memory.asm

来自「linux下的任天堂模拟器代码。供大家参考。」· 汇编 代码 · 共 2,272 行 · 第 1/3 页

    pop ecx
    xor ebx,ebx
    ret
.noaccess
    xor al,al
    xor ebx,ebx
    ret

NEWSYM sramaccessbankr16b
    cmp dword[ramsize],0
    je .noaccess
    mov ebx,[sram]
    push ecx
    and ecx,[ramsizeand]
    mov al,[ebx+ecx]
    inc ecx
    and ecx,[ramsizeand]
    mov ah,[ebx+ecx]
    pop ecx
    xor ebx,ebx
    ret
.noaccess
    xor ax,ax
    xor ebx,ebx
    ret

NEWSYM sramaccessbankw8b
    cmp dword[ramsize],0
    je .noaccess
    mov ebx,[sram]
    push ecx
    and ecx,[ramsizeand]
    mov [ebx+ecx],al
    pop ecx
    mov dword[sramb4save],5*60
.noaccess
    xor ebx,ebx
    ret

NEWSYM sramaccessbankw16b
    cmp dword[ramsize],0
    je .noaccess
    mov ebx,[sram]
    push ecx
    and ecx,[ramsizeand]
    mov [ebx+ecx],al
    inc ecx
    and ecx,[ramsizeand]
    mov [ebx+ecx],ah
    pop ecx
    mov dword[sramb4save],5*60
.noaccess
    xor ebx,ebx
    ret

%macro STsramaccess 1
    test ecx,8000h
    jz %1
%endmacro

NEWSYM stsramr8
    STsramaccess memaccessbankr8
    push ecx
    sub bl,60h
    shl ebx,15
    add ecx,ebx
    mov ebx,[sram]
    and ecx,[ramsizeand]
    mov al,[ebx+ecx]
    pop ecx
    xor ebx,ebx
    ret

NEWSYM stsramr16
    STsramaccess memaccessbankr16
    push ecx
    sub bl,60h
    shl ebx,15
    add ecx,ebx
    mov ebx,[sram]
    and ecx,[ramsizeand]
    mov al,[ebx+ecx]
    inc ecx
    and ecx,[ramsizeand]
    mov ah,[ebx+ecx]
    pop ecx
    xor ebx,ebx
    ret

NEWSYM stsramw8
    STsramaccess memaccessbankw8
    push ecx
    sub bl,60h
    shl ebx,15
    add ecx,ebx
    mov ebx,[sram]
    and ecx,[ramsizeand]
    mov [ebx+ecx],al
    pop ecx
    mov dword[sramb4save],5*60
    xor ebx,ebx
    ret

NEWSYM stsramw16
    STsramaccess memaccessbankw16
    push ecx
    sub bl,60h
    shl ebx,15
    add ecx,ebx
    mov ebx,[sram]
    and ecx,[ramsizeand]
    mov [ebx+ecx],al
    inc ecx
    and ecx,[ramsizeand]
    mov [ebx+ecx],ah
    pop ecx
    mov dword[sramb4save],5*60
    xor ebx,ebx
    ret

NEWSYM stsramr8b
    STsramaccess memaccessbankr8
    push ecx
    sub bl,70h
    shl ebx,15
    add ecx,ebx
    mov ebx,[sram2]
    and ecx,[ramsizeand]
    mov al,[ebx+ecx]
    pop ecx
    xor ebx,ebx
    ret

NEWSYM stsramr16b
    STsramaccess memaccessbankr16
    push ecx
    sub bl,70h
    shl ebx,15
    add ecx,ebx
    mov ebx,[sram2]
    and ecx,[ramsizeand]
    mov al,[ebx+ecx]
    inc ecx
    and ecx,[ramsizeand]
    mov ah,[ebx+ecx]
    pop ecx
    xor ebx,ebx
    ret

NEWSYM stsramw8b
    STsramaccess memaccessbankw8
    push ecx
    sub bl,70h
    shl ebx,15
    add ecx,ebx
    mov ebx,[sram2]
    and ecx,[ramsizeand]
    mov [ebx+ecx],al
    pop ecx
    mov dword[sramb4save],5*60
    xor ebx,ebx
    ret

NEWSYM stsramw16b
    STsramaccess memaccessbankw16
    push ecx
    sub bl,70h
    shl ebx,15
    add ecx,ebx
    mov ebx,[sram2]
    and ecx,[ramsizeand]
    mov [ebx+ecx],al
    inc ecx
    and ecx,[ramsizeand]
    mov [ebx+ecx],ah
    pop ecx
    mov dword[sramb4save],5*60
    xor ebx,ebx
    ret

;*******************************************************
; WorkRAM/ExpandRAM Access Bank (7Eh)
;*******************************************************

NEWSYM wramaccessbankr8
;    mov ebx,[wramdata]
;    mov al,[ebx+ecx]
;    xor ebx,ebx
    mov al,[wramdataa+ecx]
    ret

NEWSYM wramaccessbankr16
;    mov ebx,[wramdata]
;    mov ax,[ebx+ecx]
;    xor ebx,ebx
    mov ax,[wramdataa+ecx]
    ret

NEWSYM wramaccessbankw8
;    mov ebx,[wramdata]
;    mov [ebx+ecx],al
;    xor ebx,ebx
    mov [wramdataa+ecx],al
    ret

NEWSYM wramaccessbankw16
;    mov ebx,[wramdata]
;    mov [ebx+ecx],ax
;    xor ebx,ebx
    mov [wramdataa+ecx],ax
    ret

;*******************************************************
; ExpandRAM Access Bank (7Fh)
;*******************************************************
NEWSYM eramaccessbankr8
;    mov ebx,[ram7f]
;    mov al,[ebx+ecx]
;    xor ebx,ebx
    mov al,[ram7fa+ecx]
    ret

NEWSYM eramaccessbankr16
;    mov ebx,[ram7f]
;    mov ax,[ebx+ecx]
;    xor ebx,ebx
    mov ax,[ram7fa+ecx]
    ret

NEWSYM eramaccessbankw8
;    mov ebx,[ram7f]
;    mov [ebx+ecx],al
;    xor ebx,ebx
    mov [ram7fa+ecx],al
    ret

NEWSYM eramaccessbankw16
;    mov ebx,[ram7f]
;    mov [ebx+ecx],ax
;    xor ebx,ebx
    mov [ram7fa+ecx],ax
    ret

;*******************************************************
; SA-1 Bank Accesses
;*******************************************************

NEWSYM regaccessbankr8SA1
    test ecx,8000h
    jz .regacc
    mov ebx,[snesmmap+ebx*4]
    mov al,[ebx+ecx]
    xor ebx,ebx
    ret
.regacc
    cmp ecx,2000h
    jae .regs
    cmp byte[SA1Status],0
    jne .nowram
    mov al,[wramdataa+ecx]
    ret
.nowram
    cmp ecx,800h
    jae .invaccess
    mov al,[IRAM+ecx]
    ret
.regs
    cmp ecx,48FFh
    ja .invaccess
    call dword near [regptra+ecx*4-8000h]
    xor ebx,ebx
    ret
.invaccess
    cmp ecx,6000h
    jae .bwram
    xor al,al
    ret
.bwram
    BWCheck
    mov ebx,[CurBWPtr]
    mov al,[ebx+ecx]
    xor ebx,ebx
    ret
    BWCheck2r8

NEWSYM regaccessbankr16SA1
    test ecx,8000h
    jz .regacc
    mov ebx,[snesmmap+ebx*4]
    mov ax,[ebx+ecx]
    xor ebx,ebx
    ret
.regacc
    cmp ecx,2000h
    jae .regs
    cmp byte[SA1Status],0
    jne .nowram
    mov ax,[wramdataa+ecx]
    ret
.nowram
    cmp ecx,800h
    jae .invaccess
    mov ax,[IRAM+ecx]
    ret
.regs
    cmp ecx,48FFh
    ja .invaccess
    call dword near [regptra+ecx*4-8000h]
    inc ecx
    mov ah,al
    call dword near [regptra+ecx*4-8000h]
    mov bl,al
    dec ecx
    mov al,ah
    mov ah,bl
    xor ebx,ebx
    ret
.invaccess
    cmp ecx,6000h
    jae .bwram
    xor ax,ax
    ret
.bwram
    BWCheck
    mov ebx,[CurBWPtr]
    mov ax,[ebx+ecx]
    xor ebx,ebx
    ret
    BWCheck2r16

NEWSYM regaccessbankw8SA1
    test ecx,8000h
    jnz .romacc
    cmp ecx,2000h
    jae .regs
    cmp byte[SA1Status],0
    jne .nowram
    mov [wramdataa+ecx],al
    ret
.nowram
    cmp ecx,800h
    jae .invaccess
    mov [IRAM+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
    call dword near [regptwa+ecx*4-8000h]
    xor ebx,ebx
    ret
.invaccess
    cmp ecx,6000h
    jae .bwram
    ret
.bwram
    BWCheck
    mov ebx,[CurBWPtr]
    mov [ebx+ecx],al
    xor ebx,ebx
    ret
    BWCheck2w8

NEWSYM regaccessbankw16SA1
    test ecx,8000h
    jnz .romacc
    cmp ecx,2000h
    jae .regs
    cmp byte[SA1Status],0
    jne .nowram
    mov [wramdataa+ecx],ax
    ret
.nowram
    cmp ecx,800h
    jae .invaccess
    mov [IRAM+ecx],ax
    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
    call dword near [regptwa+ecx*4-8000h]
    inc ecx
    mov al,ah
    call dword near [regptwa+ecx*4-8000h]
    dec ecx
    xor ebx,ebx
    ret
.invaccess
    cmp ecx,6000h
    jae .bwram
    ret
.bwram
    BWCheck
    mov ebx,[CurBWPtr]
    mov [ebx+ecx],ax
    xor ebx,ebx
    ret
    BWCheck2w16

NEWSYM SA1RAMaccessbankr8
    and ebx,03h
    shl ebx,16
    add ebx,[SA1RAMArea]
    mov al,[ebx+ecx]
    xor ebx,ebx
    ret

NEWSYM SA1RAMaccessbankr16
    and ebx,03h
    shl ebx,16
    add ebx,[SA1RAMArea]
    mov ax,[ebx+ecx]
    xor ebx,ebx
    ret

NEWSYM SA1RAMaccessbankw8
    and ebx,03h
    shl ebx,16
    add ebx,[SA1RAMArea]
    mov [ebx+ecx],al
    xor ebx,ebx
    ret

NEWSYM SA1RAMaccessbankw16
    and ebx,03h
    shl ebx,16
    add ebx,[SA1RAMArea]
    mov [ebx+ecx],ax
    xor ebx,ebx
    ret


NEWSYM SA1RAMaccessbankr8b
    test byte[SA1Overflow+1],80h
    jnz .2bit
    and ebx,07h
    shl ebx,15
    test ecx,1
    jnz .4bitb
    shr ecx,1
    add ebx,[SA1RAMArea]
    mov al,[ebx+ecx]
    xor ebx,ebx
    and al,0Fh
    ret
.4bitb
    shr ecx,1
    add ebx,[SA1RAMArea]
    mov al,[ebx+ecx]
    xor ebx,ebx
    shr al,4
    ret
.2bit
    and ebx,0Fh
    shl ebx,14
    add ebx,[SA1RAMArea]
    test ecx,2
    jnz .bit1
    test ecx,1
    jnz .bit0
    shr ecx,2
    mov al,[ebx+ecx]
    and al,3
    xor ebx,ebx
    ret
.bit0
    shr ecx,2
    mov al,[ebx+ecx]
    shr al,2
    and al,3
    xor ebx,ebx
    ret
.bit1
    test ecx,1
    jnz .bit0b
    shr ecx,2
    mov al,[ebx+ecx]
    shr al,4
    and al,3
    xor ebx,ebx
    ret
.bit0b
    shr ecx,2
    mov al,[ebx+ecx]
    shr al,6
    xor ebx,ebx
    ret

NEWSYM SA1RAMaccessbankr16b
    test byte[SA1Overflow+1],80h
    jnz .2bit
    and ebx,07h
    shl ebx,15
    test ecx,1
    jnz .4bitb
    shr ecx,1
    add ebx,[SA1RAMArea]
    mov al,[ebx+ecx]
    and al,0Fh
    mov ah,[ebx+ecx]
    shr ah,4
    xor ebx,ebx
    ret
.4bitb
    shr ecx,1
    add ebx,[SA1RAMArea]
    mov ah,[ebx+ecx+1]
    and ah,0Fh
    mov al,[ebx+ecx]
    shr al,4
    xor ebx,ebx
    ret
.2bit
    and ebx,0Fh
    shl ebx,14
    add ebx,[SA1RAMArea]
    test ecx,2
    jnz .bit1
    test ecx,1
    jnz .bit0
    shr ecx,2
    mov al,[ebx+ecx]
    and al,3
    mov ah,[ebx+ecx]
    shr ah,2
    and ah,3
    xor ebx,ebx
    ret
.bit0
    shr ecx,2
    mov al,[ebx+ecx]
    shr al,2
    and al,2
    mov ah,[ebx+ecx]
    shr ah,4
    and ah,3
    xor ebx,ebx
    ret
.bit1
    test ecx,1
    jnz .bit0b
    shr ecx,2
    mov al,[ebx+ecx]
    shr al,4
    and al,3
    mov ah,[ebx+ecx]
    shr ah,6
    xor ebx,ebx
    ret
.bit0b
    shr ecx,2
    mov al,[ebx+ecx]
    shr al,6
    mov ah,[ebx+ecx+1]
    and ah,3
    xor ebx,ebx
    ret

NEWSYM SA1RAMaccessbankw8b
    test byte[SA1Overflow+1],80h
    jnz .2bit
    and ebx,07h
    shl ebx,15
    test ecx,1
    jnz .4bitb
    shr ecx,1
    add ebx,[SA1RAMArea]
    and al,0Fh
    and byte[ebx+ecx],0F0h
    or byte[ebx+ecx],al
    xor ebx,ebx
    ret
.4bitb
    shr ecx,1
    add ebx,[SA1RAMArea]
    and al,0Fh
    shl al,4
    and byte[ebx+ecx],0Fh
    or byte[ebx+ecx],al
    xor ebx,ebx
    ret
.2bit
    and ebx,0Fh
    shl ebx,14
    add ebx,[SA1RAMArea]
    test ecx,2
    jnz .bit1
    test ecx,1
    jnz .bit0
    shr ecx,2
    and byte[ebx+ecx],0FCh
    and al,3
    or byte[ebx+ecx],al
    xor ebx,ebx
    ret
.bit0
    shr ecx,2
    and byte[ebx+ecx],0F3h
    and al,3
    shl al,2
    or byte[ebx+ecx],al
    xor ebx,ebx
    ret
.bit1
    test ecx,1
    jnz .bit0b
    shr ecx,2
    and byte[ebx+ecx],0CFh
    and al,3
    shl al,4
    or byte[ebx+ecx],al
    xor ebx,ebx
    ret
.bit0b
    shr ecx,2
    and byte[ebx+ecx],03Fh
    and al,3
    shl al,6
    or byte[ebx+ecx],al
    xor ebx,ebx
    ret

NEWSYM SA1RAMaccessbankw16b
    push ecx
    push ebx
    call SA1RAMaccessbankw8b
    pop ebx
    pop ecx
    inc ecx
    mov al,ah
    call SA1RAMaccessbankw8b
    ret

SECTION .text

%macro GetBankLog 1
    cmp bl,0C0h
    jb %%illegal
    cmp bl,0D0h
    jb %%firstbank
    cmp bl,0E0h
    jb %%secondbank
    cmp bl,0F0h
    jb %%thirdbank
    mov %1,[SDD1BankA+3]
    jmp %%done
%%firstbank
    mov %1,[SDD1BankA]
    jmp %%done
%%secondbank
    mov %1,[SDD1BankA+1]
    jmp %%done
%%thirdbank
    mov %1,[SDD1BankA+2]
    jmp %%done
%%illegal
    mov %1,0Fh
%%done
%endmacro

SECTION .data
NEWSYM LatestBank, dd 0FFFFh
SECTION .text

; Software decompression version
NEWSYM memaccessbankr8sdd1
    cmp byte[AddrNoIncr],0
    je near .failed

    cmp dword[Sdd1Mode],2
    je near .decompress

    mov [Sdd1Bank],ebx
    mov [Sdd1Addr],ecx
    mov [Sdd1NewAddr],ecx

    mov dword[Sdd1Mode],2
    push edx
    push eax
    push ecx

    and ecx,0FFFFh
    xor eax,eax
    GetBankLog al
    shl eax, 20
    mov edx, [Sdd1Bank]
    and edx, 0Fh
    shl edx, 16
    add eax, edx
    add eax, [romdata]
    add eax, ecx

    pushad
    push eax
    call SDD1_init
    pop eax
    popad

    pop ecx
    pop eax
    pop edx

.decompress
    cmp [Sdd1Bank],ebx
    jne .nomoredec
    cmp [Sdd1Addr],ecx
    je .yesdec
.nomoredec
    mov ebx,[snesmmap+ebx*4]
    mov al,[ebx+ecx]
    push eax
    mov eax,memtabler8+0C0h*4
    mov ebx,40h
.loopb
    mov dword[eax],memaccessbankr8
    add eax,4
    dec ebx
    jnz .loopb
    pop eax
    xor ebx,ebx
    ret
.yesdec
    pushad
    call SDD1_get_byte
    mov [.tmpbyte], al
    popad
    mov al, [.tmpbyte]
    ret

.failed
    push ebx
    call .nomoredec
    pop ebx
    jmp memaccessbankr8
SECTION .bss
.tmpbyte resb 1