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/Main.asm | |
| parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) | |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/edk2/UefiCpuPkg/ResetVector/Vtf0/Main.asm')
| -rw-r--r-- | roms/edk2/UefiCpuPkg/ResetVector/Vtf0/Main.asm | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/roms/edk2/UefiCpuPkg/ResetVector/Vtf0/Main.asm b/roms/edk2/UefiCpuPkg/ResetVector/Vtf0/Main.asm new file mode 100644 index 000000000..19d08482f --- /dev/null +++ b/roms/edk2/UefiCpuPkg/ResetVector/Vtf0/Main.asm @@ -0,0 +1,105 @@ +;------------------------------------------------------------------------------
+; @file
+; Main routine of the pre-SEC code up through the jump into SEC
+;
+; Copyright (c) 2008 - 2009, Intel Corporation. All rights reserved.<BR>
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+;------------------------------------------------------------------------------
+
+
+BITS 16
+
+;
+; Modified: EBX, ECX, EDX, EBP
+;
+; @param[in,out] RAX/EAX Initial value of the EAX register
+; (BIST: Built-in Self Test)
+; @param[in,out] DI 'BP': boot-strap processor, or
+; 'AP': application processor
+; @param[out] RBP/EBP Address of Boot Firmware Volume (BFV)
+; @param[out] DS Selector allowing flat access to all addresses
+; @param[out] ES Selector allowing flat access to all addresses
+; @param[out] FS Selector allowing flat access to all addresses
+; @param[out] GS Selector allowing flat access to all addresses
+; @param[out] SS Selector allowing flat access to all addresses
+;
+; @return None This routine jumps to SEC and does not return
+;
+Main16:
+ OneTimeCall EarlyInit16
+
+ ;
+ ; Transition the processor from 16-bit real mode to 32-bit flat mode
+ ;
+ OneTimeCall TransitionFromReal16To32BitFlat
+
+BITS 32
+
+ ;
+ ; Search for the Boot Firmware Volume (BFV)
+ ;
+ OneTimeCall Flat32SearchForBfvBase
+
+ ;
+ ; EBP - Start of BFV
+ ;
+
+ ;
+ ; Search for the SEC entry point
+ ;
+ OneTimeCall Flat32SearchForSecEntryPoint
+
+ ;
+ ; ESI - SEC Core entry point
+ ; EBP - Start of BFV
+ ;
+
+%ifdef ARCH_IA32
+
+ ;
+ ; Restore initial EAX value into the EAX register
+ ;
+ mov eax, esp
+
+ ;
+ ; Jump to the 32-bit SEC entry point
+ ;
+ jmp esi
+
+%else
+
+ ;
+ ; Transition the processor from 32-bit flat mode to 64-bit flat mode
+ ;
+ OneTimeCall Transition32FlatTo64Flat
+
+BITS 64
+
+ ;
+ ; Some values were calculated in 32-bit mode. Make sure the upper
+ ; 32-bits of 64-bit registers are zero for these values.
+ ;
+ mov rax, 0x00000000ffffffff
+ and rsi, rax
+ and rbp, rax
+ and rsp, rax
+
+ ;
+ ; RSI - SEC Core entry point
+ ; RBP - Start of BFV
+ ;
+
+ ;
+ ; Restore initial EAX value into the RAX register
+ ;
+ mov rax, rsp
+
+ ;
+ ; Jump to the 64-bit SEC entry point
+ ;
+ jmp rsi
+
+%endif
+
+
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