- Fixed the changing of the PGE bit in cr4.  
- Check if the cpu supports global pages.

reactos/ntoskrnl/ke/i386

diff -u -r1.1 -r1.2
--- tlbflush.S	13 Oct 2004 02:58:59 -0000	1.1
+++ tlbflush.S	17 Oct 2004 17:28:45 -0000	1.2
@@ -4,16 +4,29 @@

  *	      Chapter 10 - Memory Cache Control. Section 10.9 - Invalidating the Translation Lookaside Buffers 
  */
 

+#include <internal/i386/ke.h>
+
+

 .globl _KeFlushCurrentTb@0

-_KeFlushCurrentTb@0:	

+_KeFlushCurrentTb@0:
+    /* Check for global page support */	
+	testl	$X86_FEATURE_PGE, (_Ke386CpuidFlags)
+	jz	  .L1
+

 	/* Modifying the PSE, PGE or PAE Flag in CR4 causes the TLB to be flushed */

-	andl $0xFFFFFF7F, %eax
-	movl %eax, %cr4
-	orl $0x80, %eax
-	movl %eax, %cr4

+	movl 	%cr4, %eax
+	andl 	$~X86_CR4_PGE, %eax
+	movl	%eax, %cr4
+	orl  	$X86_CR4_PGE, %eax
+	movl 	%eax, %cr4

 	
 	ret
 

-

+.L1:
+    /* the old way ... */
+	movl 	%cr3, %eax
+	movl 	%eax, %cr3
+	ret
+	

reactos/ntoskrnl/include/internal/i386

diff -u -r1.12 -r1.13
--- ke.h	1 Oct 2004 20:09:57 -0000	1.12
+++ ke.h	17 Oct 2004 17:28:45 -0000	1.13
@@ -69,6 +69,15 @@

 #define KTRAP_FRAME_RESERVED9      (0x8A)
 #define KTRAP_FRAME_SIZE           (0x8C)
 

+#define X86_EFLAGS_VM	    0x00020000 /* Virtual Mode */
+#define X86_EFLAGS_ID	    0x00200000 /* CPUID detection flag */
+
+#define X86_CR4_PAE	    0x00000020 /* enable physical address extensions */
+#define X86_CR4_PGE	    0x00000080 /* enable global pages */
+
+#define X86_FEATURE_PAE	    0x00000040 /* physical address extension is present */	
+#define X86_FEATURE_PGE	    0x00002000 /* Page Global Enable */
+

 #ifndef __ASM__
 
 typedef struct _KTRAP_FRAME

@@ -156,15 +165,6 @@

 VOID
 NtEarlyInitVdm(VOID);
 

-#define X86_EFLAGS_VM	    0x00020000 /* Virtual Mode */
-#define X86_EFLAGS_ID	    0x00200000 /* CPUID detection flag */
-
-#define X86_CR4_PAE	    0x00000020 /* enable physical address extensions */
-#define X86_CR4_PGE	    0x00000080 /* enable global pages */
-
-#define X86_FEATURE_PAE	    0x00000040 /* physical address extension is present */	
-#define X86_FEATURE_PGE	    0x00002000 /* Page Global Enable */
-

 #if defined(__GNUC__)
 #define Ke386DisableInterrupts() __asm__("cli\n\t");
 #define Ke386EnableInterrupts()  __asm__("sti\n\t");