diff --git a/AdvLoggerPkg/Library/DebugAgent/Sec/AdvancedLoggerSecDebugAgent.h b/AdvLoggerPkg/Library/DebugAgent/Sec/AdvancedLoggerSecDebugAgent.h
index 1e4dae19ef..3dd40ea5fc 100644
--- a/AdvLoggerPkg/Library/DebugAgent/Sec/AdvancedLoggerSecDebugAgent.h
+++ b/AdvLoggerPkg/Library/DebugAgent/Sec/AdvancedLoggerSecDebugAgent.h
@@ -57,7 +57,7 @@ UINT32 *
 EFIAPI
 AsmRepLodsd (
   IN UINT32  *Address,
-  IN UINT32  Length
+  IN UINTN   Length
   );
 
 #endif // __ADVANCED_LOGGER_SEC_DEBUGAGENT_H__
diff --git a/AdvLoggerPkg/Library/DebugAgent/Sec/AdvancedLoggerSecDebugAgent.inf b/AdvLoggerPkg/Library/DebugAgent/Sec/AdvancedLoggerSecDebugAgent.inf
index 9cec1e7bac..c0b4a5f64a 100644
--- a/AdvLoggerPkg/Library/DebugAgent/Sec/AdvancedLoggerSecDebugAgent.inf
+++ b/AdvLoggerPkg/Library/DebugAgent/Sec/AdvancedLoggerSecDebugAgent.inf
@@ -22,16 +22,19 @@
 #
 # The following information is for reference only and not required by the build tools.
 #
-#  VALID_ARCHITECTURES           = IA32
+#  VALID_ARCHITECTURES           = IA32 X64
 #
 
 [Sources]
   AdvancedLoggerSecDebugAgent.c
+  RamForSEC.c
 
-[Sources.Ia32]
-  ia32/RamForSEC.c
+[Sources.IA32]
   ia32/AsmRepLodsd.nasm
 
+[Sources.X64]
+  X64/AsmRepLodsd.nasm
+
 [Packages]
   MdePkg/MdePkg.dec
   MdeModulePkg/MdeModulePkg.dec
diff --git a/AdvLoggerPkg/Library/DebugAgent/Sec/ia32/RamForSEC.c b/AdvLoggerPkg/Library/DebugAgent/Sec/RamForSEC.c
similarity index 100%
rename from AdvLoggerPkg/Library/DebugAgent/Sec/ia32/RamForSEC.c
rename to AdvLoggerPkg/Library/DebugAgent/Sec/RamForSEC.c
diff --git a/AdvLoggerPkg/Library/DebugAgent/Sec/X64/AsmRepLodsd.nasm b/AdvLoggerPkg/Library/DebugAgent/Sec/X64/AsmRepLodsd.nasm
new file mode 100644
index 0000000000..fcfe34865a
--- /dev/null
+++ b/AdvLoggerPkg/Library/DebugAgent/Sec/X64/AsmRepLodsd.nasm
@@ -0,0 +1,42 @@
+;------------------------------------------------------------------------------
+;
+; Copyright (c) Microsoft Corporation. All rights reserved.
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+; Module Name:
+;
+;   RepLodsd.nasm
+;
+; Abstract:
+;
+;       Executes a rep lodsd (repeated load dword string instruction).  While there is no valid
+;       data at the address, this allocates entries in the cache with the correct address tags.
+;
+;  @param  Address The pointer to the cache location.
+;  @param  Length  The length in bytes of the region to load.
+;
+;  @return Value   Returns the next address to be touched (to verify the rep lodsd operation)
+;
+;------------------------------------------------------------------------------
+
+    SECTION .text
+
+;------------------------------------------------------------------------------
+; UINT32 *
+; EFIAPI
+; AsmRepLodsd (
+;   IN UINT32  *Address,      // rcx
+;   IN UINTN   Length         // rdx
+;   );
+;------------------------------------------------------------------------------
+global ASM_PFX(AsmRepLodsd)
+ASM_PFX(AsmRepLodsd):
+     push    rsi
+     xchg    rcx, rdx
+     mov     rsi, rdx
+     shr     rcx, 2
+     cld
+     rep     lodsd
+     mov     rax, rsi
+     pop     rsi
+    ret
diff --git a/AdvLoggerPkg/Library/DebugAgent/Sec/ia32/AsmRepLodsd.nasm b/AdvLoggerPkg/Library/DebugAgent/Sec/ia32/AsmRepLodsd.nasm
index 8499095e4c..7bc179168a 100644
--- a/AdvLoggerPkg/Library/DebugAgent/Sec/ia32/AsmRepLodsd.nasm
+++ b/AdvLoggerPkg/Library/DebugAgent/Sec/ia32/AsmRepLodsd.nasm
@@ -26,7 +26,7 @@
 ; EFIAPI
 ; AsmRepLodsd (
 ;   IN UINT32  *Address,
-;   IN UINT32   Length
+;   IN UINTN   Length
 ;   );
 ;------------------------------------------------------------------------------
 global ASM_PFX(AsmRepLodsd)