From 790760dcf4d2f80b6f34e73395945497c11ba4b9 Mon Sep 17 00:00:00 2001
From: Alex Ionescu <aionescu@gmail.com>
Date: Sun, 1 Oct 2006 06:08:05 +0000
Subject: [PATCH] - Remove all the remaining code in boot.S and make
 KiRosPrepareForSystemStartup fastcall. Now NtProcessStartup just does a jmp
 to KiRosPrepareForSystemStartup without any other code. - Use freeldr's stack
 during all of freeldr.c, and only switch to the boot stack in KiSystemStartup
 before calling KiInitializeKernel. This is what NT does as well (it
 piggybacks on NTLDR's stack until then). This allowed us to clean boot.S and
 now we can boot from NTLDR properly.

svn path=/trunk/; revision=24333
---
 reactos/ntoskrnl/ke/freeldr.c     |  5 +++--
 reactos/ntoskrnl/ke/i386/boot.S   | 14 ++------------
 reactos/ntoskrnl/ke/i386/kiinit.c | 16 ++++++++++++----
 3 files changed, 17 insertions(+), 18 deletions(-)

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;