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Diffstat (limited to 'src/VBox/ValidationKit/bootsectors/bs3kit/bs3-mode-SwitchToLM32.asm')
| -rw-r--r-- | src/VBox/ValidationKit/bootsectors/bs3kit/bs3-mode-SwitchToLM32.asm | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-mode-SwitchToLM32.asm b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-mode-SwitchToLM32.asm new file mode 100644 index 00000000..5ac49b74 --- /dev/null +++ b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-mode-SwitchToLM32.asm @@ -0,0 +1,203 @@ +; $Id: bs3-mode-SwitchToLM32.asm $ +;; @file +; BS3Kit - Bs3SwitchToLM32 +; + +; +; Copyright (C) 2007-2023 Oracle and/or its affiliates. +; +; This file is part of VirtualBox base platform packages, as +; available from https://www.virtualbox.org. +; +; This program is free software; you can redistribute it and/or +; modify it under the terms of the GNU General Public License +; as published by the Free Software Foundation, in version 3 of the +; License. +; +; This program is distributed in the hope that it will be useful, but +; WITHOUT ANY WARRANTY; without even the implied warranty of +; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +; General Public License for more details. +; +; You should have received a copy of the GNU General Public License +; along with this program; if not, see <https://www.gnu.org/licenses>. +; +; The contents of this file may alternatively be used under the terms +; of the Common Development and Distribution License Version 1.0 +; (CDDL), a copy of it is provided in the "COPYING.CDDL" file included +; in the VirtualBox distribution, in which case the provisions of the +; CDDL are applicable instead of those of the GPL. +; +; You may elect to license modified versions of this file under the +; terms and conditions of either the GPL or the CDDL or both. +; +; SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 +; + +%include "bs3kit-template-header.mac" + + +;; +; Switch to 32-bit long mode from any other mode. +; +; @cproto BS3_DECL(void) Bs3SwitchToLM32(void); +; +; @uses Nothing (except possibly high 32-bit and/or upper 64-bit register parts). +; +; @remarks There are no IDT or TSS differences between LM16, LM32 and LM64 (unlike +; PE16 & PE32, PP16 & PP32, and PAE16 & PAE32). +; +; @remarks Obviously returns to 32-bit mode, even if the caller was in 16-bit +; or 64-bit mode. It doesn't not preserve the callers ring, but +; instead changes to ring-0. +; +; @remarks Does not require 20h of parameter scratch space in 64-bit mode. +; +BS3_GLOBAL_NAME_EX TMPL_NM(Bs3SwitchToLM32_Safe), function, 0 +BS3_PROC_BEGIN_MODE Bs3SwitchToLM32, BS3_PBC_NEAR +%ifdef TMPL_LM32 + ret + +%elifdef TMPL_CMN_LM + ; + ; Already in long mode, just switch to 32-bit. + ; + extern BS3_CMN_NM(Bs3SwitchTo32Bit) + jmp BS3_CMN_NM(Bs3SwitchTo32Bit) + +%elif BS3_MODE_IS_V86(TMPL_MODE) + ; + ; V8086 - Switch to 16-bit ring-0 and call worker for that mode. + ; + extern BS3_CMN_NM(Bs3SwitchToRing0) + call BS3_CMN_NM(Bs3SwitchToRing0) + extern %[BS3_MODE_R0_NM_ %+ TMPL_MODE](Bs3SwitchToLM32) + jmp %[BS3_MODE_R0_NM_ %+ TMPL_MODE](Bs3SwitchToLM32) + +%else + %if TMPL_BITS == 16 + push word 0 ; save space for extending the return value. + %endif + + ; + ; Switch to 32-bit protected mode (for identify mapped pages). + ; + extern TMPL_NM(Bs3SwitchToPE32) + call TMPL_NM(Bs3SwitchToPE32) + BS3_SET_BITS 32 + %if TMPL_BITS == 16 + jmp .thirty_two_bit_segment +BS3_BEGIN_TEXT32 +BS3_GLOBAL_LOCAL_LABEL .thirty_two_bit_segment + %endif + + push eax + push ecx + push edx + pushfd + + ; + ; Make sure both PAE and PSE are enabled (requires pentium pro). + ; + mov eax, cr4 + mov ecx, eax + or eax, X86_CR4_PAE | X86_CR4_PSE + cmp eax, ecx + je .cr4_is_fine + mov cr4, eax +.cr4_is_fine: + + ; + ; Get the page directory (returned in eax). + ; Will lazy init page tables. + ; + extern NAME(Bs3PagingGetRootForLM64_pe32) + call NAME(Bs3PagingGetRootForLM64_pe32) + + cli + mov cr3, eax + + ; + ; Enable long mode in EFER. + ; + mov ecx, MSR_K6_EFER + rdmsr + or eax, MSR_K6_EFER_LME + wrmsr + + ; + ; Enable paging and thereby activating LM64. + ; +BS3_EXTERN_SYSTEM16 Bs3Lgdt_Gdt +BS3_BEGIN_TEXT32 + mov eax, cr0 + or eax, X86_CR0_PG + mov cr0, eax + jmp .in_lm32 +.in_lm32: + + ; + ; Call rountine for doing mode specific setups. + ; + extern NAME(Bs3EnteredMode_lm32) + call NAME(Bs3EnteredMode_lm32) + + ; + ; Load full 64-bit GDT base address from 64-bit segment. + ; + jmp dword BS3_SEL_R0_CS64:.load_full_gdt_base wrt FLAT +.load_full_gdt_base: + BS3_SET_BITS 64 + lgdt [Bs3Lgdt_Gdt wrt FLAT] + push BS3_SEL_R0_CS32 + push .back_to_32bit wrt FLAT + o64 retf +.back_to_32bit: + BS3_SET_BITS 32 + + ; + ; Restore ecx, eax and flags (IF). + ; + %if TMPL_BITS == 16 + movzx eax, word [esp + 16 + 2] ; Load return address. + add eax, BS3_ADDR_BS3TEXT16 ; Convert it to a flat address. + mov [esp + 16], eax ; Store it in the place right for 32-bit returns. + %endif + popfd + pop edx + pop ecx + pop eax + ret + + %if TMPL_BITS != 32 +TMPL_BEGIN_TEXT + %endif +%endif +BS3_PROC_END_MODE Bs3SwitchToLM32 + + +%if TMPL_BITS == 16 +;; +; Custom far stub. +BS3_BEGIN_TEXT16_FARSTUBS +BS3_PROC_BEGIN_MODE Bs3SwitchToLM32, BS3_PBC_FAR + inc bp + push bp + mov bp, sp + + ; Call the real thing. + call TMPL_NM(Bs3SwitchToLM32) + BS3_SET_BITS 32 + + ; Jmp to common code for the tedious conversion. + %if BS3_MODE_IS_RM_OR_V86(TMPL_MODE) + extern _Bs3SwitchHlpConvRealModeRetfPopBpDecBpAndReturn_c32 + jmp _Bs3SwitchHlpConvRealModeRetfPopBpDecBpAndReturn_c32 + %else + extern _Bs3SwitchHlpConvProtModeRetfPopBpDecBpAndReturn_c32 + jmp _Bs3SwitchHlpConvProtModeRetfPopBpDecBpAndReturn_c32 + %endif + BS3_SET_BITS 16 +BS3_PROC_END_MODE Bs3SwitchToLM32 +%endif + |