From 4a12e59c2f9cf64df27ed3678b7a9ed39bf9adb2 Mon Sep 17 00:00:00 2001
From: wheremyfoodat <44909372+wheremyfoodat@users.noreply.github.com>
Date: Fri, 7 Jul 2023 13:39:35 +0300
Subject: [PATCH] Slightly more robust ROM management

---
 include/emulator.hpp |  5 ++++-
 src/emulator.cpp     | 30 ++++++++++++++++++++++++------
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/include/emulator.hpp b/include/emulator.hpp
index 73929f26..309b5db6 100644
--- a/include/emulator.hpp
+++ b/include/emulator.hpp
@@ -5,6 +5,7 @@
 
 #include <filesystem>
 #include <fstream>
+#include <optional>
 
 #include "PICA/gpu.hpp"
 #include "cpu.hpp"
@@ -25,7 +26,7 @@ class Emulator {
 	GLStateManager gl;
 	SDL_Window* window;
 	SDL_GLContext glContext;
-	SDL_GameController* gameController;
+	SDL_GameController* gameController = nullptr;
 	int gameControllerID;
 
 	// Variables to keep track of whether the user is controlling the 3DS analog stick with their keyboard
@@ -44,6 +45,8 @@ class Emulator {
 	std::ifstream loadedELF;
 	NCSD loadedNCSD;
 
+	std::optional<std::filesystem::path> romPath = std::nullopt;
+
   public:
 	Emulator();
 
diff --git a/src/emulator.cpp b/src/emulator.cpp
index 45ff0b7c..24dfc0b5 100644
--- a/src/emulator.cpp
+++ b/src/emulator.cpp
@@ -63,8 +63,16 @@ void Emulator::reset() {
 	// Reloading r13 and r15 needs to happen after everything has been reset
 	// Otherwise resetting the kernel or cpu might nuke them
 	cpu.setReg(13, VirtualAddrs::StackTop);  // Set initial SP
-	if (romType == ROMType::ELF) {           // Reload ELF if we're using one
-		loadELF(loadedELF);
+	
+	// If a ROM is active and we reset, reload it. This is necessary to set up stack, executable memory, .data/.rodata/.bss all over again
+	if (romType != ROMType::None && romPath.has_value()) {
+		bool success = loadROM(romPath.value());
+		if (!success) {
+			romType = ROMType::None;
+			romPath = std::nullopt;
+
+			Helpers::panic("Failed to reload ROM. This should pause the emulator in the future GUI");
+		}
 	}
 }
 
@@ -284,17 +292,27 @@ bool Emulator::loadROM(const std::filesystem::path& path) {
 
 	kernel.initializeFS();
 	auto extension = path.extension();
+	bool success; // Tracks if we loaded the ROM successfully
 
 	if (extension == ".elf" || extension == ".axf")
-		return loadELF(path);
+		success = loadELF(path);
 	else if (extension == ".3ds")
-		return loadNCSD(path, ROMType::NCSD);
+		success = loadNCSD(path, ROMType::NCSD);
 	else if (extension == ".cxi" || extension == ".app")
-		return loadNCSD(path, ROMType::CXI);
+		success = loadNCSD(path, ROMType::CXI);
 	else {
 		printf("Unknown file type\n");
-		return false;
+		success = false;
 	}
+
+	if (success) {
+		romPath = path;
+	} else {
+		romPath = std::nullopt;
+		romType = ROMType::None;
+	}
+	
+	return success;
 }
 
 // Used for loading both CXI and NCSD files since they are both so similar and use the same interface