display logo gfx, misc gfx related helpers

2009-10-14 10:52:37 +02:00
parent b7d32d6285
commit ed22950f47
18 changed files with 3595 additions and 4 deletions
--- a/snes/reset.a65
+++ b/snes/reset.a65
@@ -0,0 +1,132 @@
+; This file is part of the snescom-asm demo - a demo of how to build a SNES program.
+; See http://bisqwit.iki.fi/source/snescom.html for details.
+
+#include "memmap.i65"
+
+
+#define TILE_ADDR_REG_VAL(addr, scsize) \
+          (((addr & $FC00) >> 8) + scsize)
+#define BMAP_ADDR_REG_VAL(addr, addr2) \
+          (((addr & $F000) >> 12) | (((addr2 & $F000) >> 12) << 4))
+
+; NMI - called once per screen refresh (or something like that)
+NMI_ROUTINE:
+        sep #$20 : .as
+        lda $4210
+        rtl
+
+; IRQ - called when triggered (which is..?)
+IRQ_ROUTINE:
+        sep #$20 : .as
+        lda $4211  ;Acknowledge irq
+        rtl
+
+; To be called regularly - updated screen contents
+; Sends the palette structure to PPU
+PaletteDMA:
+        .xl : .as
+        lda #$00 : sta $4300  ;dma type
+        lda #$22 : sta $4301  ;address $2122
+        
+        lda #^(PALETTE_ADDRESS) : sta $4304
+        ldx #!(PALETTE_ADDRESS) : stx $4302
+        
+        ldx #512 : stx $4305 ; size: 16*2*16 bytes.
+        
+        lda #$00 : sta $2121  ;Write CGRAM address (0)
+        
+        lda #$01 : sta $420B  ;Activate dma 0
+        rts
+
+; Sends the video buffer contents to PPU
+VRAMdma:
+        sty $2116  ;Write VRAM address
+        
+        sty $4302 : sta $4304 ;Write DMA address
+        stx $4305             ;Write size
+        
+        lda #$80 : sta $2115  ;PPU programming
+        
+        lda #$01 : sta $4300  ;dma type
+        lda #$18 : sta $4301  ;address $2118
+        
+        lda #$01 : sta $420B  ;Activate DMA 0
+        rts
+
+; Jumped to from snesheader.a65 - when the game is reseted.
+RESET_GAME:
+        rep #$30 : .al : .xl
+        
+        lda #$0400 : tcd
+        ldx #$03FE : txs
+        
+        sep #$20 : .as
+        
+        pha
+        plb
+        
+        lda #$01
+        sta $420D ; set "fast" mode
+        
+        ; Next initialize screen
+        
+        jsr InitializeScreen
+        jsr InitializeIRQ
+        
+        sep #$20 : .as
+        
+        ;lda #$17
+        lda #$03
+        sta $212C ; put screens on
+        sta $212D ; put screens on
+        
+        lda #$00: sta $2121
+        lda #$E0: sta $2122
+        lda #$7C: sta $2122
+        
+        jmp @GAME_MAIN
+
+InitializeIRQ:
+        sep #$20 : .as
+        
+        lda #$B1 : sta $4200
+        ldx #0   : stx $4207
+        ldx #211 : stx $4209
+        
+        sei
+
+        lda $4211
+        - lda $4210 ;: bpl -
+        
+        rts
+        
+InitializeScreen:
+        rep #$10 : .xl
+        sep #$20 : .as
+        
+        lda #$00 : sta $2101
+        
+        ldx #$0000 : stx $2102
+        
+        lda #$09 : sta $2105 ; select screen mode 1.
+
+        lda #$00 : sta $2106
+        
+        lda #TILE_ADDR_REG_VAL(BG1_TILE_ADDR, 0) : sta $2107
+        lda #TILE_ADDR_REG_VAL(BG2_TILE_ADDR, 0) : sta $2108
+        lda #TILE_ADDR_REG_VAL(BG3_TILE_ADDR, 0) : sta $2109
+        lda #TILE_ADDR_REG_VAL(BG4_TILE_ADDR, 0) : sta $210A
+        
+        lda #BMAP_ADDR_REG_VAL(BG1_BMAP_ADDR, BG2_BMAP_ADDR) : sta $210B
+        lda #BMAP_ADDR_REG_VAL(BG3_BMAP_ADDR, BG4_BMAP_ADDR) : sta $210C
+        
+        ; Set scrolling to 0,0 to all bgs
+        lda #$00 : sta $210D : sta $210D
+        lda #$00 : sta $210E : sta $210E
+        lda #$00 : sta $210F : sta $210F
+        lda #$00 : sta $2110 : sta $2110
+        lda #$00 : sta $2111 : sta $2111
+        lda #$00 : sta $2112 : sta $2112
+        lda #$00 : sta $2113 : sta $2113
+        lda #$00 : sta $2114 : sta $2114
+        rts