1 files changed, 72 insertions, 0 deletions
diff --git a/Core/MdePkg/Library/BaseLib/X64/RdRand.S b/Core/MdePkg/Library/BaseLib/X64/RdRand.S
new file mode 100644
index 0000000000..49b50e6901
--- /dev/null
+++ b/Core/MdePkg/Library/BaseLib/X64/RdRand.S
@@ -0,0 +1,72 @@
+#------------------------------------------------------------------------------ ;
+# Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
+# 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.
+#
+# Module Name:
+#
+#   RdRand.S
+#
+# Abstract:
+#
+#   Generates random number through CPU RdRand instruction under 64-bit platform.
+#
+# Notes:
+#
+#------------------------------------------------------------------------------
+
+//------------------------------------------------------------------------------
+//  Generates a 16 bit random number through RDRAND instruction.
+//  Return TRUE if Rand generated successfully, or FALSE if not.
+//
+//  BOOLEAN EFIAPI AsmRdRand16 (UINT16 *Rand);
+//------------------------------------------------------------------------------
+ASM_GLOBAL ASM_PFX(AsmRdRand16)
+ASM_PFX(AsmRdRand16):
+    .byte  0x0f, 0xc7, 0xf0        // rdrand r16: "0f c7 /6  ModRM:r/m(w)"
+    jc     rn16_ok                 // jmp if CF=1
+    xor    %rax, %rax              // reg=0 if CF=0
+    ret                            // return with failure status
+rn16_ok:
+    mov    %ax, (%rcx)
+    mov    $0x1, %rax
+    ret
+
+//------------------------------------------------------------------------------
+//  Generates a 32 bit random number through RDRAND instruction.
+//  Return TRUE if Rand generated successfully, or FALSE if not.
+//
+//  BOOLEAN EFIAPI AsmRdRand32 (UINT32 *Rand);
+//------------------------------------------------------------------------------
+ASM_GLOBAL ASM_PFX(AsmRdRand32)
+ASM_PFX(AsmRdRand32):
+    .byte  0x0f, 0xc7, 0xf0        // rdrand r32: "0f c7 /6  ModRM:r/m(w)"
+    jc     rn32_ok                 // jmp if CF=1
+    xor    %rax, %rax              // reg=0 if CF=0
+    ret                            // return with failure status
+rn32_ok:
+    mov    %eax, (%rcx)
+    mov    $0x1, %rax
+    ret
+
+//------------------------------------------------------------------------------
+//  Generates a 64 bit random number through RDRAND instruction.
+//  Return TRUE if Rand generated successfully, or FALSE if not.
+//
+//  BOOLEAN EFIAPI AsmRdRand64 (UINT64 *Rand);
+//------------------------------------------------------------------------------
+ASM_GLOBAL ASM_PFX(AsmRdRand64)
+ASM_PFX(AsmRdRand64):
+    .byte  0x48, 0x0f, 0xc7, 0xf0  // rdrand r64: "REX.W + 0f c7 /6 ModRM:r/m(w)"
+    jc     rn64_ok                 // jmp if CF=1
+    xor    %rax, %rax              // reg=0 if CF=0
+    ret                            // return with failure status
+rn64_ok:
+    mov    %rax, (%rcx)
+    mov    $0x1, %rax
+    ret