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0d4c850218
Author | SHA1 | Date |
---|---|---|
Rekai Nyangadzayi Musuka | 0d4c850218 | |
Rekai Nyangadzayi Musuka | bbe2ecfa53 | |
Rekai Nyangadzayi Musuka | c54145ce3c |
19
src/Bus.zig
19
src/Bus.zig
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@ -7,14 +7,15 @@ const Ppu = @import("ppu.zig").Ppu;
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const Scheduler = @import("scheduler.zig").Scheduler;
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const Allocator = std.mem.Allocator;
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const Self = @This();
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pak: GamePak,
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bios: Bios,
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ppu: Ppu,
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io: Io,
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pub fn init(alloc: Allocator, sched: *Scheduler, path: []const u8) !@This() {
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return @This(){
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pub fn init(alloc: Allocator, sched: *Scheduler, path: []const u8) !Self {
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return Self{
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.pak = try GamePak.init(alloc, path),
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.bios = try Bios.init(alloc, "./bin/gba_bios.bin"), // TODO: don't hardcode this + bundle open-sorce Boot ROM
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.ppu = try Ppu.init(alloc, sched),
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@ -22,13 +23,13 @@ pub fn init(alloc: Allocator, sched: *Scheduler, path: []const u8) !@This() {
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};
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}
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pub fn deinit(self: @This()) void {
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pub fn deinit(self: Self) void {
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self.pak.deinit();
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self.bios.deinit();
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self.ppu.deinit();
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}
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pub fn read32(self: *const @This(), addr: u32) u32 {
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pub fn read32(self: *const Self, addr: u32) u32 {
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return switch (addr) {
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// General Internal Memory
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0x0000_0000...0x0000_3FFF => self.bios.get32(@as(usize, addr)),
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@ -53,7 +54,7 @@ pub fn read32(self: *const @This(), addr: u32) u32 {
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};
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}
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pub fn write32(self: *@This(), addr: u32, word: u32) void {
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pub fn write32(self: *Self, addr: u32, word: u32) void {
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// TODO: write32 can write to GamePak Flash
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switch (addr) {
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@ -71,7 +72,7 @@ pub fn write32(self: *@This(), addr: u32, word: u32) void {
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}
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}
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pub fn read16(self: *const @This(), addr: u32) u16 {
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pub fn read16(self: *const Self, addr: u32) u16 {
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return switch (addr) {
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// General Internal Memory
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0x0000_0000...0x0000_3FFF => self.bios.get16(@as(usize, addr)),
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@ -96,7 +97,7 @@ pub fn read16(self: *const @This(), addr: u32) u16 {
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};
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}
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pub fn write16(self: *@This(), addr: u32, halfword: u16) void {
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pub fn write16(self: *Self, addr: u32, halfword: u16) void {
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// TODO: write16 can write to GamePak Flash
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switch (addr) {
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// General Internal Memory
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@ -113,7 +114,7 @@ pub fn write16(self: *@This(), addr: u32, halfword: u16) void {
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}
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}
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pub fn read8(self: *const @This(), addr: u32) u8 {
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pub fn read8(self: *const Self, addr: u32) u8 {
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return switch (addr) {
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// General Internal Memory
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0x0000_0000...0x0000_3FFF => self.bios.get8(@as(usize, addr)),
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@ -139,7 +140,7 @@ pub fn read8(self: *const @This(), addr: u32) u8 {
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};
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}
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pub fn write8(_: *@This(), addr: u32, byte: u8) void {
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pub fn write8(_: *Self, addr: u32, byte: u8) void {
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switch (addr) {
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// General Internal Memory
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0x0200_0000...0x0203_FFFF => std.debug.panic("[Bus:8] write 0x{X:} to 0x{X:} in IWRAM", .{ byte, addr }),
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@ -22,17 +22,17 @@ pub fn deinit(self: Self) void {
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self.alloc.free(self.buf);
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}
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pub inline fn get32(self: *const Self, idx: usize) u32 {
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pub fn get32(self: *const Self, idx: usize) u32 {
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std.debug.panic("[BIOS] TODO: BIOS is not implemented", .{});
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return (@as(u32, self.buf[idx + 3]) << 24) | (@as(u32, self.buf[idx + 2]) << 16) | (@as(u32, self.buf[idx + 1]) << 8) | (@as(u32, self.buf[idx]));
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}
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pub inline fn get16(self: *const Self, idx: usize) u16 {
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pub fn get16(self: *const Self, idx: usize) u16 {
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std.debug.panic("[BIOS] TODO: BIOS is not implemented", .{});
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return (@as(u16, self.buf[idx + 1]) << 8) | @as(u16, self.buf[idx]);
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}
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pub inline fn get8(self: *const Self, idx: usize) u8 {
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pub fn get8(self: *const Self, idx: usize) u8 {
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std.debug.panic("[BIOS] TODO: BIOS is not implemented", .{});
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return self.buf[idx];
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}
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@ -22,14 +22,14 @@ pub fn deinit(self: Self) void {
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self.alloc.free(self.buf);
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}
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pub inline fn get32(self: *const Self, idx: usize) u32 {
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pub fn get32(self: *const Self, idx: usize) u32 {
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return (@as(u32, self.get16(idx + 2)) << 16) | @as(u32, self.get16(idx));
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}
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pub inline fn get16(self: *const Self, idx: usize) u16 {
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pub fn get16(self: *const Self, idx: usize) u16 {
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return (@as(u16, self.buf[idx + 1]) << 8) | @as(u16, self.buf[idx]);
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}
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pub inline fn get8(self: *const Self, idx: usize) u8 {
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pub fn get8(self: *const Self, idx: usize) u8 {
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return self.buf[idx];
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}
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14
src/cpu.zig
14
src/cpu.zig
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@ -16,12 +16,14 @@ pub const InstrFn = fn (*Arm7tdmi, *Bus, u32) void;
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const arm_lut: [0x1000]InstrFn = populate();
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pub const Arm7tdmi = struct {
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const Self = @This();
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r: [16]u32,
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sched: *Scheduler,
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bus: *Bus,
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cpsr: CPSR,
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pub fn init(sched: *Scheduler, bus: *Bus) @This() {
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pub fn init(sched: *Scheduler, bus: *Bus) Self {
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return .{
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.r = [_]u32{0x00} ** 16,
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.sched = sched,
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@ -30,7 +32,7 @@ pub const Arm7tdmi = struct {
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};
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}
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pub fn skipBios(self: *@This()) void {
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pub fn skipBios(self: *Self) void {
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self.r[0] = 0x08000000;
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self.r[1] = 0x000000EA;
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// GPRs 2 -> 12 *should* already be 0 initialized
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@ -43,7 +45,7 @@ pub const Arm7tdmi = struct {
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self.cpsr.raw = 0x6000001F;
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}
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pub inline fn step(self: *@This()) u64 {
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pub fn step(self: *Self) u64 {
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const opcode = self.fetch();
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// self.mgbaLog(opcode);
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@ -51,17 +53,17 @@ pub const Arm7tdmi = struct {
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return 1;
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}
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fn fetch(self: *@This()) u32 {
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fn fetch(self: *Self) u32 {
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const word = self.bus.read32(self.r[15]);
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self.r[15] += 4;
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return word;
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}
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pub fn fakePC(self: *const @This()) u32 {
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pub fn fakePC(self: *const Self) u32 {
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return self.r[15] + 4;
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}
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fn mgbaLog(self: *const @This(), opcode: u32) void {
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fn mgbaLog(self: *const Self, opcode: u32) void {
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const stderr = std.io.getStdErr().writer();
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std.debug.getStderrMutex().lock();
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defer std.debug.getStderrMutex().unlock();
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@ -3,7 +3,7 @@ const std = @import("std");
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const Arm7tdmi = @import("../cpu.zig").Arm7tdmi;
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const CPSR = @import("../cpu.zig").CPSR;
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pub inline fn exec(comptime S: bool, cpu: *Arm7tdmi, opcode: u32) u32 {
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pub fn exec(comptime S: bool, cpu: *Arm7tdmi, opcode: u32) u32 {
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var shift_amt: u8 = undefined;
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if (opcode >> 4 & 1 == 1) {
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shift_amt = @truncate(u8, cpu.r[opcode >> 8 & 0xF]);
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@ -31,7 +31,7 @@ pub inline fn exec(comptime S: bool, cpu: *Arm7tdmi, opcode: u32) u32 {
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}
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}
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pub inline fn logical_left(cpsr: *CPSR, rm: u32, shift_byte: u8) u32 {
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pub fn logical_left(cpsr: *CPSR, rm: u32, shift_byte: u8) u32 {
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const shift_amt = @truncate(u5, shift_byte);
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const bit_count: u8 = @typeInfo(u32).Int.bits;
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@ -58,7 +58,7 @@ pub inline fn logical_left(cpsr: *CPSR, rm: u32, shift_byte: u8) u32 {
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return result;
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}
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pub inline fn logical_right(cpsr: *CPSR, rm: u32, shift_byte: u8) u32 {
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pub fn logical_right(cpsr: *CPSR, rm: u32, shift_byte: u8) u32 {
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const shift_amt = @truncate(u5, shift_byte);
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const bit_count: u8 = @typeInfo(u32).Int.bits;
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10
src/main.zig
10
src/main.zig
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@ -6,6 +6,8 @@ const Bus = @import("Bus.zig");
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const Arm7tdmi = @import("cpu.zig").Arm7tdmi;
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const Scheduler = @import("scheduler.zig").Scheduler;
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const Timer = std.time.Timer;
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const buf_pitch = @import("ppu.zig").buf_pitch;
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pub fn main() anyerror!void {
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@ -59,6 +61,10 @@ pub fn main() anyerror!void {
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const texture = SDL.SDL_CreateTexture(renderer, SDL.SDL_PIXELFORMAT_BGR555, SDL.SDL_TEXTUREACCESS_STREAMING, 240, 160) orelse sdlPanic();
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defer SDL.SDL_DestroyTexture(texture);
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// Init FPS Timer
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var timer = Timer.start() catch unreachable;
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var title_buf: [0x30]u8 = [_]u8{0x00} ** 0x30;
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emu_loop: while (true) {
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emu.runFrame(&scheduler, &cpu, &bus);
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@ -74,6 +80,10 @@ pub fn main() anyerror!void {
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_ = SDL.SDL_UpdateTexture(texture, null, buf_ptr, buf_pitch);
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_ = SDL.SDL_RenderCopy(renderer, texture, null, null);
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SDL.SDL_RenderPresent(renderer);
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const fps = std.time.ns_per_s / timer.lap();
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const title = std.fmt.bufPrint(&title_buf, "Gameboy Advance Emulator FPS: {d}", .{fps}) catch unreachable;
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SDL.SDL_SetWindowTitle(window, title.ptr);
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}
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}
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48
src/ppu.zig
48
src/ppu.zig
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@ -11,17 +11,19 @@ pub const buf_pitch = width * @sizeOf(u16);
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const buf_len = buf_pitch * height;
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pub const Ppu = struct {
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const Self = @This();
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vram: Vram,
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palette: Palette,
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sched: *Scheduler,
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frame_buf: []u8,
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alloc: Allocator,
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pub fn init(alloc: Allocator, sched: *Scheduler) !@This() {
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pub fn init(alloc: Allocator, sched: *Scheduler) !Self {
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// Queue first Hblank
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sched.push(.{ .kind = .Draw, .tick = sched.tick + 240 * 4 });
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sched.push(.Draw, sched.tick + (240 * 4));
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return @This(){
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return Self{
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.vram = try Vram.init(alloc),
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.palette = try Palette.init(alloc),
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.sched = sched,
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@ -30,13 +32,13 @@ pub const Ppu = struct {
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};
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}
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pub fn deinit(self: @This()) void {
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pub fn deinit(self: Self) void {
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self.alloc.free(self.frame_buf);
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self.vram.deinit();
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self.palette.deinit();
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}
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pub fn drawScanline(self: *@This(), io: *const Io) void {
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pub fn drawScanline(self: *Self, io: *const Io) void {
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const bg_mode = io.dispcnt.bg_mode.read();
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const scanline = io.vcount.scanline.read();
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@ -54,77 +56,81 @@ pub const Ppu = struct {
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};
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const Palette = struct {
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const Self = @This();
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buf: []u8,
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alloc: Allocator,
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fn init(alloc: Allocator) !@This() {
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return @This(){
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fn init(alloc: Allocator) !Self {
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return Self{
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.buf = try alloc.alloc(u8, 0x400),
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.alloc = alloc,
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};
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}
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fn deinit(self: @This()) void {
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fn deinit(self: Self) void {
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self.alloc.free(self.buf);
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}
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pub inline fn get32(self: *const @This(), idx: usize) u32 {
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pub fn get32(self: *const Self, idx: usize) u32 {
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return (@as(u32, self.get16(idx + 2)) << 16) | @as(u32, self.get16(idx));
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}
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pub inline fn set32(self: *@This(), idx: usize, word: u32) void {
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pub fn set32(self: *Self, idx: usize, word: u32) void {
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self.set16(idx + 2, @truncate(u16, word >> 16));
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self.set16(idx, @truncate(u16, word));
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}
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pub inline fn get16(self: *const @This(), idx: usize) u16 {
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pub fn get16(self: *const Self, idx: usize) u16 {
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return (@as(u16, self.buf[idx + 1]) << 8) | @as(u16, self.buf[idx]);
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}
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pub inline fn set16(self: *@This(), idx: usize, halfword: u16) void {
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pub fn set16(self: *Self, idx: usize, halfword: u16) void {
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self.buf[idx + 1] = @truncate(u8, halfword >> 8);
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self.buf[idx] = @truncate(u8, halfword);
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}
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pub inline fn get8(self: *const @This(), idx: usize) u8 {
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pub fn get8(self: *const Self, idx: usize) u8 {
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return self.buf[idx];
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}
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};
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const Vram = struct {
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const Self = @This();
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buf: []u8,
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alloc: Allocator,
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|
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fn init(alloc: Allocator) !@This() {
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return @This(){
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fn init(alloc: Allocator) !Self {
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return Self{
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.buf = try alloc.alloc(u8, 0x18000),
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.alloc = alloc,
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};
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}
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fn deinit(self: @This()) void {
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fn deinit(self: Self) void {
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self.alloc.free(self.buf);
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}
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pub inline fn get32(self: *const @This(), idx: usize) u32 {
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pub fn get32(self: *const Self, idx: usize) u32 {
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return (@as(u32, self.get16(idx + 2)) << 16) | @as(u32, self.get16(idx));
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}
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pub inline fn set32(self: *@This(), idx: usize, word: u32) void {
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pub fn set32(self: *Self, idx: usize, word: u32) void {
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self.set16(idx + 2, @truncate(u16, word >> 16));
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self.set16(idx, @truncate(u16, word));
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}
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pub inline fn get16(self: *const @This(), idx: usize) u16 {
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pub fn get16(self: *const Self, idx: usize) u16 {
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return (@as(u16, self.buf[idx + 1]) << 8) | @as(u16, self.buf[idx]);
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}
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||||
|
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pub inline fn set16(self: *@This(), idx: usize, halfword: u16) void {
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pub fn set16(self: *Self, idx: usize, halfword: u16) void {
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self.buf[idx + 1] = @truncate(u8, halfword >> 8);
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self.buf[idx] = @truncate(u8, halfword);
|
||||
}
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||||
|
||||
pub inline fn get8(self: *const @This(), idx: usize) u8 {
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||||
pub fn get8(self: *const Self, idx: usize) u8 {
|
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return self.buf[idx];
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||||
}
|
||||
};
|
||||
|
|
|
@ -8,29 +8,28 @@ const PriorityQueue = std.PriorityQueue;
|
|||
const Allocator = std.mem.Allocator;
|
||||
|
||||
pub const Scheduler = struct {
|
||||
const Self = @This();
|
||||
|
||||
tick: u64,
|
||||
queue: PriorityQueue(Event, void, lessThan),
|
||||
|
||||
pub fn init(alloc: Allocator) @This() {
|
||||
var scheduler = Scheduler{ .tick = 0, .queue = PriorityQueue(Event, void, lessThan).init(alloc, {}) };
|
||||
pub fn init(alloc: Allocator) Self {
|
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var sched = Self{ .tick = 0, .queue = PriorityQueue(Event, void, lessThan).init(alloc, {}) };
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sched.push(.HeatDeath, std.math.maxInt(u64));
|
||||
|
||||
scheduler.queue.add(.{
|
||||
.kind = EventKind.HeatDeath,
|
||||
.tick = std.math.maxInt(u64),
|
||||
}) catch unreachable;
|
||||
|
||||
return scheduler;
|
||||
return sched;
|
||||
}
|
||||
|
||||
pub fn deinit(self: @This()) void {
|
||||
pub fn deinit(self: Self) void {
|
||||
self.queue.deinit();
|
||||
}
|
||||
|
||||
pub fn handleEvent(self: *@This(), _: *Arm7tdmi, bus: *Bus) void {
|
||||
pub fn handleEvent(self: *Self, _: *Arm7tdmi, bus: *Bus) void {
|
||||
const should_handle = if (self.queue.peek()) |e| self.tick >= e.tick else false;
|
||||
|
||||
if (should_handle) {
|
||||
const event = self.queue.remove();
|
||||
// std.log.info("[Scheduler] Handle {} at {} ticks", .{ event.kind, self.tick });
|
||||
|
||||
switch (event.kind) {
|
||||
.HeatDeath => {
|
||||
|
@ -49,11 +48,11 @@ pub const Scheduler = struct {
|
|||
|
||||
if (new_scanline < 160) {
|
||||
// Transitioning to another Draw
|
||||
self.push(.{ .kind = .Draw, .tick = self.tick + (240 * 4) });
|
||||
self.push(.Draw, self.tick + (240 * 4));
|
||||
} else {
|
||||
// Transitioning to a Vblank
|
||||
bus.io.dispstat.vblank.set();
|
||||
self.push(.{ .kind = .VBlank, .tick = self.tick + (308 * 4) });
|
||||
self.push(.VBlank, self.tick + (308 * 4));
|
||||
}
|
||||
},
|
||||
.Draw => {
|
||||
|
@ -61,7 +60,7 @@ pub const Scheduler = struct {
|
|||
|
||||
// Transitioning to a Hblank
|
||||
bus.io.dispstat.hblank.set();
|
||||
self.push(.{ .kind = .HBlank, .tick = self.tick + (68 * 4) });
|
||||
self.push(.HBlank, self.tick + (68 * 4));
|
||||
},
|
||||
.VBlank => {
|
||||
// The end of a Vblank
|
||||
|
@ -72,24 +71,24 @@ pub const Scheduler = struct {
|
|||
|
||||
if (new_scanline < 228) {
|
||||
// Transition to another Vblank
|
||||
self.push(.{ .kind = .VBlank, .tick = self.tick + (308 * 4) });
|
||||
self.push(.VBlank, self.tick + (308 * 4));
|
||||
} else {
|
||||
// Transition to another Draw
|
||||
bus.io.vcount.scanline.write(0); // Reset Scanline
|
||||
|
||||
bus.io.dispstat.vblank.unset();
|
||||
self.push(.{ .kind = .Draw, .tick = self.tick + (240 * 4) });
|
||||
self.push(.Draw, self.tick + (240 * 4));
|
||||
}
|
||||
},
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
pub inline fn push(self: *@This(), event: Event) void {
|
||||
self.queue.add(event) catch unreachable;
|
||||
pub fn push(self: *Self, kind: EventKind, end: u64) void {
|
||||
self.queue.add(.{ .kind = kind, .tick = end }) catch unreachable;
|
||||
}
|
||||
|
||||
pub inline fn nextTimestamp(self: *@This()) u64 {
|
||||
pub fn nextTimestamp(self: *Self) u64 {
|
||||
if (self.queue.peek()) |e| {
|
||||
return e.tick;
|
||||
} else unreachable;
|
||||
|
|
Loading…
Reference in New Issue