ntoskrnl/ke/i386/ctxswitch.S

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS kernel
   4  * FILE:            ntoskrnl/ke/i386/ctxswitch.S
   5  * PURPOSE:         Thread Context Switching
   6  *
   7  * PROGRAMMERS:     Alex Ionescu (alex@relsoft.net)
   8  *                  Gregor Anich (FPU Code)
   9  */
  10
  11 /* INCLUDES ******************************************************************/
  12
  13 #include <ndk/asm.h>
  14 .intel_syntax noprefix
  15
  16 /* FUNCTIONS ****************************************************************/
  17
  18 .globl @KiSwapContextInternal@0
  19 .func @KiSwapContextInternal@0, @KiSwapContextInternal@0
  20 @KiSwapContextInternal@0:
  21     /* Build switch frame */
  22     sub esp, 2 * 4
  23     mov ecx, esp
  24     jmp @KiSwapContextEntry@8
  25 .endfunc
  26
  27 .globl @KiSwapContext@8
  28 .func @KiSwapContext@8, @KiSwapContext@8
  29 @KiSwapContext@8:
  30     /* Save 4 registers */
  31     sub esp, 4 * 4
  32
  33     /* Save all the non-volatile ones */
  34     mov [esp+12], ebx
  35     mov [esp+8], esi
  36     mov [esp+4], edi
  37     mov [esp+0], ebp
  38
  39     /* Get the wait IRQL */
  40     or dl, cl
  41
  42     /* Do the swap with the registers correctly setup */
  43     call @KiSwapContextInternal@0
  44
  45     /* Return the registers */
  46     mov ebp, [esp+0]
  47     mov edi, [esp+4]
  48     mov esi, [esp+8]
  49     mov ebx, [esp+12]
  50
  51     /* Clean stack */
  52     add esp, 4 * 4
  53     ret
  54 .endfunc
  55
  56 .globl @KiSwitchThreads@8
  57 .func @KiSwitchThreads@8, @KiSwitchThreads@8
  58 @KiSwitchThreads@8:
  59     /* Load the new kernel stack and switch OS to new thread */
  60     mov esp, edx
  61     call @KiSwapContextExit@8
  62
  63     /* Now we're on the new thread. Return to the caller to restore registers */
  64     add esp, 2 * 4
  65     ret
  66 .endfunc
  67
  68 .globl @KiRetireDpcListInDpcStack@8
  69 .func @KiRetireDpcListInDpcStack@8, @KiRetireDpcListInDpcStack@8
  70 @KiRetireDpcListInDpcStack@8:
  71     /* Switch stacks and retire DPCs */
  72     mov eax, esp
  73     mov esp, edx
  74     push eax
  75     call @KiRetireDpcList@4
  76
  77     /* Return on original stack */
  78     pop esp
  79     ret
  80 .endfunc
  81
  82 /* FIXFIX: Move to C code ****/
  83 .globl _Ki386SetupAndExitToV86Mode@4
  84 .func Ki386SetupAndExitToV86Mode@4
  85 _Ki386SetupAndExitToV86Mode@4:
  86
  87     /* Enter V8086 mode */
  88     pushad
  89     sub esp, (12 + KTRAP_FRAME_LENGTH + NPX_FRAME_LENGTH)
  90     mov ecx, esp
  91     call @KiEnterV86Mode@4
  92     jmp $
  93 .endfunc
  94
  95 .globl @Ki386BiosCallReturnAddress@4
  96 @Ki386BiosCallReturnAddress@4:
  97
  98     /* Exit V8086 mode */
  99     call @KiExitV86Mode@4
 100     mov esp, eax
 101     add esp, (12 + KTRAP_FRAME_LENGTH + NPX_FRAME_LENGTH)
 102     popad
 103     ret 4
 104