sound.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 ProcessSoundBuffer,DosExit,getenv,PrintStr,printhex,WaitForKey
EXTSYM SBHDMA,soundon,csounddisable,DisplayS,SPCRAM,DSPMem
EXTSYM StereoSound,SoundQuality,SoundSpeeds,SBToSPCSpeeds2
EXTSYM SoundSpeedt,DSPBuffer,BufferSize,BufferSizes,BufferSizeB
EXTSYM BufferSizeW,dssel,PrintChar

SECTION .text

printnum:
    ; process through each digit
    push edx
    push eax
    push ebx
    push cx
    xor edx,edx           ; clear high byte
    xor cx,cx             ; clear counter variable
    mov ebx,10
.loopa
    div ebx              ; get quotent and remainder
    push edx              ; store number to stack
    inc cl
    xor edx,edx
    test eax,0FFFFFFFFh
    jnz .loopa
.loopb
    pop edx              ; get number back from stack
    add dl,30h          ; adjust to ASCII value
    call PrintChar
    dec cl
    jnz .loopb
    pop cx
    pop ebx
    pop eax
    pop edx
    ret

NEWSYM SB_alloc_dma

    mov ax,0100h                ; Allocate DOS memory
    mov bx,16384/16             ; Allocate 16384 bytes
    int 31h
    ; To delocate this, use ax=0101h, dx=selector of block/int 31h
    jc near .error
    ; Check which 8192 byte boundary doesn't cross a page
    mov word[memoryloc+2],0
    mov dword[memoryloc],0
    mov [memoryloc],ax
    mov [sbselec],dx
    shl dword[memoryloc],4
    mov edx,[memoryloc]
    shr edx,16
    mov al,dl
    mov edx,[memoryloc]
    add edx,8192
    shr edx,16
    mov dword[sbpmofs],0
    cmp al,dl
    je .nonextarea
    mov dword[sbpmofs],8192
    add dword[memoryloc],8192
.nonextarea
    mov edi,[sbpmofs]
    mov [SBBufferLoc],edi
    mov dword[SBBufferMov],1
    mov dword[SBBufferInc],4
    ; clear dos memory
    push es
    mov es,[sbselec]
    mov edi,[sbpmofs]
    mov ecx,2048
    mov eax,0
    rep stosd
    pop es
    ret

.error
    mov edx,.nohand         ;use extended
    mov ah,9                ;DOS- API
    int 21h                 ;to print a string
    call DosExit

SECTION .data
.nohand db 'Unable to allocate conventional memory!',13,10,'$'
SECTION .text


NEWSYM DeInitSPC
    cmp byte[SBDeinitType],0
    je .nodoublereset
    call SB_dsp_reset
    call SB_dsp_reset
.nodoublereset
    ; Turn off speakers
    mov al,0d3h
    call SB_dsp_write

;      k) Perform Halt DMA Operation, 8-bit command (0D0h - for virtual speaker)
    mov al,0d0h
    call SB_dsp_write
;      l) Perform Exit Auto-Initialize DMA Operation, 8-bit command (0DAh)
    cmp byte[SBHDMA],0
    je .8b
    mov al,0d9h
    call SB_dsp_write
    jmp .16b
.8b
    mov al,0dAh
    call SB_dsp_write
.16b
;      m) Perform Halt DMA Operation, 8-bit command (0D0h - for virtual speaker)
    mov al,0d0h
    call SB_dsp_write
    ; Disable DMA
    mov al,4
    add al,[SBDMA]
    mov dx,0ah
    out dx,al
    ret

section .data

;SoundBlaster DSP Ports
NEWSYM SBPort, dw 220
NEWSYM SBInt,  db 5+8
NEWSYM SBIrq,  db 5
NEWSYM SBDMA,  db 1
NEWSYM SBDMAPage, db 83
;NEWSYM SBHDMA, db 0
NEWSYM SBHDMAPage, db 0
NEWSYM vibracard, db 0

NEWSYM SBBufferLoc,    dd 0
NEWSYM SBBufferMov,    dd 0
NEWSYM SBBufferInc,    dd 0
NEWSYM SoundInterrupt, dd 0


; ViBRA16X fixes!
EXTSYM MsgCount         ; points to counter
EXTSYM MessageOn        ; points to "message" delay counter
EXTSYM Msgptr           ; points to the message to be displayed
NEWSYM vibmsg, db 'VIBRA16X MODE ENABLED', 0

section .text

NEWSYM SB_dsp_reset
    mov dx,[SBPort]
    add dl,06h
    mov al,01h
    out dx,al
    in al,dx
    in al,dx
    in al,dx
    in al,dx
    mov al,00h
    out dx,al

    mov si,200
    mov dx,[SBPort]
    add dl,0Eh
.readloop

    ; wait until port[SBDSPRdStat] AND 80h = 80h
    mov cx,20000
.tryagain
    in al,dx
    dec cx
    jz .cardfailed
    or al,al
    jns .tryagain
    sub dx,4
    in al,dx
    cmp al,0AAh
    jne .tryagain2
    ret
.tryagain2
    add dx,4
    dec si
    jnz .readloop
.cardfailed
    mov ax,0003h
    int 10h
    mov edx,initfailed      ;use extended
    mov ah,9                ;DOS- API
    int 21h                 ;to print a string
    jmp DosExit

section .data
NEWSYM initfailed, db 'Sound card failed to initialize!',13,10,'$'
section .text

; Write AL into DSP port
NEWSYM SB_dsp_write
    mov dx,[SBPort]
    add dl,0Ch
    mov bl,al
.tryagain
    in al,dx
    test al,80h
    jnz .tryagain
    mov al,bl
    out dx,al
    ret

; Read DSP port into AL
NEWSYM SB_dsp_read
    mov dx,[SBPort]
    add dl,0Eh
    mov bl,al
.tryagain
    in al,dx
    test al,80h
    jz .tryagain
    mov dx,[SBPort]
    add dl,0Ah
    mov al,bl
    in al,dx
    ret

;****************************************************
; Sound Blaster Interrupt Stuff
;****************************************************

NEWSYM Interror
    sti
    mov edx,.nohand         ;use extended
    mov ah,9                ;DOS- API
    int 21h                 ;to print a string
    call DosExit

section .data
.nohand db 'Cannot process interrupt handler!',13,10,'$'

section .bss

NEWSYM oldhandSBs, resw 1
NEWSYM oldhandSBo, resd 1
NEWSYM SBswitch,   resb 1         ; which block to process next

section .text

NEWSYM SBHandler
    cli
    push ds
    push eax


NEWSYM handlersbseg
    mov ax,[cs:dssel]
    mov ds,ax

    cmp byte[SBHDMA],0
    jne near SBHandler16

    ; code added by peter santing
    cmp byte[vibracard], 1
    je  near SBHandler16

    push ebx
    push ecx
    push edx
    push edi
    push esi
    push es

    call GetCDMAPos

    cmp byte[csounddisable],1
    je near stopsbsound
    test byte[DSPMem+6Ch],11000000b
    jnz near stopsbsound

    ; Process the sound :I

    mov es,[sbselec]
    cmp byte[SBswitch],0
    jne .2ndblock
    mov edi,[sbpmofs]
    jmp .startblockcopy
.2ndblock
    ; copy to 2nd block
    ; clear memory
    mov edi,[sbpmofs]
    add edi,[BufferSizeB]
.startblockcopy

    mov esi,DSPBuffer
    mov ecx,[BufferSizeB]
.loopb
    mov eax,[esi]
    cmp eax,-32768
    jge .noneg3
    mov eax,-32768
.noneg3
    cmp eax,32767
    jle .noneg4
    mov eax,32767
.noneg4
    xor ah,80h
    mov [es:edi],ah
    add esi,4
    inc edi
    dec ecx
    jnz .loopb
    jmp .sbend
.sbend
    xor byte[SBswitch],1

   ; move the good data at SPCRAM+0f3h
      xor eax,eax
      mov al,[SPCRAM+0F2h]
      mov bl,[DSPMem+eax]
      mov [SPCRAM+0F3h],bl
    ; acknowledge SB for IRQing
    mov dx,[SBPort]
    add dl,0Eh
    in al,dx
    mov al,20h
    out 20h,al
    cmp byte[SBIrq],7
    jbe .nohighirq
    mov al,20h
    out 0A0h,al
.nohighirq
    sti
    jmp Startprocsbdata

NEWSYM stopsbsound
;    mov byte[Voice0Status],0
;    mov byte[Voice1Status],0
;    mov byte[Voice2Status],0
;    mov byte[Voice3Status],0
;    mov byte[Voice4Status],0
;    mov byte[Voice5Status],0
;    mov byte[Voice6Status],0
;    mov byte[Voice7Status],0

    mov ax,ds
    mov es,ax
    mov edi,DSPBuffer
    mov ecx,[BufferSizeB]
    xor eax,eax
    rep stosd

    cmp byte[SBswitch],0
    jne near .2ndblock

    ; clear block
    mov es,[sbselec]
    mov edi,[sbpmofs]
    mov ecx,[BufferSizeB]
    shr ecx,2
.loopa
    mov dword[es:edi],80808080h
    add edi,4
    dec ecx
    jnz .loopa
    jmp .sbend
.2ndblock
    ; copy to 2nd block
    ; clear memory
    mov es,[sbselec]
    mov edi,[sbpmofs]
    add edi,[BufferSizeB]
    mov ecx,[BufferSizeB]
    shr ecx,2
.loopb
    mov dword[es:edi],80808080h
    add edi,4
    dec ecx
    jnz .loopb
.sbend
    xor byte[SBswitch],1

    ; acknowledge SB for IRQing
    mov dx,[SBPort]
    add dl,0Eh
    in al,dx
    mov al,20h
    out 20h,al
    cmp byte[SBIrq],7
    jbe .nohighirq
    mov al,20h
    out 0A0h,al
.nohighirq

    pop es
    pop esi
    pop edi
    pop edx
    pop ecx
    pop ebx
    pop eax
    pop ds
    sti
    iretd

section .bss
NEWSYM sbhandexec, resd 1
section .text

; Process 20 blocks * 8 voices (no pitch yet)
NEWSYM SBHandler16
    push ebx
    push ecx
    push edx
    push edi
    push esi
    push es
    inc dword[sbhandexec]

    cmp byte[vibracard], 1
    je .donotcallcmdapos
    call GetCDMAPos
.donotcallcmdapos

    cmp byte[csounddisable],1
    je near stopsbsound16
    test byte[DSPMem+6Ch],11000000b
    jnz near stopsbsound16

    mov es,[sbselec]

    cmp byte[SBswitch],0
    jne near .2ndblock
    mov edi,[sbpmofs]
    jmp .doneblock
.2ndblock
    ; copy to 2nd block
    ; clear memory
    mov edi,[sbpmofs]
    add edi,[BufferSizeW]
.doneblock
    mov esi,DSPBuffer
    mov ecx,[BufferSizeB]
.loopb
    mov eax,[esi]
    cmp eax,-32768
    jge .noneg5
    mov eax,-32768
.noneg5
    cmp eax,32767
    jle .noneg6
    mov eax,32767
.noneg6
    mov [es:edi],ax
    add esi,4
    add edi,2
    dec ecx
    jnz .loopb
    jmp .sbend
.sbend
    xor byte[SBswitch],1

    ; acknowledge SB for IRQing
    mov dx,[SBPort]
    add dl,0Fh
    in al,dx
    mov al,20h
    out 20h,al
    cmp byte[SBIrq],7
    jbe .nohighirq
    mov al,20h
    out 0A0h,al
.nohighirq
    sti


Startprocsbdata:
    push ebp
    call ProcessSoundBuffer
    pop ebp
    pop es
    pop esi
    pop edi
    pop edx
    pop ecx
    pop ebx
    pop eax
    pop ds
    iretd

NEWSYM stopsbsound16
;    mov byte[Voice0Status],0
;    mov byte[Voice1Status],0
;    mov byte[Voice2Status],0
;    mov byte[Voice3Status],0
;    mov byte[Voice4Status],0
;    mov byte[Voice5Status],0
;    mov byte[Voice6Status],0
;    mov byte[Voice7Status],0

    mov ax,ds
    mov es,ax
    mov edi,DSPBuffer
    mov ecx,[BufferSizeB]
    xor eax,eax
    rep stosd

    cmp byte[SBswitch],0
    jne near .2ndblock

    ; clear block
    mov es,[sbselec]
    mov edi,[sbpmofs]
    mov ecx,[BufferSizeB]
    shr ecx,1
.loopa
    mov dword[es:edi],00000000h
    add edi,4
    dec ecx
    jnz .loopa
    jmp .sbend
.2ndblock
    ; copy to 2nd block
    ; clear memory
    mov es,[sbselec]
    mov edi,[sbpmofs]
    add edi,[BufferSizeW]
    mov ecx,[BufferSizeB]
    shr ecx,1
.loopb
    mov dword[es:edi],00000000h
    add edi,4
    dec ecx
    jnz .loopb
.sbend
    xor byte[SBswitch],1

    ; acknowledge SB for IRQing
    mov dx,[SBPort]
    add dl,0Fh
    in al,dx
    mov al,20h
    out 20h,al
    cmp byte[SBIrq],7
    jbe .nohighirq
    mov al,20h
    out 0A0h,al
.nohighirq

    pop es
    pop esi
    pop edi
    pop edx
    pop ecx
    pop ebx
    pop eax
    pop ds
    sti
    iretd

;****************************************************
; Sound Blaster Initialization Stuff
;****************************************************

section .bss
NEWSYM memoryloc, resd 1        ; Memory offset in conventional memory
NEWSYM memoryloc2, resd 1       ; Memory offset in conventional memory
NEWSYM sbselec,   resw 1        ; Selector of Memory location
NEWSYM sbpmofs,   resd 1        ; offset of Memory location
SBDeinitType resb 1
section .text

NEWSYM InitSB
    mov eax,[SoundQuality]
    cmp byte[StereoSound],1
    jne .nostereobuf
    mov ax,[BufferSizes+eax*2]
    jmp .skipstereobuf
.nostereobuf
    mov ax,[BufferSize+eax*2]
.skipstereobuf

    mov [BufferSizeB],ax
    add ax,ax
    mov [BufferSizeW],ax

    mov byte[SBswitch],0
    ; Allocate pointer
    ; Set up SB
    call SB_dsp_reset

    ; code added by peter santing
    cmp byte[vibracard], 1
    je  near .vibrafix2

    cmp byte[SBHDMA],0
    je .no16bit
    cmp byte[SBHDMA],4
    jb near .init16bitlowhdma
    jmp .init16bit
.no16bit

    ; Determine Version #
    mov al,0E1h
    call SB_dsp_write
    call SB_dsp_read
    mov [.Versionnum],al
    call SB_dsp_read
    mov [.Versionnum+1],al

    ; Turn on speakers
    mov al,0D1h
    call SB_dsp_write

    ; Set Time-Constant Data ( = 256 - (1000000/sampling rate) )
    ; 8000=131, 22050=210, 44100=233, 11025=165
    mov al,40h
    call SB_dsp_write

    cmp byte[StereoSound],1
    jne .nostereo8b
.surround8b
    mov eax,[SoundQuality]
    cmp eax,4
    je .okay
    cmp eax,2
    jbe .okay
    mov eax,2
.okay
    mov al,[SoundSpeedt+eax]
    call SB_dsp_write
    ; Set Stereo
    mov dx, [SBPort]
    add dx, 04h
    mov al,0Eh
    out dx,al
    inc dx
    in  al,dx
    or  al,022h
    out dx,al
    jmp .donestereo
.nostereo8b
    mov eax,[SoundQuality]
    mov al,[SoundSpeeds+eax]
    call SB_dsp_write
.donestereo

    cmp byte[StereoSound],1
    je .highmode
    mov eax,[SoundQuality]
    cmp byte[SoundSpeeds+eax],211
    ja .highmode
    mov byte[.Versionnum],1
.highmode
    ; Setup DMA
    ; Select DMA channel
    mov al,[SBDMA]
    add al,4
    mov dx,000Ah
    out dx,al
    ; Clear DMA
    mov al,00h
    mov dx,000Ch
    out dx,al
    ; Set autoinit/write (set as DAC)
    mov al,58h
    add al,[SBDMA]
    mov dx,000Bh
    out dx,al
    ; Send Offset Address
    mov al,[memoryloc]
    mov dl,[SBDMA]
    shl dl,1
    out dx,al
    mov al,[memoryloc+1]
    out dx,al
    ; Send length of entire block
    mov ax,[BufferSizeW]
    dec ax
    inc dx
    out dx,al
    mov al,ah
    out dx,al
    ; Send page # (address/65536)
    mov al,[memoryloc+2]
    mov dl,[SBDMAPage]
    out dx,al
    ; turn on DMA
    mov al,[SBDMA]
    mov dx,000Ah
    out dx,al

    ; Prepare SB for the first block
    ; 8-bit auto-init, mono, unsigned
    mov al,048h   ; Sb 2.0 version...
    call SB_dsp_write

    ; Send Length-1 to DSP port