summaryrefslogtreecommitdiff
path: root/home/copy.asm
diff options
context:
space:
mode:
Diffstat (limited to 'home/copy.asm')
-rw-r--r--home/copy.asm591
1 files changed, 591 insertions, 0 deletions
diff --git a/home/copy.asm b/home/copy.asm
new file mode 100644
index 0000000..d8f2a74
--- /dev/null
+++ b/home/copy.asm
@@ -0,0 +1,591 @@
+__memset_8: ; 0xc3e
+ dec bc
+.asm_63f
+ ld [hli], a
+ dec bc
+ bit 7, b
+ jr z, .asm_63f
+ ret
+
+__memset_16:
+ srl b
+ rr c
+.asm_064a
+ ld a, e
+ ld [hli], a
+ ld a, d
+ ld [hli], a
+ dec bc
+ ld a, b
+ or c
+ jr nz, .asm_064a
+ ret
+
+ClearData: ; 0x654
+; Clears bc bytes starting at hl.
+; bc can be a maximum of $7fff, since it checks bit 7 of b when looping.
+ xor a
+ dec bc
+.clearLoop
+ ld [hli], a
+ dec bc
+ bit 7, b
+ jr z, .clearLoop
+ ret
+
+LocalCopyData: ; 0x65d
+ ld a, [hli]
+ ld [de], a
+ inc de
+ dec bc
+ ld a, c
+ or b
+ jr nz, LocalCopyData
+ ret
+
+FarCopyData: ; 0x666 spooky
+; Copies data from any bank to either working RAM or video RAM
+; Input: hl = address of data to copy
+; a = bank of data to copy
+; de = destination for data
+; bc = number of bytes to copy
+ bit 7, h
+ jr nz, .copyFromSRAM
+ ld [hROMBankBuffer], a
+ ld a, [hLoadedROMBank]
+ push af
+ ld a, [hROMBankBuffer]
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ scf
+ jr .copyData
+
+.copyFromSRAM
+ ld [MBC5SRamBank], a
+ and a
+.copyData
+ push af
+.copyLoop
+ ld a, [hli]
+ ld [de], a
+ inc de
+ dec bc
+ ld a, c
+ or b
+ jr nz, .copyLoop
+ pop af
+ ret nc
+ pop af
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ ret
+
+ReadByteFromBank: ; 0x68f
+; Input: a = bank
+; hl = address of byte to read
+; Output: a = byte at a:hl
+ push de
+ ld d, a
+ ld a, [hLoadedROMBank]
+ ld e, a
+ ld a, d
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ ld d, [hl]
+ ld a, e
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ ld a, d
+ pop de
+ ret
+
+LoadVideoData: ; 0x6a4
+; Input:
+; hl = address of pointer table
+; a = index of item to load in pointer table
+; This needs more documentation. It loads things like graphics and palettes.
+ sla a
+ ld c, a
+ ld b, $0
+ add hl, bc
+ ld a, [hli]
+ ld h, [hl]
+ ld l, a
+.loadItem
+ ld a, [hli]
+ ld c, a
+ and [hl]
+ cp $ff ; two consecutive $ff bytes terminate the array
+ ret z
+ ld a, [hli]
+ ld b, a ; bc contains pointer to data to be loaded
+ push hl
+ push bc
+ ld a, [hli] ; a contains bank of data to be loaded
+ ld e, [hl]
+ inc hl
+ ld d, [hl] ; de contains destination address or palette offset for data
+ inc hl
+ ld c, [hl]
+ inc hl
+ ld b, [hl] ; bc contains size and flags
+ inc hl ; this is a wasted instruction
+ pop hl
+ call .autoCopyVideoData
+ pop hl
+ ld bc, $0005
+ add hl, bc
+ jr .loadItem
+
+.autoCopyVideoData
+; a: bank
+; hl: source
+; bc: flags and size rolled into one
+; bit 0: CGB palette data if set, tile data else
+; If tile data:
+; bit 1: VBank
+; de = dest
+; Else:
+; de = palette offset
+; remaining bits: size
+ srl b
+ rr c
+ jp c, FarCopyCGBPals ; if lowest bit of bc is set
+ jp @ + 2
+ ld [hROMBankBuffer], a ; save bank of data to be loaded
+ ld a, [hLoadedROMBank]
+ push af
+ ld a, [hROMBankBuffer] ; a contains bank of data to be loaded
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a ; switch bank to the bank of data to be loaded
+ srl b
+ rr c
+ rl a
+ and $1 ; checks bit 1 of the last word in the data struct
+ ld [rVBK], a ; set VRAM Bank
+.copyByte
+ ld a, [hli]
+ ld [de], a
+ inc de
+ dec bc
+ ld a, c
+ or b ; does bc = 0?
+ jr nz, .copyByte
+ xor a
+ ld [rVBK], a ; set VRAM Bank to Bank 0
+ pop af
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a ; reload the previous ROM Bank
+ ret
+
+FarCopyCGBPals: ; 0x6fd
+; a: bank
+; hl: source
+; e: dest offset
+; bc: size
+ ld [hROMBankBuffer], a ; save bank of data to be loaded
+ ld a, [hLoadedROMBank]
+ push af
+ ld a, [hROMBankBuffer] ; a contains bank of data to be loaded
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a ; switch bank to the bank of data to be loaded
+ ld a, e
+ bit 6, a
+ jr nz, .do_obp
+ ld de, rBGPI
+ call .copyPaletteData
+ jr z, .no_obp
+ xor a
+.do_obp
+ ld de, rOBPI
+ call .copyPaletteData
+.no_obp
+ pop af
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ ret
+
+.copyPaletteData
+ res 6, a ; only 64 bytes fit here
+ ld b, a
+ set 7, a ; auto-increment
+ ld [de], a
+ inc de
+.copyByte
+ ld a, [hli]
+ ld [de], a
+ inc b
+ dec c
+ ret z
+ bit 6, b
+ jr z, .copyByte
+ ret
+
+LoadOrCopyVRAMData: ; 0x735
+ push hl
+ ld hl, rLCDC
+ bit 7, [hl]
+ pop hl
+ jp z, FarCopyData
+ ; fall through
+LoadVRAMData: ; 0x73f
+; This loads some data into VRAM. It waits for the LCD H-Blank to copy the data 4 bytes at a time.
+; input: hl = source of data
+; a = bank of data to load
+; de = destination of data
+; bc = number of bytes to copy
+ bit 7, h
+ jr nz, .asm_752
+ ld [hROMBankBuffer], a
+ ld a, [hLoadedROMBank]
+ push af
+ ld a, [hROMBankBuffer]
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ scf
+ jr .asm_756
+
+.asm_752
+ ld [MBC5SRamBank], a
+ and a
+.asm_756
+ push af
+ call WaitForLCD
+.loop
+ call Func_61b
+.waitForHBlank
+ ld a, [rSTAT]
+ and $3
+ jr nz, .waitForHBlank
+ ld a, [hli]
+ ld [de], a
+ inc de
+ ld a, [hli]
+ ld [de], a
+ inc de
+ ld a, [hli]
+ ld [de], a
+ inc de
+ ld a, [hli]
+ ld [de], a
+ inc de
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ dec bc
+ dec bc
+ dec bc
+ dec bc
+ nop
+ nop
+ nop
+ nop
+ ld a, b
+ or c
+ jr nz, .loop
+ pop af
+ ret nc
+ pop af
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ ret
+
+FarCopyPalettes: ; 0x790
+ push hl
+ ld hl, rLCDC
+ bit 7, [hl]
+ pop hl
+ jp nz, Func_7dc
+ bit 7, h
+ jr nz, .asm_7ad
+ ld [hROMBankBuffer], a
+ ld a, [hLoadedROMBank]
+ push af
+ ld a, [hROMBankBuffer]
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ scf
+ jr .asm_7b1
+
+.asm_7ad
+ ld [MBC5SRamBank], a
+ and a
+.asm_7b1
+ push af
+ ld a, e
+ bit 6, e
+ ld de, rBGPI
+ jr z, .asm_7bf
+ res 6, a
+ ld de, rOBPI
+.asm_7bf
+ set 7, a
+ ld [de], a
+ inc de
+.asm_7c3
+ ld a, [hli]
+ ld [de], a
+ ld a, [hli]
+ ld [de], a
+ ld a, [hli]
+ ld [de], a
+ ld a, [hli]
+ ld [de], a
+ dec bc
+ dec bc
+ dec bc
+ dec bc
+ ld a, b
+ or c
+ jr nz, .asm_7c3
+ pop af
+ ret nc
+ pop af
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ ret
+
+Func_7dc: ; 0x7dc
+ bit 7, h
+ jr nz, .asm_7ef
+ ld [hROMBankBuffer], a
+ ld a, [hLoadedROMBank]
+ push af
+ ld a, [hROMBankBuffer]
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ scf
+ jr .asm_7f3
+
+.asm_7ef
+ ld [MBC5SRamBank], a
+ and a
+.asm_7f3
+ push af
+ ld a, e
+ bit 6, e
+ ld de, rBGPI
+ jr z, .asm_801
+ res 6, a
+ ld de, rOBPI
+.asm_801
+ push hl
+ ld h, d
+ ld l, e
+ set 7, a
+ call PutTileInVRAM
+ inc de
+ pop hl
+ call WaitForLCD
+.asm_80e
+ call Func_61b
+.asm_811
+ ld a, [rSTAT]
+ and $3
+ jr nz, .asm_811
+ ld a, [hli]
+ ld [de], a
+ ld a, [hli]
+ ld [de], a
+ ld a, [hli]
+ ld [de], a
+ ld a, [hli]
+ ld [de], a
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ dec bc
+ dec bc
+ dec bc
+ dec bc
+ nop
+ nop
+ nop
+ nop
+ ld a, b
+ or c
+ jr nz, .asm_80e
+ pop af
+ ret nc
+ pop af
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ ret
+
+PutTileInVRAM: ; 0x848
+; Puts a tile in VRAM.
+; input: a = tile number
+; hl = pointer to VRAM location where tile should be placed
+ push af
+ call WaitForLCD
+ call Func_61b
+.asm_84f
+ ld a, [rSTAT]
+ and $3
+ jr nz, .asm_84f ; wait for lcd controller to finish transferring data
+ pop af
+ ld [hl], a ; Store tile number in VRAM background map
+ ret
+
+Func_858: ; 0x858
+ push af
+ call WaitForLCD
+ call Func_61b
+.asm_85f
+ ld a, [rSTAT]
+ and $3
+ jr nz, .asm_85f
+ ld a, $1
+ ld [rVBK], a
+ pop af
+ ld [hl], a
+ xor a
+ ld [rVBK], a
+ ret
+
+LoadBillboardPaletteMap: ; 0x86f
+; Loads the background palette map for a 6x4-tile billboard picture.
+ ld [hROMBankBuffer], a
+ ld a, [hLoadedROMBank]
+ push af
+ ld a, [hROMBankBuffer]
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ ld a, [rLCDC]
+ bit 7, a
+ jr nz, .asm_8ac
+ ld a, $1
+ ld [rVBK], a
+ ld b, $4
+.loop
+ push bc
+ ld a, [de]
+ ld [hli], a
+ inc de
+ ld a, [de]
+ ld [hli], a
+ inc de
+ ld a, [de]
+ ld [hli], a
+ inc de
+ ld a, [de]
+ ld [hli], a
+ inc de
+ ld a, [de]
+ ld [hli], a
+ inc de
+ ld a, [de]
+ ld [hli], a
+ inc de
+ ld bc, $001a
+ add hl, bc
+ pop bc
+ dec b
+ jr nz, .loop
+ xor a
+ ld [rVBK], a
+ pop af
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ ret
+
+.asm_8ac
+ ld b, $4
+.asm_8ae
+ push bc
+ ld a, [de]
+ call Func_858
+ inc hl
+ inc de
+ ld a, [de]
+ call Func_858
+ inc hl
+ inc de
+ ld a, [de]
+ call Func_858
+ inc hl
+ inc de
+ ld a, [de]
+ call Func_858
+ inc hl
+ inc de
+ ld a, [de]
+ call Func_858
+ inc hl
+ inc de
+ ld a, [de]
+ call Func_858
+ inc de
+ ld bc, $001b
+ add hl, bc
+ pop bc
+ dec b
+ jr nz, .asm_8ae
+ pop af
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ ret
+
+Func_8e1: ; 0x8e1
+ ld [hROMBankBuffer], a
+ ld a, [hLoadedROMBank]
+ push af
+ ld a, [hROMBankBuffer]
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ ld a, [rLCDC]
+ bit 7, a
+ jr nz, .asm_902
+ ld a, c
+ ld [hli], a
+.asm_8f5
+ ld a, [de]
+ ld [hl], a
+ inc de
+ dec b
+ jr nz, .asm_8f5
+ pop af
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ ret
+
+.asm_902
+ ld a, c
+ call PutTileInVRAM
+ inc hl
+.asm_907
+ ld a, [de]
+ call PutTileInVRAM
+ inc de
+ dec b
+ jr nz, .asm_907
+ pop af
+ ld [hLoadedROMBank], a
+ ld [MBC5RomBank], a
+ ret
generated by cgit v1.2.3 (git 2.25.1) at 2025-08-05 10:58:42 +0000