zba/src/bus/io.zig
Rekai Musuka be2dfb379a chore: document select unimplmented I/O registers
These registers are written to / read from Kirby: Nightmare in Dream Land
2022-02-22 17:14:30 -06:00

304 lines
12 KiB
Zig

const std = @import("std");
const Bit = @import("bitfield").Bit;
const Bitfield = @import("bitfield").Bitfield;
const Bus = @import("../Bus.zig");
const log = std.log.scoped(.@"I/O");
pub const Io = struct {
const Self = @This();
/// Read / Write
ime: bool,
ie: InterruptEnable,
irq: InterruptRequest,
postflg: PostFlag,
is_halted: bool,
keyinput: KeyInput,
pub fn init() Self {
return .{
.ime = false,
.ie = .{ .raw = 0x0000 },
.irq = .{ .raw = 0x0000 },
.postflg = .{ .raw = 0x00 },
.keyinput = .{ .raw = 0x03FF },
.is_halted = false,
};
}
};
pub fn read32(bus: *const Bus, addr: u32) u32 {
return switch (addr) {
0x0400_0000 => bus.ppu.dispcnt.raw,
0x0400_0004 => bus.ppu.dispstat.raw,
0x0400_0006 => bus.ppu.vcount.raw,
0x0400_0200 => bus.io.ie.raw,
0x0400_0208 => @boolToInt(bus.io.ime),
0x0400_00C4 => failed_read("Tried to read word from DMA1CNT", .{}),
0x0400_00D0 => failed_read("Tried to read word from DMA2CNT", .{}),
else => std.debug.panic("Tried to read word from 0x{X:0>8}", .{addr}),
};
}
pub fn write32(bus: *Bus, addr: u32, word: u32) void {
switch (addr) {
0x0400_0000 => bus.ppu.dispcnt.raw = @truncate(u16, word),
0x0400_0004 => {
bus.ppu.dispstat.raw = @truncate(u16, word);
bus.ppu.vcount.raw = @truncate(u16, word >> 16);
},
0x0400_0008 => {
bus.ppu.bg[0].cnt.raw = @truncate(u16, word);
bus.ppu.bg[1].cnt.raw = @truncate(u16, word >> 16);
},
0x0400_000C => {
bus.ppu.bg[2].cnt.raw = @truncate(u16, word);
bus.ppu.bg[3].cnt.raw = @truncate(u16, word >> 16);
},
0x0400_0010 => {
bus.ppu.bg[0].hofs.raw = @truncate(u16, word);
bus.ppu.bg[0].vofs.raw = @truncate(u16, word >> 16);
},
0x0400_0014 => {
bus.ppu.bg[1].hofs.raw = @truncate(u16, word);
bus.ppu.bg[1].vofs.raw = @truncate(u16, word >> 16);
},
0x0400_0018 => {
bus.ppu.bg[2].hofs.raw = @truncate(u16, word);
bus.ppu.bg[2].vofs.raw = @truncate(u16, word >> 16);
},
0x0400_001C => {
bus.ppu.bg[3].hofs.raw = @truncate(u16, word);
bus.ppu.bg[3].vofs.raw = @truncate(u16, word >> 16);
},
0x0400_00BC => log.warn("Wrote 0x{X:0>8} to DMA1SAD", .{word}),
0x0400_00C0 => log.warn("Wrote 0x{X:0>8} to DMA1DAD", .{word}),
0x0400_00C8 => log.warn("Wrote 0x{X:0>8} to DMA2SAD", .{word}),
0x0400_00CC => log.warn("Wrote 0x{X:0>8} to DMA2DAD", .{word}),
0x0400_0200 => bus.io.ie.raw = @truncate(u16, word),
0x0400_0204 => log.warn("Wrote 0x{X:0>8} to WAITCNT", .{word}),
0x0400_0208 => bus.io.ime = word & 1 == 1,
else => std.debug.panic("Tried to write 0x{X:0>8} to 0x{X:0>8}", .{ word, addr }),
}
}
pub fn read16(bus: *const Bus, addr: u32) u16 {
return switch (addr) {
0x0400_0000 => bus.ppu.dispcnt.raw,
0x0400_0004 => bus.ppu.dispstat.raw,
0x0400_0006 => bus.ppu.vcount.raw,
0x0400_0130 => bus.io.keyinput.raw,
0x0400_0200 => bus.io.ie.raw,
0x0400_0208 => @boolToInt(bus.io.ime),
0x0400_0102 => failed_read("Tried to read halfword from TM0CNT_H", .{}),
0x0400_0106 => failed_read("Tried to read halfword from TM1CNT_H", .{}),
0x0400_010A => failed_read("Tried to read halfword from TM2CNT_H", .{}),
0x0400_010E => failed_read("Tried to read halfword from TM3CNT_H", .{}),
0x0400_0204 => failed_read("Tried to read halfword from WAITCNT", .{}),
else => std.debug.panic("Tried to read halfword from 0x{X:0>8}", .{addr}),
};
}
pub fn write16(bus: *Bus, addr: u32, halfword: u16) void {
switch (addr) {
0x0400_0000 => bus.ppu.dispcnt.raw = halfword,
0x0400_0004 => bus.ppu.dispstat.raw = halfword,
0x0400_0008...0x0400_000F => bus.ppu.bg[addr & 0x3].cnt.raw = halfword,
0x0400_0010 => bus.ppu.bg[0].hofs.raw = halfword, // TODO: Don't write out every HOFS / VOFS?
0x0400_0012 => bus.ppu.bg[0].vofs.raw = halfword,
0x0400_0014 => bus.ppu.bg[1].hofs.raw = halfword,
0x0400_0016 => bus.ppu.bg[1].vofs.raw = halfword,
0x0400_0018 => bus.ppu.bg[2].hofs.raw = halfword,
0x0400_001A => bus.ppu.bg[2].vofs.raw = halfword,
0x0400_001C => bus.ppu.bg[3].hofs.raw = halfword,
0x0400_001E => bus.ppu.bg[3].vofs.raw = halfword,
0x0400_0040 => log.warn("Wrote 0x{X:0>4} to WIN0H", .{halfword}),
0x0400_0042 => log.warn("Wrote 0x{X:0>4} to WIN1H", .{halfword}),
0x0400_0044 => log.warn("Wrote 0x{X:0>4} to WIN0V", .{halfword}),
0x0400_0046 => log.warn("Wrote 0x{X:0>4} to WIN1V", .{halfword}),
0x0400_0048 => log.warn("Wrote 0x{X:0>4} to WININ", .{halfword}),
0x0400_004A => log.warn("Wrote 0x{X:0>4} to WINOUT", .{halfword}),
0x0400_004C => log.warn("Wrote 0x{X:0>4} to MOSAIC", .{halfword}),
0x0400_0050 => log.warn("Wrote 0x{X:0>4} to BLDCNT", .{halfword}),
0x0400_0052 => log.warn("Wrote 0x{X:0>4} to BLDALPHA", .{halfword}),
0x0400_0054 => log.warn("Wrote 0x{X:0>4} to BLDY", .{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_00BA => log.warn("Wrote 0x{X:0>4} to DMA0CNT_H", .{halfword}),
0x0400_00C6 => log.warn("Wrote 0x{X:0>4} to DMA1CNT_H", .{halfword}),
0x0400_00D2 => log.warn("Wrote 0x{X:0>4} to DMA2CNT_H", .{halfword}),
0x0400_00DE => log.warn("Wrote 0x{X:0>4} to DMA3CNT_H", .{halfword}),
0x0400_0100 => log.warn("Wrote 0x{X:0>4} to TM0CNT_L", .{halfword}),
0x0400_0102 => log.warn("Wrote 0x{X:0>4} to TM0CNT_H", .{halfword}),
0x0400_0104 => log.warn("Wrote 0x{X:0>4} to TM1CNT_L", .{halfword}),
0x0400_0106 => log.warn("Wrote 0x{X:0>4} to TM1CNT_H", .{halfword}),
0x0400_0108 => log.warn("Wrote 0x{X:0>4} to TM2CNT_L", .{halfword}),
0x0400_010A => log.warn("Wrote 0x{X:0>4} to TM2CNT_H", .{halfword}),
0x0400_010C => log.warn("Wrote 0x{X:0>4} to TM3CNT_L", .{halfword}),
0x0400_010E => log.warn("Wrote 0x{X:0>4} to TM3CNT_H", .{halfword}),
0x0400_0120 => log.warn("Wrote 0x{X:0>4} to SIOMULTI0", .{halfword}),
0x0400_0122 => log.warn("Wrote 0x{X:0>4} to SIOMULTI1", .{halfword}),
0x0400_0124 => log.warn("Wrote 0x{X:0>4} to SIOMULTI2", .{halfword}),
0x0400_0126 => log.warn("Wrote 0x{X:0>4} to SIOMULTI3", .{halfword}),
0x0400_0128 => log.warn("Wrote 0x{X:0>4} to SIOCNT", .{halfword}),
0x0400_012A => log.warn("Wrote 0x{X:0>4} to SIOMLT_SEND", .{halfword}),
0x0400_0130 => log.warn("Wrote 0x{X:0>4} to KEYINPUT. Ignored", .{halfword}),
0x0400_0132 => log.warn("Wrote 0x{X:0>4} to KEYCNT", .{halfword}),
0x0400_0134 => log.warn("Wrote 0x{X:0>4} to RCNT", .{halfword}),
0x0400_0200 => bus.io.ie.raw = halfword,
0x0400_0202 => bus.io.irq.raw &= ~halfword,
0x0400_0204 => log.warn("Wrote 0x{X:0>4} to WAITCNT", .{halfword}),
0x0400_0208 => bus.io.ime = halfword & 1 == 1,
else => std.debug.panic("Tried to write 0x{X:0>4} to 0x{X:0>8}", .{ halfword, addr }),
}
}
pub fn read8(bus: *const Bus, addr: u32) u8 {
return switch (addr) {
0x0400_0000 => @truncate(u8, bus.ppu.dispcnt.raw),
0x0400_0004 => @truncate(u8, bus.ppu.dispstat.raw),
0x0400_0200 => @truncate(u8, bus.io.ie.raw),
0x0400_0300 => bus.io.postflg.raw,
0x0400_0006 => @truncate(u8, bus.ppu.vcount.raw),
0x0400_0089 => failed_read("Tried to read (high) byte from SOUNDBIAS", .{}),
else => std.debug.panic("Tried to read byte from 0x{X:0>8}", .{addr}),
};
}
pub fn write8(self: *Bus, addr: u32, byte: u8) void {
switch (addr) {
0x0400_0208 => self.io.ime = byte & 1 == 1,
0x0400_0301 => self.io.is_halted = byte >> 7 & 1 == 0, // TODO: Implement Stop?
0x0400_0063 => log.warn("Tried to write 0x{X:0>2} to SOUND1CNT_H (high)", .{byte}),
0x0400_0065 => log.warn("Tried to write 0x{X:0>2} to SOUND1CNT_X (high)", .{byte}),
0x0400_0069 => log.warn("Tried to write 0x{X:0>2} to SOUND2CNT_L (high)", .{byte}),
0x0400_006D => log.warn("Tried to write 0x{X:0>2} to SOUND2CNT_H (high)", .{byte}),
0x0400_0070 => log.warn("Tried to write 0x{X:0>2} to SOUND3CNT_L (low)", .{byte}),
0x0400_0079 => log.warn("Tried to write 0x{X:0>2} to SOUND4CNT_L (high)", .{byte}),
0x0400_007D => log.warn("Tried to write 0x{X:0>2} to SOUND4CNT_H (high)", .{byte}),
0x0400_0080 => log.warn("Tried to write 0x{X:0>2} to SOUNDCNT_L (low)", .{byte}),
0x0400_0089 => log.warn("Tried to write 0x{X:0>2} to SOUNDBIAS (high)", .{byte}),
else => std.debug.panic("Tried to write 0x{X:0>2} to 0x{X:0>8}", .{ byte, addr }),
}
}
fn failed_read(comptime format: []const u8, args: anytype) u8 {
log.warn(format, args);
return 0;
}
/// Read / Write
pub const PostFlag = extern union {
/// 0 if First Boot, 1 if a Reset has been done
not_first_boot: Bit(u8, 0),
raw: u8,
};
/// Read / Write
pub const DisplayControl = extern union {
bg_mode: Bitfield(u16, 0, 3),
frame_select: Bit(u16, 4),
hblank_interval_free: Bit(u16, 5),
obj_mapping: Bit(u16, 6),
forced_blank: Bit(u16, 7),
bg_enable: Bitfield(u16, 8, 4),
obj_enable: Bit(u16, 12),
win_enable: Bitfield(u16, 13, 2),
obj_win_enable: Bit(u16, 15),
raw: u16,
};
/// Read / Write
pub const DisplayStatus = extern union {
vblank: Bit(u16, 0),
hblank: Bit(u16, 1),
coincidence: Bit(u16, 2),
vblank_irq: Bit(u16, 3),
hblank_irq: Bit(u16, 4),
vcount_irq: Bit(u16, 5),
vcount_trigger: Bitfield(u16, 8, 8),
raw: u16,
};
/// Read Only
pub const VCount = extern union {
scanline: Bitfield(u16, 0, 8),
raw: u16,
};
/// Read / Write
const InterruptEnable = extern union {
vblank: Bit(u16, 0),
hblank: Bit(u16, 1),
coincidence: Bit(u16, 2),
tm0_overflow: Bit(u16, 3),
tm1_overflow: Bit(u16, 4),
tm2_overflow: Bit(u16, 5),
tm3_overflow: Bit(u16, 6),
serial: Bit(u16, 7),
dma0: Bit(u16, 8),
dma1: Bit(u16, 9),
dma2: Bit(u16, 10),
dma3: Bit(u16, 11),
keypad: Bit(u16, 12),
game_pak: Bit(u16, 13),
raw: u16,
};
/// Read Only
/// 0 = Pressed, 1 = Released
const KeyInput = extern union {
a: Bit(u16, 0),
b: Bit(u16, 1),
select: Bit(u16, 2),
start: Bit(u16, 3),
right: Bit(u16, 4),
left: Bit(u16, 5),
up: Bit(u16, 6),
down: Bit(u16, 7),
shoulder_r: Bit(u16, 8),
shoulder_l: Bit(u16, 9),
raw: u16,
};
// Read / Write
pub const BackgroundControl = extern union {
priority: Bitfield(u16, 0, 2),
char_base: Bitfield(u16, 2, 2),
mosaic_enable: Bit(u16, 6),
colour_mode: Bit(u16, 7),
screen_base: Bitfield(u16, 8, 5),
display_overflow: Bit(u16, 13),
size: Bitfield(u16, 14, 2),
raw: u16,
};
/// Write Only
pub const BackgroundOffset = extern union {
offset: Bitfield(u16, 0, 9),
raw: u16,
};
/// Read / Write
const InterruptRequest = extern union {
vblank: Bit(u16, 0),
hblank: Bit(u16, 1),
coincidence: Bit(u16, 2),
tim0_overflow: Bit(u16, 3),
tim1_overflow: Bit(u16, 4),
tim2_overflow: Bit(u16, 5),
tim3_overflow: Bit(u16, 6),
serial: Bit(u16, 7),
dma0: Bit(u16, 8),
dma1: Bit(u16, 9),
dma2: Bit(u16, 10),
dma3: Bit(u16, 11),
keypad: Bit(u16, 12),
game_pak: Bit(u16, 13),
raw: u16,
};