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-rw-r--r--EmulatorPkg/Sec/X64/SwitchRam.S72
1 files changed, 72 insertions, 0 deletions
diff --git a/EmulatorPkg/Sec/X64/SwitchRam.S b/EmulatorPkg/Sec/X64/SwitchRam.S
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+++ b/EmulatorPkg/Sec/X64/SwitchRam.S
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+#------------------------------------------------------------------------------
+#
+# Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
+# Portitions copyright (c) 2011, Apple Inc. All rights reserved.
+# This program and the accompanying materials
+# are licensed and made available under the terms and conditions of the BSD License
+# which accompanies this distribution. The full text of the license may be found at
+# http://opensource.org/licenses/bsd-license.php.
+#
+# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+#
+#------------------------------------------------------------------------------
+
+
+
+// EFI_STATUS
+// EFIAPI
+// SecTemporaryRamSupport (
+// IN CONST EFI_PEI_SERVICES **PeiServices, // %rcx
+// IN EFI_PHYSICAL_ADDRESS TemporaryMemoryBase, // %rdx
+// IN EFI_PHYSICAL_ADDRESS PermanentMemoryBase, // %r8
+// IN UINTN CopySize // %r9
+// )
+//
+ASM_GLOBAL ASM_PFX(SecTemporaryRamSupport)
+ASM_PFX(SecTemporaryRamSupport):
+ // Adjust callers %rbp to account for stack move
+ subq %rdx, %rbp // Calc offset of %rbp in Temp Memory
+ addq %r8, %rbp // add in permanent base to offset
+
+ pushq %rbp // stack frame is for the debugger
+ movq %rsp, %rbp
+
+ pushq %rdx // Save TemporaryMemoryBase
+ pushq %r8 // Save PermanentMemoryBase
+ pushq %r9 // Save CopySize
+
+ //
+ // Copy all of temp RAM to permanent memory, including stack
+ //
+ // CopyMem (PermanentMemoryBase, TemporaryMemoryBase, CopySize);
+ // %rcx, %rdx, %r8
+ movq %r8, %rcx // Shift arguments
+ movq %r9, %r8
+ subq $0x28, %rsp // Allocate register spill area & 16-byte align stack
+ call ASM_PFX(CopyMem)
+ // Temp mem stack now copied to permanent location. %esp still in temp memory
+ addq $0x28, %rsp
+
+ popq %r9 // CopySize (old stack)
+ popq %r8 // PermanentMemoryBase (old stack)
+ popq %rdx // TemporaryMemoryBase (old stack)
+
+ movq %rsp, %rcx // Move to new stack
+ subq %rdx, %rcx // Calc offset of stack in Temp Memory
+ addq %r8, %rcx // Calc PermanentMemoryBase address
+ movq %rcx, %rsp // Update stack
+ // Stack now points to permanent memory
+
+ // ZeroMem (TemporaryMemoryBase /* rcx */, CopySize /* rdx */);
+ movq %rdx, %rcx
+ movq %r9, %rdx
+ subq $0x28, %rsp // Allocate register spill area & 16-byte align stack
+ call ASM_PFX(ZeroMem)
+ addq $0x28, %rsp
+
+ // This data comes off the NEW stack
+ popq %rbp
+ ret
+
+