General PMD fixes

elf/src/main/java/com/ledmington/elf/section/note/NoteSectionEntryType.java

@@ -63,13 +63,13 @@ public static NoteSectionEntryType fromCode(final String owner, final int type)
 				case 3 -> NT_GNU_BUILD_ID;
 				case 4 -> NT_GNU_GOLD_VERSION;
 				case 5 -> NT_GNU_PROPERTY_TYPE_0;
-				default -> throw new IllegalArgumentException(String.format(
-						"Unknown note section entry type %d (0x%08x) for owner '%s'", type, type, owner));
+				default -> throw new IllegalArgumentException(
+						String.format("Unknown note section entry type %d (0x%08x) for owner '%s'", type, type, owner));
 			};
 			case "stapsdt" -> switch (type) {
 				case 3 -> NT_STAPSDT;
-				default -> throw new IllegalArgumentException(String.format(
-						"Unknown note section entry type %d (0x%08x) for owner '%s'", type, type, owner));
+				default -> throw new IllegalArgumentException(
+						String.format("Unknown note section entry type %d (0x%08x) for owner '%s'", type, type, owner));
 			};
 			default -> throw new IllegalArgumentException(
 					String.format("Unknown note section entry owner '%s'", owner));

emu-cli/src/main/java/com/ledmington/emu/Main.java

@@ -75,8 +75,7 @@ private static void run(final String filename, final String... commandLineArgume
 		}
 
 		final MemoryController mem = new MemoryController(EmulatorConstants.getMemoryInitializer());
-		final X86RegisterFile rf = new X86RegisterFile();
-		final X86Emulator cpu = new X86Cpu(rf, mem);
+		final X86Emulator cpu = new X86Cpu(mem);
 
 		ELFLoader.load(
 				elf,

emu-gui/src/main/java/com/ledmington/view/ELFViewer.java

@@ -35,7 +35,7 @@ public final class ELFViewer extends Stage {
 	public ELFViewer(final double width, final double height) {
 		final BorderPane mainPane = new BorderPane();
 
-		this.view = new ELFView(this);
+		this.view = new ELFView();
 
 		final FlowPane topPane = new FlowPane();
 		final Button load = new Button();

emu-gui/src/main/java/com/ledmington/view/EmulatorView.java

@@ -25,6 +25,7 @@
 import java.util.Comparator;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.stream.Collectors;
 
 import javafx.geometry.Insets;
 import javafx.scene.Scene;
@@ -50,9 +51,10 @@
 import com.ledmington.elf.ELFReader;
 import com.ledmington.emu.ELFLoader;
 import com.ledmington.emu.EmulatorConstants;
+import com.ledmington.emu.ImmutableRegisterFile;
 import com.ledmington.emu.InstructionFetcher;
 import com.ledmington.emu.RFlags;
-import com.ledmington.emu.X86RegisterFile;
+import com.ledmington.emu.RegisterFile;
 import com.ledmington.mem.MemoryController;
 import com.ledmington.utils.MiniLogger;
 
@@ -63,13 +65,8 @@ public final class EmulatorView extends Stage {
 
 	// The CPU used to emulate
 	private X86CpuAdapter cpu;
-	// The register file of the CPU
-	private X86RegisterFile regFile;
 	// The memory controller used by the CPU
 	private MemoryController mem;
-	// An external decoder used to decode instructions in the GUI without modifying
-	// the state of the CPU
-	private InstructionDecoder decoder;
 	private final Button stepBtn = new Button();
 	private final Button runBtn = new Button();
 	private final TextArea codeArea = new TextArea();
@@ -133,16 +130,16 @@ public EmulatorView() {
 			for (final Register64 r : Register64.values()) {
 				registerPane.add(LabelFactory.getDefaultLabel(r.name()), 0, row);
 				final Label rl = LabelFactory.getDefaultLabel("0x" + "0".repeat(16));
-				rl.setTooltip(new Tooltip("Click to see the memory at [" + r.name() + "]"));
-				rl.setOnMouseClicked(e -> updateMemory(regFile.get(r)
+				rl.setTooltip(TooltipFactory.getDefaultTooltip("Click to see the memory at [" + r.name() + "]"));
+				rl.setOnMouseClicked(e -> updateMemory(cpu.getRegisters().get(r)
 						- ((long) AppConstants.getMaxMemoryLines() * AppConstants.getMemoryBytesPerLine()) / 2L));
 				registerPane.add(rl, 1, row);
 				regLabels.put(r, rl);
 				row++;
 			}
 
 			registerPane.add(LabelFactory.getDefaultLabel("RFLAGS"), 0, row);
-			this.rflagsLabel = LabelFactory.getDefaultLabel("-".repeat(RFlags.values().length));
+			this.rflagsLabel = LabelFactory.getDefaultLabel("");
 			registerPane.add(rflagsLabel, 1, row);
 			row++;
 
@@ -189,7 +186,7 @@ public EmulatorView() {
 			this.cpu.doExecuteOne();
 			updateRegisters();
 			updateCode();
-			updateMemory(regFile.get(Register64.RIP));
+			updateMemory(cpu.getRegisters().get(Register64.RIP));
 		});
 		this.stepBtn.setTooltip(new Tooltip("Step"));
 
@@ -204,7 +201,7 @@ public EmulatorView() {
 			this.cpu.doExecute();
 			updateRegisters();
 			updateCode();
-			updateMemory(regFile.get(Register64.RIP));
+			updateMemory(cpu.getRegisters().get(Register64.RIP));
 		});
 		this.runBtn.setTooltip(new Tooltip("Run"));
 
@@ -231,9 +228,7 @@ private InputStream getResourceStream(final String name) {
 	private void loadFile(final File file) {
 		logger.info("Loading file '%s'", file.toString());
 		this.mem = new MemoryController(EmulatorConstants.getMemoryInitializer(), false);
-		this.regFile = new X86RegisterFile();
-		this.cpu = new X86CpuAdapter(regFile, mem);
-		this.decoder = new InstructionDecoderV1(new InstructionFetcher(mem, regFile));
+		this.cpu = new X86CpuAdapter(mem);
 
 		// TODO: implement this
 		final String[] commandLineArguments = new String[0];
@@ -252,49 +247,54 @@ private void loadFile(final File file) {
 
 		updateRegisters();
 		updateCode();
-		updateMemory(regFile.get(Register64.RIP));
+		updateMemory(cpu.getRegisters().get(Register64.RIP));
 	}
 
 	private void updateRegisters() {
+		final ImmutableRegisterFile regFile = this.cpu.getRegisters();
+
 		for (final Register64 r : Register64.values()) {
-			this.regLabels.get(r).setText(String.format("0x%016x", this.regFile.get(r)));
+			this.regLabels.get(r).setText(String.format("0x%016x", regFile.get(r)));
 		}
 
 		for (final Register16 s : new Register16[] {
 			Register16.CS, Register16.DS, Register16.SS, Register16.ES, Register16.FS, Register16.GS
 		}) {
-			this.segLabels.get(s).setText(String.format("0x%04x", this.regFile.get(s)));
+			this.segLabels.get(s).setText(String.format("0x%04x", regFile.get(s)));
 		}
 
-		final StringBuilder sb = new StringBuilder();
-		Arrays.stream(RFlags.values())
-				.sorted(Comparator.comparingInt(RFlags::bit))
-				.forEach(f -> sb.append(regFile.isSet(f) ? f.getInitial() : '-'));
-		this.rflagsLabel.setText(sb.toString());
+		this.rflagsLabel.setText("|"
+				+ Arrays.stream(RFlags.values())
+						.sorted(Comparator.comparingInt(RFlags::bit))
+						.map(f -> regFile.isSet(f) ? f.getSymbol() : "")
+						.collect(Collectors.joining("|"))
+				+ "|");
 	}
 
 	private void updateCode() {
+		final RegisterFile regFile = (RegisterFile) cpu.getRegisters();
+		final InstructionDecoder decoder = new InstructionDecoderV1(new InstructionFetcher(this.mem, regFile));
 		final StringBuilder sb = new StringBuilder();
 		final int n = AppConstants.getMaxCodeInstructions();
-		final long originalRIP = this.regFile.get(Register64.RIP);
+		final long originalRIP = regFile.get(Register64.RIP);
 		long rip = originalRIP;
 		for (int i = 0; i < n; i++) {
 			final long startRIP = rip;
-			this.regFile.set(Register64.RIP, rip);
+			regFile.set(Register64.RIP, rip);
 			sb.append("0x").append(String.format("%0" + (2 * ADDRESS_BYTES) + "x", rip));
 
 			String inst;
 			try {
-				inst = this.decoder.decode().toIntelSyntax();
-				rip = this.regFile.get(Register64.RIP);
+				inst = decoder.decode().toIntelSyntax();
+				rip = regFile.get(Register64.RIP);
 			} catch (final UnknownOpcode | ReservedOpcode | IllegalArgumentException e) {
 				inst = String.format(".byte 0x%02x", this.mem.readCode(rip));
 				rip = startRIP + 1L;
 			}
 			sb.append(" : ").append(inst).append('\n');
 		}
 		this.codeArea.setText(sb.toString());
-		this.regFile.set(Register64.RIP, originalRIP);
+		regFile.set(Register64.RIP, originalRIP);
 	}
 
 	private void updateMemory(final long baseAddress) {

emu-gui/src/main/java/com/ledmington/view/Main.java

@@ -73,7 +73,7 @@ public static void main(final String[] args) {
 				case verboseFlag -> MiniLogger.setMinimumLevel(MiniLogger.LoggingLevel.INFO);
 				case veryVerboseFlag -> MiniLogger.setMinimumLevel(MiniLogger.LoggingLevel.DEBUG);
 				default -> {
-					out.printf("Unknown flag '%s'\n", arg);
+					out.printf("Unknown flag '%s'%n", arg);
 					out.flush();
 					Platform.exit();
 					System.exit(-1);

emu-gui/src/main/java/com/ledmington/view/TooltipFactory.java

@@ -0,0 +1,33 @@
+/*
+ * emu - Processor Emulator
+ * Copyright (C) 2023-2024 Filippo Barbari <filippo.barbari@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.ledmington.view;
+
+import javafx.scene.control.Tooltip;
+import javafx.scene.text.Font;
+
+public final class TooltipFactory {
+
+	private TooltipFactory() {}
+
+	public static Tooltip getDefaultTooltip(final String text) {
+		final Tooltip lbl = new Tooltip(text);
+		lbl.setWrapText(false);
+		lbl.setFont(new Font(AppConstants.getDefaultMonospaceFont(), AppConstants.getDefaultFontSize()));
+		return lbl;
+	}
+}

emu-gui/src/main/java/com/ledmington/view/X86CpuAdapter.java

@@ -22,7 +22,6 @@
 
 import com.ledmington.cpu.x86.Instruction;
 import com.ledmington.emu.X86Cpu;
-import com.ledmington.emu.X86RegisterFile;
 import com.ledmington.mem.MemoryController;
 
 // TODO: refactor avoiding inheritance (and avoiding two queues)
@@ -31,8 +30,8 @@ public final class X86CpuAdapter extends X86Cpu {
 	private final BlockingQueue<Object> execute = new ArrayBlockingQueue<>(1);
 	private final BlockingQueue<Object> executionCompleted = new ArrayBlockingQueue<>(1);
 
-	public X86CpuAdapter(final X86RegisterFile regFile, final MemoryController mem) {
-		super(regFile, mem);
+	public X86CpuAdapter(final MemoryController mem) {
+		super(mem);
 	}
 
 	private void waitToStartExecution() {

emu/src/main/java/com/ledmington/emu/ELFLoader.java

@@ -31,12 +31,15 @@
 import com.ledmington.elf.PHTEntryType;
 import com.ledmington.elf.ProgramHeaderTable;
 import com.ledmington.elf.SectionTable;
+import com.ledmington.elf.section.BasicProgBitsSection;
 import com.ledmington.elf.section.ConstructorsSection;
 import com.ledmington.elf.section.LoadableSection;
 import com.ledmington.elf.section.NoBitsSection;
 import com.ledmington.elf.section.Section;
 import com.ledmington.elf.section.SectionHeaderFlags;
 import com.ledmington.elf.section.StringTableSection;
+import com.ledmington.elf.section.sym.SymbolTableEntry;
+import com.ledmington.elf.section.sym.SymbolTableEntryType;
 import com.ledmington.elf.section.sym.SymbolTableSection;
 import com.ledmington.mem.MemoryController;
 import com.ledmington.utils.BitUtils;
@@ -59,6 +62,7 @@ private ELFLoader() {}
 	 * Loads the given ELF file in the emulated memory.
 	 *
 	 * @param elf The file to be loaded.
+	 * @param cpu The CPU to be used to execute some instructions, if needed.
 	 * @param mem The emulated memory where to load the file.
 	 * @param commandLineArguments The arguments to pass to the program.
 	 * @param baseAddress The address where to start loading the file.
@@ -78,8 +82,9 @@ public static void load(
 		// We make RSP point at the last 8 bytes of allocated memory
 		final long stackPointer = highestAddress + stackSize - 8L;
 
-		// This is a fake instruction
+		// These are fake instructions to setup the stack
 		cpu.executeOne(new Instruction(Opcode.MOV, Register64.RSP, new Immediate(stackPointer)));
+		cpu.executeOne(new Instruction(Opcode.PUSH, new Immediate(0L)));
 
 		loadCommandLineArgumentsAndEnvironmentVariables(
 				mem, highestAddress, elf.getFileHeader().is32Bit(), commandLineArguments);
@@ -96,7 +101,12 @@ public static void load(
 					(StringTableSection) elf.getSectionByName(".strtab").orElseThrow());
 		}
 		if (elf.getSectionByName(".init").isPresent()) {
-			runInit();
+			runInit(
+					(BasicProgBitsSection) elf.getSectionByName(".init").orElseThrow(),
+					cpu,
+					baseAddress,
+					(SymbolTableSection) elf.getSectionByName(".symtab").orElseThrow(),
+					(StringTableSection) elf.getSectionByName(".strtab").orElseThrow());
 		}
 		if (elf.getSectionByName(".ctors").isPresent()) {
 			runCtors();
@@ -121,6 +131,11 @@ public static void unload(final ELF elf) {
 		}
 	}
 
+	private static void runFrom(final X86Emulator cpu, final long startAddress) {
+		cpu.executeOne(new Instruction(Opcode.MOV, Register64.RIP, new Immediate(startAddress)));
+		cpu.execute();
+	}
+
 	private static void runPreInitArray() {
 		notImplemented();
 	}
@@ -137,13 +152,27 @@ private static void runInitArray(
 			final String ctorName =
 					strtab.getString(symtab.getSymbolWithValue(c).nameOffset());
 			logger.debug("Running .init_array[%d] = %,d (0x%016x) '%s'", i, c, c, ctorName);
-			cpu.executeOne(new Instruction(Opcode.MOV, Register64.RIP, new Immediate(entryPointVirtualAddress + c)));
-			cpu.execute();
+			runFrom(cpu, entryPointVirtualAddress + c);
 		}
 	}
 
-	private static void runInit() {
-		notImplemented();
+	private static void runInit(
+			final BasicProgBitsSection init,
+			final X86Emulator cpu,
+			final long entryPointVirtualAddress,
+			final SymbolTableSection symtab,
+			final StringTableSection strtab) {
+		for (int i = 0; i < symtab.getSymbolTableLength(); i++) {
+			final SymbolTableEntry ste = symtab.getSymbolTableEntry(i);
+			if (ste.info().getType() == SymbolTableEntryType.STT_FUNC
+					&& ste.value() >= init.getHeader().getFileOffset()
+					&& ste.value()
+							< init.getHeader().getFileOffset()
+									+ init.getHeader().getSectionSize()) {
+				logger.debug("Running constructor '%s' from .init", strtab.getString(ste.nameOffset()));
+				runFrom(cpu, entryPointVirtualAddress + ste.value());
+			}
+		}
 	}
 
 	private static void runCtors() {