Modernize Shoebill for macOS ARM64: SwiftUI GUI + core optimizations

.gitignore

@@ -1,8 +1,11 @@
 /intermediates
+/build
 /shoebill
 .DS_Store
 *.xcworkspace
 xcuserdata
 /gui/build
 /debugger/debugger
 /debugger/debugger.dSYM
+/sdl-gui/shoebill
+/sdl-gui/shoebill.dSYM

CHANGELOG.md

@@ -0,0 +1,61 @@
+# Changelog
+
+## [0.2.0] - 2026-03-21
+
+### Core Emulation Overhaul
+- **Event-driven timer scheduler**: VIA timer checks are now inline with the CPU loop (every 512 steps), eliminating the dedicated VIA clock thread and `via_cpu_lock` contention in normal mode. Debug mode retains the legacy thread for compatibility.
+- **CPU dispatch optimization**: Single direct 64K function pointer dispatch table (`inst_direct_dispatch[]`) replaces the two-level `inst_opcode_map` + `inst_instruction_to_pointer` indirection. `cpu_step()` marked `__attribute__((hot))`.
+- **4-way set-associative PMMU cache**: Upgraded from direct-mapped to 4-way set-associative TLB, reducing conflict misses for workloads with aliased page addresses. Pseudo-LRU eviction per set.
+- **SoftFloat 2b upgraded to 3e**: Berkeley SoftFloat library upgraded from version 2b to 3e with full backward-compatible API shim (`softfloat_compat.h`). Improved accuracy and ARM64 performance.
+- **Core Audio sound output**: Apple Sound Chip (ASC) now outputs audio via Core Audio AudioQueue API — 22254 Hz stereo 8-bit unsigned PCM with proper FIFO ring buffer management and thread-safe access.
+
+### Modernized APIs
+- Replaced all `gettimeofday()` with `clock_gettime(CLOCK_MONOTONIC)` across `core_api.c`, `via.c`, `ethernet.c`
+- Replaced `sys_errlist[errno]` with `strerror(errno)` in SDL GUI
+- Replaced `bzero()` with `memset()` in debugger
+- Ethernet receiver: replaced busy-polling `usleep(50)` with `pthread_cond_timedwait` on a dedicated condition variable, signaled when `bnry` register is updated
+
+### SDL GUI Modernization
+- Replaced all deprecated immediate-mode OpenGL rendering (`glDrawPixels`, etc.) with SDL_Renderer + SDL_Texture (`SDL_PIXELFORMAT_ABGR8888`, `SDL_TEXTUREACCESS_STREAMING`)
+- Removed OpenGL dependency entirely from SDL GUI
+
+### Debugger Rewrite
+- Migrated from deprecated GLUT to SDL2 for windowing and rendering
+- Fixed GLUT init order bug (display mode was set after window creation)
+- Replaced hardcoded ROM/disk paths with configurable sources: command-line arguments, environment variables (`SHOEBILL_ROM`, `SHOEBILL_DISK`), and defaults
+- Replaced deprecated OpenGL rendering with SDL_Renderer + SDL_Texture
+
+## [0.1.0] - 2026-03-21
+
+### Added
+- Apple Silicon (ARM64) native support — universal binary (arm64 + x86_64)
+- New SwiftUI + Metal GUI application (`ShoebillApp/`)
+  - Modern macOS 14+ interface with SwiftUI Settings, toolbar controls
+  - Metal-based framebuffer rendering replacing deprecated OpenGL
+  - Proper HiDPI/Retina display scaling
+  - Mouse capture/release (click to capture, right-click to release)
+  - Full ADB keyboard mapping
+  - PRAM persistence via Application Support directory
+- C bridge helper (`shoebill_swift_helpers.h`) for Swift interop with anonymous C struct fields
+- Xcode project for the SwiftUI app with "Build Core Library" script phase
+
+### Changed
+- `core/Makefile`: replaced i386 target with arm64; builds universal library
+- `gui/Shoebill.xcodeproj`: updated to macOS 14.0 deployment target, `SDKROOT = macosx`, `VALID_ARCHS = x86_64 arm64`
+- `core/fpu.c`: renamed `HACKY_MATH_X86` to `HACKY_MATH_NATIVE` — the `double`/`math.h` path is architecture-independent
+- Top-level `Makefile`: new targets (`app`, `core`, `sdl`, `legacy-gui`, `debugger`)
+- `README.md`: rewritten with updated build instructions and credits
+- Version bumped to 0.1.0
+
+### Fixed
+- `core/fpu.c`: corrected `memset()` argument order in `fpu_initialize()` (issue [#20])
+- `core/fpu.c`: fixed K&R-style `_native_tentox(a)` declaration to `_native_tentox(double a)` (issue [#15])
+- `README.md`: fixed broken relative image URL (from PR [#19])
+
+### Credits
+- ARM64 build support based on [PR #19](https://github.com/pruten/shoebill/pull/19) by [@calmsacibis995](https://github.com/calmsacibis995)
+- Bug reports by [@mitchblank](https://github.com/mitchblank) ([#15](https://github.com/pruten/shoebill/issues/15), [#20](https://github.com/pruten/shoebill/issues/20))
+
+## [0.0.5] - 2015-09-13
+
+Last release by original author Peter Rutenbar.

Makefile

@@ -1,19 +1,33 @@
 
 CC = clang
 CFLAGS = -O3 -flto -Wno-deprecated-declarations
+NPROC = $(shell sysctl -n hw.ncpu 2>/dev/null || echo 4)
 
-all: shoebill
+all: app
 
-shoebill: make_gui debugger
+# New SwiftUI + Metal GUI (recommended)
+app: core
+	@if command -v xcodebuild >/dev/null 2>&1 && xcodebuild -version >/dev/null 2>&1; then \
+		xcodebuild -project ShoebillApp/ShoebillApp.xcodeproj -scheme ShoebillApp -configuration Release SYMROOT=build/ShoebillApp; \
+	else \
+		ShoebillApp/build.sh; \
+	fi
 
-make_gui: make_core
-	xcodebuild -project gui/Shoebill.xcodeproj SYMROOT=build
+# Legacy Cocoa GUI
+legacy-gui: core
+	xcodebuild -project gui/Shoebill.xcodeproj SYMROOT=build/LegacyGUI
 
-debugger: make_core
-	$(MAKE) -C debugger
+# Core emulator library only
+core:
+	$(MAKE) -C core -j $(NPROC)
+
+# SDL2 cross-platform GUI
+sdl: core
+	cd sdl-gui && ./osx_build.sh
 
-make_core:
-	$(MAKE) -C core -j 4
+# Debugger
+debugger: core
+	$(MAKE) -C debugger
 
 clean:
-	rm -rf intermediates gui/build
+	rm -rf intermediates build gui/build

README.md

@@ -1,46 +1,111 @@
-<h1><img align=right src="../../../pruten.github.io/raw/master/web/stork_tiny_head3.jpg"/>Shoebill</h1>
+<h1><img align=right src="https://github.com/pruten/pruten.github.io/raw/master/web/stork_tiny_head3.jpg"/>Shoebill</h1>
 
-A Macintosh II emulator that runs A/UX (and A/UX only). 
+A Macintosh II emulator that runs A/UX (and A/UX only).
 
-Shoebill is an all-new, BSD-licensed Macintosh II emulator designed from the ground up with the singular goal of running A/UX. 
+Shoebill is a BSD-licensed Macintosh II emulator designed from the ground up with the singular goal of running A/UX.
 
 Shoebill requires a Macintosh II, IIx or IIcx ROM, and a disk image with A/UX installed.
 
-[Download the latest release], and then see the [getting started] wiki.  
-Also check out [screenshots].
+See the [getting started] wiki for setup instructions.
 
-__Update (March 29, 2023): About issues/pull requests__
+## What's New (v0.1.0)
 
-__I just wanted to say that I appreciate some folks are still using Shoebill and submitting issues and pull requests. I wish I could continue working on this project, but there's a likely conflict of interest, and so I've mostly avoided pushing changes. I apologize for being unable to address the many, many bugs in this repo. (Also for anyone unaware, [Qemu is now able] now to run A/UX 3.x on its emulated Quadra 800.)__
+This fork modernizes Shoebill for current macOS:
 
-__Update (Sept 13, 2015): [Shoebill 0.0.5 is available]__
+- **Apple Silicon (ARM64) support** — native builds for M1/M2/M3/M4 Macs (universal binary with x86_64)
+- **New SwiftUI + Metal GUI** — modern macOS interface replacing the legacy Objective-C/OpenGL app, with HiDPI/Retina display support
+- **Bug fixes** from community issues:
+  - Fixed `memset()` argument swap in FPU initialization ([#20])
+  - Fixed K&R-style function declaration causing build errors on modern compilers ([#15])
+  - Renamed `HACKY_MATH_X86` to `HACKY_MATH_NATIVE` (the `double` math path works on all architectures)
+- **Build system** updated: dropped i386, targets macOS 14.0+
 
-__This will probably be the last release. I won't be able to work on Shoebill going forward (by contractual obligation), so I wanted to race out one last release. Only an OS X binary is available, sorry, and it's very unpolished. But the SDL GUI should still build on linux/windows.__
+Based on ARM64 build support from [PR #19] by [@calmsacibis995], with bug fixes reported by [@mitchblank].
 
+## Requirements
 
-#### Supports
-* A/UX 1.1.1 through 3.1 (and 3.1.1 a little)
+- macOS 14.0 (Sonoma) or later
+- Xcode 15+ (for building the SwiftUI app) or Command Line Tools (for building the core library)
+- A Macintosh II/IIx/IIcx ROM image
+- An A/UX disk image (1.1.1 through 3.1)
+
+## Building
+
+### SwiftUI App (recommended, requires Xcode)
+
+```bash
+make app
+```
+
+The built application will be in `build/ShoebillApp/`.
+
+### Core Library Only (Command Line Tools sufficient)
+
+```bash
+make core
+```
+
+Produces `intermediates/libshoebill_core.a` (universal: arm64 + x86_64).
+
+### Legacy Cocoa GUI
+
+```bash
+make legacy-gui
+```
+
+### SDL2 GUI (cross-platform)
+
+```bash
+make sdl        # macOS
+cd sdl-gui && ./lin_build.sh   # Linux
+cd sdl-gui && win_build.bat    # Windows
+```
+
+### Debugger
+
+```bash
+make debugger
+```
+
+## Supports
+
+* A/UX 1.1.1 through 3.1 (and 3.1.1 partially)
+
+## Currently Implements
 
-#### Currently Implements
 * 68020 CPU (mostly)
 * 68881 FPU (mostly)
-* 68851 PMMU (just enough to boot A/UX)
-* SCSI
-* ADB
+* 68851 PMMU (enough to boot A/UX)
+* SCSI (NCR 5380)
+* ADB (keyboard/mouse)
 * PRAM
 * Ethernet (via emulated Apple EtherTalk/DP8390 card)
-* A NuBus video card with 24-bit depth. 
+* NuBus video card with 24-bit depth
+
+## Not Yet Implemented
 
-#### Does not implement (yet)
-* Sound
-* Floppy
+* Sound (ASC chip partially implemented)
+* Floppy (IWM)
 * Serial ports
 
-
-[Download the latest release]:https://github.com/pruten/Shoebill/releases
-[getting started]:https://github.com/pruten/Shoebill/wiki/Getting-Started
-[screenshots]:https://github.com/pruten/Shoebill/wiki/Screenshots
-[Shoebill 0.0.5 is available]:https://github.com/pruten/Shoebill/releases
-[The thread on emaculation.com]:http://www.emaculation.com/forum/viewtopic.php?f=7&t=8288
-[Qemu is now able]:https://virtuallyfun.com/2021/09/02/qemus-macintosh-quadra-in-alpha-usability-runs-a-ux/
+## License
 
+BSD 2-Clause. See [LICENSE](LICENSE).
+
+## Credits
+
+- Original author: [Peter Rutenbar](https://github.com/pruten) ([@pruten])
+- ARM64/Apple Silicon support: [@calmsacibis995] ([PR #19])
+- Bug reports and testing: [@mitchblank] ([#15], [#20])
+
+## See Also
+
+- [QEMU Quadra 800](https://virtuallyfun.com/2021/09/02/qemus-macintosh-quadra-in-alpha-usability-runs-a-ux/) can also run A/UX 3.x
+
+[getting started]:https://github.com/pruten/Shoebill/wiki/Getting-Started
+[#15]:https://github.com/pruten/shoebill/issues/15
+[#20]:https://github.com/pruten/shoebill/issues/20
+[PR #19]:https://github.com/pruten/shoebill/pull/19
+[@pruten]:https://github.com/pruten
+[@calmsacibis995]:https://github.com/calmsacibis995
+[@mitchblank]:https://github.com/mitchblank

ShoebillApp/EmulatorViewModel.swift

@@ -0,0 +1,111 @@
+import SwiftUI
+import Foundation
+
+@Observable
+final class EmulatorViewModel {
+    let bridge = ShoebillBridge()
+    private(set) var isRunning = false
+    private(set) var isMouseCaptured = false
+    private(set) var isKeyboardCaptured = false
+    var errorMessage: String?
+
+    private var keyboardHandler: KeyboardHandler?
+    private let mouseHandler = MouseHandler()
+    private var fallbackVBLTimer: Timer?
+
+    var screenSlot: UInt8 = 9
+    var metalRendering = false
+
+    func startEmulator() {
+        guard !isRunning else { return }
+        errorMessage = nil
+
+        let defaults = UserDefaults.standard
+        let romPath = defaults.string(forKey: "romPath") ?? ""
+        let kernelPath = defaults.string(forKey: "rootKernelPath").flatMap { $0.isEmpty ? nil : $0 } ?? "/unix"
+        let memSize = defaults.integer(forKey: "memorySize")
+        let verbose = defaults.object(forKey: "verboseState") != nil ? defaults.bool(forKey: "verboseState") : true
+
+        guard !romPath.isEmpty else {
+            errorMessage = "ROM path is not set. Open Settings to configure."
+            return
+        }
+
+        guard defaults.string(forKey: "scsiPath0")?.isEmpty == false else {
+            errorMessage = "Boot disk (SCSI 0) is not set. Open Settings to configure."
+            return
+        }
+
+        var scsiPaths: [String?] = []
+        for i in 0..<7 {
+            let p = defaults.string(forKey: "scsiPath\(i)")
+            scsiPaths.append(p?.isEmpty == false ? p : nil)
+        }
+
+        let screenWidth = UInt16(defaults.integer(forKey: "screenWidth0").clamped(to: 512...2560))
+        let screenHeight = UInt16(defaults.integer(forKey: "screenHeight0").clamped(to: 342...1600))
+
+        let config = ShoebillBridge.EmulatorConfig(
+            romPath: romPath,
+            kernelPath: kernelPath,
+            ramSizeMB: UInt32(max(4, min(1024, memSize == 0 ? 16 : memSize))),
+            verbose: verbose,
+            scsiPaths: scsiPaths,
+            screenWidth: screenWidth,
+            screenHeight: screenHeight,
+            screenSlot: screenSlot
+        )
+
+        do {
+            try bridge.initialize(with: config)
+            bridge.start()
+            startVBLTimer()
+            isRunning = true
+        } catch {
+            errorMessage = error.localizedDescription
+        }
+    }
+
+    func stopEmulator() {
+        guard isRunning else { return }
+        releaseInput()
+        fallbackVBLTimer?.invalidate()
+        fallbackVBLTimer = nil
+        bridge.stop()
+        isRunning = false
+    }
+
+    private func startVBLTimer() {
+        let slot = screenSlot
+        fallbackVBLTimer = Timer.scheduledTimer(withTimeInterval: 1.0 / 60.0, repeats: true) { [weak self] _ in
+            guard let self, self.isRunning, !self.metalRendering else { return }
+            self.bridge.sendVBLInterrupt(slot: slot)
+        }
+        RunLoop.main.add(fallbackVBLTimer!, forMode: .common)
+    }
+
+    func captureInput() {
+        guard isRunning, !isMouseCaptured else { return }
+        mouseHandler.capture()
+        isMouseCaptured = true
+
+        if keyboardHandler == nil {
+            keyboardHandler = KeyboardHandler(bridge: bridge)
+        }
+        keyboardHandler?.startCapturing()
+        isKeyboardCaptured = true
+    }
+
+    func releaseInput() {
+        mouseHandler.release()
+        isMouseCaptured = false
+        keyboardHandler?.stopCapturing()
+        isKeyboardCaptured = false
+    }
+}
+
+private extension Comparable {
+    func clamped(to range: ClosedRange<Self>) -> Self {
+        min(max(self, range.lowerBound), range.upperBound)
+    }
+}

ShoebillApp/Info.plist

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>en</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>Shoebill</string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>0.1.0</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>LSMinimumSystemVersion</key>
+	<string>$(MACOSX_DEPLOYMENT_TARGET)</string>
+	<key>NSHumanReadableCopyright</key>
+	<string>Copyright 2013-2015 Peter Rutenbar, 2026 Contributors. BSD 2-Clause.</string>
+</dict>
+</plist>