From 5630141ad77e52af4e2c70fa9b9fff8d8268f04e Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Thu, 13 Jun 2019 13:35:16 -0400
Subject: [PATCH] Ensures randomised memory contents at startup.

---
 Machines/Apple/Macintosh/Macintosh.cpp                | 4 ++++
 Machines/Apple/Macintosh/RealTimeClock.hpp            | 8 ++++++++
 Machines/Utility/MemoryFuzzer.cpp                     | 4 ++++
 Machines/Utility/MemoryFuzzer.hpp                     | 3 +++
 OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj | 4 ++--
 5 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/Machines/Apple/Macintosh/Macintosh.cpp b/Machines/Apple/Macintosh/Macintosh.cpp
index 7b8a512ec..97da812f8 100644
--- a/Machines/Apple/Macintosh/Macintosh.cpp
+++ b/Machines/Apple/Macintosh/Macintosh.cpp
@@ -33,6 +33,7 @@
 #include "../../../Analyser/Static/Macintosh/Target.hpp"
 
 #include "../../Utility/MemoryPacker.hpp"
+#include "../../Utility/MemoryFuzzer.hpp"
 
 namespace {
 
@@ -100,6 +101,9 @@ template <Analyser::Static::Macintosh::Target::Model model> class ConcreteMachin
 			roms[0]->resize(rom_size);
 			Memory::PackBigEndian16(*roms[0], rom_);
 
+			// Randomise memory contents.
+			Memory::Fuzz(ram_, sizeof(ram_));
+
 			// Attach the drives to the IWM.
 			iwm_.iwm.set_drive(0, &drives_[0]);
 			iwm_.iwm.set_drive(1, &drives_[1]);
diff --git a/Machines/Apple/Macintosh/RealTimeClock.hpp b/Machines/Apple/Macintosh/RealTimeClock.hpp
index 7cb7fe744..5a1f01496 100644
--- a/Machines/Apple/Macintosh/RealTimeClock.hpp
+++ b/Machines/Apple/Macintosh/RealTimeClock.hpp
@@ -9,6 +9,8 @@
 #ifndef RealTimeClock_hpp
 #define RealTimeClock_hpp
 
+#include "../../Utility/MemoryFuzzer.hpp"
+
 namespace Apple {
 namespace Macintosh {
 
@@ -21,6 +23,12 @@ namespace Macintosh {
 */
 class RealTimeClock {
 	public:
+		RealTimeClock() {
+			// TODO: this should persist, if possible, rather than
+			// being randomly initialised.
+			Memory::Fuzz(data_, sizeof(data_));
+		}
+
 		/*!
 			Advances the clock by 1 second.
 
diff --git a/Machines/Utility/MemoryFuzzer.cpp b/Machines/Utility/MemoryFuzzer.cpp
index fdcdaa01e..c423cc5d1 100644
--- a/Machines/Utility/MemoryFuzzer.cpp
+++ b/Machines/Utility/MemoryFuzzer.cpp
@@ -23,6 +23,10 @@ void Memory::Fuzz(uint8_t *buffer, std::size_t size) {
 	}
 }
 
+void Memory::Fuzz(uint16_t *buffer, std::size_t size) {
+	Fuzz(reinterpret_cast<uint8_t *>(buffer), size * sizeof(uint16_t));
+}
+
 void Memory::Fuzz(std::vector<uint8_t> &buffer) {
 	Fuzz(buffer.data(), buffer.size());
 }
diff --git a/Machines/Utility/MemoryFuzzer.hpp b/Machines/Utility/MemoryFuzzer.hpp
index bd097aeed..9beecd2f6 100644
--- a/Machines/Utility/MemoryFuzzer.hpp
+++ b/Machines/Utility/MemoryFuzzer.hpp
@@ -18,6 +18,9 @@ namespace Memory {
 /// Stores @c size random bytes from @c buffer onwards.
 void Fuzz(uint8_t *buffer, std::size_t size);
 
+/// Stores @c size random 16-bit words from @c buffer onwards.
+void Fuzz(uint16_t *buffer, std::size_t size);
+
 /// Replaces all existing vector contents with random bytes.
 void Fuzz(std::vector<uint8_t> &buffer);
 
diff --git a/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj b/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj
index 446546b3f..a2dc8adfb 100644
--- a/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj	
+++ b/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj	
@@ -3132,6 +3132,7 @@
 				4B9378E222A199C600973513 /* Audio.cpp */,
 				4BB4BFAC22A33DE50069048D /* DriveSpeedAccumulator.cpp */,
 				4BCE0058227CFFCA000CA200 /* Macintosh.cpp */,
+				4B0C956F22A74E880015A8F6 /* SonyDrive.cpp */,
 				4BCE005E227D39AB000CA200 /* Video.cpp */,
 				4B9378E322A199C600973513 /* Audio.hpp */,
 				4BB4BFAA22A300710069048D /* DeferredAudio.hpp */,
@@ -3139,9 +3140,8 @@
 				4BDB3D8522833321002D3CEE /* Keyboard.hpp */,
 				4BCE0059227CFFCA000CA200 /* Macintosh.hpp */,
 				4BD0692B22828A2D00D2A54F /* RealTimeClock.hpp */,
-				4BCE005F227D39AB000CA200 /* Video.hpp */,
-				4B0C956F22A74E880015A8F6 /* SonyDrive.cpp */,
 				4B0C957022A74E880015A8F6 /* SonyDrive.hpp */,
+				4BCE005F227D39AB000CA200 /* Video.hpp */,
 			);
 			path = Macintosh;
 			sourceTree = "<group>";