Add M12 Intro Screen

src/m12-intro.asm

@@ -0,0 +1,117 @@
+REG_DISPCNT  equ 0x04000000 //Display Control, 16-bit
+REG_DISPSTAT equ 0x04000004 //General LCD Status
+REG_BG0CNT  equ 0x04000008 //BG0 Control
+REG_IME  equ 0x04000208 //Interrupt Master Enable Register
+REG_IE  equ 0x04000200 //Interrupt Enable Register
+REG_IF  equ 0x04000202 //Interrupt Request Flags / IRQ Acknowledge
+REG_BLDCNT  equ 0x04000050 //Color Special Effects Selection
+REG_BLDY  equ 0x04000054 //Brightness Coefficient
+VRAM equ 0x06000000 //Video RAM, 16-bit
+BGCRAM equ 0x05000000 //BG Color RAM, 16-bit
+REG_KEYINPUT  equ 0x04000130 //Key Status
+LZ77UnCompVRAM equ #18
+
+m12_intro_screen:
+	push {r0-r4}
+	ldr r0,=REG_DISPCNT
+	mov r1,#0xFF
+	add r1,r1,#1
+	strh r1,[r0]
+
+	ldr r0,=REG_DISPSTAT
+	mov r1,#8
+	strh r1,[r0]
+	
+	ldr r0,=REG_BG0CNT
+	mov r1,#0x80
+	strh r1,[r0]
+	
+	ldr r0,=REG_IME
+	mov r1,#0x1
+	strh r1,[r0]
+	
+	ldr r0,=REG_IE
+	mov r1,#0x1
+	strh r1,[r0]
+	
+	ldr r0,=REG_IF
+	mov r1,#0x1
+	strh r1,[r0]
+	
+	ldr r0,=REG_BLDCNT
+	mov r1,#0xA1
+	strh r1,[r0]
+	
+	ldr r0,=REG_BLDY
+	mov r1,#16
+	strh r1,[r0]
+		
+	ldr r0,=disclaimer_palette
+	ldr r1,=BGCRAM
+	ldr r4,=#159*2
+	@@palette:
+		ldrh r3,[r0,r5]
+		strh r3,[r1,r5]
+		add r5,#2
+		cmp r5,r4
+		bne @@palette
+
+	ldr r2,=#0x100
+	ldr r0,=disclaimer_map
+	ldr r1,=VRAM
+	ldr r4,=#1280
+	@@map:
+		sub r4,#2
+		ldrh r3,[r0,r4]
+		add r3,r2
+		strh r3,[r1,r4]
+		cmp r4,#0
+		bne @@map
+
+	ldr r0,=#disclaimer_graphics
+	ldr r1,=VRAM+0x4000
+	swi LZ77UnCompVRAM
+
+	ldr r2,=REG_BLDCNT
+	mov  r4,#0x10
+	@@fadein:
+		strh r4,[r2,#4]
+		swi  #5
+		swi  #5 // 15 loops with 2 intrs each gives a total fade-in time of 0.5 seconds
+		sub  r4,#1
+		bpl  @@fadein
+
+	ldr  r2,=REG_KEYINPUT
+	ldr  r4,=#0x3FF
+	@@loop3:
+		swi  #5 // VBlankIntrWait
+		ldrh r0,[r2,#0]	
+		cmp  r0,r4
+		beq  @@loop3
+	
+	@@next:
+		ldr r2,=REG_BLDCNT
+		mov  r4,#0x00
+		@@fadeout:
+			strh r4,[r2,#4]
+			swi  #5
+			swi  #5 // 15 loops with 2 intrs each gives a total fade-in time of 0.5 seconds
+			add  r4,#1
+			cmp r4,#0x11
+			bne @@fadeout
+		
+	mov r0,#0
+	ldr r1,=BGCRAM
+	ldr r4,=#74
+	@@cpal:
+		sub r4,#2
+		strh r0,[r1,r4]
+		cmp r4,#0
+		bne @@cpal
+
+	pop {r0-r4}
+	push {lr}
+	ldr r0,=#0x3007FFC
+	str r1,[r0,#0]
+	pop  {pc}
+.pool

src/m2-hack.asm

@@ -45,6 +45,12 @@ mov     r1,4
 mov     r2,1
 mov     r3,6
 
+//---------------------------------------------------------
+// 00270 hacks (intro screen)
+//---------------------------------------------------------
+
+.org 0x800027A :: bl m12_intro_screen
+
 //---------------------------------------------------------
 // C0A5C hacks (status window)
 //---------------------------------------------------------
@@ -1856,6 +1862,16 @@ optimized_byte_4bpp_to_1bpp_table:
 m12_cartridge_palettes_dimmed:
 .incbin "data/m12-cartridge-palettes-dimmed.bin"
 
+.org 0x8FEE000
+disclaimer_palette:
+.incbin "data/intro-screen-pal.bin"
+.align 4
+disclaimer_graphics:
+.incbin "data/intro-screen-gfx.bin"
+.align 4
+disclaimer_map:
+.incbin "data/intro-screen-map.bin"
+
 
 //==============================================================================
 // Existing subroutines/data
@@ -1944,5 +1960,6 @@ m12_cartridge_palettes_dimmed:
 .include "m2-customcodes.asm"
 .include "m2-compiled.asm"
 .include "m2-flyover.asm"
+.include "m12-intro.asm"
 
 .close