[NTOS:FORMATTING]

[reactos.git] / reactos / ntoskrnl / ke / i386 / ctxswitch.S

diff --git a/reactos/ntoskrnl/ke/i386/ctxswitch.S b/reactos/ntoskrnl/ke/i386/ctxswitch.S
index 8fba093..3491fcb 100644 (file)
--- a/reactos/ntoskrnl/ke/i386/ctxswitch.S
+++ b/reactos/ntoskrnl/ke/i386/ctxswitch.S
@@ -3,7 +3,7 @@
  * PROJECT:         ReactOS kernel
  * FILE:            ntoskrnl/ke/i386/ctxswitch.S
  * PURPOSE:         Thread Context Switching
- * 
+ *
  * PROGRAMMERS:     Alex Ionescu (alex@relsoft.net)
  *                  Gregor Anich (FPU Code)
  */
@@ -63,7 +63,7 @@ PUBLIC @KiSwitchThreads@8
     /* Load the new kernel stack and switch OS to new thread */
     mov esp, edx
     call @KiSwapContextExit@8
-    
+
     /* Now we're on the new thread. Return to the caller to restore registers */
     add esp, 2 * 4
     ret
@@ -81,6 +81,61 @@ PUBLIC @KiRetireDpcListInDpcStack@8
     pop esp
     ret
 
+PUBLIC _Ki386EnableCurrentLargePage@8
+_Ki386EnableCurrentLargePage@8:
+    /* Save StartAddress in eax */
+    mov eax, [esp + 4]
+
+    /* Save new CR3 value in ecx */
+    mov ecx, [esp + 8]
+
+    /* Save flags value */
+    pushfd
+
+    /* Disable interrupts */
+    cli
+
+    /* Compute linear address */
+    sub eax, offset _Ki386EnableCurrentLargePage@8
+    add eax, offset _Ki386LargePageIdentityLabel
+
+    /* Save old CR3 in edx and replace with a new one */
+    mov edx, cr3
+    mov cr3, ecx
+
+    /* Jump to the next instruction but in linear mapping */
+    jmp eax
+
+_Ki386LargePageIdentityLabel:
+    /* Disable paging */
+    mov eax, cr0
+    and eax, NOT CR0_PG
+    mov cr0, eax
+
+    /* Jump to the next instruction to clear the prefetch queue */
+    jmp $+2
+
+    /* Enable Page Size Extension in CR4 */
+    mov ecx, cr4
+    or ecx, CR4_PSE
+    mov cr4, ecx
+
+    /* Done, now re-enable paging */
+    or eax, CR0_PG
+    mov cr0, eax
+
+    /* Jump to virtual address */
+    mov eax, offset VirtualSpace
+    jmp eax
+
+VirtualSpace:
+    /* Restore CR3 contents */
+    mov cr3, edx
+
+    /* Restore flags */
+    popfd
+
+    ret 8
 
 /* FIXFIX: Move to C code ****/
 PUBLIC _Ki386SetupAndExitToV86Mode@4
@@ -88,7 +143,7 @@ _Ki386SetupAndExitToV86Mode@4:
 
     /* Enter V8086 mode */
     pushad
-    sub esp, (12 + KTRAP_FRAME_LENGTH + NPX_FRAME_LENGTH)
+    sub esp, (12 + KTRAP_FRAME_LENGTH + NPX_FRAME_LENGTH + 16)
     mov ecx, esp
     call @KiEnterV86Mode@4
     jmp $
@@ -100,7 +155,7 @@ PUBLIC @Ki386BiosCallReturnAddress@4
     /* Exit V8086 mode */
     call @KiExitV86Mode@4
     mov esp, eax
-    add esp, (12 + KTRAP_FRAME_LENGTH + NPX_FRAME_LENGTH)
+    add esp, (12 + KTRAP_FRAME_LENGTH + NPX_FRAME_LENGTH + 16)
     popad
     ret 4