Merge pull request #450 from remind-me-later/bootrom_reg_names

use friendly names for HW registers instead of magic numbers

BootROMs/cgb_boot.asm

@@ -1,5 +1,13 @@
 ; SameBoy CGB bootstrap ROM
-; Todo: use friendly names for HW registers instead of magic numbers
+
+INCLUDE	"hardware.inc"
+
+; Registers used only by the boot ROM
+
+DEF rKEY0 EQU $FF4C
+DEF rBANK EQU $FF50
+DEF rOPRI EQU $FF6C
+
 SECTION "BootCode", ROM0[$0]
 Start:
 ; Init stack pointer
@@ -32,18 +40,19 @@ ENDC
 ; Clear title checksum
     ldh [TitleChecksum], a
 
+; Init Audio
     ld a, $80
-    ldh [$26], a
+    ldh [rNR52], a
-    ldh [$11], a
+    ldh [rNR11], a
     ld a, $f3
-    ldh [$12], a
+    ldh [rNR12], a
-    ldh [$25], a
+    ldh [rNR51], a
     ld a, $77
-    ldh [$24], a
+    ldh [rNR50], a
 
 ; Init BG palette
     ld a, $fc
-    ldh [$47], a
+    ldh [rBGP], a
 
 ; Load logo from ROM.
 ; A nibble represents a 4-pixels line, 2 bytes represent a 4x4 tile, scaled to 8x8.
@@ -65,14 +74,14 @@ ENDC
 
 ; Clear the second VRAM bank
     ld a, 1
-    ldh [$4F], a
+    ldh [rVBK], a
     call ClearMemoryPage8000
     call LoadTileset
 
     ld b, 3
 IF DEF(FAST)
     xor a
-    ldh [$4F], a
+    ldh [rVBK], a
 ELSE
 ; Load Tilemap
     ld hl, $98C2
@@ -122,11 +131,11 @@ ELSE
     push af
     ; Switch to second VRAM Bank
     ld a, 1
-    ldh [$4F], a
+    ldh [rVBK], a
     ld [hl], 8
     ; Switch to back first VRAM Bank
     xor a
-    ldh [$4F], a
+    ldh [rVBK], a
     pop af
     ldi [hl], a
     ret
@@ -180,7 +189,7 @@ ENDC
 
     ; Turn on LCD
     ld a, $91
-    ldh [$40], a
+    ldh [rLCDC], a
 
 IF !DEF(FAST)
     call DoIntroAnimation
@@ -221,7 +230,7 @@ HDMAData:
 
 SECTION "BootGame", ROM0[$fe]
 BootGame:
-    ldh [$50], a
+    ldh [rBANK], a ; unmap boot ROM
 
 SECTION "MoreStuff", ROM0[$200]
 ; Game Palettes Data
@@ -606,9 +615,9 @@ WaitBFrames:
     ret
 
 PlaySound:
-    ldh [$13], a
+    ldh [rNR13], a
     ld a, $87
-    ldh [$14], a
+    ldh [rNR14], a
     ret
 
 ClearMemoryPage8000:
@@ -759,7 +768,7 @@ ReadTrademarkSymbol:
 DoIntroAnimation:
     ; Animate the intro
     ld a, 1
-    ldh [$4F], a
+    ldh [rVBK], a
     ld d, 26
 .animationLoop
     ld b, 2
@@ -849,7 +858,7 @@ IF !DEF(FAST)
     jr nz, .fadeLoop
 ENDC
     ld a, 2
-    ldh [$70], a
+    ldh [rSVBK], a
     ; Clear RAM Bank 2 (Like the original boot ROM)
     ld hl, $D000
     call ClearMemoryPage
@@ -858,9 +867,9 @@ ENDC
     call _ClearVRAMViaHDMA
     call ClearVRAMViaHDMA ; A = $40, so it's bank 0
     xor a
-    ldh [$70], a
+    ldh [rSVBK], a
     cpl
-    ldh [$00], a
+    ldh [rP1], a
 
     ; Final values for CGB mode
     ld d, a
@@ -872,7 +881,7 @@ ENDC
     call z, EmulateDMG
     bit 7, a
 
-    ldh [$4C], a
+    ldh [rKEY0], a ; write CGB compatibility byte, CGB mode
     ldh a, [TitleChecksum]
     ld b, a
 
@@ -902,7 +911,7 @@ ENDC
 
 .emulateDMGForCGBGame
     call EmulateDMG
-    ldh [$4C], a
+    ldh [rKEY0], a ; write $04, DMG emulation mode
     ld a, $1
     ret
 
@@ -916,7 +925,7 @@ GetKeyComboPalette:
 
 EmulateDMG:
     ld a, 1
-    ldh [$6C], a ; DMG Emulation
+    ldh [rOPRI], a ; DMG Emulation sprite priority
     call GetPaletteIndex
     bit 7, a
     call nz, LoadDMGTilemap
@@ -1068,7 +1077,7 @@ LoadPalettes:
     ret
 
 ClearVRAMViaHDMA:
-    ldh [$4F], a
+    ldh [rVBK], a
     ld hl, HDMAData
 _ClearVRAMViaHDMA:
     call WaitFrame ; Wait for vblank
@@ -1085,8 +1094,8 @@ _ClearVRAMViaHDMA:
 ; clobbers AF and HL
 GetInputPaletteIndex:
     ld a, $20 ; Select directions
-    ldh [$00], a
+    ldh [rP1], a
-    ldh a, [$00]
+    ldh a, [rP1]
     cpl
     and $F
     ret z ; No direction keys pressed, no palette
@@ -1100,8 +1109,8 @@ GetInputPaletteIndex:
     ; c = 1: Right, 2: Left, 3: Up, 4: Down
 
     ld a, $10 ; Select buttons
-    ldh [$00], a
+    ldh [rP1], a
-    ldh a, [$00]
+    ldh a, [rP1]
     cpl
     rla
     rla

BootROMs/dmg_boot.asm

@@ -1,5 +1,11 @@
 ; SameBoy DMG bootstrap ROM
-; Todo: use friendly names for HW registers instead of magic numbers
+
+INCLUDE	"hardware.inc"
+
+; Registers used only by the boot ROM
+
+DEF rBANK EQU $FF50
+
 SECTION "BootCode", ROM0[$0]
 Start:
 ; Init stack pointer
@@ -15,17 +21,17 @@ Start:
 
 ; Init Audio
     ld a, $80
-    ldh [$26], a
+    ldh [rNR52], a
-    ldh [$11], a
+    ldh [rNR11], a
     ld a, $f3
-    ldh [$12], a
+    ldh [rNR12], a
-    ldh [$25], a
+    ldh [rNR51], a
     ld a, $77
-    ldh [$24], a
+    ldh [rNR50], a
 
 ; Init BG palette
     ld a, $54
-    ldh [$47], a
+    ldh [rBGP], a
 
 ; Load logo from ROM.
 ; A nibble represents a 4-pixels line, 2 bytes represent a 4x4 tile, scaled to 8x8.
@@ -70,11 +76,11 @@ Start:
 .tilemapDone
 
     ld a, 30
-    ldh [$ff42], a
+    ldh [rSCY], a
     
     ; Turn on LCD
     ld a, $91
-    ldh [$40], a
+    ldh [rLCDC], a
 
     ld d, (-119) & $FF
     ld c, 15
@@ -84,7 +90,7 @@ Start:
     ld a, d
     sra a
     sra a
-    ldh [$ff42], a
+    ldh [rSCY], a
     ld a, d
     add c
     ld d, a
@@ -92,12 +98,12 @@ Start:
     cp 8
     jr nz, .noPaletteChange
     ld a, $A8
-    ldh [$47], a
+    ldh [rBGP], a
 .noPaletteChange
     dec c
     jr nz, .animate
     ld a, $fc
-    ldh [$47], a
+    ldh [rBGP], a
     
     ; Play first sound
     ld a, $83
@@ -167,9 +173,9 @@ WaitBFrames:
     ret
 
 PlaySound:
-    ldh [$13], a
+    ldh [rNR13], a
     ld a, $87
-    ldh [$14], a
+    ldh [rNR14], a
     ret
 
 
@@ -178,4 +184,4 @@ db $3c,$42,$b9,$a5,$b9,$a5,$42,$3c
 
 SECTION "BootGame", ROM0[$fe]
 BootGame:
-    ldh [$50], a
+    ldh [rBANK], a ; unmap boot ROM

BootROMs/hardware.inc

@@ -0,0 +1,977 @@
+;*
+;* Gameboy Hardware definitions
+;*
+;* Based on Jones' hardware.inc
+;* And based on Carsten Sorensen's ideas.
+;*
+;* Rev 1.1 - 15-Jul-97 : Added define check
+;* Rev 1.2 - 18-Jul-97 : Added revision check macro
+;* Rev 1.3 - 19-Jul-97 : Modified for RGBASM V1.05
+;* Rev 1.4 - 27-Jul-97 : Modified for new subroutine prefixes
+;* Rev 1.5 - 15-Aug-97 : Added _HRAM, PAD, CART defines
+;*                     :  and Nintendo Logo
+;* Rev 1.6 - 30-Nov-97 : Added rDIV, rTIMA, rTMA, & rTAC
+;* Rev 1.7 - 31-Jan-98 : Added _SCRN0, _SCRN1
+;* Rev 1.8 - 15-Feb-98 : Added rSB, rSC
+;* Rev 1.9 - 16-Feb-98 : Converted I/O registers to $FFXX format
+;* Rev 2.0 -           : Added GBC registers
+;* Rev 2.1 -           : Added MBC5 & cart RAM enable/disable defines
+;* Rev 2.2 -           : Fixed NR42,NR43, & NR44 equates
+;* Rev 2.3 -           : Fixed incorrect _HRAM equate
+;* Rev 2.4 - 27-Apr-13 : Added some cart defines (AntonioND)
+;* Rev 2.5 - 03-May-15 : Fixed format (AntonioND)
+;* Rev 2.6 - 09-Apr-16 : Added GBC OAM and cart defines (AntonioND)
+;* Rev 2.7 - 19-Jan-19 : Added rPCMXX (ISSOtm)
+;* Rev 2.8 - 03-Feb-19 : Added audio registers flags (Álvaro Cuesta)
+;* Rev 2.9 - 28-Feb-20 : Added utility rP1 constants
+;* Rev 3.0 - 27-Aug-20 : Register ordering, byte-based sizes, OAM additions, general cleanup (Blitter Object)
+;* Rev 4.0 - 03-May-21 : Updated to use RGBDS 0.5.0 syntax, changed IEF_LCDC to IEF_STAT (Eievui)
+;* Rev 4.1 - 16-Aug-21 : Added more flags, bit number defines, and offset constants for OAM and window positions (rondnelson99)
+;* Rev 4.2 - 04-Sep-21 : Added CH3- and CH4-specific audio registers flags (ISSOtm)
+;* Rev 4.3 - 07-Nov-21 : Deprecate VRAM address constants (Eievui)
+;* Rev 4.4 - 11-Jan-22 : Deprecate VRAM CART_SRAM_2KB constant (avivace)
+;* Rev 4.5 - 03-Mar-22 : Added bit number definitions for OCPS, BCPS and LCDC (sukus)
+
+IF __RGBDS_MAJOR__ == 0 && __RGBDS_MINOR__ < 5
+    FAIL "This version of 'hardware.inc' requires RGBDS version 0.5.0 or later."
+ENDC
+
+; If all of these are already defined, don't do it again.
+
+    IF !DEF(HARDWARE_INC)
+DEF HARDWARE_INC EQU 1
+
+MACRO rev_Check_hardware_inc
+;NOTE: REVISION NUMBER CHANGES MUST BE ADDED
+;TO SECOND PARAMETER IN FOLLOWING LINE.
+    IF  \1 > 4.5 ;PUT REVISION NUMBER HERE
+        WARN    "Version \1 or later of 'hardware.inc' is required."
+    ENDC
+ENDM
+
+DEF _VRAM        EQU $8000 ; $8000->$9FFF
+DEF _SCRN0       EQU $9800 ; $9800->$9BFF
+DEF _SCRN1       EQU $9C00 ; $9C00->$9FFF
+DEF _SRAM        EQU $A000 ; $A000->$BFFF
+DEF _RAM         EQU $C000 ; $C000->$CFFF / $C000->$DFFF
+DEF _RAMBANK     EQU $D000 ; $D000->$DFFF
+DEF _OAMRAM      EQU $FE00 ; $FE00->$FE9F
+DEF _IO          EQU $FF00 ; $FF00->$FF7F,$FFFF
+DEF _AUD3WAVERAM EQU $FF30 ; $FF30->$FF3F
+DEF _HRAM        EQU $FF80 ; $FF80->$FFFE
+
+; *** MBC5 Equates ***
+
+DEF rRAMG        EQU $0000 ; $0000->$1fff
+DEF rROMB0       EQU $2000 ; $2000->$2fff
+DEF rROMB1       EQU $3000 ; $3000->$3fff - If more than 256 ROM banks are present.
+DEF rRAMB        EQU $4000 ; $4000->$5fff - Bit 3 enables rumble (if present)
+
+
+;***************************************************************************
+;*
+;* Custom registers
+;*
+;***************************************************************************
+
+; --
+; -- P1 ($FF00)
+; -- Register for reading joy pad info. (R/W)
+; --
+DEF rP1 EQU $FF00
+
+DEF P1F_5 EQU %00100000 ; P15 out port, set to 0 to get buttons
+DEF P1F_4 EQU %00010000 ; P14 out port, set to 0 to get dpad
+DEF P1F_3 EQU %00001000 ; P13 in port
+DEF P1F_2 EQU %00000100 ; P12 in port
+DEF P1F_1 EQU %00000010 ; P11 in port
+DEF P1F_0 EQU %00000001 ; P10 in port
+
+DEF P1F_GET_DPAD EQU P1F_5
+DEF P1F_GET_BTN  EQU P1F_4
+DEF P1F_GET_NONE EQU P1F_4 | P1F_5
+
+
+; --
+; -- SB ($FF01)
+; -- Serial Transfer Data (R/W)
+; --
+DEF rSB EQU $FF01
+
+
+; --
+; -- SC ($FF02)
+; -- Serial I/O Control (R/W)
+; --
+DEF rSC EQU $FF02
+
+DEF SCF_START  EQU %10000000 ;Transfer Start Flag (1=Transfer in progress, or requested)
+DEF SCF_SPEED  EQU %00000010 ;Clock Speed (0=Normal, 1=Fast) ** CGB Mode Only **
+DEF SCF_SOURCE EQU %00000001 ;Shift Clock (0=External Clock, 1=Internal Clock)
+
+DEF SCB_START  EQU 7
+DEF SCB_SPEED  EQU 1
+DEF SCB_SOURCE EQU 0
+
+; --
+; -- DIV ($FF04)
+; -- Divider register (R/W)
+; --
+DEF rDIV EQU $FF04
+
+
+; --
+; -- TIMA ($FF05)
+; -- Timer counter (R/W)
+; --
+DEF rTIMA EQU $FF05
+
+
+; --
+; -- TMA ($FF06)
+; -- Timer modulo (R/W)
+; --
+DEF rTMA EQU $FF06
+
+
+; --
+; -- TAC ($FF07)
+; -- Timer control (R/W)
+; --
+DEF rTAC EQU $FF07
+
+DEF TACF_START  EQU %00000100
+DEF TACF_STOP   EQU %00000000
+DEF TACF_4KHZ   EQU %00000000
+DEF TACF_16KHZ  EQU %00000011
+DEF TACF_65KHZ  EQU %00000010
+DEF TACF_262KHZ EQU %00000001
+
+DEF TACB_START  EQU 2
+
+
+; --
+; -- IF ($FF0F)
+; -- Interrupt Flag (R/W)
+; --
+DEF rIF EQU $FF0F
+
+
+; --
+; -- AUD1SWEEP/NR10 ($FF10)
+; -- Sweep register (R/W)
+; --
+; -- Bit 6-4 - Sweep Time
+; -- Bit 3   - Sweep Increase/Decrease
+; --           0: Addition    (frequency increases???)
+; --           1: Subtraction (frequency increases???)
+; -- Bit 2-0 - Number of sweep shift (# 0-7)
+; -- Sweep Time: (n*7.8ms)
+; --
+DEF rNR10 EQU $FF10
+DEF rAUD1SWEEP EQU rNR10
+
+DEF AUD1SWEEP_UP   EQU %00000000
+DEF AUD1SWEEP_DOWN EQU %00001000
+
+
+; --
+; -- AUD1LEN/NR11 ($FF11)
+; -- Sound length/Wave pattern duty (R/W)
+; --
+; -- Bit 7-6 - Wave Pattern Duty (00:12.5% 01:25% 10:50% 11:75%)
+; -- Bit 5-0 - Sound length data (# 0-63)
+; --
+DEF rNR11 EQU $FF11
+DEF rAUD1LEN EQU rNR11
+
+
+; --
+; -- AUD1ENV/NR12 ($FF12)
+; -- Envelope (R/W)
+; --
+; -- Bit 7-4 - Initial value of envelope
+; -- Bit 3   - Envelope UP/DOWN
+; --           0: Decrease
+; --           1: Range of increase
+; -- Bit 2-0 - Number of envelope sweep (# 0-7)
+; --
+DEF rNR12 EQU $FF12
+DEF rAUD1ENV EQU rNR12
+
+
+; --
+; -- AUD1LOW/NR13 ($FF13)
+; -- Frequency low byte (W)
+; --
+DEF rNR13 EQU $FF13
+DEF rAUD1LOW EQU rNR13
+
+
+; --
+; -- AUD1HIGH/NR14 ($FF14)
+; -- Frequency high byte (W)
+; --
+; -- Bit 7   - Initial (when set, sound restarts)
+; -- Bit 6   - Counter/consecutive selection
+; -- Bit 2-0 - Frequency's higher 3 bits
+; --
+DEF rNR14 EQU $FF14
+DEF rAUD1HIGH EQU rNR14
+
+
+; --
+; -- AUD2LEN/NR21 ($FF16)
+; -- Sound Length; Wave Pattern Duty (R/W)
+; --
+; -- see AUD1LEN for info
+; --
+DEF rNR21 EQU $FF16
+DEF rAUD2LEN EQU rNR21
+
+
+; --
+; -- AUD2ENV/NR22 ($FF17)
+; -- Envelope (R/W)
+; --
+; -- see AUD1ENV for info
+; --
+DEF rNR22 EQU $FF17
+DEF rAUD2ENV EQU rNR22
+
+
+; --
+; -- AUD2LOW/NR23 ($FF18)
+; -- Frequency low byte (W)
+; --
+DEF rNR23 EQU $FF18
+DEF rAUD2LOW EQU rNR23
+
+
+; --
+; -- AUD2HIGH/NR24 ($FF19)
+; -- Frequency high byte (W)
+; --
+; -- see AUD1HIGH for info
+; --
+DEF rNR24 EQU $FF19
+DEF rAUD2HIGH EQU rNR24
+
+
+; --
+; -- AUD3ENA/NR30 ($FF1A)
+; -- Sound on/off (R/W)
+; --
+; -- Bit 7   - Sound ON/OFF (1=ON,0=OFF)
+; --
+DEF rNR30 EQU $FF1A
+DEF rAUD3ENA EQU rNR30
+
+DEF AUD3ENA_OFF EQU %00000000
+DEF AUD3ENA_ON  EQU %10000000
+
+
+; --
+; -- AUD3LEN/NR31 ($FF1B)
+; -- Sound length (R/W)
+; --
+; -- Bit 7-0 - Sound length
+; --
+DEF rNR31 EQU $FF1B
+DEF rAUD3LEN EQU rNR31
+
+
+; --
+; -- AUD3LEVEL/NR32 ($FF1C)
+; -- Select output level
+; --
+; -- Bit 6-5 - Select output level
+; --           00: 0/1 (mute)
+; --           01: 1/1
+; --           10: 1/2
+; --           11: 1/4
+; --
+DEF rNR32 EQU $FF1C
+DEF rAUD3LEVEL EQU rNR32
+
+DEF AUD3LEVEL_MUTE EQU %00000000
+DEF AUD3LEVEL_100  EQU %00100000
+DEF AUD3LEVEL_50   EQU %01000000
+DEF AUD3LEVEL_25   EQU %01100000
+
+
+; --
+; -- AUD3LOW/NR33 ($FF1D)
+; -- Frequency low byte (W)
+; --
+; -- see AUD1LOW for info
+; --
+DEF rNR33 EQU $FF1D
+DEF rAUD3LOW EQU rNR33
+
+
+; --
+; -- AUD3HIGH/NR34 ($FF1E)
+; -- Frequency high byte (W)
+; --
+; -- see AUD1HIGH for info
+; --
+DEF rNR34 EQU $FF1E
+DEF rAUD3HIGH EQU rNR34
+
+
+; --
+; -- AUD4LEN/NR41 ($FF20)
+; -- Sound length (R/W)
+; --
+; -- Bit 5-0 - Sound length data (# 0-63)
+; --
+DEF rNR41 EQU $FF20
+DEF rAUD4LEN EQU rNR41
+
+
+; --
+; -- AUD4ENV/NR42 ($FF21)
+; -- Envelope (R/W)
+; --
+; -- see AUD1ENV for info
+; --
+DEF rNR42 EQU $FF21
+DEF rAUD4ENV EQU rNR42
+
+
+; --
+; -- AUD4POLY/NR43 ($FF22)
+; -- Polynomial counter (R/W)
+; --
+; -- Bit 7-4 - Selection of the shift clock frequency of the (scf)
+; --           polynomial counter (0000-1101)
+; --           freq=drf*1/2^scf (not sure)
+; -- Bit 3 -   Selection of the polynomial counter's step
+; --           0: 15 steps
+; --           1: 7 steps
+; -- Bit 2-0 - Selection of the dividing ratio of frequencies (drf)
+; --           000: f/4   001: f/8   010: f/16  011: f/24
+; --           100: f/32  101: f/40  110: f/48  111: f/56  (f=4.194304 Mhz)
+; --
+DEF rNR43 EQU $FF22
+DEF rAUD4POLY EQU rNR43
+
+DEF AUD4POLY_15STEP EQU %00000000
+DEF AUD4POLY_7STEP  EQU %00001000
+
+
+; --
+; -- AUD4GO/NR44 ($FF23)
+; --
+; -- Bit 7 -   Initial (when set, sound restarts)
+; -- Bit 6 -   Counter/consecutive selection
+; --
+DEF rNR44 EQU $FF23
+DEF rAUD4GO EQU rNR44
+
+
+; --
+; -- AUDVOL/NR50 ($FF24)
+; -- Channel control / ON-OFF / Volume (R/W)
+; --
+; -- Bit 7   - Vin->SO2 ON/OFF (left)
+; -- Bit 6-4 - SO2 output level (left speaker) (# 0-7)
+; -- Bit 3   - Vin->SO1 ON/OFF (right)
+; -- Bit 2-0 - SO1 output level (right speaker) (# 0-7)
+; --
+DEF rNR50 EQU $FF24
+DEF rAUDVOL EQU rNR50
+
+DEF AUDVOL_VIN_LEFT  EQU %10000000 ; SO2
+DEF AUDVOL_VIN_RIGHT EQU %00001000 ; SO1
+
+
+; --
+; -- AUDTERM/NR51 ($FF25)
+; -- Selection of Sound output terminal (R/W)
+; --
+; -- Bit 7   - Output channel 4 to SO2 terminal (left)
+; -- Bit 6   - Output channel 3 to SO2 terminal (left)
+; -- Bit 5   - Output channel 2 to SO2 terminal (left)
+; -- Bit 4   - Output channel 1 to SO2 terminal (left)
+; -- Bit 3   - Output channel 4 to SO1 terminal (right)
+; -- Bit 2   - Output channel 3 to SO1 terminal (right)
+; -- Bit 1   - Output channel 2 to SO1 terminal (right)
+; -- Bit 0   - Output channel 1 to SO1 terminal (right)
+; --
+DEF rNR51 EQU $FF25
+DEF rAUDTERM EQU rNR51
+
+; SO2
+DEF AUDTERM_4_LEFT  EQU %10000000
+DEF AUDTERM_3_LEFT  EQU %01000000
+DEF AUDTERM_2_LEFT  EQU %00100000
+DEF AUDTERM_1_LEFT  EQU %00010000
+; SO1
+DEF AUDTERM_4_RIGHT EQU %00001000
+DEF AUDTERM_3_RIGHT EQU %00000100
+DEF AUDTERM_2_RIGHT EQU %00000010
+DEF AUDTERM_1_RIGHT EQU %00000001
+
+
+; --
+; -- AUDENA/NR52 ($FF26)
+; -- Sound on/off (R/W)
+; --
+; -- Bit 7   - All sound on/off (sets all audio regs to 0!)
+; -- Bit 3   - Sound 4 ON flag (read only)
+; -- Bit 2   - Sound 3 ON flag (read only)
+; -- Bit 1   - Sound 2 ON flag (read only)
+; -- Bit 0   - Sound 1 ON flag (read only)
+; --
+DEF rNR52 EQU $FF26
+DEF rAUDENA EQU rNR52
+
+DEF AUDENA_ON    EQU %10000000
+DEF AUDENA_OFF   EQU %00000000  ; sets all audio regs to 0!
+
+
+; --
+; -- LCDC ($FF40)
+; -- LCD Control (R/W)
+; --
+DEF rLCDC EQU $FF40
+
+DEF LCDCF_OFF     EQU %00000000 ; LCD Control Operation
+DEF LCDCF_ON      EQU %10000000 ; LCD Control Operation
+DEF LCDCF_WIN9800 EQU %00000000 ; Window Tile Map Display Select
+DEF LCDCF_WIN9C00 EQU %01000000 ; Window Tile Map Display Select
+DEF LCDCF_WINOFF  EQU %00000000 ; Window Display
+DEF LCDCF_WINON   EQU %00100000 ; Window Display
+DEF LCDCF_BG8800  EQU %00000000 ; BG & Window Tile Data Select
+DEF LCDCF_BG8000  EQU %00010000 ; BG & Window Tile Data Select
+DEF LCDCF_BG9800  EQU %00000000 ; BG Tile Map Display Select
+DEF LCDCF_BG9C00  EQU %00001000 ; BG Tile Map Display Select
+DEF LCDCF_OBJ8    EQU %00000000 ; OBJ Construction
+DEF LCDCF_OBJ16   EQU %00000100 ; OBJ Construction
+DEF LCDCF_OBJOFF  EQU %00000000 ; OBJ Display
+DEF LCDCF_OBJON   EQU %00000010 ; OBJ Display
+DEF LCDCF_BGOFF   EQU %00000000 ; BG Display
+DEF LCDCF_BGON    EQU %00000001 ; BG Display
+
+DEF LCDCB_ON      EQU 7 ; LCD Control Operation
+DEF LCDCB_WIN9C00 EQU 6 ; Window Tile Map Display Select
+DEF LCDCB_WINON   EQU 5 ; Window Display
+DEF LCDCB_BG8000  EQU 4 ; BG & Window Tile Data Select
+DEF LCDCB_BG9C00  EQU 3 ; BG Tile Map Display Select
+DEF LCDCB_OBJ16   EQU 2 ; OBJ Construction
+DEF LCDCB_OBJON   EQU 1 ; OBJ Display
+DEF LCDCB_BGON    EQU 0 ; BG Display
+; "Window Character Data Select" follows BG
+
+
+; --
+; -- STAT ($FF41)
+; -- LCDC Status   (R/W)
+; --
+DEF rSTAT EQU $FF41
+
+DEF STATF_LYC     EQU  %01000000 ; LYC=LY Coincidence (Selectable)
+DEF STATF_MODE10  EQU  %00100000 ; Mode 10
+DEF STATF_MODE01  EQU  %00010000 ; Mode 01 (V-Blank)
+DEF STATF_MODE00  EQU  %00001000 ; Mode 00 (H-Blank)
+DEF STATF_LYCF    EQU  %00000100 ; Coincidence Flag
+DEF STATF_HBL     EQU  %00000000 ; H-Blank
+DEF STATF_VBL     EQU  %00000001 ; V-Blank
+DEF STATF_OAM     EQU  %00000010 ; OAM-RAM is used by system
+DEF STATF_LCD     EQU  %00000011 ; Both OAM and VRAM used by system
+DEF STATF_BUSY    EQU  %00000010 ; When set, VRAM access is unsafe
+
+DEF STATB_LYC     EQU  6
+DEF STATB_MODE10  EQU  5
+DEF STATB_MODE01  EQU  4
+DEF STATB_MODE00  EQU  3
+DEF STATB_LYCF    EQU  2
+DEF STATB_BUSY    EQU  1
+
+; --
+; -- SCY ($FF42)
+; -- Scroll Y (R/W)
+; --
+DEF rSCY EQU $FF42
+
+
+; --
+; -- SCX ($FF43)
+; -- Scroll X (R/W)
+; --
+DEF rSCX EQU $FF43
+
+
+; --
+; -- LY ($FF44)
+; -- LCDC Y-Coordinate (R)
+; --
+; -- Values range from 0->153. 144->153 is the VBlank period.
+; --
+DEF rLY EQU $FF44
+
+
+; --
+; -- LYC ($FF45)
+; -- LY Compare (R/W)
+; --
+; -- When LY==LYC, STATF_LYCF will be set in STAT
+; --
+DEF rLYC EQU $FF45
+
+
+; --
+; -- DMA ($FF46)
+; -- DMA Transfer and Start Address (W)
+; --
+DEF rDMA EQU $FF46
+
+
+; --
+; -- BGP ($FF47)
+; -- BG Palette Data (W)
+; --
+; -- Bit 7-6 - Intensity for %11
+; -- Bit 5-4 - Intensity for %10
+; -- Bit 3-2 - Intensity for %01
+; -- Bit 1-0 - Intensity for %00
+; --
+DEF rBGP EQU $FF47
+
+
+; --
+; -- OBP0 ($FF48)
+; -- Object Palette 0 Data (W)
+; --
+; -- See BGP for info
+; --
+DEF rOBP0 EQU $FF48
+
+
+; --
+; -- OBP1 ($FF49)
+; -- Object Palette 1 Data (W)
+; --
+; -- See BGP for info
+; --
+DEF rOBP1 EQU $FF49
+
+
+; --
+; -- WY ($FF4A)
+; -- Window Y Position (R/W)
+; --
+; -- 0 <= WY <= 143
+; -- When WY = 0, the window is displayed from the top edge of the LCD screen.
+; --
+DEF rWY EQU $FF4A
+
+
+; --
+; -- WX ($FF4B)
+; -- Window X Position (R/W)
+; --
+; -- 7 <= WX <= 166
+; -- When WX = 7, the window is displayed from the left edge of the LCD screen.
+; -- Values of 0-6 and 166 are unreliable due to hardware bugs.
+; --
+DEF rWX EQU $FF4B
+
+DEF WX_OFS EQU 7 ; add this to a screen position to get a WX position
+
+
+; --
+; -- SPEED ($FF4D)
+; -- Select CPU Speed (R/W)
+; --
+DEF rKEY1 EQU $FF4D
+DEF rSPD  EQU rKEY1
+
+DEF KEY1F_DBLSPEED EQU %10000000 ; 0=Normal Speed, 1=Double Speed (R)
+DEF KEY1F_PREPARE  EQU %00000001 ; 0=No, 1=Prepare (R/W)
+
+
+; --
+; -- VBK ($FF4F)
+; -- Select Video RAM Bank (R/W)
+; --
+; -- Bit 0 - Bank Specification (0: Specify Bank 0; 1: Specify Bank 1)
+; --
+DEF rVBK EQU $FF4F
+
+
+; --
+; -- HDMA1 ($FF51)
+; -- High byte for Horizontal Blanking/General Purpose DMA source address (W)
+; -- CGB Mode Only
+; --
+DEF rHDMA1 EQU $FF51
+
+
+; --
+; -- HDMA2 ($FF52)
+; -- Low byte for Horizontal Blanking/General Purpose DMA source address (W)
+; -- CGB Mode Only
+; --
+DEF rHDMA2 EQU $FF52
+
+
+; --
+; -- HDMA3 ($FF53)
+; -- High byte for Horizontal Blanking/General Purpose DMA destination address (W)
+; -- CGB Mode Only
+; --
+DEF rHDMA3 EQU $FF53
+
+
+; --
+; -- HDMA4 ($FF54)
+; -- Low byte for Horizontal Blanking/General Purpose DMA destination address (W)
+; -- CGB Mode Only
+; --
+DEF rHDMA4 EQU $FF54
+
+
+; --
+; -- HDMA5 ($FF55)
+; -- Transfer length (in tiles minus 1)/mode/start for Horizontal Blanking, General Purpose DMA (R/W)
+; -- CGB Mode Only
+; --
+DEF rHDMA5 EQU $FF55
+
+DEF HDMA5F_MODE_GP  EQU %00000000 ; General Purpose DMA (W)
+DEF HDMA5F_MODE_HBL EQU %10000000 ; HBlank DMA (W)
+DEF HDMA5B_MODE EQU 7 ; DMA mode select (W)
+
+; -- Once DMA has started, use HDMA5F_BUSY to check when the transfer is complete
+DEF HDMA5F_BUSY EQU %10000000 ; 0=Busy (DMA still in progress), 1=Transfer complete (R)
+
+
+; --
+; -- RP ($FF56)
+; -- Infrared Communications Port (R/W)
+; -- CGB Mode Only
+; --
+DEF rRP EQU $FF56
+
+DEF RPF_ENREAD   EQU %11000000
+DEF RPF_DATAIN   EQU %00000010 ; 0=Receiving IR Signal, 1=Normal
+DEF RPF_WRITE_HI EQU %00000001
+DEF RPF_WRITE_LO EQU %00000000
+
+
+; --
+; -- BCPS ($FF68)
+; -- Background Color Palette Specification (R/W)
+; --
+DEF rBCPS EQU $FF68
+
+DEF BCPSF_AUTOINC EQU %10000000 ; Auto Increment (0=Disabled, 1=Increment after Writing)
+DEF BCPSB_AUTOINC EQU 7
+
+
+; --
+; -- BCPD ($FF69)
+; -- Background Color Palette Data (R/W)
+; --
+DEF rBCPD EQU $FF69
+
+
+; --
+; -- OCPS ($FF6A)
+; -- Object Color Palette Specification (R/W)
+; --
+DEF rOCPS EQU $FF6A
+
+DEF OCPSF_AUTOINC EQU %10000000 ; Auto Increment (0=Disabled, 1=Increment after Writing)
+DEF OCPSB_AUTOINC EQU 7
+
+
+; --
+; -- OCPD ($FF6B)
+; -- Object Color Palette Data (R/W)
+; --
+DEF rOCPD EQU $FF6B
+
+
+; --
+; -- SMBK/SVBK ($FF70)
+; -- Select Main RAM Bank (R/W)
+; --
+; -- Bit 2-0 - Bank Specification (0,1: Specify Bank 1; 2-7: Specify Banks 2-7)
+; --
+DEF rSVBK EQU $FF70
+DEF rSMBK EQU rSVBK
+
+
+; --
+; -- PCM12 ($FF76)
+; -- Sound channel 1&2 PCM amplitude (R)
+; --
+; -- Bit 7-4 - Copy of sound channel 2's PCM amplitude
+; -- Bit 3-0 - Copy of sound channel 1's PCM amplitude
+; --
+DEF rPCM12 EQU $FF76
+
+
+; --
+; -- PCM34 ($FF77)
+; -- Sound channel 3&4 PCM amplitude (R)
+; --
+; -- Bit 7-4 - Copy of sound channel 4's PCM amplitude
+; -- Bit 3-0 - Copy of sound channel 3's PCM amplitude
+; --
+DEF rPCM34 EQU $FF77
+
+
+; --
+; -- IE ($FFFF)
+; -- Interrupt Enable (R/W)
+; --
+DEF rIE EQU $FFFF
+
+DEF IEF_HILO   EQU %00010000 ; Transition from High to Low of Pin number P10-P13
+DEF IEF_SERIAL EQU %00001000 ; Serial I/O transfer end
+DEF IEF_TIMER  EQU %00000100 ; Timer Overflow
+DEF IEF_STAT   EQU %00000010 ; STAT
+DEF IEF_VBLANK EQU %00000001 ; V-Blank
+
+DEF IEB_HILO   EQU 4
+DEF IEB_SERIAL EQU 3
+DEF IEB_TIMER  EQU 2
+DEF IEB_STAT   EQU 1
+DEF IEB_VBLANK EQU 0
+
+
+;***************************************************************************
+;*
+;* Flags common to multiple sound channels
+;*
+;***************************************************************************
+
+; --
+; -- Square wave duty cycle
+; --
+; -- Can be used with AUD1LEN and AUD2LEN
+; -- See AUD1LEN for more info
+; --
+DEF AUDLEN_DUTY_12_5    EQU %00000000 ; 12.5%
+DEF AUDLEN_DUTY_25      EQU %01000000 ; 25%
+DEF AUDLEN_DUTY_50      EQU %10000000 ; 50%
+DEF AUDLEN_DUTY_75      EQU %11000000 ; 75%
+
+
+; --
+; -- Audio envelope flags
+; --
+; -- Can be used with AUD1ENV, AUD2ENV, AUD4ENV
+; -- See AUD1ENV for more info
+; --
+DEF AUDENV_UP           EQU %00001000
+DEF AUDENV_DOWN         EQU %00000000
+
+
+; --
+; -- Audio trigger flags
+; --
+; -- Can be used with AUD1HIGH, AUD2HIGH, AUD3HIGH
+; -- See AUD1HIGH for more info
+; --
+
+DEF AUDHIGH_RESTART     EQU %10000000
+DEF AUDHIGH_LENGTH_ON   EQU %01000000
+DEF AUDHIGH_LENGTH_OFF  EQU %00000000
+
+
+;***************************************************************************
+;*
+;* CPU values on bootup (a=type, b=qualifier)
+;*
+;***************************************************************************
+
+DEF BOOTUP_A_DMG    EQU $01 ; Dot Matrix Game
+DEF BOOTUP_A_CGB    EQU $11 ; Color GameBoy
+DEF BOOTUP_A_MGB    EQU $FF ; Mini GameBoy (Pocket GameBoy)
+
+; if a=BOOTUP_A_CGB, bit 0 in b can be checked to determine if real CGB or
+; other system running in GBC mode
+DEF BOOTUP_B_CGB    EQU %00000000
+DEF BOOTUP_B_AGB    EQU %00000001   ; GBA, GBA SP, Game Boy Player, or New GBA SP
+
+
+;***************************************************************************
+;*
+;* Cart related
+;*
+;***************************************************************************
+
+; $0143 Color GameBoy compatibility code
+DEF CART_COMPATIBLE_DMG     EQU $00
+DEF CART_COMPATIBLE_DMG_GBC EQU $80
+DEF CART_COMPATIBLE_GBC     EQU $C0
+
+; $0146 GameBoy/Super GameBoy indicator
+DEF CART_INDICATOR_GB       EQU $00
+DEF CART_INDICATOR_SGB      EQU $03
+
+; $0147 Cartridge type
+DEF CART_ROM                     EQU $00
+DEF CART_ROM_MBC1                EQU $01
+DEF CART_ROM_MBC1_RAM            EQU $02
+DEF CART_ROM_MBC1_RAM_BAT        EQU $03
+DEF CART_ROM_MBC2                EQU $05
+DEF CART_ROM_MBC2_BAT            EQU $06
+DEF CART_ROM_RAM                 EQU $08
+DEF CART_ROM_RAM_BAT             EQU $09
+DEF CART_ROM_MMM01               EQU $0B
+DEF CART_ROM_MMM01_RAM           EQU $0C
+DEF CART_ROM_MMM01_RAM_BAT       EQU $0D
+DEF CART_ROM_MBC3_BAT_RTC        EQU $0F
+DEF CART_ROM_MBC3_RAM_BAT_RTC    EQU $10
+DEF CART_ROM_MBC3                EQU $11
+DEF CART_ROM_MBC3_RAM            EQU $12
+DEF CART_ROM_MBC3_RAM_BAT        EQU $13
+DEF CART_ROM_MBC5                EQU $19
+DEF CART_ROM_MBC5_BAT            EQU $1A
+DEF CART_ROM_MBC5_RAM_BAT        EQU $1B
+DEF CART_ROM_MBC5_RUMBLE         EQU $1C
+DEF CART_ROM_MBC5_RAM_RUMBLE     EQU $1D
+DEF CART_ROM_MBC5_RAM_BAT_RUMBLE EQU $1E
+DEF CART_ROM_MBC7_RAM_BAT_GYRO   EQU $22
+DEF CART_ROM_POCKET_CAMERA       EQU $FC
+DEF CART_ROM_BANDAI_TAMA5        EQU $FD
+DEF CART_ROM_HUDSON_HUC3         EQU $FE
+DEF CART_ROM_HUDSON_HUC1         EQU $FF
+
+; $0148 ROM size
+; these are kilobytes
+DEF CART_ROM_32KB   EQU $00 ; 2 banks
+DEF CART_ROM_64KB   EQU $01 ; 4 banks
+DEF CART_ROM_128KB  EQU $02 ; 8 banks
+DEF CART_ROM_256KB  EQU $03 ; 16 banks
+DEF CART_ROM_512KB  EQU $04 ; 32 banks
+DEF CART_ROM_1024KB EQU $05 ; 64 banks
+DEF CART_ROM_2048KB EQU $06 ; 128 banks
+DEF CART_ROM_4096KB EQU $07 ; 256 banks
+DEF CART_ROM_8192KB EQU $08 ; 512 banks
+DEF CART_ROM_1152KB EQU $52 ; 72 banks
+DEF CART_ROM_1280KB EQU $53 ; 80 banks
+DEF CART_ROM_1536KB EQU $54 ; 96 banks
+
+; $0149 SRAM size
+; these are kilobytes
+DEF CART_SRAM_NONE  EQU 0
+DEF CART_SRAM_8KB   EQU 2 ; 1 bank
+DEF CART_SRAM_32KB  EQU 3 ; 4 banks
+DEF CART_SRAM_128KB EQU 4 ; 16 banks
+
+DEF CART_SRAM_ENABLE  EQU $0A
+DEF CART_SRAM_DISABLE EQU $00
+
+; $014A Destination code
+DEF CART_DEST_JAPANESE     EQU $00
+DEF CART_DEST_NON_JAPANESE EQU $01
+
+
+;***************************************************************************
+;*
+;* Keypad related
+;*
+;***************************************************************************
+
+DEF PADF_DOWN   EQU $80
+DEF PADF_UP     EQU $40
+DEF PADF_LEFT   EQU $20
+DEF PADF_RIGHT  EQU $10
+DEF PADF_START  EQU $08
+DEF PADF_SELECT EQU $04
+DEF PADF_B      EQU $02
+DEF PADF_A      EQU $01
+
+DEF PADB_DOWN   EQU $7
+DEF PADB_UP     EQU $6
+DEF PADB_LEFT   EQU $5
+DEF PADB_RIGHT  EQU $4
+DEF PADB_START  EQU $3
+DEF PADB_SELECT EQU $2
+DEF PADB_B      EQU $1
+DEF PADB_A      EQU $0
+
+
+;***************************************************************************
+;*
+;* Screen related
+;*
+;***************************************************************************
+
+DEF SCRN_X    EQU 160 ; Width of screen in pixels
+DEF SCRN_Y    EQU 144 ; Height of screen in pixels
+DEF SCRN_X_B  EQU 20  ; Width of screen in bytes
+DEF SCRN_Y_B  EQU 18  ; Height of screen in bytes
+
+DEF SCRN_VX   EQU 256 ; Virtual width of screen in pixels
+DEF SCRN_VY   EQU 256 ; Virtual height of screen in pixels
+DEF SCRN_VX_B EQU 32  ; Virtual width of screen in bytes
+DEF SCRN_VY_B EQU 32  ; Virtual height of screen in bytes
+
+
+;***************************************************************************
+;*
+;* OAM related
+;*
+;***************************************************************************
+
+; OAM attributes
+; each entry in OAM RAM is 4 bytes (sizeof_OAM_ATTRS)
+RSRESET
+DEF OAMA_Y              RB  1   ; y pos plus 16
+DEF OAMA_X              RB  1   ; x pos plus 8
+DEF OAMA_TILEID         RB  1   ; tile id
+DEF OAMA_FLAGS          RB  1   ; flags (see below)
+DEF sizeof_OAM_ATTRS    RB  0
+
+DEF OAM_Y_OFS EQU 16 ; add this to a screen-relative Y position to get an OAM Y position
+DEF OAM_X_OFS EQU 8  ; add this to a screen-relative X position to get an OAM X position
+
+DEF OAM_COUNT           EQU 40  ; number of OAM entries in OAM RAM
+
+; flags
+DEF OAMF_PRI        EQU %10000000 ; Priority
+DEF OAMF_YFLIP      EQU %01000000 ; Y flip
+DEF OAMF_XFLIP      EQU %00100000 ; X flip
+DEF OAMF_PAL0       EQU %00000000 ; Palette number; 0,1 (DMG)
+DEF OAMF_PAL1       EQU %00010000 ; Palette number; 0,1 (DMG)
+DEF OAMF_BANK0      EQU %00000000 ; Bank number; 0,1 (GBC)
+DEF OAMF_BANK1      EQU %00001000 ; Bank number; 0,1 (GBC)
+
+DEF OAMF_PALMASK    EQU %00000111 ; Palette (GBC)
+
+DEF OAMB_PRI        EQU 7 ; Priority
+DEF OAMB_YFLIP      EQU 6 ; Y flip
+DEF OAMB_XFLIP      EQU 5 ; X flip
+DEF OAMB_PAL1       EQU 4 ; Palette number; 0,1 (DMG)
+DEF OAMB_BANK1      EQU 3 ; Bank number; 0,1 (GBC)
+
+
+;*
+;* Nintendo scrolling logo
+;* (Code won't work on a real GameBoy)
+;* (if next lines are altered.)
+MACRO NINTENDO_LOGO
+    DB  $CE,$ED,$66,$66,$CC,$0D,$00,$0B,$03,$73,$00,$83,$00,$0C,$00,$0D
+    DB  $00,$08,$11,$1F,$88,$89,$00,$0E,$DC,$CC,$6E,$E6,$DD,$DD,$D9,$99
+    DB  $BB,$BB,$67,$63,$6E,$0E,$EC,$CC,$DD,$DC,$99,$9F,$BB,$B9,$33,$3E
+ENDM
+
+; Deprecated constants. Please avoid using.
+
+DEF IEF_LCDC   EQU %00000010 ; LCDC (see STAT)
+DEF _VRAM8000  EQU _VRAM
+DEF _VRAM8800  EQU _VRAM+$800
+DEF _VRAM9000  EQU _VRAM+$1000
+DEF CART_SRAM_2KB   EQU 1 ; 1 incomplete bank
+
+
+    ENDC ;HARDWARE_INC

BootROMs/sgb_boot.asm

@@ -1,5 +1,11 @@
 ; SameBoy SGB bootstrap ROM
-; Todo: use friendly names for HW registers instead of magic numbers
+
+INCLUDE	"hardware.inc"
+
+; Registers used only by the boot ROM
+
+DEF rBANK EQU $FF50
+
 SECTION "BootCode", ROM0[$0]
 Start:
 ; Init stack pointer
@@ -15,17 +21,17 @@ Start:
 
 ; Init Audio
     ld a, $80
-    ldh [$26], a
+    ldh [rNR52], a
-    ldh [$11], a
+    ldh [rNR11], a
     ld a, $f3
-    ldh [$12], a
+    ldh [rNR12], a
-    ldh [$25], a
+    ldh [rNR51], a
     ld a, $77
-    ldh [$24], a
+    ldh [rNR50], a
 
 ; Init BG palette to white
     ld a, $0
-    ldh [$47], a
+    ldh [rBGP], a
 
 ; Load logo from ROM.
 ; A nibble represents a 4-pixels line, 2 bytes represent a 4x4 tile, scaled to 8x8.
@@ -71,10 +77,10 @@ Start:
 
     ; Turn on LCD
     ld a, $91
-    ldh [$40], a
+    ldh [rLCDC], a
 
     ld a, $f1 ; Packet magic, increases by 2 for every packet
-    ldh [$80], a
+    ldh [_HRAM], a
     ld hl, $104 ; Header start
     
     xor a
@@ -86,7 +92,7 @@ Start:
     ld a, $30
     ld [c], a
     
-    ldh a, [$80]
+    ldh a, [_HRAM]
     call SendByte
     push hl
     ld b, $e
@@ -117,9 +123,9 @@ Start:
     ld [c], a
     
     ; Update command
-    ldh a, [$80]
+    ldh a, [_HRAM]
     add 2
-    ldh [$80], a
+    ldh [_HRAM], a
     
     ld a, $58
     cp l
@@ -135,7 +141,7 @@ Start:
     
     ; Init BG palette
     ld a, $fc
-    ldh [$47], a
+    ldh [rBGP], a
     
 ; Set registers to match the original SGB boot
 IF DEF(SGB2)
@@ -210,4 +216,4 @@ db $3c,$42,$b9,$a5,$b9,$a5,$42,$3c
 
 SECTION "BootGame", ROM0[$fe]
 BootGame:
-    ldh [$50], a
+    ldh [rBANK], a