| 1 | ; $Id: bs3-cmn-SwitchTo64Bit.asm 59885 2016-03-01 12:13:37Z vboxsync $
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| 2 | ;; @file
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| 3 | ; BS3Kit - Bs3SwitchTo64Bit
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| 4 | ;
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| 5 |
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| 6 | ;
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| 7 | ; Copyright (C) 2007-2015 Oracle Corporation
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| 8 | ;
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| 9 | ; This file is part of VirtualBox Open Source Edition (OSE), as
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| 10 | ; available from http://www.virtualbox.org. This file is free software;
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| 11 | ; you can redistribute it and/or modify it under the terms of the GNU
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| 12 | ; General Public License (GPL) as published by the Free Software
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| 13 | ; Foundation, in version 2 as it comes in the "COPYING" file of the
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| 14 | ; VirtualBox OSE distribution. VirtualBox OSE is distributed in the
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| 15 | ; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
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| 16 | ;
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| 17 | ; The contents of this file may alternatively be used under the terms
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| 18 | ; of the Common Development and Distribution License Version 1.0
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| 19 | ; (CDDL) only, as it comes in the "COPYING.CDDL" file of the
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| 20 | ; VirtualBox OSE distribution, in which case the provisions of the
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| 21 | ; CDDL are applicable instead of those of the GPL.
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| 22 | ;
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| 23 | ; You may elect to license modified versions of this file under the
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| 24 | ; terms and conditions of either the GPL or the CDDL or both.
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| 25 | ;
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| 26 |
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| 27 | %include "bs3kit-template-header.mac"
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| 28 |
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| 29 | %if TMPL_BITS != 64
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| 30 | BS3_EXTERN_DATA16 g_bBs3CurrentMode
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| 31 | TMPL_BEGIN_TEXT
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| 32 | %endif
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| 33 |
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| 34 |
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| 35 | ;;
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| 36 | ; @cproto BS3_DECL(void) Bs3SwitchTo64Bit(void);
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| 37 | ;
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| 38 | ; @remarks Does not require 20h of parameter scratch space in 64-bit mode.
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| 39 | ;
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| 40 | BS3_PROC_BEGIN_CMN Bs3SwitchTo64Bit
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| 41 | %if TMPL_BITS == 64
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| 42 | ret
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| 43 |
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| 44 | %elif BS3_MODE_IS_RM_OR_V86(TMPL_MODE)
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| 45 | .again: int3 ; Makes no sense to go to 64-bit mode from real or v8086 mode.
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| 46 | jmp .again
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| 47 |
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| 48 | %else
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| 49 | %if TMPL_BITS == 16
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| 50 | sub sp, 6 ; Space for extended return value (corrected in 64-bit mode).
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| 51 | %else
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| 52 | push xPRE [xSP] ; Duplicate the return address.
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| 53 | and dword [xSP + xCB], 0 ; Clear the high dword or it.
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| 54 | %endif
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| 55 | push dword 0
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| 56 | push sAX
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| 57 | push dword 0
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| 58 | pushfd
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| 59 | cli
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| 60 |
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| 61 | ; Calc ring addend.
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| 62 | mov ax, cs
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| 63 | and xAX, 3
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| 64 | shl xAX, BS3_SEL_RING_SHIFT
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| 65 | add xAX, BS3_SEL_R0_CS64
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| 66 |
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| 67 | ; setup far return.
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| 68 | push sAX
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| 69 | %if TMPL_BITS == 16
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| 70 | push dword .sixty_four_bit
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| 71 | o32 retf
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| 72 | %else
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| 73 | push .sixty_four_bit
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| 74 | retf
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| 75 | %endif
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| 76 |
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| 77 | BS3_SET_BITS 64
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| 78 | .sixty_four_bit:
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| 79 |
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| 80 | ; Load 64-bit segment registers (SS64==DS64).
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| 81 | add eax, BS3_SEL_R0_DS64 - BS3_SEL_R0_CS64
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| 82 | mov ss, ax
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| 83 | mov ds, ax
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| 84 | mov es, ax
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| 85 |
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| 86 | ; Update globals.
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| 87 | and byte [BS3_WRT_RIP(g_bBs3CurrentMode)], ~BS3_MODE_CODE_MASK
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| 88 | or byte [BS3_WRT_RIP(g_bBs3CurrentMode)], BS3_MODE_CODE_64
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| 89 |
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| 90 | %if TMPL_BITS == 16
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| 91 | movzx eax, word [rsp + 8*2+6]
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| 92 | add eax, BS3_ADDR_BS3TEXT16
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| 93 | mov [rsp + 8*2], rax
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| 94 | %endif
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| 95 |
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| 96 | popfq
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| 97 | pop rax
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| 98 | ret
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| 99 | %endif
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| 100 | BS3_PROC_END_CMN Bs3SwitchTo64Bit
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| 101 |
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