path: root/src/VBox/ValidationKit/bootsectors/bootsector2-cpu-a20-1-template.mac

; $Id: bootsector2-cpu-a20-1-template.mac $
;; @file
; bootsector2 A20 - multi mode template.
;

;
; 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 "bootsector2-template-header.mac"


;;
; Inner loop dealing with one 64KB segment.
;
BEGINPROC TMPL_NM(TestA20_EnabledInner)
.inner_loop:
        mov     ah, [es:xDI]
        mov     al, [ds:xSI]
        cmp     al, ah
        jne     .inner_next

        not     al
        mov     [es:xDI], al
        cmp     al, [ds:xSI]
        mov     [es:xDI], ah
        je      .failed

.inner_next:
        inc     xDI
        inc     xSI
        dec     ecx
        jnz     .inner_loop

        clc
        ret

.failed:
        push    sBX
        push    sAX
        push    sSI
        push    sDI
%ifdef TMPL_16BIT
        push    cs
%endif
        push    .s_szModifiyError
        call    TMPL_NM_CMN(TestFailedF)
        add     xSP, sCB * 5
        stc
        ret
.s_szModifiyError:
        db      TMPL_MODE_STR, '- Same memory; EDI=%RX32 ESI=%RX32 EAX=%RX32 EBX=%RX32', 13, 10, 0
ENDPROC   TMPL_NM(TestA20_EnabledInner)


;;
; Inner loop dealing with one 64KB segment.
;
BEGINPROC TMPL_NM(TestA20_DisabledInner)
.inner_loop:
        mov     ah, [es:xDI]
        mov     al, [ds:xSI]
        cmp     al, ah
        jne     .failed1

        not     al
        mov     [es:xDI], al
        cmp     al, [ds:xSI]
        mov     [es:xDI], ah
        jne     .failed2

        inc     xDI
        inc     xSI
        dec     ecx
        jnz     .inner_loop

        clc
        ret

.failed1:
        push    sCX
        push    sBX
        push    sAX
        push    sSI
        push    sDI
%ifdef TMPL_16BIT
        push    cs
%endif
        push    .s_szNotEqual
        call    TMPL_NM_CMN(TestFailedF)
        add     xSP, sCB * 6
        stc
        ret
.s_szNotEqual:
        db      TMPL_MODE_STR, ' - Not equal; EDI=%RX32 ESI=%RX32 EAX=%RX32 EBX=%RX32 ECX=%RX32', 13, 10, 0

.failed2:
        push    sCX
        push    sBX
        push    sAX
        push    sSI
        push    sDI
%ifdef TMPL_16BIT
        push    cs
%endif
        push    .s_szModifiyError
        call    TMPL_NM_CMN(TestFailedF)
        add     xSP, sCB * 6
        stc
        ret

.s_szModifiyError:
        db      TMPL_MODE_STR, ' - Modify error; EDI=%RX32 ESI=%RX32 EAX=%RX32 EBX=%RX32 ECX=%RX32', 13, 10, 0
ENDPROC   TMPL_NM(TestA20_DisabledInner)


;;
; Scans memory calling sDX for each segment.
;
BEGINPROC TMPL_NM(TestA20_ScanMemory)
        push    sAX
        push    sBX
        push    sCX
        push    sDX
        push    sSI
        push    sDI
        pushf
        cli
%ifdef TMPL_16BIT
        push    es
        push    ds
%endif

        ;
        ; The outer loop walks a segment (64 KB) at a time.
        ;
        mov     ebx, _1M
.outer_loop:

        ; Set up the registers.
%ifdef TMPL_CMN_R86
        mov     ax,  0ffffh
        mov     edi, 00010h
        mov     es, ax
        mov     ax,  00000h
        mov     esi, 00000h
        mov     ds, ax
        mov     ecx, 01000h             ; at 101000 there was a VMMDevTesting MMIO page.
%elifdef TMPL_16BIT
        ;; @todo need a selector we can modify.
        jmp     .done

%else
        mov     edi, ebx
        mov     esi, ebx
        and     esi, ~_1M
        mov     ecx, _64K
%endif
%ifndef TMPL_CMN_R86
        ; Should we skip this segment or only check parts of it?
        cmp     esi, edi                ; affected by A20?
        je      .outer_next

%if BS2_PXX_LAST != 09ffffh
 %error BS2_PXX_LAST does not have the expected value.
%endif
        cmp     ebx, BS2_PXX_BASE + _1M ; don't mess with page tables, stacks, MMIO or ROMs.
        jb      .not_low_rom_mmio_region
        cmp     ebx, _1M + _1M
        jb      .outer_next
.not_low_rom_mmio_region:

        cmp     ebx, BS2_ADDR + _1M
        ja      .not_bs2
        mov     ecx, BS2_ADDR           ; don't overwrite our own code.
.not_bs2:
        cmp     ebx, _1M
        jne     .not_VMMDevTestingMMIO
        mov     ecx, 1000h              ; don't bother with the MMIO
.not_VMMDevTestingMMIO:
%endif ; TMPL_CMN_R86

        ; Invoke the callback.
        call    xDX
        jc      .failure

%ifndef TMPL_CMN_R86
.outer_next:
        add     ebx, _64K
        cmp     ebx, 32*_1M
        jbe     .outer_loop
%endif

.done:
%ifdef TMPL_16BIT
        pop     ds
        pop     es
%endif
        popf
        pop     sDI
        pop     sSI
        pop     sDX
        pop     sCX
        pop     sBX
        pop     sAX
        ret

.failure:
%if 1
        cmp     ebx, _1M
        je      .contine_at_next_MB
        cmp     ebx, _2M
        je      .contine_at_next_MB
        cmp     ebx, _1M + _2M
        je      .contine_at_next_MB
        cmp     ebx, _4M
        je      .contine_at_next_MB
%endif
        jmp     .done

.contine_at_next_MB:
        add     ebx, _1M
        jmp     .outer_loop
ENDPROC   TMPL_NM(TestA20_ScanMemory)


BEGINPROC TMPL_NM(TestA20_Enabled)
        push    sDX
        mov     xDX, TMPL_NM(TestA20_EnabledInner)
        call    TMPL_NM(TestA20_ScanMemory)
        pop     sDX
        ret
ENDPROC   TMPL_NM(TestA20_Enabled)


;;
; Checks that the first 64KB at 1MB wraps is the same physical memory as at
; address 0.
;
BEGINPROC TMPL_NM(TestA20_Disabled)
        push    sDX
        mov     xDX, TMPL_NM(TestA20_DisabledInner)
        call    TMPL_NM(TestA20_ScanMemory)
        pop     sDX
        ret
ENDPROC   TMPL_NM(TestA20_Disabled)


BEGINPROC TMPL_NM(TestA20_FlushAll)
        push    sAX
        wbinvd
        mov     sAX, cr3
        mov     cr3, sAX
        wbinvd
        pop     sAX
        ret
ENDPROC   TMPL_NM(TestA20_FlushAll)



;;
; Do the A20 tests for this mode.
;
; @uses nothing
;
BEGINCODELOW
BITS 16
BEGINPROC TMPL_NM(TestA20_rm)
        push    eax

        mov     ax, .s_szTestName
        call    TestSub_r86

        call    TMPL_NM(Bs2IsModeSupported_rm)
        jz      .skip_not_supported

        ;
        ; Do tests with A20 enabled.
        ;
        call    Bs2EnableA20_r86
        call    TMPL_NM(Bs2EnterMode_rm)
BITS TMPL_BITS
        call    TMPL_NM(TestA20_FlushAll)
        call    TMPL_NM(TestA20_Enabled)
        call    TMPL_NM(Bs2ExitMode)
BITS 16
        call    TestSubErrorCount_r86
        cmp     ax, 0
        jne     .done

        ;
        ; Do tests with A20 disabled.
        ;
        call    Bs2DisableA20_r86
        call    TMPL_NM(Bs2EnterMode_rm)
BITS TMPL_BITS
        call    TMPL_NM(TestA20_FlushAll)
        call    TMPL_NM(TestA20_Disabled)
        call    TMPL_NM(Bs2ExitMode)
BITS 16
        call    TestSubErrorCount_r86
        cmp     ax, 0
        jne     .done

%ifndef TMPL_CMN_V86
        ;
        ; Change A20 state without leaving and entering the CPU mode.
        ;
        call    Bs2EnableA20_r86
        call    TMPL_NM(Bs2EnterMode_rm)
BITS TMPL_BITS
        call    TMPL_NM(TestA20_Enabled)

        call    TMPL_NM_CMN(Bs2DisableA20)
        call    TMPL_NM(TestA20_FlushAll)
        call    TMPL_NM(TestA20_Disabled)

        call    TMPL_NM_CMN(Bs2EnableA20)
        call    TMPL_NM(TestA20_FlushAll)
        call    TMPL_NM(TestA20_Enabled)

        call    TMPL_NM_CMN(Bs2DisableA20)
        call    TMPL_NM(TestA20_FlushAll)
        call    TMPL_NM(TestA20_Disabled)

        call    TMPL_NM_CMN(Bs2EnableA20)
        call    TMPL_NM(TestA20_FlushAll)
        call    TMPL_NM(TestA20_Enabled)

        call    TMPL_NM(Bs2ExitMode)
BITS 16
%endif ; !TMPL_CMN_V86

.done:
        call    Bs2DisableA20_r86
.done1:
        call    TestSubDone_r86

        pop     eax
        ret

.skip_not_supported:
        mov     eax, .s_szSkipNotSupported
        call    TestSkipped_r86
        jmp     .done1

.s_szTestName:
        db      TMPL_MODE_STR, 0
.s_szSkipNotSupported:
        db      TMPL_MODE_STR, ' is not supported by the CPU', 10, 13, 0
ENDPROC TMPL_NM(TestA20_rm)
TMPL_BEGINCODE
BITS TMPL_BITS


%include "bootsector2-template-footer.mac"