[PATCH 05/10] OvmfPkg/Sec: Swap TemporaryRam Stack and Heap locations

[Jordan Justen <jordan.l.justen@intel.com>]

Apparently something depends on the heap being above the stack after
TemporaryRamMigration.

This is the opposite order that OVMF has always used for TempRam
before migration to permanent ram. In 42a83e80f37c (svn r10770), Mike
changed OVMF's TemporaryRamMigration to swap the locations of heap and
stack during the migration.

Rather than doing the swap during TemporaryRamMigration, this change
causes OVMF to boot with TemporaryRam setup with heap being above the
stack. Then, during TemporaryRamMigration, we can directly copy all of
TemporaryRam.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Julien Grall <julien.grall@linaro.org>
---
 OvmfPkg/Sec/Ia32/SecEntry.nasm |  2 +-
 OvmfPkg/Sec/SecMain.c          | 39 +++++++++++++++++-----------------
 OvmfPkg/Sec/X64/SecEntry.nasm  |  2 +-
 3 files changed, 22 insertions(+), 21 deletions(-)

diff --git a/OvmfPkg/Sec/Ia32/SecEntry.nasm b/OvmfPkg/Sec/Ia32/SecEntry.nasm
index 03501969eb..61917b9eef 100644
--- a/OvmfPkg/Sec/Ia32/SecEntry.nasm
+++ b/OvmfPkg/Sec/Ia32/SecEntry.nasm
@@ -57,7 +57,7 @@ ASM_PFX(_ModuleEntryPoint):
     ; Load temporary RAM stack based on PCDs
     ;
     %define SEC_TOP_OF_STACK (FixedPcdGet32 (PcdOvmfSecPeiTempRamBase) + \
-                          FixedPcdGet32 (PcdOvmfSecPeiTempRamSize))
+                          (FixedPcdGet32 (PcdOvmfSecPeiTempRamSize) / 2))
     mov     eax, SEC_TOP_OF_STACK
     mov     esp, eax
     nop
diff --git a/OvmfPkg/Sec/SecMain.c b/OvmfPkg/Sec/SecMain.c
index f7fec3d8c0..46ac739862 100644
--- a/OvmfPkg/Sec/SecMain.c
+++ b/OvmfPkg/Sec/SecMain.c
@@ -1,7 +1,7 @@
 /** @file
   Main SEC phase code.  Transitions to PEI.
 
-  Copyright (c) 2008 - 2015, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2008 - 2019, Intel Corporation. All rights reserved.<BR>
   (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>
 
   This program and the accompanying materials
@@ -779,15 +779,15 @@ SecCoreStartupWithStack (
 #endif
 
   //
-  // |-------------|       <-- TopOfCurrentStack
-  // |   Stack     | 32k
   // |-------------|
   // |    Heap     | 32k
+  // |-------------|       <-- TopOfCurrentStack
+  // |   Stack     | 32k
   // |-------------|       <-- SecCoreData.TemporaryRamBase
   //
 
   ASSERT ((UINTN) (PcdGet32 (PcdOvmfSecPeiTempRamBase) +
-                   PcdGet32 (PcdOvmfSecPeiTempRamSize)) ==
+                   (PcdGet32 (PcdOvmfSecPeiTempRamSize) / 2)) ==
           (UINTN) TopOfCurrentStack);
 
   //
@@ -795,14 +795,17 @@ SecCoreStartupWithStack (
   //
   SecCoreData.DataSize = sizeof(EFI_SEC_PEI_HAND_OFF);
 
-  SecCoreData.TemporaryRamSize       = (UINTN) PcdGet32 (PcdOvmfSecPeiTempRamSize);
-  SecCoreData.TemporaryRamBase       = (VOID*)((UINT8 *)TopOfCurrentStack - SecCoreData.TemporaryRamSize);
+  SecCoreData.TemporaryRamBase =
+    (VOID*)(UINTN) PcdGet32 (PcdOvmfSecPeiTempRamBase);
+  SecCoreData.TemporaryRamSize = (UINTN) PcdGet32 (PcdOvmfSecPeiTempRamSize);
 
-  SecCoreData.PeiTemporaryRamBase    = SecCoreData.TemporaryRamBase;
-  SecCoreData.PeiTemporaryRamSize    = SecCoreData.TemporaryRamSize >> 1;
+  SecCoreData.PeiTemporaryRamBase =
+    (UINT8*)(VOID*)(UINTN) PcdGet32 (PcdOvmfSecPeiTempRamBase) +
+    ((UINTN) PcdGet32 (PcdOvmfSecPeiTempRamSize) / 2);
+  SecCoreData.PeiTemporaryRamSize = PcdGet32 (PcdOvmfSecPeiTempRamSize) / 2;
 
-  SecCoreData.StackBase              = (UINT8 *)SecCoreData.TemporaryRamBase + SecCoreData.PeiTemporaryRamSize;
-  SecCoreData.StackSize              = SecCoreData.TemporaryRamSize >> 1;
+  SecCoreData.StackBase = (VOID*)(UINTN) PcdGet32 (PcdOvmfSecPeiTempRamBase);
+  SecCoreData.StackSize = PcdGet32 (PcdOvmfSecPeiTempRamSize) / 2;
 
   SecCoreData.BootFirmwareVolumeBase = BootFv;
   SecCoreData.BootFirmwareVolumeSize = (UINTN) BootFv->FvLength;
@@ -895,10 +898,10 @@ TemporaryRamMigration (
     (UINT64)CopySize
     ));
   
-  OldHeap = (VOID*)(UINTN)TemporaryMemoryBase;
+  OldHeap = (VOID*)((UINTN)TemporaryMemoryBase + (CopySize >> 1));
   NewHeap = (VOID*)((UINTN)PermanentMemoryBase + (CopySize >> 1));
   
-  OldStack = (VOID*)((UINTN)TemporaryMemoryBase + (CopySize >> 1));
+  OldStack = (VOID*)(UINTN)TemporaryMemoryBase;
   NewStack = (VOID*)(UINTN)PermanentMemoryBase;
 
   DebugAgentContext.HeapMigrateOffset = (UINTN)NewHeap - (UINTN)OldHeap;
@@ -908,15 +911,13 @@ TemporaryRamMigration (
   InitializeDebugAgent (DEBUG_AGENT_INIT_POSTMEM_SEC, (VOID *) &DebugAgentContext, NULL);
 
   //
-  // Migrate Heap
+  // Migrate the whole temporary memory to permenent memory.
   //
-  CopyMem (NewHeap, OldHeap, CopySize >> 1);
+  CopyMem(
+    (VOID*)(UINTN)PermanentMemoryBase,
+    (VOID*)(UINTN)TemporaryMemoryBase,
+    CopySize);
 
-  //
-  // Migrate Stack
-  //
-  CopyMem (NewStack, OldStack, CopySize >> 1);
-  
   //
   // Rebase IDT table in permanent memory
   //
diff --git a/OvmfPkg/Sec/X64/SecEntry.nasm b/OvmfPkg/Sec/X64/SecEntry.nasm
index d76adcffd8..dd603d6eb0 100644
--- a/OvmfPkg/Sec/X64/SecEntry.nasm
+++ b/OvmfPkg/Sec/X64/SecEntry.nasm
@@ -59,7 +59,7 @@ ASM_PFX(_ModuleEntryPoint):
     ; Load temporary RAM stack based on PCDs
     ;
     %define SEC_TOP_OF_STACK (FixedPcdGet32 (PcdOvmfSecPeiTempRamBase) + \
-                          FixedPcdGet32 (PcdOvmfSecPeiTempRamSize))
+                          (FixedPcdGet32 (PcdOvmfSecPeiTempRamSize) / 2))
     mov     rsp, SEC_TOP_OF_STACK
     nop
 
-- 
2.20.0.rc1