Add NES building and adapt example functions

2025-06-05 22:09:21 +02:00 · 2023-11-01 13:58:22 +01:00
parent 5c404b5faf
commit 9be90d7629
33 changed files with 3951 additions and 35 deletions
--- a/LibMultiSpacc/neslib/crt0.s
+++ b/LibMultiSpacc/neslib/crt0.s
@ -0,0 +1,208 @@
+; Startup code for cc65 and Shiru's NES library
+; based on code by Groepaz/Hitmen <groepaz@gmx.net>, Ullrich von Bassewitz <uz@cc65.org>
+; edited by Steven Hugg (remove integrated Famitone2 library, add NMICallback)
+
+	.export _exit,__STARTUP__:absolute=1
+	.import initlib,push0,popa,popax,_main,zerobss,copydata
+
+	; Linker generated symbols
+	.import __RAM_START__   ,__RAM_SIZE__
+	.import __ROM0_START__  ,__ROM0_SIZE__
+	.import __STARTUP_LOAD__,__STARTUP_RUN__,__STARTUP_SIZE__
+	.import	__CODE_LOAD__   ,__CODE_RUN__   ,__CODE_SIZE__
+	.import	__RODATA_LOAD__ ,__RODATA_RUN__ ,__RODATA_SIZE__
+	.import NES_MAPPER,NES_PRG_BANKS,NES_CHR_BANKS,NES_MIRRORING
+
+	.include "zeropage.inc"
+	.include "nes.inc"
+
+FT_BASE_ADR		=$0100	;page in RAM, should be $xx00
+
+.define FT_THREAD       1	;undefine if you call sound effects in the same thread as sound update
+.define FT_PAL_SUPPORT	1   ;undefine to exclude PAL support
+.define FT_NTSC_SUPPORT	1   ;undefine to exclude NTSC support
+
+.segment "ZEROPAGE"
+
+NTSC_MODE: 		.res 1
+FRAME_CNT1: 		.res 1
+FRAME_CNT2: 		.res 1
+VRAM_UPDATE: 		.res 1
+NAME_UPD_ADR: 		.res 2
+NAME_UPD_ENABLE: 	.res 1
+PAL_UPDATE: 		.res 1
+PAL_BG_PTR: 		.res 2
+PAL_SPR_PTR: 		.res 2
+SCROLL_X: 		.res 1
+SCROLL_Y: 		.res 1
+SCROLL_X1: 		.res 1
+SCROLL_Y1: 		.res 1
+PPU_CTRL_VAR:		.res 1
+PPU_CTRL_VAR1:		.res 1
+PPU_MASK_VAR: 		.res 1
+;;FT_TEMP: 		.res 3
+_oam_off:		.res 1
+NMICallback:		.res 3
+
+TEMP: 			.res 11
+
+.exportzp NTSC_MODE, FRAME_CNT1, FRAME_CNT2, VRAM_UPDATE
+.exportzp NAME_UPD_ADR, NAME_UPD_ENABLE
+.exportzp PAL_UPDATE, PAL_BG_PTR, PAL_SPR_PTR
+.exportzp SCROLL_X, SCROLL_Y, SCROLL_X1, SCROLL_Y1
+.exportzp PPU_CTRL_VAR, PPU_CTRL_VAR1, PPU_MASK_VAR
+.exportzp _oam_off, NMICallback
+.exportzp TEMP
+
+.include "zpvars.inc"
+
+.segment "HEADER"
+
+    .byte $4e,$45,$53,$1a
+	.byte <NES_PRG_BANKS
+	.byte <NES_CHR_BANKS
+	.byte <NES_MIRRORING|(<NES_MAPPER<<4)
+	.byte <NES_MAPPER&$f0
+	.res 8,0
+
+
+
+.segment "STARTUP"
+
+start:
+_exit:
+
+    sei
+    ldx #$ff
+    txs
+    inx
+    stx PPU_MASK
+    stx DMC_FREQ
+    stx PPU_CTRL		;no NMI
+
+initPPU:
+
+    bit PPU_STATUS
+@1:
+    bit PPU_STATUS
+    bpl @1
+@2:
+    bit PPU_STATUS
+    bpl @2
+
+; no APU frame counter IRQs
+	lda #$40
+	sta PPU_FRAMECNT
+
+clearPalette:
+
+	lda #$3f
+	sta PPU_ADDR
+	stx PPU_ADDR
+	lda #$0f
+	ldx #$20
+@1:
+	sta PPU_DATA
+	dex
+	bne @1
+
+clearVRAM:
+
+	txa
+	ldy #$20
+	sty PPU_ADDR
+	sta PPU_ADDR
+	ldy #$10
+@1:
+	sta PPU_DATA
+	inx
+	bne @1
+	dey
+	bne @1
+
+clearRAM:
+
+    txa
+@1:
+    sta $000,x
+    sta $100,x
+    sta $200,x
+    sta $300,x
+    sta $400,x
+    sta $500,x
+    sta $600,x
+    sta $700,x
+    inx
+    bne @1
+
+	lda #4
+	jsr _pal_bright
+	jsr _pal_clear
+	jsr _oam_clear
+
+    jsr	zerobss
+	jsr	copydata
+
+    lda #<(__RAM_START__+__RAM_SIZE__)
+    sta	sp
+    lda	#>(__RAM_START__+__RAM_SIZE__)
+    sta	sp+1            ; Set argument stack ptr
+
+	jsr	initlib
+
+; setup NMICallback trampoline to NOP
+	lda #$4C	;JMP xxxx
+	sta NMICallback
+	lda #<HandyRTS
+	sta NMICallback+1
+	lda #>HandyRTS
+	sta NMICallback+2
+
+	lda #%10000000
+	sta <PPU_CTRL_VAR
+	sta PPU_CTRL		;enable NMI
+	lda #%00000110
+	sta <PPU_MASK_VAR
+
+waitSync3:
+	lda <FRAME_CNT1
+@1:
+	cmp <FRAME_CNT1
+	beq @1
+
+detectNTSC:
+	ldx #52				;blargg's code
+	ldy #24
+@1:
+	dex
+	bne @1
+	dey
+	bne @1
+
+	lda PPU_STATUS
+	and #$80
+	sta <NTSC_MODE
+
+	jsr _ppu_off
+
+	lda #0
+	sta PPU_SCROLL
+	sta PPU_SCROLL
+	sta PPU_OAM_ADDR
+
+	jmp _main			;no parameters
+
+	.include "neslib.sinc"
+
+.segment "CHARS"
+	;;
+
+.segment "SAMPLES"
+	;;
+
+.segment "VECTORS"
+
+	.word nmi	;$fffa vblank nmi
+	.word start	;$fffc reset
+	.word irq	;$fffe irq / brk
+