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authorAngelos Mouzakitis <a.mouzakitis@virtualopensystems.com>2023-10-10 14:33:42 +0000
committerAngelos Mouzakitis <a.mouzakitis@virtualopensystems.com>2023-10-10 14:33:42 +0000
commitaf1a266670d040d2f4083ff309d732d648afba2a (patch)
tree2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/edk2/UefiCpuPkg/PiSmmCpuDxeSmm/X64/Cet.nasm
parente02cda008591317b1625707ff8e115a4841aa889 (diff)
Add submodule dependency filesHEADmaster
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/edk2/UefiCpuPkg/PiSmmCpuDxeSmm/X64/Cet.nasm')
-rw-r--r--roms/edk2/UefiCpuPkg/PiSmmCpuDxeSmm/X64/Cet.nasm34
1 files changed, 34 insertions, 0 deletions
diff --git a/roms/edk2/UefiCpuPkg/PiSmmCpuDxeSmm/X64/Cet.nasm b/roms/edk2/UefiCpuPkg/PiSmmCpuDxeSmm/X64/Cet.nasm
new file mode 100644
index 000000000..3240f9d97
--- /dev/null
+++ b/roms/edk2/UefiCpuPkg/PiSmmCpuDxeSmm/X64/Cet.nasm
@@ -0,0 +1,34 @@
+;------------------------------------------------------------------------------ ;
+; Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+;-------------------------------------------------------------------------------
+
+%include "Nasm.inc"
+
+DEFAULT REL
+SECTION .text
+
+global ASM_PFX(DisableCet)
+ASM_PFX(DisableCet):
+
+ ; Skip the pushed data for call
+ mov rax, 1
+ INCSSP_RAX
+
+ mov rax, cr4
+ btr eax, 23 ; clear CET
+ mov cr4, rax
+ ret
+
+global ASM_PFX(EnableCet)
+ASM_PFX(EnableCet):
+
+ mov rax, cr4
+ bts eax, 23 ; set CET
+ mov cr4, rax
+
+ ; use jmp to skip the check for ret
+ pop rax
+ jmp rax
+