fix: move code in scheduler to ppu

src/Bus.zig

@@ -6,7 +6,6 @@ const GamePak = @import("bus/GamePak.zig");
 const Io = @import("bus/io.zig").Io;
 const Iwram = @import("bus/Iwram.zig");
 const Ppu = @import("ppu.zig").Ppu;
-const Apu = @import("apu.zig").Apu;
 const Scheduler = @import("scheduler.zig").Scheduler;
 
 const io = @import("bus/io.zig");
@@ -19,7 +18,6 @@ const panic_on_und_bus: bool = false;
 pak: GamePak,
 bios: Bios,
 ppu: Ppu,
-apu: Apu,
 iwram: Iwram,
 ewram: Ewram,
 io: Io,
@@ -29,7 +27,6 @@ pub fn init(alloc: Allocator, sched: *Scheduler, rom_path: []const u8, maybe_bio
         .pak = try GamePak.init(alloc, rom_path),
         .bios = try Bios.init(alloc, maybe_bios),
         .ppu = try Ppu.init(alloc, sched),
-        .apu = Apu.init(),
         .iwram = try Iwram.init(alloc),
         .ewram = try Ewram.init(alloc),
         .io = Io.init(sched),

src/apu.zig

@@ -1,144 +0,0 @@
-const std = @import("std");
-
-const SoundFifo = std.fifo.LinearFifo(u8, .{ .Static = 0x20 });
-
-const io = @import("bus/io.zig");
-
-pub const Apu = struct {
-    const Self = @This();
-
-    ch1: ToneSweep,
-    ch2: Tone,
-    ch3: Wave,
-    ch4: Noise,
-    chA: DmaSound,
-    chB: DmaSound,
-
-    bias: io.SoundBias,
-    ch_vol_cnt: io.ChannelVolumeControl,
-    dma_cnt: io.DmaSoundControl,
-    cnt: io.SoundControl,
-
-    pub fn init() Self {
-        return .{
-            .ch1 = ToneSweep.init(),
-            .ch2 = Tone.init(),
-            .ch3 = Wave.init(),
-            .ch4 = Noise.init(),
-            .chA = DmaSound.init(),
-            .chB = DmaSound.init(),
-
-            .ch_vol_cnt = .{ .raw = 0 },
-            .dma_cnt = .{ .raw = 0 },
-            .cnt = .{ .raw = 0 },
-            .bias = .{ .raw = 0x0200 },
-        };
-    }
-
-    pub fn setSoundCntX(self: *Self, value: bool) void {
-        self.cnt.apu_enable.write(value);
-    }
-
-    pub fn setSoundCntLLow(self: *Self, byte: u8) void {
-        self.ch_vol_cnt.raw = (self.ch_vol_cnt.raw & 0xFF00) | byte;
-    }
-
-    pub fn setBiasHigh(self: *Self, byte: u8) void {
-        self.bias.raw = (@as(u16, byte) << 8) | (self.bias.raw & 0xFF);
-    }
-};
-
-const ToneSweep = struct {
-    const Self = @This();
-
-    sweep: io.Sweep,
-    duty: io.Duty,
-    envelope: io.Envelope,
-    freq: io.Frequency,
-
-    fn init() Self {
-        return .{
-            .sweep = .{ .raw = 0 },
-            .duty = .{ .raw = 0 },
-            .envelope = .{ .raw = 0 },
-            .freq = .{ .raw = 0 },
-        };
-    }
-
-    pub fn setFreqHigh(self: *Self, byte: u8) void {
-        self.freq.raw = (@as(u16, byte) << 8) | (self.freq.raw & 0xFF);
-    }
-};
-
-const Tone = struct {
-    const Self = @This();
-
-    duty: io.Duty,
-    envelope: io.Envelope,
-    freq: io.Frequency,
-
-    fn init() Self {
-        return .{
-            .duty = .{ .raw = 0 },
-            .envelope = .{ .raw = 0 },
-            .freq = .{ .raw = 0 },
-        };
-    }
-
-    pub fn setFreqHigh(self: *Self, byte: u8) void {
-        self.freq.raw = (self.freq.raw & 0x00FF) | (@as(u16, byte) << 8);
-    }
-};
-
-const Wave = struct {
-    const Self = @This();
-
-    /// Write-only
-    select: io.WaveSelect,
-    /// NR31    
-    length: u8,
-    vol: io.WaveVolume,
-    freq: io.Frequency,
-
-    fn init() Self {
-        return .{
-            .select = .{ .raw = 0 },
-            .vol = .{ .raw = 0 },
-            .freq = .{ .raw = 0 },
-            .length = 0,
-        };
-    }
-};
-
-const Noise = struct {
-    const Self = @This();
-
-    /// Write-only
-    /// NR41
-    len: u6,
-    envelope: io.Envelope,
-    poly: io.PolyCounter,
-    cnt: io.NoiseControl,
-
-    fn init() Self {
-        return .{
-            .len = 0,
-            .envelope = .{ .raw = 0 },
-            .poly = .{ .raw = 0 },
-            .cnt = .{ .raw = 0 },
-        };
-    }
-};
-const DmaSound = struct {
-    const Self = @This();
-
-    a: SoundFifo,
-    b: SoundFifo,
-
-    fn init() Self {
-        return .{
-            .a = SoundFifo.init(),
-            .b = SoundFifo.init(),
-        };
-    }
-};

src/bus/io.zig

@@ -150,7 +150,7 @@ pub fn read16(bus: *const Bus, addr: u32) u16 {
         0x0400_0006 => bus.ppu.vcount.raw,
 
         // Sound
-        0x0400_0088 => bus.apu.bias.raw,
+        0x0400_0088 => unimplementedRead("Read halfword from SOUNDBIAS", .{}),
 
         // Timers
         0x0400_0100 => bus.io.tim0.counter(),
@@ -210,10 +210,10 @@ pub fn write16(bus: *Bus, addr: u32, halfword: u16) void {
         0x0400_0054 => log.warn("Wrote 0x{X:0>4} to BLDY", .{halfword}),
 
         // Sound
-        0x0400_0080 => bus.apu.ch_vol_cnt.raw = halfword,
-        0x0400_0082 => bus.apu.dma_cnt.raw = halfword,
-        0x0400_0084 => bus.apu.setSoundCntX(halfword >> 7 & 1 == 1),
-        0x0400_0088 => bus.apu.bias.raw = halfword,
+        0x0400_0080 => log.warn("Wrote 0x{X:0>4} to SOUNDCNT_L", .{halfword}),
+        0x0400_0082 => log.warn("Wrote 0x{X:0>4} to SOUNDCNT_H", .{halfword}),
+        0x0400_0084 => log.warn("Wrote 0x{X:0>4} to SOUNDCNT_X", .{halfword}),
+        0x0400_0088 => log.warn("Wrote 0x{X:0>4} to SOUNDBIAS", .{halfword}),
 
         // Dma Transfers
         0x0400_00B8 => bus.io.dma0.writeWordCount(halfword),
@@ -267,7 +267,7 @@ pub fn read8(bus: *const Bus, addr: u32) u8 {
         0x0400_0006 => @truncate(u8, bus.ppu.vcount.raw),
 
         // Sound
-        0x0400_0089 => @truncate(u8, bus.apu.bias.raw >> 8),
+        0x0400_0089 => unimplementedRead("Read (high) byte from SOUNDBIAS", .{}),
 
         // Serial Communication 1
         0x0400_0128 => unimplementedRead("Read (low) byte from SIOCNT", .{}),
@@ -279,23 +279,23 @@ pub fn read8(bus: *const Bus, addr: u32) u8 {
     };
 }
 
-pub fn write8(bus: *Bus, addr: u32, byte: u8) void {
+pub fn write8(self: *Bus, addr: u32, byte: u8) void {
     switch (addr) {
         // Display
-        0x0400_0004 => bus.ppu.dispstat.raw = (bus.ppu.dispstat.raw & 0xFF00) | byte,
-        0x0400_0005 => bus.ppu.dispstat.raw = (@as(u16, byte) << 8) | (bus.ppu.dispstat.raw & 0xFF),
+        0x0400_0004 => self.ppu.dispstat.raw = (self.ppu.dispstat.raw & 0xFF00) | byte,
+        0x0400_0005 => self.ppu.dispstat.raw = (@as(u16, byte) << 8) | (self.ppu.dispstat.raw & 0xFF),
 
         // Sound
-        0x0400_0063 => bus.apu.ch1.envelope.raw = byte,
-        0x0400_0065 => bus.apu.ch1.setFreqHigh(byte),
-        0x0400_0069 => bus.apu.ch2.envelope.raw = byte,
-        0x0400_006D => bus.apu.ch2.setFreqHigh(byte),
-        0x0400_0070 => bus.apu.ch3.select.raw = byte,
-        0x0400_0079 => bus.apu.ch4.envelope.raw = byte,
-        0x0400_007D => bus.apu.ch4.cnt.raw = byte,
-        0x0400_0080 => bus.apu.setSoundCntLLow(byte),
-        0x0400_0084 => bus.apu.setSoundCntX(byte >> 7 & 1 == 1),
-        0x0400_0089 => bus.apu.setBiasHigh(byte),
+        0x0400_0063 => log.warn("Wrote 0x{X:0>2} to SOUND1CNT_H (high)", .{byte}),
+        0x0400_0065 => log.warn("Wrote 0x{X:0>2} to SOUND1CNT_X (high)", .{byte}),
+        0x0400_0069 => log.warn("Wrote 0x{X:0>2} to SOUND2CNT_L (high)", .{byte}),
+        0x0400_006D => log.warn("Wrote 0x{X:0>2} to SOUND2CNT_H (high)", .{byte}),
+        0x0400_0070 => log.warn("Wrote 0x{X:0>2} to SOUND3CNT_L (low)", .{byte}),
+        0x0400_0079 => log.warn("Wrote 0x{X:0>2} to SOUND4CNT_L (high)", .{byte}),
+        0x0400_007D => log.warn("Wrote 0x{X:0>2} to SOUND4CNT_H (high)", .{byte}),
+        0x0400_0080 => log.warn("Wrote 0x{X:0>2} to SOUNDCNT_L (low)", .{byte}),
+        0x0400_0084 => log.warn("Wrote 0x{X:0>2} to SOUNDCNT_X (low)", .{byte}),
+        0x0400_0089 => log.warn("Wrote 0x{X:0>2} to SOUNDBIAS (high)", .{byte}),
 
         // Serial Communication 1
         0x0400_0128 => log.warn("Wrote 0x{X:0>2} to SIOCNT (low)", .{byte}),
@@ -304,8 +304,8 @@ pub fn write8(bus: *Bus, addr: u32, byte: u8) void {
         0x0400_0140 => log.warn("Wrote 0x{X:0>2} to JOYCNT (low)", .{byte}),
 
         // Interrupts
-        0x0400_0208 => bus.io.ime = byte & 1 == 1,
-        0x0400_0301 => bus.io.haltcnt = if (byte >> 7 & 1 == 0) .Halt else std.debug.panic("TODO: Implement STOP", .{}),
+        0x0400_0208 => self.io.ime = byte & 1 == 1,
+        0x0400_0301 => self.io.haltcnt = if (byte >> 7 & 1 == 0) .Halt else std.debug.panic("TODO: Implement STOP", .{}),
         else => undWrite("Tried to write 0x{X:0>2} to 0x{X:0>8}", .{ byte, addr }),
     }
 }
@@ -462,135 +462,3 @@ pub const TimerControl = extern union {
     enabled: Bit(u16, 7),
     raw: u16,
 };
-
-/// Read / Write
-/// NR10
-pub const Sweep = extern union {
-    shift: Bitfield(u8, 0, 3),
-    direction: Bit(u8, 3),
-    period: Bitfield(u8, 4, 3),
-    raw: u8,
-};
-
-/// Read / Write
-/// This represents the Duty / Len
-/// NRx1
-pub const Duty = extern union {
-    /// Write-only
-    /// Only used when bit 6 is set
-    length: Bitfield(u16, 0, 6),
-    pattern: Bitfield(u16, 6, 2),
-    raw: u8,
-};
-
-/// Read / Write 
-/// NRx2
-pub const Envelope = extern union {
-    period: Bitfield(u8, 0, 3),
-    direction: Bit(u8, 3),
-    init_vol: Bitfield(u8, 4, 4),
-    raw: u8,
-};
-
-/// Read / Write
-/// NRx3, NRx4
-pub const Frequency = extern union {
-    /// Write-only
-    frequency: Bitfield(u16, 0, 11),
-    length_enable: Bit(u16, 14),
-    /// Write-only
-    trigger: Bit(u16, 15),
-
-    raw: u16,
-};
-
-/// Read / Write
-/// NR30
-pub const WaveSelect = extern union {
-    dimension: Bit(u8, 5),
-    bank: Bit(u8, 6),
-    enabled: Bit(u8, 7),
-    raw: u8,
-};
-
-/// Read / Write
-/// NR32
-pub const WaveVolume = extern union {
-    kind: Bitfield(u8, 5, 2),
-    force: Bit(u8, 7),
-    raw: u8,
-};
-
-/// Read / Write
-/// NR43
-pub const PolyCounter = extern union {
-    div_ratio: Bitfield(u8, 0, 3),
-    width: Bit(u8, 3),
-    shift: Bitfield(u8, 4, 4),
-    raw: u8,
-};
-
-/// Read / Write
-/// NR44
-pub const NoiseControl = extern union {
-    length_enable: Bit(u8, 6),
-    trigger: Bit(u8, 7),
-    raw: u8,
-};
-
-/// Read / Write
-pub const ChannelVolumeControl = extern union {
-    left_vol: Bitfield(u16, 0, 3),
-    right_vol: Bitfield(u16, 4, 3),
-
-    ch1_right: Bit(u16, 8),
-    ch2_right: Bit(u16, 9),
-    ch3_right: Bit(u16, 10),
-    ch4_right: Bit(u16, 11),
-    ch1_left: Bit(u16, 12),
-    ch2_left: Bit(u16, 13),
-    ch3_left: Bit(u16, 14),
-    ch4_left: Bit(u16, 15),
-    raw: u16,
-};
-
-/// Read / Write
-pub const DmaSoundControl = extern union {
-    ch_vol: Bitfield(u16, 0, 2),
-    sa_vol: Bit(u16, 2),
-    sb_vol: Bit(u16, 3),
-
-    sa_right_enable: Bit(u16, 8),
-    sa_left_enable: Bit(u16, 9),
-    sa_timer: Bit(u16, 10),
-    /// Write only?
-    sa_reset: Bit(u16, 11),
-
-    sb_right_enable: Bit(u16, 12),
-    sb_left_enable: Bit(u16, 13),
-    sb_timer: Bit(u16, 14),
-    /// Write only?
-    sb_reset: Bit(u16, 15),
-    raw: u16,
-};
-
-/// Read / Write
-pub const SoundControl = extern union {
-    /// Read-only
-    ch1_enable: Bit(u8, 0),
-    /// Read-only
-    ch2_enable: Bit(u8, 1),
-    /// Read-only
-    ch3_enable: Bit(u8, 2),
-    /// Read-only
-    ch4_enable: Bit(u8, 3),
-    apu_enable: Bit(u8, 7),
-    raw: u8,
-};
-
-/// Read / Write
-pub const SoundBias = extern union {
-    level: Bitfield(u16, 1, 9),
-    sampling_cycle: Bitfield(u16, 14, 2),
-    raw: u16,
-};

src/scheduler.zig

@@ -79,7 +79,7 @@ pub const Scheduler = struct {
     }
 
     pub fn nextTimestamp(self: *Self) u64 {
-        if (self.queue.peek()) |e| return e.tick;
+        if (self.queue.peek()) |e| return e;
 
         unreachable; // There's always the HeatDeath event scheduled
     }