diff options
| author | Qin Long <qin.long@intel.com> | 2015-09-21 05:53:52 +0000 |
|---|---|---|
| committer | qlong <qlong@Edk2> | 2015-09-21 05:53:52 +0000 |
| commit | 3cfc7813bb7e904c4a940d638facc10be5e22645 (patch) | |
| tree | 714169431ab0af3ca0faecb44e0faa212b2ffff4 /MdePkg/Library/BaseLib/Ia32/RdRand.S | |
| parent | 82f3edf26a7f60e50b0133cdc5ec689d2b7f502e (diff) | |
| download | edk2-platforms-3cfc7813bb7e904c4a940d638facc10be5e22645.tar.xz | |
MdePkg: Add CPU RdRand access APIs for random number generation
Add AsmRdRand16/32/64 APIs for RdRand instruction access to generate
high-quality random number.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Qin Long <qin.long@intel.com>
Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18518 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'MdePkg/Library/BaseLib/Ia32/RdRand.S')
| -rw-r--r-- | MdePkg/Library/BaseLib/Ia32/RdRand.S | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseLib/Ia32/RdRand.S b/MdePkg/Library/BaseLib/Ia32/RdRand.S new file mode 100644 index 0000000000..503f65a721 --- /dev/null +++ b/MdePkg/Library/BaseLib/Ia32/RdRand.S @@ -0,0 +1,80 @@ +#------------------------------------------------------------------------------ ;
+# 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 32-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 %eax, %eax // reg=0 if CF=0
+ ret // return with failure status
+rn16_ok:
+ mov 0x4(%esp), %edx
+ mov %ax, (%edx)
+ mov $0x1, %eax
+ 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 %eax, %eax // reg=0 if CF=0
+ ret // return with failure status
+rn32_ok:
+ mov 0x4(%esp), %edx
+ mov %eax, (%edx)
+ mov $0x1, %eax
+ 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 0x0f, 0xc7, 0xf0 // rdrand r32: "0f c7 /6 ModRM:r/m(w)"
+ jnc rn64_ret // jmp if CF=0
+ mov 0x4(%esp), %edx
+ mov %eax, (%edx)
+
+ .byte 0x0f, 0xc7, 0xf0 // generate another 32 bit RN
+ jnc rn64_ret // jmp if CF=0
+ mov %eax, 0x4(%edx)
+
+ mov $0x1, %eax
+ ret
+rn64_ret:
+ xor %eax, %eax
+ ret // return with failure status
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