timeCS/ppu.s at master · aberranthacker/timeCS

645 lines (555 loc) · 23.6 KB
               .nolist
               .title Chibi Akumas PPU module
               .global start # make the entry point available to a linker
               .global PPU_ModuleSize
               .global PPU_ModuleSizeWords
               .include "macros.s"
               .include "hwdefs.s"
               .include "defs.s"
               .equiv  PPU_ModuleSize, (end - start)
               .equiv  PPU_ModuleSizeWords, PPU_ModuleSize >> 1
               .=PPU_UserRamStart
        MTPS $PR7
        MOV $0100000,SP
      # bit 0 if clear, disables ROM chip in range 0100000..0117777
      #       which allows to enable RW access to RAM in that range
      #       when bit 4 is set as well
      # bits 1-3 used to select ROM cartridge banks
      # bit 4 replaces ROM in range 0100000..0117777 with RAM, see bit 0
      # bit 5 replaces ROM in range 0120000..0137777 with write only RAM
      # bit 6 replaces ROM in range 0140000..0157777 with write only RAM
      # bit 7 replaces ROM in range 0160000..0176777 with write only RAM
      # bit 8 enables PPU Vblank interrupt when clear, disables when set
      # bit 9 enables CPU Vblank interrupt when clear, disables when set
      # WARNING: since there is no way to disable ROM chips in range
      # 0120000..0176777, we can only write to the RAM in that range.
      # **But** UKNCBL emulator allows to read from the RAM as well!
      # **Beware** this is **not** how the real hardware behaves!
        MOV  $0x0F0,@$PASWCR
#-------------------------------------------------------------------------------
        CALL ClearOffscreenArea
# initialize our scanlines parameters table (SLTAB): ------------------------{{{
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
312 (1..312) lines is SECAM half-frame
309 (1..309) SLTAB records in total (lines 4..312 of SECAM's half-frame)
  scanlines   1..19  are not visible due to the vertical blanking interval
  scanlines  20..307 are visible (lines 23-310 of SECAM's half-frame)
  scanlines 308..309 are not visible due to the vertical blanking interval
| 2-word records | 4-word records |
| 0 address      | 0 data         | data - words that will be loaded into
| 2 next record  | 2 data         |        control registers
|                | 4 address      | address - address of the line to display
|                | 6 next record  | next record - address of the next record of
Very first record of the table is 2-word and has fixed address 0270
--------------------------------------------------------------------------------
"next record" word description: ---------------------------------------------{{{
+--+--+--+--+--+--+--+--+--+--+--+--+--+-----+-----+------+
|15|14|13|12|11|10| 9| 8| 7| 6| 5| 4| 3|   2 |   1 |    0 |
+--+--+--+--+--+--+--+--+--+--+--+--+--+-----+-----+------+
|     address of the next record       | sel |2W/4W|cursor|
+--+--+--+--+--+--+--+--+--+--+--+--+--+-----+-----+------+
bit 0: cursor switching control
       1 - switch cursor state (on/off)
       0 - save cursor state
       Hardware draws cursor in a range of sequential lines.
       The cursor has to be switched "on" on the first line of the sequence,
       saved in between, and turned "off" on the last line of the sequence.
bit 1: size of the next record
       1 - next is a 4-word record
       0 - next is a 2-word record
bit 2: 1) for 2-word record - bit 2 of address of the next element of the table
       2) for 4-word record - selects register to which data will be loaded:
          0 - cursor, pallete, and horizontal scale control register
          1 - colors control register
-----------------------------------------------------------------------------}}}
cursor, pallete and horizontal scale control registers desription: ----------{{{
+----+----+----+----+----+----+----+----+----+----+----+----+---+---+---+---+
| 15 | 14 | 13 | 12 | 11 | 10 |  9 |  8 |  7 |  6 |  5 |  4 | 3 | 2 | 1 | 0 |
+----+----+----+----+----+----+----+----+----+----+----+----+---+---+---+---+
| X  | cursor position within a line    |graph curs pos|type| Y | R | G | B |
+----+----+----+----+----+----+----+----+----+----+----+----+---+---+---+---+
bits 0-3:  cursor color and brightness
bit 4:     cursor type
           1 - graphic cursor
           0 - character cursor
bits 5-7:  graphic cursor position within pixels octet
           0 - least significant bit (on the left side of the octet)
           7 - most significant bit (on the right side of the octet)
bits 8-14: cursor position within a text line
           from 0 to 79
+----+----+----+----+----+----+---+---+---+---+---+---+---+----+----+----+
| 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 |  2 |  1 |  0 |
+----+----+----+----+----+----+---+---+---+---+---+---+---+----+----+----+
|                     unused                  | scale | X | PB | PG | PR |
+----+----+----+----+----+----+---+---+---+---+---+---+---+----+----+----+
bits 0-2:  brightness of RGB components on the whole line
           1 - full brightness
           0 - 50% of the full brightness
bit 3:     unused
bits 4,5:  horizontal scale
           | 5 | 4 | width px | width chars | last char pos |
           +---+---+----------+-------------+---------------+
bits 6-15: unused
-----------------------------------------------------------------------------}}}
colors control registers description:----------------------------------------{{{
           +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
           |15 |14 |13 |12 |11 |10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
           +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
           | Y | R | G | B | Y | R | G | B | Y | R | G | B | Y | R | G | B |
           +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
           +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
           |15 |14 |13 |12 |11 |10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
           +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
           | Y | R | G | B | Y | R | G | B | Y | R | G | B | Y | R | G | B |
           +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
-----------------------------------------------------------------------------}}}
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
        MOV  $SLTAB,R0       # set R0 to beginning of SLTAB
        MOV  R0,R1           # R0 address of current record (2)
        MOV  $15,R2          #  records 2..16 are same
            CLR  (R0)+       #--addresses of lines 2..16
            ADD  $4,R1       #  calc address of next record of SLTAB
            MOV  R1,(R0)+    #--address of records 3..17
        SOB  R2,1$
      # we are switching from 2-word records to 4-word records
      # so we have to align at 4 words (8 bytes)
        CLR  (R0)+           #--address of line 17
        ADD  $0b1000,R1      #  align
        BIS  $0b0010,R1      #  next record is 4-word
        BIC  $0b0100,R1      #  set cursor/scale/palette
        MOV  R1,(R0)+        #--address of the record 18
        ADD  $0b100,R0       #  correct R0 due to alignment
        BIC  $0b100,R0
        MOV  $0b10000,(R0)+  #--cursor settings, graphical cursor
        MOV  $0b10111,(R0)+  #  320 dots per line, palette 7
        CLR  (R0)+           #  address of line 18
        BIS  $0b110,R1       #  next record is 4-word, color settings
        ADD  $8,R1           #  calculate address to next record
        MOV  R1,(R0)+        #--pointer to record 19
        MOV  R0,@$TopAreaColors # store the address for future use
        MOV  $0xBA90,(R0)+   # colors  011  010  001  000 (YRGB)
        MOV  $0xFEDC,(R0)+   # colors  111  110  101  100 (YRGB)
        CLR  (R0)+           #--address of line 19
        BIC  $0b110,R1       #  next record is 2-word
        ADD  $8,R1           #  calculate pointer to next record
        MOV  R1,(R0)+        #--pointer to the record 20
#------------------------------------- top region, header
        MOV  $AUX_SCREEN_ADDR,R2 # scanlines 20..307 are visible
        MOV  $AUX_SCREEN_LINES_COUNT >> 1 - 1,R3       #
            MOV  R2,(R0)+    #--address of screenline
            ADD  $4,R1       #  calc address of next record of SLTAB
            MOV  R1,(R0)+    #--set address of next record of SLTAB
            ADD  $40,R2      #  calculate address of next screenline
        SOB  R3,2$           #
      # we are switching from 2-word records to 4-word records
      # so we have to align at 8 bytes
        MOV  R2,(R0)+        #--address of a screenline
        BIS  $0b0010,R1      #  next record is 4-word
        BIC  $0b0100,R1      #  display settings
        ADD  $0b1000,R1      #  calc address of next record of SLTAB
                             #  taking alignment into account
        MOV  R1,(R0)+        #--pointer to record 63
        ADD  $0b100,R0       #  correct R0
        BIC  $0b100,R0       #  due to alignment
        ADD  $40,R2          #  calculate address of next screenline
        MOV  R0,@$MainScreenLinesTable   #
        SUB  $2,@$MainScreenLinesTable   #
        MOV  $0b10000,(R0)+  #--cursor settings: graphical cursor
        MOV  $0b10111,(R0)+  #  320 dots per line, pallete 7
        MOV  R2,(R0)+        #--address of a screenline
        ADD  $8,R1           #  calc address of next record of SLTAB
        BIS  $0b110,R1       #  next record is 4-word, color settings
        MOV  R0,@$MainScreenFirstRecAddr
        MOV  R1,(R0)+        #--pointer to record 64
        MOV  R0,@$FB0_FirstRecAddr
#----------------------------- main screen area
        MOV  $(FB0 - 8) >> 1,R2    # address of second frame-buffer
        MOV  $MAIN_SCREEN_LINES_COUNT,R3 # number of lines on main screen area
           .ifdef DEBUG
            MOV  $0x3300,(R0)+ #  colors  011  010  001  000 (YRGB)
            MOV  $0xFFDD,(R0)+ #  colors  111  110  101  100 (YRGB)
           .else
            MOV  $0x0000,(R0)+ #  colors  011  010  001  000 (YRGB)
            MOV  $0x0000,(R0)+ #  colors  111  110  101  100 (YRGB)
           .endif
            MOV  R2,(R0)+      #--main RAM address of a scanline
           #ADD  $40,R2        #  calculate address of next screenline
            ADD  $36,R2        #  calculate address of next screenline
            ADD  $8,R1         #  calc address of next record of SLTAB
            MOV  R1,(R0)+      #--pointer to the next record of SLTAB
        SOB  R3,3$             #
        MOV  R1,BottomAreaFirstRec
#------------------------------------- bottom region, footer
        MOV  R0,@$BottomAreaColors # store the address for future use
        MOV  $0xBA90,(R0)+   # colors  011  010  001  000 (YRGB)
        MOV  $0xFEDC,(R0)+   # colors  111  110  101  100 (YRGB)
       .equiv BOTTOM_AREA_OFFSET, (AUX_SCREEN_LINES_COUNT >> 1) * 40 + 40
        MOV  $AUX_SCREEN_ADDR + BOTTOM_AREA_OFFSET, R2  #
        MOV  R2,(R0)+        #
        ADD  $40,R2          # calculate address of next screenline
        ADD  $8,R1           # calculate pointer to next record
        BIC  $0b110,R1       # next record consists of 2 words
        MOV  R1,(R0)+        #--set address of record 265
        MOV  $AUX_SCREEN_LINES_COUNT >> 1 - 2,R3          #
            MOV  R2,(R0)+    #--address of a screenline
            ADD  $4,R1       #  calc address of next record of SLTAB
            MOV  R1,(R0)+    #--pointer to the next record of SLTAB
            ADD  $40,R2      # calculate address of next screenline
        SOB  R3,4$           #
        CLR  (R0)+           #--address of line 308
        MOV  R1,(R0)+        #--pointer back to record 308
        ADD  $0b111,R0      #  correct R0
        BIC  $0b111,R0      #  due to alignment
        MOV  R0, @$FB1_FirstRecAddr
        MOV  R0, R1
        BIS  $0b110,R1
        MOV  $(FB1 - 8) >> 1,R2    # address of second frame-buffer
        MOV  $MAIN_SCREEN_LINES_COUNT,R3 # number of lines on main screen area
            MOV  $0x3300,(R0)+
            MOV  $0xFFDD,(R0)+
            MOV  R2,(R0)+
            ADD  $36,R2
            ADD  $8,R1
            MOV  R1,(R0)+
        SOB  R3,5$
       .equiv BottomAreaFirstRec, .+2
        MOV  $0,-(R0)
#----------------------------------------------------------------------------}}}
        MOV  $0x001,@$PASWCR
#-------------------------------------------------------------------------------
        MOV  $SLTAB, @$0272   # use our SLTAB
        MOV  $KeyboardIntHadler,@$KBINT
        MOV  $PCH0II, R0
        MOV  $Channel0In_IntHandler, (R0)+
        MOV  $0200, (R0)
      # read from the channel, just in case
        TST  @$PCH0ID
        MOV  $PCH1II, R0
        MOV  $Channel1In_IntHandler, (R0)+
        MOV  $0200, (R0)
        BIS  $Ch1StateInInt,@$PCHSIS # enable channel 1 input interrupt
      # read from the channel, just in case
        TST  @$PCH1ID
       .equiv ScanRangeWords, 3
      # Aberrant Sound Module detection
        MOV  $PSG0+ScanRangeWords * 2,R1
        MOV  $PSG1,R2
        MOV  $Trap4,@$4
      # Aberrant Sound Module uses addresses range 0177360-0177377
      # 16 addresses in total
        MOV  $ScanRangeWords,R0
        TestNextSoundBoardAddress:
            TST  -(R1)
        SOB  R0,TestNextSoundBoardAddress
      # R1 now contains 0177360, address of PSG0
        TST  @$Trap4Detected
        BZE  AberrantSoundModulePresent
        MOV  $DummyPSG,R1
        MOV  R1,R2
AberrantSoundModulePresent:
        CLR  @$Trap4Detected
        MOV  R1,@$psgplayer.PSG0
        MOV  R2,@$psgplayer.PSG1
        MOV  R1,@$pt3play2.PSG0
        MOV  R2,@$pt3play2.PSG1
        MOV  $0173362,@$4 # restore back Trap 4 handler
        MOV @$023166, rseed1 # set cursor presence counter value as random seed
        MOV  $VblankIntHandler, @$100
      # inform loader that PPU is ready to receive commands
        MOV  $CPU_PPUCommandArg,@$PBPADR
        CLR  @$PBP12D
        MOV  $CommandsQueue_CurrentPosition,R4
        MTPS $PR0
#-------------------------------------------------------------------------------
Queue_Loop:
        MOV  (R4),R5
        CMP  R5,$CommandsQueue_Bottom
        BEQ  Queue_Loop
        MTPS $PR7
        MOV  (R5)+,R1
        MOV  (R5)+,R0
        MOV  R5,(R4)
        MTPS $PR0
    .ifdef DEBUG
        CMP  R1,$PPU.LastJMPTableIndex
        BHI  .
        CALL @CommandVectors(R1)
        MOV  $CommandsQueue_CurrentPosition,R4
        BR   Queue_Loop
#-------------------------------------------------------------------------------
CommandVectors:
       .word LoadDiskFile
       .word SetPalette            # PPU.SetPalette
       .word SetPaletteFB1         # PPU.SetPalette
       .word psgplayer.MUS_INIT
       .word psgplayer.Play
       .word psgplayer.Stop
       .word pt3play2.INIT
       .word pt3play2.MUTE
       .word pt3play2.Start
       .word pt3play2.Stop
#-------------------------------------------------------------------------------
SetPalette: #----------------------------------------------------------------{{{
        PUSH @$PASWCR
        MOV  $0x040,@$PASWCR
        MOV  $PBPADR,R4
        CLC
        ROR  R0
        MOV  R0,(R4) # palette address
      # R0 - first parameter word
      # R1 - second parameter word
      # R2 - display/color parameters flag
      # R3 - current line
      # R4 - next line where parameters change
      # R5 - pointer to a word that we'll modify
    .ifdef WORD_LINE_NUMBERS
        MOV  @$PBP12D,@$NextLineNum  # get line number
        MOVB @$PBP1DT,@$NextLineNum  # get line number
        PUSH (R4)
SetPalette_NextRecord:
        MOV  @$NextLineNum,R3 # R3 = previous iteration's next line
        MOV  R3,R5            # prepare to calculate address of SLTAB section to modify
        ASH  $3,R5            # calculate offset by multiplying by 8 (by shifting R5 left by 3 bits)
       .equiv MainScreenLinesTable, .+2
        ADD  $0,R5            # and add address of SLTAB section we modify
        POP  (R4)
    .ifdef WORD_LINE_NUMBERS
        INC  (R4)
        MOV  @$PBP12D,R2         # get display/color parameters flag
        MOVB @$PBP2DT,R2         # get display/color parameters flag
        BMI  SetPalette_Finalize # negative value - terminator
        INC  (R4)
        MOV  @$PBP12D,R0     # get first data word
        INC  (R4)
        MOV  @$PBP12D,R1     # get second data word
        INC  (R4)
    .ifdef WORD_LINE_NUMBERS
        MOV  @$PBP12D,@$NextLineNum # get next line idx
        MOVB @$PBP1DT,@$NextLineNum # get next line idx
        PUSH (R4)
        CMP  R2,$2
        BEQ  SetPalette_OffscreenColors
    set_params$:
        TSTB R2
        BNZ  SetPalette_SetColorRegisters # 1 - set colors
SetPalette_SetControlRegisters:
        MOV  R5,(R4)
        BICB $0b100,@$PBP0DT    # 0 - set data
        INC  R5
        INC  R5
        BR   set_data$
SetPalette_SetColorRegisters:
        MOV  R5,(R4)
        BISB $0b100,@$PBP0DT    # 0 - set data
        INC  R5
        INC  R5
    set_data$:
        MOV  R0,(R5)+
        MOV  R1,(R5)+
        INC  R5
        INC  R5           # skip third word (screen line address)
        INC  R3           # increase current line idx
       .equiv NextLineNum, .+2
        CMP  R3,$0        # compare current line idx with next line idx
        BLO  set_params$  # branch if lower
        CMP  @$NextLineNum,$MAIN_SCREEN_LINES_COUNT + 1
        BNE  SetPalette_NextRecord
        BR   SetPalette_Finalize_POP_R4
SetPalette_OffscreenColors:
       .equiv TopAreaColors, .+2
        MOV  $0,R2
        MOV  R0,(R2)+
        MOV  R1,(R2)
       .equiv BottomAreaColors, .+2
        MOV  $0,R2
        MOV  R0,(R2)+
        MOV  R1,(R2)
        BR   SetPalette_NextRecord
SetPalette_Finalize_POP_R4:
        POP  R4 # remove a value from the stack
SetPalette_Finalize:
        POP  @$PASWCR
        RETURN
#----------------------------------------------------------------------------}}}
SetPaletteFB1: #-------------------------------------------------------------{{{
        PUSH @$PASWCR
        MOV  $0x0F0,@$PASWCR
        MOV  $PBPADR,R4
        CLC
        ROR  R0
        MOV  R0,(R4) # palette address
      # R0 - first parameter word
      # R1 - second parameter word
      # R2 - display/color parameters flag
      # R3 - current line
      # R4 - next line where parameters change
      # R5 - pointer to a word that we'll modify
    .ifdef WORD_LINE_NUMBERS
        MOV  @$PBP12D,@$SetPaletteFB1_NextLineNum  # get line number
        MOVB @$PBP1DT,@$SetPaletteFB1_NextLineNum  # get line number
        PUSH (R4)
SetPaletteFB1_NextRecord:
        MOV  @$SetPaletteFB1_NextLineNum,R3 # R3 = previous iteration's next line
        MOV  R3,R5            # prepare to calculate address of SLTAB section to modify
        DEC  R5
        ASH  $3,R5            # calculate offset by multiplying by 8 (by shifting R5 left by 3 bits)
        ADD  @$FB1_FirstRecAddr,R5 # and add address of SLTAB section we modify
        SUB  $2,R5
        POP  (R4)
    .ifdef WORD_LINE_NUMBERS
        INC  (R4)
        MOV  @$PBP12D,R2         # get display/color parameters flag
        MOVB @$PBP2DT,R2         # get display/color parameters flag
        BMI  SetPaletteFB1_Finalize # negative value - terminator
        INC  (R4)
        MOV  @$PBP12D,R0     # get first data word
        INC  (R4)
        MOV  @$PBP12D,R1     # get second data word
        INC  (R4)
    .ifdef WORD_LINE_NUMBERS
        MOV  @$PBP12D,@$SetPaletteFB1_NextLineNum # get next line idx
        MOVB @$PBP1DT,@$SetPaletteFB1_NextLineNum # get next line idx
        PUSH (R4)
    SetPaletteFB1_set_params$:
        TSTB R2
        BNZ  SetPaletteFB1_SetColorRegisters # 1 - set colors
SetPaletteFB1_SetControlRegisters:
        MOV  R5,(R4)
        BICB $0b100,@$PBP0DT    # 0 - set data
        INC  R5
        INC  R5
        BR   SetPaletteFB1_set_data$
SetPaletteFB1_SetColorRegisters:
        MOV  R5,(R4)
        BISB $0b100,@$PBP0DT    # 0 - set data
        INC  R5
        INC  R5
    SetPaletteFB1_set_data$:
        MOV  R0,(R5)+
        MOV  R1,(R5)+
        INC  R5
        INC  R5           # skip third word (screen line address)
        INC  R3           # increase current line idx
       .equiv SetPaletteFB1_NextLineNum, .+2
        CMP  R3,$0        # compare current line idx with next line idx
        BLO  SetPaletteFB1_set_params$  # branch if lower
        CMP  @$SetPaletteFB1_NextLineNum,$MAIN_SCREEN_LINES_COUNT + 1
        BNE  SetPaletteFB1_NextRecord
        POP  R4 # remove a value from the stack
SetPaletteFB1_Finalize:
        POP  @$PASWCR
        RETURN
#----------------------------------------------------------------------------}}}
ClearOffscreenArea: # -------------------------------------------------------{{{
        MOV  $AUX_SCREEN_LINES_COUNT * 4,R1
        MOV  $DTSOCT,R4
        MOV  $PBPADR,R5
        MOV  $AUX_SCREEN_ADDR,(R5)
        CLR  @$PBPMSK # write to all bit-planes
        CLR  @$BP01BC # background color, pixels 0-3
        CLR  @$BP12BC # background color, pixels 4-7
           .rept 10
            CLR  (R4)
            INC  (R5)
           .endr
        SOB  R1,100$
        RETURN
#----------------------------------------------------------------------------}}}
psgplayer.Play:
        MOV $psgplayer.MUS_PLAY, @$PlayMusicProc
        MOV $-1, FRAME_NUMBER
        MOV $CPU.Title.PLAY_NOW, @$PBPADR
        INC @$PBP12D
        RETURN
psgplayer.Stop:
        MOV $NULL, @$PlayMusicProc
        CALL psgplayer.MUTE
        CALL Glitch.RemoveStale
        RETURN
pt3play2.Start:
        MOV $pt3play2.PLAY, @$PlayMusicProc
        MOV $-1, FRAME_NUMBER
        RETURN
pt3play2.Stop:
        MOV $NULL, @$PlayMusicProc
        CALL pt3play2.MUTE
        RETURN
LoadDiskFile: # -------------------------------------------------------------{{{
        MOV $VblankIntHandler.Minimal, @$0100 #
        MOV R0, @$023200 # set ParamsStruct address for firmware proc to use
        CALL @$0125030   # firmware proc that handles channel 2
        BMI 10$          # wait until loaded
        RETURN
#----------------------------------------------------------------------------}}}
# Generates a next 16-bit pseudorandom number
# generator period is 0xfffe0000 (4294836224)
#       None
#       R0 - next pseudorandom number
# Corrupts:
#       None
 # Author: Alexander "Sandro" Tishin
        .equiv rseed1, .+2
         MOV $0, R0
         ADD R0, R0
         BHI 1$
         ADD $39, R0
         MOV R0, @$rseed1
        .equiv rseed2, .+2
         ADD $0, R0
         MOV R0, @$rseed2
NULL:    RETURN
       .include "ppu/interrupts_handlers.s"
       .include "psgplayer.s"
DummyPSG: .word
CommandsQueue_Top:
       .space 2*2*16
CommandsQueue_Bottom:
       .include "pt3play2.s"
       .nolist
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