Attempt to support reset-by-8042, resulting in boot loop.

Machines/PCCompatible/CPUControl.hpp

@@ -0,0 +1,45 @@
+//
+//  CPUControl.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 08/03/2025.
+//  Copyright © 2025 Thomas Harte. All rights reserved.
+//
+
+#pragma once
+
+#include "Memory.hpp"
+#include "ProcessorByModel.hpp"
+#include "Registers.hpp"
+#include "Segments.hpp"
+
+#include "Analyser/Static/PCCompatible/Target.hpp"
+
+namespace PCCompatible {
+
+template <Analyser::Static::PCCompatible::Model model>
+class CPUControl {
+public:
+	CPUControl(
+		Registers<processor_model(model)> &registers,
+		Segments<processor_model(model)> &segments,
+		Memory<model> &memory
+	) : registers_(registers), segments_(segments), memory_(memory) {}
+
+	void reset() {
+		registers_.reset();
+		segments_.reset();
+	}
+
+	void set_a20_enabled(bool) {
+		// Assumed: this'll be something to set on Memory.
+	}
+
+private:
+	Registers<processor_model(model)> &registers_;
+	Segments<processor_model(model)> &segments_;
+	Memory<model> &memory_;
+};
+
+
+}

Machines/PCCompatible/KeyboardController.hpp

@@ -8,6 +8,7 @@
 
 #pragma once
 
+#include "CPUControl.hpp"
 #include "PIC.hpp"
 #include "Speaker.hpp"
 
@@ -92,6 +93,8 @@ public:
 		pics_.pic[0].template apply_edge<1>(true);
 	}
 
+	void set_cpu_control(CPUControl<model> *) {}
+
 private:
 	enum class Mode {
 		NormalOperation = 0b01,
@@ -117,7 +120,11 @@ public:
 	void run_for([[maybe_unused]] const Cycles cycles) {
 	}
 
-	void post([[maybe_unused]] const uint8_t value) {
+	void post(const uint8_t value) {
+		parameter_ = value;
+		has_input_ = true;
+		is_command_ = false;
+		pics_.pic[0].template apply_edge<1>(true);
 	}
 
 	void write(const uint16_t port, const uint8_t value) {
@@ -141,11 +148,6 @@ public:
 
 			case 0x0064:
 				is_command_ = true;
-				const auto set_input = [&](const uint8_t input) {
-					parameter_ = input;
-					has_input_ = true;
-					is_command_ = false;
-				};
 
 				auto info = log_.info();
 				info.append("AT keyboard command %04x", value);
@@ -156,10 +158,23 @@ public:
 
 					case 0xaa:	// Self-test; 0x55 => no issues found.
 						log_.error().append("Keyboard self-test");
-						set_input(0x55);
+						post(0x55);
 					break;
 
-					case 0xd1:	// Set output byte. b0 = the A20 gate.
+					case 0xd1:	// Set output byte. b1 = the A20 gate.
+						log_.error().append("Should set A20 gate: %d", value & 0x02);
+						cpu_control_->set_a20_enabled(value & 0x02);
+					break;
+
+					case 0xf0:	case 0xf1:	case 0xf2:	case 0xf3:
+					case 0xf4:	case 0xf5:	case 0xf6:	case 0xf7:
+					case 0xf8:	case 0xf9:	case 0xfa:	case 0xfb:
+					case 0xfc:	case 0xfd:	case 0xfe:	case 0xff:
+						log_.error().append("Should reset: %x", value & 0x0f);
+
+						if(!(value & 1)) {
+							cpu_control_->reset();
+						}
 					break;
 				}
 			break;
@@ -167,7 +182,7 @@ public:
 	}
 
 	template <typename IntT>
-	IntT read([[maybe_unused]] const uint16_t port) {
+	IntT read(const uint16_t port) {
 		switch(port) {
 			default:
 				log_.error().append("Unimplemented AT keyboard read from %04x", port);
@@ -175,7 +190,10 @@ public:
 
 			case 0x0060:
 				log_.error().append("Read keyboard parameter of %02x", parameter_);
-				has_input_ = false;
+
+				// TODO: disabled in response to BIOS expectations but possibly a false
+				// positive because commands are responded to instantly?
+//				has_input_ = false;
 			return parameter_;
 
 			case 0x0061:
@@ -198,6 +216,7 @@ public:
 				//	b1 = 1 => 'input' buffer full (i.e. don't write 0x60 or 0x64 now — this is input to the controller);
 				//	b0 = 1 => 'output' data is full (i.e. reading from 0x60 now makes sense — output is to PC).
 				const uint8_t status =
+					0x10 |
 					(is_command_	? 0x08 : 0x00) |
 					(has_output_	? 0x02 : 0x00) |
 					(has_input_		? 0x01 : 0x00);
@@ -208,11 +227,17 @@ public:
 		return IntT(~0);
 	}
 
+	void set_cpu_control(CPUControl<model> *const control) {
+		cpu_control_ = control;
+	}
+
 private:
 	Log::Logger<Log::Source::PCCompatible> log_;
 
 	PICs<model> &pics_;
 	Speaker &speaker_;
+	CPUControl<model> *cpu_control_ = nullptr;
+
 	uint8_t refresh_toggle_ = 0;
 
 	bool has_input_ = false;

Machines/PCCompatible/PCCompatible.cpp

@@ -9,6 +9,7 @@
 #include "PCCompatible.hpp"
 
 #include "CGA.hpp"
+#include "CPUControl.hpp"
 #include "DMA.hpp"
 #include "FloppyController.hpp"
 #include "KeyboardController.hpp"
@@ -884,14 +885,15 @@ private:
 			segments(registers),
 			memory(registers, segments),
 			flow_controller(registers, segments),
+			cpu_control(registers, segments, memory),
 			io(pit, dma, ppi, pics, card, fdc, keyboard, rtc)
 		{
+			keyboard.set_cpu_control(&cpu_control);
 			reset();
 		}
 
 		void reset() {
-			registers.reset();
-			segments.reset();
+			cpu_control.reset();
 		}
 
 		InstructionSet::x86::Flags flags;
@@ -899,6 +901,7 @@ private:
 		Segments<x86_model> segments;
 		Memory<pc_model> memory;
 		FlowController<pc_model> flow_controller;
+		CPUControl<pc_model> cpu_control;
 		IO<pc_model, video> io;
 		static constexpr auto model = processor_model(pc_model);
 	} context_;

Machines/PCCompatible/Registers.hpp

@@ -9,6 +9,7 @@
 #pragma once
 
 #include "InstructionSets/x86/Model.hpp"
+#include "Numeric/RegisterSizes.hpp"
 
 namespace PCCompatible {
 

OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj

@@ -1457,6 +1457,7 @@
 		4B1FBE222D7B739700BAC888 /* FloppyController.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = FloppyController.hpp; sourceTree = "<group>"; };
 		4B1FBE232D7B73C800BAC888 /* Speaker.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = Speaker.hpp; sourceTree = "<group>"; };
 		4B1FBE242D7B753000BAC888 /* KeyboardController.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = KeyboardController.hpp; sourceTree = "<group>"; };
+		4B1FBE252D7C0B2200BAC888 /* CPUControl.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = CPUControl.hpp; sourceTree = "<group>"; };
 		4B2005402B804AA300420C5C /* OperationMapper.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = OperationMapper.hpp; sourceTree = "<group>"; };
 		4B2005422B804D6400420C5C /* ARMDecoderTests.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ARMDecoderTests.mm; sourceTree = "<group>"; };
 		4B2005462B8BD7A500420C5C /* Registers.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = Registers.hpp; sourceTree = "<group>"; };
@@ -2560,6 +2561,7 @@
 			children = (
 				425739372B051EA800B7D1E4 /* PCCompatible.cpp */,
 				429B13632B20234B006BB4CB /* CGA.hpp */,
+				4B1FBE252D7C0B2200BAC888 /* CPUControl.hpp */,
 				4267A9C92B0D4F17008A59BB /* DMA.hpp */,
 				4B1FBE222D7B739700BAC888 /* FloppyController.hpp */,
 				4B1FBE242D7B753000BAC888 /* KeyboardController.hpp */,