diff --git a/reactos/ntoskrnl/ke/freeldr.c b/reactos/ntoskrnl/ke/freeldr.c
index eca793b029d..8b47b5ad3d1 100644
--- a/reactos/ntoskrnl/ke/freeldr.c
+++ b/reactos/ntoskrnl/ke/freeldr.c
@@ -244,8 +244,9 @@ KiRosFrldrLpbToNtLpb(IN PROS_LOADER_PARAMETER_BLOCK RosLoaderBlock,
 }
 
 VOID
-NTAPI
-KiRosPrepareForSystemStartup(IN PROS_LOADER_PARAMETER_BLOCK LoaderBlock)
+FASTCALL
+KiRosPrepareForSystemStartup(IN ULONG Dummy,
+                             IN PROS_LOADER_PARAMETER_BLOCK LoaderBlock)
 {
     ULONG i;
     ULONG size;
diff --git a/reactos/ntoskrnl/ke/i386/boot.S b/reactos/ntoskrnl/ke/i386/boot.S
index 000a5d9bc40..c0a68014fc4 100644
--- a/reactos/ntoskrnl/ke/i386/boot.S
+++ b/reactos/ntoskrnl/ke/i386/boot.S
@@ -1,7 +1,7 @@
 /*
  * FILE:            ntoskrnl/ke/i386/boot.S
  * COPYRIGHT:       See COPYING in the top level directory
- * PURPOSE:         Kernel Bootstrap Code
+ * PURPOSE:         FreeLDR Wrapper Bootstrap Code
  * PROGRAMMER:      Alex Ionescu (alex@relsoft.net)
  */
 
@@ -30,16 +30,6 @@ _KiDoubleFaultStack:
 .text
 .func NtProcessStartup
 _NtProcessStartup:
-
-    /* Load the initial kernel stack */
-    lea eax, _P0BootStack
-    sub eax, (NPX_FRAME_LENGTH + KTRAP_FRAME_LENGTH + KTRAP_FRAME_ALIGN)
-    mov esp, eax
-
-    /* Save initial CR0 state */
-    push CR0_EM + CR0_TS + CR0_MP
-
     /* Call the main kernel initialization */
-    push edx
-    call _KiRosPrepareForSystemStartup@4
+    jmp @KiRosPrepareForSystemStartup@8
 .endfunc
diff --git a/reactos/ntoskrnl/ke/i386/kiinit.c b/reactos/ntoskrnl/ke/i386/kiinit.c
index 54980a609ec..154be617d13 100644
--- a/reactos/ntoskrnl/ke/i386/kiinit.c
+++ b/reactos/ntoskrnl/ke/i386/kiinit.c
@@ -281,7 +281,7 @@ KiSystemStartup(IN PLOADER_PARAMETER_BLOCK LoaderBlock)
 {
     ULONG Cpu;
     PKTHREAD InitialThread;
-    PVOID InitialStack;
+    ULONG InitialStack;
     PKGDTENTRY Gdt;
     PKIDTENTRY Idt;
     PKTSS Tss;
@@ -302,7 +302,7 @@ KiSystemStartup(IN PLOADER_PARAMETER_BLOCK LoaderBlock)
     }
 
     /* Save the initial thread and stack */
-    InitialStack = (PVOID)LoaderBlock->KernelStack;
+    InitialStack = LoaderBlock->KernelStack;
     InitialThread = (PKTHREAD)LoaderBlock->Thread;
 
     /* Clean the APC List Head */
@@ -375,13 +375,21 @@ AppCpuInit:
     /* Raise to HIGH_LEVEL */
     KfRaiseIrql(HIGH_LEVEL);
 
+    /* Align stack and make space for the trap frame and NPX frame */
+    InitialStack &= ~KTRAP_FRAME_ALIGN;
+    __asm__ __volatile__("movl %0,%%esp" : :"r" (InitialStack));
+    __asm__ __volatile__("subl %0,%%esp" : :"r" (NPX_FRAME_LENGTH +
+                                                 KTRAP_FRAME_LENGTH +
+                                                 KTRAP_FRAME_ALIGN));
+    __asm__ __volatile__("push %0" : :"r" (CR0_EM + CR0_TS + CR0_MP));
+
     /* Call main kernel initialization */
     KiInitializeKernel(&KiInitialProcess.Pcb,
                        InitialThread,
-                       InitialStack,
+                       (PVOID)InitialStack,
                        (PKPRCB)__readfsdword(KPCR_PRCB),
                        Cpu,
-                       LoaderBlock);
+                       KeLoaderBlock);
 
     /* Set the priority of this thread to 0 */
     KeGetCurrentThread()->Priority = 0;