/* * Snes9x - Portable Super Nintendo Entertainment System (TM) emulator. * * (c) Copyright 1996, 1997, 1998 Gary Henderson (gary@daniver.demon.co.uk) and * Jerremy Koot (jkoot@euronet.nl) * * Super FX C emulator code * (c) Copyright 1997, 1998 Lestat (lstat@hotmail.com) and * Gary Henderson. * Super FX assembler emulator code (c) Copyright 1998 zsKnight and _Demo_. * * DSP1 emulator code (c) Copyright 1998 Lestat and Gary Henderson. * DOS port code contains the works of other authors. See headers in * individual files. * * Permission to use, copy, modify and distribute Snes9x in both binary and * source form, for non-commercial purposes, is hereby granted without fee, * providing that this license information and copyright notice appear with * all copies and any derived work. * * This software is provided 'as-is', without any express or implied * warranty. In no event shall the authors be held liable for any damages * arising from the use of this software. * * Snes9x is freeware for PERSONAL USE only. Commercial users should * seek permission of the copyright holders first. Commercial use includes * charging money for Snes9x or software derived from Snes9x. * * The copyright holders request that bug fixes and improvements to the code * should be forwarded to them so everyone can benefit from the modifications * in future versions. * * Super NES and Super Nintendo Entertainment System are trademarks of * Nintendo Co., Limited and its subsidiary companies. */ #include "asmstruc.h" #include "asmops.h" #include "spcops.h" .globl MainAsmLoop .text .align 4 .globl S9xMainLoop S9xMainLoop: pushl %ebp pushl %edi pushl %esi pushl %ebx LOAD_REGISTERS .L9: cmpb $0,APUExecuting je .L12 decl APUCycles jnz .L12 movl SPCTo65c816Ratio,%eax movl %eax, APUCycles #ifdef DEBUGGER testb $2,APUFlags je .L14 STORE_REGISTERS ccall S9xTraceAPU LOAD_REGISTERS .L14: #endif xorl %eax,%eax movb (APUPC),%al movl S9xApuOpcodes(,%eax,4),%eax call *%eax .L12: cmpl $0, Flags je .L15 movl Flags, %eax testb %al, %al jge .NO_NMI andb $~NMI_FLAG, %al movl %eax, Flags cmpb $0, WaitingForInterrupt je .L17 movb $0, WaitingForInterrupt incl PC .L17: call S9xOpcode_NMI .NO_NMI: movl Flags, %eax testl $DELAYED_NMI_FLAG2, %eax jz .NO_DELAYED_NMI andl $~DELAYED_NMI_FLAG2, %eax orb $NMI_FLAG, %al movl %eax, Flags .NO_DELAYED_NMI: testb $DELAYED_NMI_FLAG, %al jz .NO_DELAYED_NMI2 andb $~DELAYED_NMI_FLAG, %al orl $DELAYED_NMI_FLAG2, %eax movl %eax, Flags .NO_DELAYED_NMI2: #ifdef DEBUGGER testb $BREAK_FLAG, Flags jz .NO_BREAK_POINTS pushl %esi pushl %ebx movl $S9xBreakpoint, %esi movb PB, %bl xorl %edx, %edx movl PC, %ecx subl PCBase, %ecx .BREAK_CHECK_LOOP: movzwl %dx, %eax sall $2, %eax cmpb $0, S9xBreakpoint(%eax) je .BREAK_MATCH_FAILED cmpb %bl, 1(%esi, %eax) jne .BREAK_MATCH_FAILED movzwl 2(%esi, %eax), %eax cmpl %ecx, %eax jne .BREAK_MATCH_FAILED orb $DEBUG_MODE_FLAG, Flags .BREAK_MATCH_FAILED: incw %dx cmpw $6, %dx jne .BREAK_CHECK_LOOP popl %ebx popl %esi .NO_BREAK_POINTS: #endif #if defined(__linux) && !defined(__msdos) movl Flags, %eax testl $PROCESS_SOUND_FLAG,%eax jz .NO_SOUND STORE_REGISTERS ccall S9xUnixProcessSound LOAD_REGISTERS .NO_SOUND: #endif #ifdef DEBUGGER movl Flags, %eax testb $DEBUG_MODE_FLAG,%al jnz .L31 #else movl Flags, %eax #endif testb $SCAN_KEYS_FLAG, %al jnz .L31 .L28: #ifdef DEBUGGER testb $TRACE_FLAG, %al jz .NO_TRACE STORE_REGISTERS ccall S9xTrace LOAD_REGISTERS .NO_TRACE: movl Flags, %eax testb $SINGLE_STEP_FLAG, %al jz .L15 andb $~SINGLE_STEP_FLAG, %al orb $DEBUG_MODE_FLAG, %al movl %eax, Flags #endif .L15: xorl %eax,%eax #ifdef VAR_CYCLES addl MemSpeed, CYCLES movb (PC), %al #else xorl %ecx, %ecx movl CPUSpeed, %edx movb (PC), %al movb (%edx,%eax), %cl addl %ecx, CYCLES #endif movl CPUOpcodes, %ecx movl (%ecx,%eax,4), %eax #ifdef CPU_SHUTDOWN movl PC, PCAtOpcodeStart #endif incl PC jmp *%eax MainAsmLoop: cmpl NextEvent, CYCLES jl .L9 STORE_REGISTERS call S9xDoHBlankProcessing LOAD_REGISTERS jmp .L9 .L31: S9xPackStatus S9xMainLoop STORE_REGISTERS subl PCBase, PC movw %di, PCR subl APURAM, APUPC movw %bp, APUPCR APUS9xPackStatus S9xMainLoop movl Flags, %eax testb $SCAN_KEYS_FLAG, %al jz .NoScanKeys andb $~SCAN_KEYS_FLAG, %al movl %eax, Flags #ifdef DEBUGGER testl $FRAME_ADVANCE_FLAG, %eax jnz .NoScanKeys #endif ccall S9xSyncSpeed .NoScanKeys: popl %ebx popl %esi popl %edi popl %ebp ret .globl S9xDoHBlankProcessing S9xDoHBlankProcessing: pushl %edi pushl %esi pushl %ebx #ifdef CPU_SHUTDOWN incl WaitCounter #endif movb WhichEvent,%bl andl $255,%ebx cmpl $1,%ebx je .L160 jg .L196 testl %ebx,%ebx je .L158 jmp .L157 .L196: cmpl $2,%ebx je .L189 jmp .L157 .L158: movb HDMA,%dl testb %dl,%dl je .L157 movl V_Counter, %eax cmpw ScreenHeight, %ax jae .L157 xorl %eax,%eax movb %dl,%al pushl %eax ccall S9xDoHDMA movb %al,HDMA addl $4,%esp jmp .L157 .L160: #ifdef EXECUTE_SUPERFX_PER_LINE ccall S9xSuperFXExec #endif movl H_Max,%eax movl Cycles,%ecx subl %eax,%ecx movl %ecx,Cycles movl V_Counter,%ecx incl %ecx movl $-1,NextEvent movl %ecx,V_Counter testb $0xff, PAL jz .ntsc_tv cmpl $312,%ecx jbe .L161 jmp .endofframe .ntsc_tv: cmpl $262,%ecx jbe .L161 .endofframe: movw SavedOAMAddr,%ax xorl %edx,%edx movl Flags,%ecx movw %ax,OAMAddr movb %dl,OAMFlip orl $16,%ecx movl %edx,V_Counter movb %dl,HVBeamCounterLatched movl %ecx,Flags ccall S9xStartHDMA .L161: movb VTimerEnabled,%al testb %al,%al je .L162 movb HTimerEnabled,%dl testb %dl,%dl jne .L162 xorl %eax,%eax movw IRQVBeamPos,%ax movl V_Counter,%ecx cmpl %eax,%ecx jne .L162 orb $2,IRQActive movb WaitingForInterrupt,%al testb %al,%al je .L163 incl PCS movb %dl,WaitingForInterrupt .L163: movb DisableIRQ,%al testb %al,%al jne .L162 testb $4,PP jne .L162 PUSH_REGISTERS LOAD_REGISTERS call S9xOpcode_IRQ STORE_REGISTERS POP_REGISTERS .L162: xorl %eax,%eax movw ScreenHeight,%ax movl V_Counter,%edx incl %eax cmpl %eax,%edx jne .L165 ccall S9xEndScreenRefresh xorl %ecx,%ecx movb %cl,FirstSprite movb %cl,HDMA movl FillRAM,%eax movl $128,%edx movb %dl,16912(%eax) movb Brightness,%al xorl %ecx,%ecx movb %al,MaxBrightness movl FillRAM,%eax movb 8448(%eax),%cl shrb $7,%cl movb %cl,ForcedBlanking movb 16896(%eax),%dl testb %dl,%dl jge .L166 movb WaitingForInterrupt,%cl testb %cl,%cl je .L167 incl PCS movb $0,WaitingForInterrupt .L167: movl Flags,%ecx orl $64,%ecx movl %ecx,Flags .L166: .L165: xorl %eax, %eax movw ScreenHeight,%ax addl $3,%eax cmpl V_Counter,%eax jne .NoJoypadUpdate ccall S9xUpdateJoypads .NoJoypadUpdate: movl V_Counter,%eax cmpl $1,%eax jne .L177 movl FillRAM,%eax xorl %edx,%edx movb %dl,16912(%eax) ccall S9xStartScreenRefresh .L177: movl V_Counter,%edx testl %edx,%edx je .L178 xorl %eax,%eax movw ScreenHeight,%ax incl %eax cmpl %eax,%edx jae .L178 movb V_Counter,%al decb %al andl $255,%eax pushl %eax ccall RenderLine addl $4,%esp .L178: movl APUTimerErrorCounter,%eax incl %eax movl %eax,APUTimerErrorCounter andl $63,%eax jz .L157 movb APUTimerEnabled + 2,%cl testb %cl,%cl je .L179 movw APUTimer + 4,%ax addl $4,%eax movw %ax,APUTimer + 4 cmpw %ax,APUTimerTarget + 4 ja .L179 .L182: movl APURAM,%edx movb 255(%edx),%al incb %al andb $15,%al movb %al,255(%edx) movw APUTimerTarget + 4,%dx movw APUTimer + 4,%ax movl APUWaitCounter,%ecx movl $1,%ebx subl %edx,%eax incl %ecx movb %bl,APUExecuting movw %ax,APUTimer + 4 movl %ecx,APUWaitCounter cmpw %dx,%ax jae .L182 .L179: testb $1,V_Counter je .L157 movb APUTimerEnabled,%al testb %al,%al je .L185 incw APUTimer movw APUTimerTarget,%ax cmpw %ax,APUTimer jb .L185 movl APURAM,%edx movb 253(%edx),%al incb %al andb $15,%al movb %al,253(%edx) movl APUWaitCounter,%edx movl $1,%ecx incl %edx movw $0,APUTimer movb %cl,APUExecuting movl %edx,APUWaitCounter .L185: movb APUTimerEnabled + 1,%al testb %al,%al je .L157 incw APUTimer + 2 movw APUTimerTarget + 2,%ax cmpw %ax,APUTimer + 2 jb .L157 movl APURAM,%edx movb 254(%edx),%al incb %al andb $15,%al movb %al,254(%edx) movl APUWaitCounter,%edx movl $1,%ecx incl %edx movw $0,APUTimer + 2 movb %cl,APUExecuting movl %edx,APUWaitCounter jmp .L157 .L189: movb VTimerEnabled,%al testb %al,%al je .L191 xorl %eax,%eax movw IRQVBeamPos,%ax movl V_Counter,%edx cmpl %eax,%edx jne .L157 .L191: orb $1,IRQActive movb WaitingForInterrupt,%al testb %al,%al je .L192 movb $0, WaitingForInterrupt incl PCS .L192: movb DisableIRQ,%al testb %al,%al jne .L157 testb $4,PP jne .L157 PUSH_REGISTERS LOAD_REGISTERS call S9xOpcode_IRQ STORE_REGISTERS POP_REGISTERS .L157: movl HBlankStart,%edx movl NextEvent,%ecx cmpl %edx,%ecx #if 0 jge .L199 xorl %eax,%eax movw ScreenHeight,%ax movl V_Counter,%ecx incl %eax cmpl %eax,%ecx jb .L198 .L199: #else jl .L198 #endif movb $1,%bl movl H_Max,%edx jmp .L200 .L198: xorl %ebx,%ebx .L200: movswl HTimerPosition,%esi cmpl %edx,%esi jge .L201 movl NextEvent,%eax cmpl %eax,%esi jle .L201 movb VTimerEnabled,%cl testb %cl,%cl je .L202 xorl %eax,%eax movw IRQVBeamPos,%ax movl V_Counter,%ecx cmpl %eax,%ecx jne .L201 .L202: movb $2,%bl movl %esi,%edx .L201: movb %bl,WhichEvent popl %ebx popl %esi movl %edx,NextEvent popl %edi ret