diff options
| author |   Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
|---|---|---|
| committer | Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
| commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
| tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/edk2/UefiCpuPkg/ResetVector/Vtf0/Ia32/Flat32ToFlat64.asm | |
| parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) | |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/edk2/UefiCpuPkg/ResetVector/Vtf0/Ia32/Flat32ToFlat64.asm')
| -rw-r--r-- | roms/edk2/UefiCpuPkg/ResetVector/Vtf0/Ia32/Flat32ToFlat64.asm | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/roms/edk2/UefiCpuPkg/ResetVector/Vtf0/Ia32/Flat32ToFlat64.asm b/roms/edk2/UefiCpuPkg/ResetVector/Vtf0/Ia32/Flat32ToFlat64.asm new file mode 100644 index 000000000..6891397c2 --- /dev/null +++ b/roms/edk2/UefiCpuPkg/ResetVector/Vtf0/Ia32/Flat32ToFlat64.asm @@ -0,0 +1,39 @@ +;------------------------------------------------------------------------------
+; @file
+; Transition from 32 bit flat protected mode into 64 bit flat protected mode
+;
+; Copyright (c) 2008 - 2018, Intel Corporation. All rights reserved.<BR>
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+;------------------------------------------------------------------------------
+
+BITS 32
+
+;
+; Modified: EAX
+;
+Transition32FlatTo64Flat:
+
+ OneTimeCall SetCr3ForPageTables64
+
+ mov eax, cr4
+ bts eax, 5 ; enable PAE
+ mov cr4, eax
+
+ mov ecx, 0xc0000080
+ rdmsr
+ bts eax, 8 ; set LME
+ wrmsr
+
+ mov eax, cr0
+ bts eax, 31 ; set PG
+ mov cr0, eax ; enable paging
+
+ jmp LINEAR_CODE64_SEL:ADDR_OF(jumpTo64BitAndLandHere)
+BITS 64
+jumpTo64BitAndLandHere:
+
+ debugShowPostCode POSTCODE_64BIT_MODE
+
+ OneTimeCallRet Transition32FlatTo64Flat
+
|