diff options
Diffstat (limited to 'src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SwitchTo64Bit.asm')
| -rw-r--r-- | src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SwitchTo64Bit.asm | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SwitchTo64Bit.asm b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SwitchTo64Bit.asm new file mode 100644 index 00000000..dfa70f58 --- /dev/null +++ b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SwitchTo64Bit.asm @@ -0,0 +1,120 @@ +; $Id: bs3-cmn-SwitchTo64Bit.asm $ +;; @file +; BS3Kit - Bs3SwitchTo64Bit +; + +; +; 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" + +%if TMPL_BITS != 64 +BS3_EXTERN_DATA16 g_bBs3CurrentMode +TMPL_BEGIN_TEXT +%endif + + +;; +; @cproto BS3_DECL(void) Bs3SwitchTo64Bit(void); +; +; @remarks Does not require 20h of parameter scratch space in 64-bit mode. +; @uses No GPRs. +; +BS3_PROC_BEGIN_CMN Bs3SwitchTo64Bit, BS3_PBC_NEAR +%if TMPL_BITS == 64 + ret + +%else + %if TMPL_BITS == 16 + sub sp, 6 ; Space for extended return value (corrected in 64-bit mode). + %else + push xPRE [xSP] ; Duplicate the return address. + and dword [xSP + xCB], 0 ; Clear the high dword or it. + %endif + push dword 0 + push sAX + push dword 0 + pushfd + cli + + %if TMPL_BITS == 16 + ; Check that this is LM16 + mov ax, seg g_bBs3CurrentMode + cmp byte [BS3_DATA16_WRT(g_bBs3CurrentMode)], BS3_MODE_LM16 + je .ok_lm16 + int3 + .ok_lm16: + %endif + + ; Calc ring addend. + mov ax, cs + and xAX, 3 + shl xAX, BS3_SEL_RING_SHIFT + add xAX, BS3_SEL_R0_CS64 + + ; setup far return. + push sAX + %if TMPL_BITS == 16 + push dword .sixty_four_bit wrt FLAT + o32 retf + %else + push .sixty_four_bit + retf + %endif + +BS3_SET_BITS 64 +.sixty_four_bit: + + ; Load 64-bit segment registers (SS64==DS64). + add eax, BS3_SEL_R0_DS64 - BS3_SEL_R0_CS64 + mov ss, ax + mov ds, ax + mov es, ax + + ; Update globals. + and byte [BS3_DATA16_WRT(g_bBs3CurrentMode)], ~BS3_MODE_CODE_MASK + or byte [BS3_DATA16_WRT(g_bBs3CurrentMode)], BS3_MODE_CODE_64 + + %if TMPL_BITS == 16 + movzx eax, word [rsp + 8*2+6] + add eax, BS3_ADDR_BS3TEXT16 + mov [rsp + 8*2], rax + %endif + + popfq + pop rax + ret +%endif +BS3_PROC_END_CMN Bs3SwitchTo64Bit + + +;; @todo far 16-bit variant. + |