⮣,  楤, ᮧ  㪠⥫,
    ࠢ 㯠   ᥣ.

2. ஢ઠ ⮣,  ⨯ ᥣ ᮢ⨬  襭
   ᯮᮡ  ᯮ짮.

3. ஢ઠ ⮣,  ᬥ饭 㪠⥫  ॢ蠥 ࠭
   ᥣ.

  i486 ⮬᪨ 믮 ஢ન 2  3 
믮 ,  믮 ࢮ ஢ન 
⢮ ணࠬ ᯥ祭.  ⮣ ।祭
 ARPL. ணࠬ ᯥ祭  ⠪ 믮
஢ન 2  3  ,  㤥 ᣥ஢ ᪫祭
.  ⮣ ।祭  LAR, LSL, VERR 
VERW.

 ० 짮⥫  믮 ⥫쭠 ஢ઠ
ࠢ.  ६ ⠭  AM ॣ CR0
 䫠 AC, ࠢ 뫪     樨
᪫祭.  ᢮⢮   ணࠬ, 
ᯮ  訥  㪠⥫  䨪樨 ⨯
 㥬 㪠⥫ . ਬ, ணࠬ 
⥪ ⥬᪨ 㭪権  ਭ 㪠⥫ 
᫮  . ᫨ ⨯ ⠪  ᢮
 10 (), ᠭ     㪠⥫ 
 ⨯,  ⥬᪨ ணࠬ  믮
४   ⨯, ਡ ᬥ饭 -10 (筮). 
祭 ணࠬ ୮ 㪠⥫ ⨯ 뫪 㤥
ࠢ,  ਢ  樨 ᪫祭. ஢ઠ
ࠢ ᪮ ࠡ ணࠬ, ᠭ  몠
⢥ ⥫, ⠪  Lisp, Prolog, Smalltalk 
C++.  ⠪  ᯮ짮  ᪮७ ஢ન
ਧ ⨯ 㪠⥫.

LAR (㧨 ࠢ 㯠) ᯮ  䨪樨 ⮣,
 㪠⥫ 뫠  ᥣ  ᮢ⨬  ஢
ਢ஢  ⨯.  LAR   ࠭ -
ᥫ ᥣ  ਯ, ࠢ 㯠 ண 
 ஢७. ਯ ᥣ   㯭 
⥭  ஢ ਢ஢, ᫥ 襬 (..
 ਢ஢), 祬 CPL  RPL ᥫ. ᫨
ਯ 㯥  ⥭,   LAR ਭ ஥
 ᫮ ਯ, ᪨  祭 00FxFF00H,
뢠 १   32-ࠧ來 ॣ 祭
 ⠭ 䫠 ZF. (x 砥,  ᮮ⢥騥 
 ᠭ 祭 ।).  
㦥, ஢ 㯠   ⥬ ஢७. 
LAR  ஢  ⨬몥 ⨯ ਯ஢.
᫨ RPL  CPL ॢ蠥 DPL,  ᫨ ᥫ ᥣ
ॢ蠥 ࠭  ⠡ ਯ஢, ࠢ 㯠 
,  䫠 ZF 頥.   ଭ 
ᥣ⠬ ᪠   ஢ ਢ஢.

LSL (㧨 ࠭ ᥣ)  ணࠬ
஢ ࠭ ਯ ᥣ, ᫨ ਯ, 
 뫠 ᥫ ᥣ (    ॣ),
㯥  ⥭  ⥪饬 CPL.  LSL 㦠
 32-ࠧ來 ॣ 32-ࠧ來 ࠭㫨஢
⭮ 祭 ࠭, ᫥  ᭮
⥭஢  ࠭   ࠭樨 G ਯ.
   ᤥ ⮫쪮  ਯ஢, 뢠
ᥣ (, , ﭨ   ⠡ ਯ஢);
ਯ  ⠪ ᯮᮡ 㯭. ( ⠡ 6-3
஡ ᫥,  ⨯ ⨬,   ).
 ࠭   ⨯ ᥣ. ਬ,
ᥣ , 騥  (⥪ ᥣ)
ᬠਢ ࠭ , 祬  稥 ⨯ ᥣ⮢. 
 , LAR  LSL, 䫠 ZF ⠭  ⮬ 砥,
᫨ 㧪 뫠 믮 ᯥ譮;  ⨢ 砥 䫠 ZF
頥.

      6-3. ⨬ ⨯ ਯ஢  LSL
-----------------------------------------------------------------
 ⨯              ਯ                  ⨬?
-----------------------------------------------------------------
   0                 १ࢨ஢                   
   1                 १ࢨ஢                   
   2                 LDT                              
   3                 १ࢨ஢                   
   4                 १ࢨ஢                   
   5                                        
   6                 १ࢨ஢                   
   7                 १ࢨ஢                   
   8                 १ࢨ஢                   
   9                 㯥 TSS 業ࠫ쭮
                      i486                  
   A                 १ࢨ஢                   
   B                  TSS 業ࠫ쭮
                      i486                  
                     맮 業ࠫ쭮
                      i486                  
   D                 १ࢨ஢                   
   E                  뢠 業ࠫ쭮
                      i486                  
                     誨 業ࠫ쭮
                      i486                  
-----------------------------------------------------------------

6.7.1  ஢ઠ ⮢୮ ਯ
-----------------------------------------------------------------

 i486   , VERR  VERW, 
।, 㪠뢠  ᥫ ᥣ  ᥣ, 
㯥  ⥭    ⥪饣 CPL.    
  뢠 ⭮ ᪫祭, ᫨ ᥣ
㯥.

VERR (䨪 㯭 ⥭) 믮 䨪
㯭 ᥣ  ⥭  ⠭ 䫠 ZF, ᫨
 ⥪饣 CPL  ᥣ 㯥  ⥭.  VERR
஢ ᫥饥:

-  ᥣ 㪠뢠  ਯ ᥣ  ।
  ࠭ GDT  LDT.

-  ᥣ  ਯ ᥣ  
  .

-  㯥  ⥭     ᮢ⨬  ஢
  ਢ஢.

஢ઠ ਢ஢  ᥣ⮢  
-ଭ  ᥣ⮢ 㤮⮢,  DPL 
訩 ஢ ਢ஢, 祬 CPL  RPL ᥫ.
ଭ ᥣ  ஢ ਢ஢ 
஢.

VERW (䨪 㯭 ) 筠  VERR :
 믮 䨪 㯭 ᥣ   
⠭ 䫠 ZF, ᫨  ᥣ 㯥  ⥭.
 VERW 㤮⮢,  ਯ   㦭
࠭, ⢨⥫쭮  ਯ஬ ᥣ, ᥣ
㯥  ⥭   DPL   ਢ஢
஢,  CPL  RPL ᥫ.  ᥣ 
 뢠 㯭묨  :  ଭ, ⠪ 
-ଭ.

6.7.2  ⭮ 㪠⥫  RPL
-----------------------------------------------------------------

襭 ஢ ਢ஢ (RPL) 
। 砩 ᯮ짮 㪠⥫, ࠧ
 ਢ஢     訬 ஢
ਢ஢.

࠭ ਬ஬  㦨 䠩 ⥬
楤 FREAD (䨪_䠩, n_⮢,
㪠⥫_).  ᪠ 楤 뢠 
 ᪮ 䠩  ,   ࠭ ᠭ
ᮤন ⮣ .  㦨  ணࠬ,
ࠡ  ਪ ஢,  ᠬ  ࠡ 
ਢ஢ ஢, ⮡ ᥣ  
㦨 /뢮 樮 ⥬. ᫨ ਪ
ணࠬ । ⮩ 楤  㪠⥫ ,
 㪠뢠   ⪨    
ਢ஢ ᭮ ࠭⢥, 楤 
믮 ⢨, 騥  ࠧ襭 ⥬.

  ஡  ᯮ짮 RPL. RPL
  ᥫ ८।
ਢ஢.  ८। ਢ஢
।⠢ ᮡ ஢ ਢ஢ 
ᥣ, ᣥ஢襣  ᥫ ᥣ. 
襯ਢ ਬ RPL  ।⠢ ᮡ CPL
ਪ ணࠬ, 맢襩 楤 ⥬ ஢.
 i486 ⮬᪨ ஢  㦥 
ᥣ ॣ ᥫ, ।, ᪠   RPL
믮 襭 .

 ⮣, ⮡ ᯮ짮 २⢠, 묨 ⠪
஢મ ஬ RPL, 뢠 楤  ⮫쪮
஢, ⮡  ।  ᥫ ᥣ 
RPL  ⥬   訬 ஢ ਢ஢,   CPL
室 筨 . ᫨ ᥫ ᯮ 
㯠  ᥣ,  ஬ 筨   
 , .. RPL ண  
ਢ஢, 祬 DPL 襭 ᥣ,  
㧪 ᥫ  ᥣ ॣ  ᪫祭
饩 .

ARPL (ந 襭 ஢ ਢ஢)
ࠨ  RPL ᥫ ᥣ  襥  祭
(訩 ஢ ਢ஢), 롨   室
祭  祭  RPL  ᥫ ᥣ, ᠭ
 ॣ 饣 祭.  RPL 室   
 ᥫ ᥣ  ॣ. ᫥ 筮
।⠢ ᮡ  ॣ CS 뢠饩 楤 
⥪. ᫨  ⠪ ன RPL ᥫ , 
ந室 ⠭ 䫠 ZF;  ⨢ 砥 䫠 ZF
頥.

6.8    ஢ ࠭
-----------------------------------------------------------------

 ࠡ⠥   ஢ ᥣ⮢, ⠪   ஢
࠭.  ᯮ짮 ᪮  ᥣ樨 
  ஢ ࠭ ⠪ ।頥 ⨬
 ﭨ  ணࠬ.

 뫪   ஫  㤮⢮७ ஢ப
.  ஢ન 믮  砫 横 饭 
;  襭  ।頥 砫 ⮣ 横
  ᪫祭. ᪮  ஢ન 믮
ࠫ쭮  ࠭樥 ,    ⥫
 ६ .    ஢ન 
 ஢ ࠭:

1. ࠭祭  㥬  .

2. ஢ઠ ⨯.

襭  ਢ  樨 ᪫祭. 堭
᪫祭 ᠭ   9.    ᠭ 襭
, 騥  ᪫祭.

6.8.1   ࠭ ⠡ ᮤঠ ࠬ 
-----------------------------------------------------------------

 㭪 6-10    ࠭筮 ⠡,
 ࠢ 㯮  ࠭. ஢ન 
ਬ  ࠭ ⠡栬  ࢮ, ⠪  ண
஢.

6.8.1.1  ࠭祭 㥬  
-----------------------------------------------------------------

 ࠭  ᥣ⮢ ⨥ ਢ஢
 -ࠧ.  ᥣ⮢  
஢ ਢ஢,     0 (訩
஢ ਢ஢)  3 (訩 ஢
ਢ஢).  ࠭   ஢
ਢ஢:

1. ஢ 㯥ࢨ (U/S=0) -  樮 ⥬,
   祣 ⥬ ணࠬ ᯥ祭 (ਬ,
   ࠩ஢ ன),  ⠪  頥 ⥬ 
   (ਬ, ࠭ ⠡).

2. ஢ 짮⥫ (U/S=1) -  ਪ   .

஢ ਢ஢, ᯮ㥬  ᥣ樨,
⮡ࠦ  ஢ ਢ஢ ࠭. ᫨ CPL
ࠢ 0, 1  2,   ࠡ⠥  ஢ 㯥ࢨ.
᫨  CPL ࠢ 3,   ࠡ⠥  ஢
짮⥫.   ࠡ⠥  ஢ 㯥ࢨ,
 ࠭  㯭묨.   ࠡ⠥ 
஢ 짮⥫, 㯭 ⮫쪮 ࠭, 騥 ஢
짮⥫.

31                               12 11                      0
--------------------------------------------------------------
|                                  |       |   | | |P|P|U|R| |
|  ࠭筮  31...12  |㯭|0 0|D|A|C|W|/|/|P|
|                                  |       |   | | |D|T|S|W| |
--------------------------------------------------------------

R/W   ⥭/
U/S   짮⥫/㯥ࢨ

     㭮 6-10.    ࠭筮 ⠡

6.8.1.2  ஢ઠ ⨯
-----------------------------------------------------------------

堭  ᯮ ⮫쪮   ࠭:

1.  쪮  ⥭ (R/W=0)

2.   ⥭/ (R/W=1).

  ࠡ⠥  ஢ 㯥ࢨ  饭
 WP  ॣ CR0 ( ﭨ , ᮮ⢥饬
樠樨   ⥬),  ࠭ 
६ 㯭묨  ⥭   (ਧ 
 ).   ࠡ⠥  ஢
짮⥫,    㯭  ࠭ ஢
짮⥫, 祭 ਧ ⥭/. ࠭
஢ 짮⥫, 祭  ⥭/  쪮 
⥭,  㯭묨  ⥭. ࠭ ஢
㯥ࢨ  ஢ 짮⥫ 㯭   ⥭, 
 .  ⪥ 襭 ࠢ 㯠  饭
࠭栬  ᪫祭 饩 .

 ⫨稥   386 DX  i486  
࠭ ஢ 짮⥫    ० 㯠
㯥ࢨ. ⠭  WP  ॣ CR0 砥
⢨⥫쭮 ० 㯥ࢨ   ࠭   
० 짮⥫.  ।⢮   ॠ樨
⥣ "--", ᯮ㥬 묨
樮묨 ⥬, ਬ UNIX,  ᮧ  (
।⢮ ⠪ 뢠 ஦ ࠫ ᮢ 
 ஦).

 ᮧ    ᪮஢  ᭮
࠭⢮ ஦饩 .   ஦ 
, 㡫  ᥣ⮢  ࠭ ஦饩
. ⥣ "--"    
६, ⮡ࠦ ஦ ᥣ  ࠭   
ᥣ  ࠭,  ᯮ ஦饩 祩.
⭠  ࠭ ᮧ ⮫쪮  砥,   
 믮    ࠭.

6.8.2  ꥤ  ࠭ ⠡  ஢
-----------------------------------------------------------------

  ⤥쭮 ࠭ ਡ  ᮮ⢥饣
  ⠫ ࠭ (⠡ ࠭ ࢮ ஢)
 ⫨  ਡ⮢   ⠡ ࠭
ண ஢.  i486 ஢  ࠭,
ᬠਢ ਡ ,   ⠡ 
஢.   6-4  , ᯥ稢
묨 ﬨ ਡ⮢   饭  WP.

        6-4. ꥤ  ⠫ ࠭
                        ⠡ ࠭
----------------------------------------------------------------
|   ⠫      ⠡       ꥤ     |
|      ࠭              ࠭               䥪       |
|--------------------------------------------------------------|
|ਢ|         |ਢ|         |ਢ|         |
|஢|㯠     |஢|㯠     |஢|㯠     |
|  |            |  |            |  |            |
|--------------------------------------------------------------|
|짮|쪮⥭|짮|쪮⥭|짮|쪮⥭|
|짮|쪮⥭|짮|⥭|짮|쪮⥭|
|짮|⥭|짮|쪮⥭|짮|쪮⥭|
|짮|⥭|짮|⥭|짮|⥭|
|짮|쪮⥭|㯥 |쪮⥭|짮|쪮⥭|
|짮|쪮⥭|㯥 |⥭|짮|쪮⥭|
|짮|⥭|㯥 |쪮⥭|짮|쪮⥭|
|짮|⥭|㯥 |⥭|짮|⥭|
|㯥 |쪮⥭|짮|쪮⥭|짮|쪮⥭|
|㯥 |쪮⥭|짮|⥭|짮|쪮⥭|
|㯥 |⥭|짮|쪮⥭|짮|쪮⥭|
|㯥 |⥭|짮|⥭|짮|⥭|
|㯥 |쪮⥭|㯥 |쪮⥭|㯥 |⥭|
|㯥 |쪮⥭|㯥 |⥭|㯥 |⥭|
|㯥 |⥭|㯥 |쪮⥭|㯥 |⥭|
|㯥 |⥭|㯥 |⥭|㯥 |⥭|
----------------------------------------------------------------


6.8.3  ८।  ࠭
-----------------------------------------------------------------

  㯠 ஢,  騥 ஢
ਢ஢ 0,   祭 CPL:

-   ਯࠬ ᥣ⮢ (LDT, GDT, TSS  IDT).

-   ७ ⥪  ६ 믮  CALL,
   ᪫祭  뢠,  ந室  ஢
  ਢ஢.

6.9 ꥤ  ᥣ⮢  ࠭
-----------------------------------------------------------------

 ࠧ襭 堭 窨 ࠭  i486
᭠砫 믮 ஢ન  ᥣ,  ⥬ ஢ન
 ࠭. ᫨  㦨 襭  
  ஢ ,  ᥣ, ⠪  ࠭,
믮  த:  ᪫祭. ᫨
᪫祭  堭  ᥣ⮢, ᪫祭
 ࠭  .

ਬ,  । 让 ᥣ , 騩
   ਡ⮬ 㯠 쪮  ⥭,  㣨
 -  ⥭/.  ⮬ 砥  ⠫
࠭ ( ⠡ ࠭)  ⥩  㯮 쪮 
⥭    U/S  R/W, 騥 ⢨ ࠢ
㯠  ᥬ ࠭栬, ᠭ  ⮬ ⠫
( ⤥ ࠭栬,   ࠭ ⠡ ண
஢).  ⮤   ᯮ짮, ਬ, 
। 讣 ᥣ ,  ண
।祭 쪮  ⥭ ( ࠧ塞 
-१ ).  ᠬ । "᪮"
࠭⢮    让 ᥣ,  "᪨"
㪠⥫ﬨ, ᯮ㥬묨  㯠  ⮬ "᪮"
࠭⢮,  ⮩ ࠧ塞 , ࠧ塞 䠩,
⮡ࠦ  㠫쭮 ࠭⢥,  ⠪ ⥩
㯥ࢨ.
