Disable correct usage of ESP0 since it seems the V86 code is still not ready to handle that. This should fix the V86 exceptions some people have been having.

Modified: trunk/reactos/ntoskrnl/ke/i386/ctxswitch.S
Modified: trunk/reactos/ntoskrnl/ke/i386/thread.c

--- trunk/reactos/ntoskrnl/ke/i386/ctxswitch.S	2006-01-16 16:45:27 UTC (rev 20913)
+++ trunk/reactos/ntoskrnl/ke/i386/ctxswitch.S	2006-01-16 17:05:50 UTC (rev 20914)
@@ -171,8 +171,11 @@

 NoAdjust:
 
     /* Set new ESP0 */

-    mov [ebp+KTSS_ESP0], eax

+    //mov [ebp+KTSS_ESP0], eax

+    /* Save it */
+    push [ebp+KTSS_ESP0]
+

     /* Set TEB pointer */
     mov eax, [esi+KTHREAD_TEB]
     mov [ebx+KPCR_TEB], eax
@@ -257,6 +260,9 @@

     mov cr0, eax
 4:
 

+    /* Restore ESP0 */
+    pop [ebp+KTSS_ESP0]
+

     /* Restore exception list */
     pop [ebx+KPCR_EXCEPTION_LIST]
 

--- trunk/reactos/ntoskrnl/ke/i386/thread.c	2006-01-16 16:45:27 UTC (rev 20913)
+++ trunk/reactos/ntoskrnl/ke/i386/thread.c	2006-01-16 17:05:50 UTC (rev 20914)
@@ -14,6 +14,7 @@

 
 typedef struct _KSHARED_CTXSWITCH_FRAME
 {

+    ULONG Esp0;

     PVOID ExceptionList;
     PVOID RetEip;
 } KSHARED_CTXSWITCH_FRAME, *PKSHARED_CTXSWITCH_FRAME;
@@ -231,6 +232,9 @@

 
     /* And set up the Context Switch Frame */
     CtxSwitchFrame->RetEip = KiThreadStartup;

+    CtxSwitchFrame->Esp0 = (ULONG_PTR)Thread->InitialStack -
+                                      sizeof(FX_SAVE_AREA) -
+                                      0x10;

     CtxSwitchFrame->ExceptionList = (PVOID)0xFFFFFFFF;
 
     /* Save back the new value of the kernel stack. */