cpu: bugfixes

13 files changed, 145 insertions, 17 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 68ba329..b997a1d 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,9 +1,12 @@
 add_subdirectory(nes)
+#add_subdirectory(ref)
+#add_subdirectory(test)
 
 target_sources(
     nes
     PRIVATE
         main.mm
+        status.hh
         scene.hh
         scene.mm)
 
diff --git a/src/main.mm b/src/main.mm
index 7543e0c..5ca7c5c 100644
--- a/src/main.mm
+++ b/src/main.mm
@@ -13,7 +13,6 @@ int main(int argc, char** argv)
     }
 
     auto filePath = [NSString stringWithUTF8String:argv[1]];
-    //auto filePath = @"/Users/hannes/Documents/temp/nes-test-roms/nes_instr_test/rom_singles/01-implied.nes";
 
     auto app = [NSApplication sharedApplication];
     [app setActivationPolicy:NSApplicationActivationPolicyRegular];
diff --git a/src/nes/cpu.cc b/src/nes/cpu.cc
index 277c05d..2a079cc 100644
--- a/src/nes/cpu.cc
+++ b/src/nes/cpu.cc
@@ -14,6 +14,25 @@ namespace nes
 		registers_.pc = read16(address{ 0xFFFC });
 	}
 
+	auto cpu::snapshot(test::status& snapshot) -> void
+	{
+		snapshot.cpu_cycle = current_cycles_;
+		snapshot.ram = std::vector(std::begin(ram_), std::end(ram_));
+		snapshot.registers.pc = registers_.pc;
+		snapshot.registers.sp = registers_.sp;
+		snapshot.registers.a = registers_.a;
+		snapshot.registers.x = registers_.x;
+		snapshot.registers.y = registers_.y;
+		snapshot.registers.p = registers_.p;
+		snapshot.registers.c = registers_.c;
+		snapshot.registers.z = registers_.z;
+		snapshot.registers.i = registers_.i;
+		snapshot.registers.d = registers_.d;
+		snapshot.registers.b = registers_.b;
+		snapshot.registers.v = registers_.v;
+		snapshot.registers.n = registers_.n;
+	}
+
 	auto cpu::step_to(cycle_count const target) -> void
 	{
 		while (current_cycles_ < target)
@@ -71,7 +90,7 @@ namespace nes
 			case 0x27: run_rla<addressing_mode::zero_page>(); break;
 			case 0x28: run_plp(); break;
 			case 0x29: run_and<addressing_mode::immediate>(); break;
-			case 0x2A: run_rol<addressing_mode::absolute>(); break;
+			case 0x2A: run_rol<addressing_mode::accumulator>(); break;
 			case 0x2B: run_anc<addressing_mode::immediate>(); break;
 			case 0x2C: run_bit<addressing_mode::absolute>(); break;
 			case 0x2D: run_and<addressing_mode::absolute>(); break;
@@ -352,7 +371,7 @@ namespace nes
 	{
 		// ASL: Arithmetic Shift Left
 		auto operand = fetch_operand<Mode>();
-		eval_asl(operand.read());
+		operand.write(eval_asl(operand.read()));
 		current_cycles_ += shift_cycle_count<Mode>();
 	}
 
@@ -613,7 +632,7 @@ namespace nes
 	template<cpu::addressing_mode Mode>
 	auto cpu::run_ahx() -> void
 	{
-		// AHX: AND A X H
+		// AHX: ???
 		// TODO
 		std::abort();
 	}
@@ -694,7 +713,7 @@ namespace nes
 	template<cpu::addressing_mode Mode>
 	auto cpu::run_tas() -> void
 	{
-		// TAS: S = A & X + AND S H
+		// TAS: ???
 		// TODO
 		std::abort();
 	}
@@ -702,7 +721,7 @@ namespace nes
 	template<cpu::addressing_mode Mode>
 	auto cpu::run_shy() -> void
 	{
-		// SHY: AND Y H
+		// SHY: ???
 		// TODO
 		std::abort();
 	}
@@ -710,7 +729,7 @@ namespace nes
 	template<cpu::addressing_mode Mode>
 	auto cpu::run_shx() -> void
 	{
-		// SHY: AND X H
+		// SHY: ???
 		// TODO
 		std::abort();
 	}
@@ -796,7 +815,7 @@ namespace nes
 	template<cpu::addressing_mode Mode>
 	auto cpu::run_las() -> void
 	{
-		// LAS: AND S, store into A, X, S
+		// LAS: ???
 		// TODO
 		std::abort();
 	}
@@ -1055,7 +1074,7 @@ namespace nes
 
 		registers_.a = new_val;
 		registers_.c = tmp > 0xFF;
-		registers_.v = ((old_val ^ arg) & 0x80) == 0 && ((old_val ^ new_val) & 0x80) == 0;
+		registers_.v = ((old_val ^ arg) & 0x80) == 0 && ((old_val ^ new_val) & 0x80) != 0;
 		update_alu_flags(registers_.a);
 	}
 
diff --git a/src/nes/cpu.hh b/src/nes/cpu.hh
index 59f2db4..3587fd6 100644
--- a/src/nes/cpu.hh
+++ b/src/nes/cpu.hh
@@ -2,6 +2,7 @@
 
 #include "nes/util/cycle_count.hh"
 #include "nes/util/address.hh"
+#include "status.hh"
 
 namespace nes
 {
@@ -114,7 +115,7 @@ namespace nes
 					bool i : 1; // interrupt inhibit
 					bool d : 1; // decimal
 					bool b : 1; // break
-					bool _ : 1; // (unused, always true)
+					bool   : 1; // (unused, always true)
 					bool v : 1; // overflow
 					bool n : 1; // negative
 				};
@@ -130,6 +131,8 @@ namespace nes
 		auto operator=(cpu const&) -> cpu& = delete;
 		auto operator=(cpu&&) -> cpu& = delete;
 
+		auto snapshot(test::status&) -> void;
+
 		auto step_to(cycle_count) -> void;
 
 	private:
@@ -251,8 +254,8 @@ namespace nes
 	template<> auto name##_cycle_count<addressing_mode::mode>() -> cycle_count { return cycle_count::from_cpu(value); }
 
 		DEFINE_CYCLE_COUNT(jump)
-		DEFINE_CYCLE_COUNT_INSTANCE(jump, absolute, 2)
-		DEFINE_CYCLE_COUNT_INSTANCE(jump, indirect, 2)
+		DEFINE_CYCLE_COUNT_INSTANCE(jump, absolute, 3)
+		DEFINE_CYCLE_COUNT_INSTANCE(jump, indirect, 5)
 
 		DEFINE_CYCLE_COUNT(shift)
 		DEFINE_CYCLE_COUNT_INSTANCE(shift, accumulator, 2)
diff --git a/src/nes/mapper.cc b/src/nes/mapper.cc
index a540dbf..a451e3a 100644
--- a/src/nes/mapper.cc
+++ b/src/nes/mapper.cc
@@ -27,9 +27,13 @@ namespace nes
 
 	auto mapper::nrom_read(address const addr) -> std::uint8_t
 	{
+		if (addr <= address{ 0x5FFF })
+		{
+			return 0x0;
+		}
 		if (addr <= address{ 0x7FFF })
 		{
-			return cartridge_.get_ram()[addr.get_absolute() % 0x2000];
+			return cartridge_.get_ram()[addr.get_absolute() - 0x6000];
 		}
 		if (addr <= address{ 0xBFFF })
 		{
@@ -52,9 +56,13 @@ namespace nes
 
 	auto mapper::nrom_write(address const addr, std::uint8_t const value) -> void
 	{
+		if (addr <= address{ 0x5FFF })
+		{
+			return;
+		}
 		if (addr <= address{ 0x7FFF })
 		{
-			cartridge_.get_ram_mut()[addr.get_absolute() % 0x2000] = value;
+			cartridge_.get_ram_mut()[addr.get_absolute() - 0x6000] = value;
 		}
 	}
 
diff --git a/src/nes/nes.cc b/src/nes/nes.cc
index 0579735..84f3309 100644
--- a/src/nes/nes.cc
+++ b/src/nes/nes.cc
@@ -10,6 +10,7 @@ namespace nes
 		: cartridge_{ std::move(cartridge) }
 		, display_{ display }
 		, mapper_{ mapper::select(cartridge_) }
+		, ppu_{ cpu_, mapper_ }
 		, cpu_{ ppu_, mapper_, controller_1_, controller_2_ }
 	{
 		if (!cartridge_.is_valid())
@@ -24,7 +25,12 @@ namespace nes
 
 	auto nes::step(std::chrono::microseconds const delta) -> void
 	{
-		current_cycles_ += cycle_count::from_duration(delta);
+		step(cycle_count::from_duration(delta));
+	}
+
+	auto nes::step(cycle_count const delta) -> void
+	{
+		current_cycles_ += delta;
 		cpu_.step_to(current_cycles_);
 		ppu_.step_to(current_cycles_);
 
@@ -32,4 +38,12 @@ namespace nes
 		display_.clear(rgb{ animation_progress_, animation_progress_, animation_progress_ });
 		display_.switch_buffers();
 	}
+
+	auto nes::snapshot() -> test::status
+	{
+		auto res = test::status{};
+		res.sram = std::vector(cartridge_.get_ram(), cartridge_.get_ram() + cartridge_.get_ram_length());
+		cpu_.snapshot(res);
+		return res;
+	}
 } // namespace nes
\ No newline at end of file
diff --git a/src/nes/nes.hh b/src/nes/nes.hh
index be50bbb..2701f4b 100644
--- a/src/nes/nes.hh
+++ b/src/nes/nes.hh
@@ -6,6 +6,7 @@
 #include "nes/cpu.hh"
 #include "nes/ppu.hh"
 #include "nes/mapper.hh"
+#include "status.hh"
 
 namespace nes
 {
@@ -38,5 +39,8 @@ namespace nes
 		auto get_controller_2() -> controller& { return controller_2_; }
 
 		auto step(std::chrono::microseconds delta) -> void;
+		auto step(cycle_count delta) -> void;
+
+		auto snapshot() -> test::status;
 	};
 } // namespace nes
\ No newline at end of file
diff --git a/src/nes/ppu.cc b/src/nes/ppu.cc
index c2ec439..302b395 100644
--- a/src/nes/ppu.cc
+++ b/src/nes/ppu.cc
@@ -2,7 +2,17 @@
 
 namespace nes
 {
+	ppu::ppu(cpu& cpu, mapper& mapper)
+		: cpu_{ cpu }
+		, mapper_{ mapper }
+	{
+	}
+
 	auto ppu::step_to(cycle_count const cycle) -> void
 	{
+		while (current_cycles_ < cycle)
+		{
+			current_cycles_ += cycle_count::from_ppu(1);
+		}
 	}
 } // namespace nes
\ No newline at end of file
diff --git a/src/nes/ppu.hh b/src/nes/ppu.hh
index edb7aba..8f116c7 100644
--- a/src/nes/ppu.hh
+++ b/src/nes/ppu.hh
@@ -4,10 +4,20 @@
 
 namespace nes
 {
+	class cpu;
+	class mapper;
+
 	class ppu
 	{
+		static constexpr auto vram_size = std::size_t{ 0x800 };
+
+		cycle_count current_cycles_;
+		cpu& cpu_;
+		mapper& mapper_;
+		std::uint8_t vram_[vram_size]{};
+
 	public:
-		explicit ppu() = default;
+		explicit ppu(cpu& cpu, mapper& mapper);
 
 		ppu(ppu const&) = delete;
 		ppu(ppu&&) = delete;
diff --git a/src/nes/util/address.hh b/src/nes/util/address.hh
index 0161998..77ee76a 100644
--- a/src/nes/util/address.hh
+++ b/src/nes/util/address.hh
@@ -21,7 +21,7 @@ namespace nes
 
 		/// Create an address from its page and offset combination.
 		constexpr explicit address(std::uint8_t const page, std::uint8_t const offset)
-			: address{ static_cast<std::uint16_t>((page << 8) | (offset < 0)) }
+			: address{ static_cast<std::uint16_t>((page << 8) | (offset << 0)) }
 		{
 		}
 
diff --git a/src/status.hh b/src/status.hh
new file mode 100644
index 0000000..705ae6e
--- /dev/null
+++ b/src/status.hh
@@ -0,0 +1,55 @@
+#pragma once
+
+#include "nes/util/cycle_count.hh"
+#include <vector>
+#include <cstdint>
+
+namespace test
+{
+	/// System status used for comparison.
+	struct status
+	{
+		explicit status() = default;
+
+		nes::cycle_count cpu_cycle;
+		std::vector<std::uint8_t> ram;
+		std::vector<std::uint8_t> sram;
+		struct
+		{
+			std::uint16_t pc{};
+			std::uint8_t sp{};
+			std::uint8_t a{};
+			std::uint8_t x{};
+			std::uint8_t y{};
+			std::uint8_t p{};
+			bool c{};
+			bool z{};
+			bool i{};
+			bool d{};
+			bool b{};
+			bool v{};
+			bool n{};
+		} registers{};
+
+		static auto equal(status const& a, status const& b) -> bool
+		{
+			if (a.cpu_cycle != b.cpu_cycle) { return false; }
+			if (a.ram != b.ram) { return false; }
+			if (a.sram != b.sram) { return false; }
+			if (a.registers.pc != b.registers.pc) { return false; }
+			if (a.registers.sp != b.registers.sp) { return false; }
+			if (a.registers.a != b.registers.a) { return false; }
+			if (a.registers.x != b.registers.x) { return false; }
+			if (a.registers.y != b.registers.y) { return false; }
+			if (a.registers.p != b.registers.p) { return false; }
+			if (a.registers.c != b.registers.c) { return false; }
+			if (a.registers.z != b.registers.z) { return false; }
+			if (a.registers.i != b.registers.i) { return false; }
+			if (a.registers.d != b.registers.d) { return false; }
+			if (a.registers.b != b.registers.b) { return false; }
+			if (a.registers.v != b.registers.v) { return false; }
+			if (a.registers.n != b.registers.n) { return false; }
+			return true;
+		}
+	};
+} // namespace test
\ No newline at end of file
diff --git a/src/test/CMakeLists.txt b/src/test/CMakeLists.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/src/test/CMakeLists.txt
diff --git a/src/test/main.cc b/src/test/main.cc
new file mode 100644
index 0000000..58e618d
--- /dev/null
+++ b/src/test/main.cc
@@ -0,0 +1,3 @@
+//
+// Created by Hannes Schulze on 17.01.25.
+//