memory.asm

linux下的任天堂模拟器代码。供大家参考。

;Copyright (C) 1997-2007 ZSNES Team ( zsKnight, _Demo_, pagefault, Nach )
;
;http://www.zsnes.com
;http://sourceforge.net/projects/zsnes
;https://zsnes.bountysource.com
;
;This program is free software; you can redistribute it and/or
;modify it under the terms of the GNU General Public License
;version 2 as published by the Free Software Foundation.
;
;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, write to the Free Software
;Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

%include "macros.mac"

EXTSYM romdata,sramb4save,curromspace,SA1Overflow
EXTSYM SFXEnable,regptra,sfxramdata,snesmmap,wramdataa
EXTSYM DSP1Write8b,regptwa,writeon,DSP1Read16b
EXTSYM Bank0datr8,Bank0datw8,Bank0datr16,Bank0datw16,xd,SA1xd
EXTSYM DSP1Read8b,DSP1Type,SA1Enable,DSP1Write16b
EXTSYM ramsize,ramsizeand,sram,sram2,ram7fa
EXTSYM SA1Status,IRAM,CurBWPtr,SA1RAMArea
EXTSYM Sdd1Mode,Sdd1Bank,Sdd1Addr,Sdd1NewAddr,memtabler8,AddrNoIncr,SDD1BankA
EXTSYM SDD1_init,SDD1_get_byte,BWShift,SA1BWPtr

;*******************************************************
; Register & Memory Access Banks (0 - 3F) / (80 - BF)
;*******************************************************
; enter : BL = bank number, CX = address location
; leave : AL = value read

SECTION .text

NEWSYM regaccessbankr8
    test ecx,8000h
    jz .regacc
    mov ebx,[snesmmap+ebx*4]
    mov al,[ebx+ecx]
    xor ebx,ebx
    ret
.regacc
    cmp ecx,2000h
    jae .regs
    mov al,[wramdataa+ecx]
    ret
.regs
    cmp ecx,48FFh
    ja .invaccess
    call dword near [regptra+ecx*4-8000h]
    xor ebx,ebx
    ret
.invaccess
    cmp ecx,6000h
    jae .hiromsram
    mov al,ch
    ret
.hiromsram
    cmp byte[SFXEnable],1
    je .sfxram
    and ebx,7Fh
    cmp bl,10h
    jb .dsp1
    cmp bl,30h
    jae .hiromsramok
    xor al,al
    xor ebx,ebx
    ret
.dsp1
    xor al,al
    cmp byte[DSP1Type],2
    jne .nodsp1
    call DSP1Read8b
.nodsp1
    xor ebx,ebx
    ret
.hiromsramok
    push ecx
    sub ecx,6000h
    and ecx,1fffh
    sub bl,30h
    shl ebx,13
    add ecx,ebx
    and ecx,0FFFFh
    call sramaccessbankr8b
    pop ecx
    ret
.sfxram
    push ecx
    sub ecx,6000h
    and ecx,1fffh
    mov ebx,[sfxramdata]
    mov al,[ebx+ecx]
    xor ebx,ebx
    pop ecx
    ret

NEWSYM regaccessbankr16
    test ecx,8000h
    jz .regacc
    mov ebx,[snesmmap+ebx*4]
    mov ax,[ebx+ecx]
    xor ebx,ebx
    ret
.regacc
    cmp ecx,2000h
    jae .regs
    mov ax,[wramdataa+ecx]
    cmp ecx,1FFFh
    jne .notopenbus
    mov ah,al
.notopenbus
    ret
.regs
    cmp ecx,48FFh
    ja .invaccess
;    mov ebx,ecx
;    shl ebx,2
;    add ebx,[regptr]
;    call dword near [ebx]
    call dword near [regptra+ecx*4-8000h]
    inc ecx
    mov ah,al
;    mov ebx,ecx
;    shl ebx,2
;    add ebx,[regptr]
;    call dword near [ebx]
    call dword near [regptra+ecx*4-8000h]
    mov bl,al
    dec ecx
    mov al,ah
    mov ah,bl
    xor ebx,ebx
    ret
.invaccess
;    jmp regexiter
    cmp ecx,6000h
    jae .hiromsram
    mov al,ch
    mov ah,ch
    ret
.hiromsram
    cmp byte[SFXEnable],1
    je .sfxram
    and ebx,7Fh
    cmp bl,10h
    jb .dsp1
    cmp bl,30h
    jae .hiromsramok
    xor ax,ax
    xor ebx,ebx
    ret
.dsp1
    xor ax,ax
    cmp byte[DSP1Type],2
    jne .nodsp1
    call DSP1Read16b
.nodsp1
    xor ebx,ebx
    ret
.hiromsramok
    push ecx
    sub ecx,6000h
    and ecx,1fffh
    sub bl,30h
    shl ebx,13
    add ecx,ebx
    and ecx,0FFFFh
    call sramaccessbankr16b
    pop ecx
    ret
.sfxram
    push ecx
    sub ecx,6000h
    and ecx,1fffh
    mov ebx,[sfxramdata]
    mov ax,[ebx+ecx]
    xor ebx,ebx
    pop ecx
    ret

NEWSYM regaccessbankw8
    test ecx,8000h
    jnz .romacc
    cmp ecx,2000h
    jae .regs
    mov [wramdataa+ecx],al
    ret
.romacc
    cmp byte[writeon],0
    jne .modrom
    ret
.modrom
    mov ebx,[snesmmap+ebx*4]
    mov [ebx+ecx],al
    xor ebx,ebx
    ret
.regs
    cmp ecx,48FFh
    ja .invaccess
;    mov ebx,ecx
;    shl ebx,2
;    add ebx,[regptw]
;    call dword near [ebx]
    call dword near [regptwa+ecx*4-8000h]
    xor ebx,ebx
    ret
.invaccess
;    jmp regexiter
    cmp ecx,6000h
    jae .hiromsram
    ret
.hiromsram
    cmp byte[SFXEnable],1
    je .sfxram
    and ebx,7Fh
    cmp bl,10h
    jb .dsp1
    cmp bl,30h
    jae .hiromsramok
    xor ebx,ebx
    ret
.dsp1
    cmp byte[DSP1Type],2
    jne .nodsp1
    call DSP1Write8b
.nodsp1
    xor ebx,ebx
    ret
.hiromsramok
    push ecx
    sub ecx,6000h
    and ecx,1fffh
    sub bl,30h
    shl ebx,13
    add ecx,ebx
    and ecx,0FFFFh
    call sramaccessbankw8b
    pop ecx
    ret
.sfxram
    push ecx
    sub ecx,6000h
    and ecx,1fffh
    mov ebx,[sfxramdata]
    mov [ebx+ecx],al
    xor ebx,ebx
    pop ecx
    ret

NEWSYM regaccessbankw16
    test ecx,8000h
    jnz .romacc
    cmp ecx,2000h
    jae .regs
    cmp ecx,1FFFh
    je .endwram
    mov [wramdataa+ecx],ax
    ret
.endwram
    mov [wramdataa+ecx],al
    ret
.romacc
    cmp byte[writeon],0
    jne .modrom
    ret
.modrom
    mov ebx,[snesmmap+ebx*4]
    mov [ebx+ecx],ax
    xor ebx,ebx
    ret
.regs
    cmp cx,48FFh
    ja .invaccess
;    mov ebx,ecx
;    shl ebx,2
;    add ebx,[regptw]
;    call dword near [ebx]
    call dword near [regptwa+ecx*4-8000h]
    inc ecx
    mov al,ah
;    mov ebx,ecx
;    shl ebx,2
;    add ebx,[regptw]
;    call dword near [ebx]
    call dword near [regptwa+ecx*4-8000h]
    dec ecx
    xor ebx,ebx
    ret
.invaccess
;    jmp regexiter
    cmp ecx,6000h
    jae .hiromsram
    ret
.hiromsram
    cmp byte[SFXEnable],1
    je .sfxram
    and ebx,7Fh
    cmp bl,10h
    jb .dsp1
    cmp bl,30h
    jae .hiromsramok
    xor al,al
    xor ebx,ebx
    ret
.dsp1
    cmp byte[DSP1Type],2
    jne .nodsp1
    call DSP1Write16b
.nodsp1
    ret
.hiromsramok
    push ecx
    sub ecx,6000h
    and ecx,1fffh
    sub bl,30h
    shl ebx,13
    add ecx,ebx
    and ecx,0FFFFh
    call sramaccessbankw16b
    pop ecx
    ret
.sfxram
    push ecx
    sub ecx,6000h
    and ecx,1fffh
    mov ebx,[sfxramdata]
    mov [ebx+ecx],ax
    xor ebx,ebx
    pop ecx
    ret

NEWSYM regaccessbankr8mp
    ret

;*******************************************************
; Register & Memory Bank (Bank 0)
;*******************************************************
; enter : BL = bank number, CX = address location
; leave : AL = value read

%macro BWCheck 0
    cmp byte[BWShift],0
    jne near .shift
.nosa1
%endmacro

section .bss
NEWSYM BWUsed2, resb 1
NEWSYM BWUsed, resb 1
section .text

%macro BWCheck2r8 0
.shift
    cmp byte[SA1Status],0
    je .nosa1
    ; value of 8Fh
    test byte[SA1Overflow+1],80h
    jnz .2bit
    push ecx
    push ebx
    sub ecx,6000h
    push eax
    mov eax,ecx
    and eax,01h
    shl eax,2
    shr ecx,1
    mov ebx,ecx
    mov cl,al
    pop eax
    mov al,0Fh
    shl al,cl
    add ebx,[SA1BWPtr]
    and al,[ebx]
    shr al,cl
    pop ebx
    pop ecx
    ret
.2bit
    push ecx
    push ebx
    sub ecx,6000h
    push eax
    mov eax,ecx
    and eax,03h
    shl eax,1
    shr ecx,2
    mov ebx,ecx
    mov cl,al
    pop eax
    mov al,03h
    shl al,cl
    add ebx,[SA1BWPtr]
    and al,[ebx]
    shr al,cl
    pop ebx
    pop ecx
    ret
%endmacro

%macro BWCheck2r16 0
.shift
    cmp byte[SA1Status],0
    je .nosa1
    ; value of 8Fh
    test byte[SA1Overflow+1],80h
    jnz .2bit
    push ecx
    push ebx
    sub ecx,6000h
    push eax
    mov eax,ecx
    and eax,01h
    shl eax,2
    shr ecx,1
    mov ebx,ecx
    mov cl,al
    pop eax
    mov al,0Fh
    shl al,cl
    add ebx,[SA1BWPtr]
    and al,[ebx]
    shr al,cl
    pop ebx
    pop ecx
    push ecx
    push ebx
    sub ecx,6000h
    inc ecx
    push eax
    mov eax,ecx
    and eax,01h
    shl eax,2
    shr ecx,1
    mov ebx,ecx
    mov cl,al
    pop eax
    mov ah,0Fh
    shl ah,cl
    add ebx,[SA1BWPtr]
    and ah,[ebx]
    shr ah,cl
    pop ebx
    pop ecx
    ret
.2bit
    push ecx
    push ebx
    sub ecx,6000h
    push eax
    mov eax,ecx
    and eax,03h
    shl eax,1
    shr ecx,2
    mov ebx,ecx
    mov cl,al
    pop eax
    mov al,03h
    shl al,cl
    add ebx,[SA1BWPtr]
    and al,[ebx]
    shr al,cl
    pop ebx
    pop ecx
    push ecx
    push ebx
    inc ecx
    sub ecx,6000h
    push eax
    mov eax,ecx
    and eax,03h
    shl eax,1
    shr ecx,2
    mov ebx,ecx
    mov cl,al
    pop eax
    mov ah,03h
    shl ah,cl
    add ebx,[SA1BWPtr]
    and ah,[ebx]
    shr ah,cl
    pop ebx
    pop ecx
    ret
%endmacro

%macro BWCheck2w8 0
.shift
    cmp byte[SA1Status],0
    je .nosa1
    test byte[SA1Overflow+1],80h
    jnz .2bit
    push ecx
    push ebx
    push edx
    sub ecx,6000h
    push eax
    mov eax,ecx
    and eax,01h
    shl eax,2
    shr ecx,1
    mov ebx,ecx
    mov cl,al
    pop eax
    mov dh,0Fh
    shl dh,cl
    xor dh,0FFh
    and al,0Fh
    shl al,cl
    add ebx,[SA1BWPtr]
    and byte[ebx],dh
    or byte[ebx],al
    pop edx
    pop ebx
    pop ecx
    ret
.2bit
    push ecx
    push ebx
    push edx
    sub ecx,6000h
    push eax
    mov eax,ecx
    and eax,03h
    shl eax,1
    shr ecx,2
    mov ebx,ecx
    mov cl,al
    pop eax
    mov dh,03h
    shl dh,cl
    xor dh,0FFh
    and al,03h
    shl al,cl
    add ebx,[SA1BWPtr]
    and byte[ebx],dh
    or byte[ebx],al
    pop edx
    pop ebx
    pop ecx
    ret
%endmacro

%macro BWCheck2w16 0
.shift
    cmp byte[SA1Status],0
    je .nosa1
    test byte[SA1Overflow+1],80h
    jnz .2bit
    push eax
    push ecx
    push ebx
    push edx
    sub ecx,6000h
    push eax
    mov eax,ecx
    and eax,01h
    shl eax,2
    shr ecx,1
    mov ebx,ecx
    mov cl,al
    pop eax
    mov dh,0Fh
    shl dh,cl
    xor dh,0FFh
    and al,0Fh
    shl al,cl
    add ebx,[SA1BWPtr]
    and byte[ebx],dh
    or byte[ebx],al
    pop edx
    pop ebx
    pop ecx
    pop eax
    push ecx
    push ebx
    push edx
    inc ecx
    sub ecx,6000h
    push eax
    mov eax,ecx
    and eax,01h
    shl eax,2
    shr ecx,1
    mov ebx,ecx
    mov cl,al
    pop eax
    mov dh,0Fh
    shl dh,cl
    xor dh,0FFh
    and ah,0Fh
    shl ah,cl
    add ebx,[SA1BWPtr]
    and byte[ebx],dh
    or byte[ebx],ah
    pop edx
    pop ebx
    pop ecx
    ret
.2bit
    push eax
    push ecx
    push ebx
    push edx
    sub ecx,6000h
    push eax
    mov eax,ecx
    and eax,03h
    shl eax,1
    shr ecx,2
    mov ebx,ecx
    mov cl,al
    pop eax
    mov dh,03h
    shl dh,cl
    xor dh,0FFh
    and al,03h
    shl al,cl
    add ebx,[SA1BWPtr]
    and byte[ebx],dh
    or byte[ebx],al
    pop edx
    pop ebx
    pop ecx
    pop eax
    push ecx
    push ebx
    push edx
    inc ecx
    sub ecx,6000h
    push eax
    mov eax,ecx
    and eax,03h
    shl eax,1
    shr ecx,2
    mov ebx,ecx
    mov cl,al
    pop eax
    mov dh,03h
    shl dh,cl
    xor dh,0FFh
    and ah,03h
    shl ah,cl
    add ebx,[SA1BWPtr]
    and byte[ebx],dh
    or byte[ebx],ah
    pop edx
    pop ebx
    pop ecx
    ret
%endmacro

%macro writetobank0table 2
    mov ebx,%1
    mov ecx,%2
%%loop
    mov [eax],ebx
    add eax,4
    dec ecx
    jnz %%loop
%endmacro

section .bss
NEWSYM DPageR8, resd 1
NEWSYM DPageR16, resd 1
NEWSYM DPageW8, resd 1
NEWSYM DPageW16, resd 1
NEWSYM SA1DPageR8, resd 1
NEWSYM SA1DPageR16, resd 1
NEWSYM SA1DPageW8, resd 1
NEWSYM SA1DPageW16, resd 1
section .text

NEWSYM UpdateDPage
    push eax
    movzx eax,byte[xd+1]
    push ecx
    mov ecx,[Bank0datr8+eax*4]
    mov [DPageR8],ecx
    mov ecx,[Bank0datr16+eax*4]
    mov [DPageR16],ecx
    mov ecx,[Bank0datw8+eax*4]
    mov [DPageW8],ecx
    mov ecx,[Bank0datw16+eax*4]
    mov [DPageW16],ecx
    pop ecx
    pop eax
    ret

NEWSYM SA1UpdateDPage
    push eax
    movzx eax,byte[SA1xd+1]
    push ecx
    mov ecx,[Bank0datr8+eax*4]
    mov [SA1DPageR8],ecx
    mov ecx,[Bank0datr16+eax*4]
    mov [SA1DPageR16],ecx
    mov ecx,[Bank0datw8+eax*4]
    mov [SA1DPageW8],ecx
    mov ecx,[Bank0datw16+eax*4]
    mov [SA1DPageW16],ecx
    pop ecx
    pop eax
    ret

; SA1 Stuff
NEWSYM membank0r8ramSA1             ; 0000-1FFF
    cmp byte[SA1Status],0
    jne .nowram
    mov al,[wramdataa+ecx+ebx]
    ret
.nowram
    cmp ecx,800h
    jae .invaccess
    mov al,[IRAM+ecx+ebx]
    ret
.invaccess
    xor al,al
    ret
NEWSYM membank0r16ramSA1             ; 0000-1FFF
    cmp byte[SA1Status],0
    jne .nowram
    mov ax,[wramdataa+ecx+ebx]
    ret
.nowram
    cmp ecx,800h
    jae .invaccess
    mov ax,[IRAM+ecx+ebx]
    ret
.invaccess
    xor ax,ax
    ret
NEWSYM membank0w8ramSA1             ; 0000-1FFF
    cmp byte[SA1Status],0
    jne .nowram
    mov [wramdataa+ecx+ebx],al
    ret
.nowram
    cmp ecx,800h
    jae .invaccess
    mov [IRAM+ecx+ebx],al
.invaccess
    ret
NEWSYM membank0w16ramSA1             ; 0000-1FFF
    cmp byte[SA1Status],0
    jne .nowram
    mov [wramdataa+ecx+ebx],ax
    ret
.nowram
    cmp ecx,800h
    jae .invaccess
    mov [IRAM+ecx+ebx],ax
.invaccess