GBA support

Author: tommitytom

CMakeLists.txt

@@ -184,6 +184,7 @@ dpf_add_plugin(${NAME}
       src/system/sameboy/roles/MgbPassthroughRole.cpp
       src/system/mesen/MesenSystem.cpp
       src/system/mesen/MesenVideoDevice.cpp
+      src/system/mesen/GbaSystem.cpp
       src/system/mesen/roles/NesN8MidiRole.cpp
   FILES_UI
       src/PluginUI.cpp
@@ -204,6 +205,7 @@ dpf_add_plugin(${NAME}
       src/system/sameboy/roles/MgbPassthroughRole.cpp
       src/system/mesen/MesenSystem.cpp
       src/system/mesen/MesenVideoDevice.cpp
+      src/system/mesen/GbaSystem.cpp
       src/system/mesen/roles/NesN8MidiRole.cpp
       ${UI_BUNDLE_C}
       deps/dpf-widgets/generic/LVGL.cpp)
@@ -283,6 +285,19 @@ if(BUILD_CLI)
         COMMENT "Rendering examples/scripts/nes_smoke.json -> /tmp/nes-smoke.wav + boot.png"
     )
 
+    # `make cli-gba-smoke` -> boot the nanoloop demo GBA ROM under GbaSystem,
+    # render 5 s, capture two screenshots. End-to-end verification of the
+    # Mesen-backed GBA dispatch (audio + video + boot).
+    add_custom_target(cli-gba-smoke
+        COMMAND ${CMAKE_BINARY_DIR}/bin/retroplug-cli
+                --script ${CMAKE_SOURCE_DIR}/examples/scripts/gba_smoke.json
+                --screenshot-dir ${CMAKE_BINARY_DIR}/gba-smoke
+        WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+        DEPENDS retroplug-cli
+        USES_TERMINAL
+        COMMENT "Rendering examples/scripts/gba_smoke.json -> /tmp/gba-smoke.wav + boot.png"
+    )
+
     # `make cli-n8-midi` -> end-to-end MIDI-input test for the n8-midi ROM.
     # Pumps note-ons across the four standard NES channels (pulse1=ch0,
     # pulse2=ch1, triangle=ch2, noise=ch3) into the FIFO and captures the

cli/CMakeLists.txt

@@ -14,6 +14,7 @@ add_executable(retroplug-cli
     ${PROJECT_SOURCE_DIR}/src/system/sameboy/roles/MgbPassthroughRole.cpp
     ${PROJECT_SOURCE_DIR}/src/system/mesen/MesenSystem.cpp
     ${PROJECT_SOURCE_DIR}/src/system/mesen/MesenVideoDevice.cpp
+    ${PROJECT_SOURCE_DIR}/src/system/mesen/GbaSystem.cpp
     ${PROJECT_SOURCE_DIR}/src/system/mesen/roles/NesN8MidiRole.cpp
     # lodepng (vendored under lv_binding_js). Compiled directly so the CLI
     # doesn't have to pull in the full lvgl-js-native static lib for one

cli/Script.hpp

@@ -66,6 +66,12 @@ struct ScriptSystem {
     // "KeyboardMidi", "MidiPassthrough", "ArduinoboyMaster"). Only meaningful
     // when the ROM is sniffed as LSDJ; ignored otherwise.
     std::optional<std::string>   lsdj_sync_mode;
+    // GBA-only: path to a real GBA BIOS file (16384 bytes; filename can be
+    // anything — Mesen requires it to be named gba_bios.bin so GbaSystem
+    // copies it into its firmware folder on activate). Without it most ROMs
+    // hang at the first BIOS SWI; the Cult-of-GBA open-source BIOS works as
+    // a drop-in for the smoke test. Ignored for SameBoy / NES ROMs.
+    std::optional<std::string>   bios_path;
 };
 
 struct Script {
@@ -90,7 +96,7 @@ struct Script {
 struct TimedButton {
     std::uint64_t sample;
     std::uint32_t systemIndex;
-    std::uint8_t  button;   // SameBoy: GameboyButton; Mesen: NesButton (cast)
+    std::uint8_t  button;   // SameBoy: GameboyButton; Mesen: NesButton; Gba: GbaButton (cast)
     bool          down;
 };
 
@@ -114,9 +120,13 @@ struct TimedTransport {
     std::optional<double> setBpm;
 };
 
-// Returns a button opcode as a raw uint8_t. Both GameboyButton and NesButton
-// are position-aligned (Right=0..Start=7) so the same name table works for
-// either system kind; the receiving system reinterprets the byte.
+// Returns a button opcode as a raw uint8_t. GameboyButton, NesButton, and
+// GbaButton all use the same position-aligned encoding (Right=0..Start=7)
+// for the shared eight buttons, so a single name table works for any
+// system kind; the receiving system reinterprets the byte. L and R are
+// GBA-only (wire bytes 8 and 9 from GbaButton); pressing them at a
+// SameBoy or Mesen system is a no-op (their toXButton switches return A
+// for unknown values).
 inline std::uint8_t parseButtonName(const std::string& s) {
     std::string lower(s.size(), '\0');
     std::transform(s.begin(), s.end(), lower.begin(),
@@ -129,6 +139,8 @@ inline std::uint8_t parseButtonName(const std::string& s) {
     if (lower == "b")      return static_cast<std::uint8_t>(GameboyButton::B);
     if (lower == "select") return static_cast<std::uint8_t>(GameboyButton::Select);
     if (lower == "start")  return static_cast<std::uint8_t>(GameboyButton::Start);
+    if (lower == "l")      return static_cast<std::uint8_t>(GbaButton::L);
+    if (lower == "r")      return static_cast<std::uint8_t>(GbaButton::R);
     throw std::runtime_error("unknown button name: " + s);
 }
 

cli/main.cpp

@@ -37,6 +37,8 @@
 #include "project/Project.hpp"
 #include "system/RomFormat.hpp"
 #include "system/SystemBase.hpp"
+#include "system/mesen/GbaConfig.hpp"
+#include "system/mesen/GbaSystem.hpp"
 #include "system/mesen/MesenConfig.hpp"
 #include "system/mesen/MesenSystem.hpp"
 #include "system/sameboy/SameBoyConfig.hpp"
@@ -278,7 +280,7 @@ int main(int argc, char** argv) try {
         std::unique_ptr<SystemBase> sys;
         if (fmt == RomFormat::Unknown) {
             std::fprintf(stderr,
-                "script: systems[%u].rom '%s' is not a recognised Game Boy or NES ROM\n",
+                "script: systems[%u].rom '%s' is not a recognised Game Boy, NES, or GBA ROM\n",
                 i, s.rom.c_str());
             return 1;
         }
@@ -295,6 +297,20 @@ int main(int argc, char** argv) try {
             cfg.romPath = s.rom;
             sys = std::make_unique<MesenSystem>(
                 project.nextSystemId(), cfg, std::move(bytes));
+        } else if (fmt == RomFormat::Gba) {
+            if (s.link_group.value_or(0) != 0) {
+                std::fprintf(stderr, "script: systems[%u] is GBA; link_group not supported\n", i);
+                return 1;
+            }
+            if (s.lsdj_sync_mode) {
+                std::fprintf(stderr, "script: systems[%u] is GBA; lsdj_sync_mode not applicable\n", i);
+                return 1;
+            }
+            GbaSystemConfig cfg;
+            cfg.romPath = s.rom;
+            if (s.bios_path) cfg.biosPath = *s.bios_path;
+            sys = std::make_unique<GbaSystem>(
+                project.nextSystemId(), cfg, std::move(bytes));
         } else {
             SameBoyConfig cfg;
             cfg.romPath     = s.rom;

deps/mesen/Core/GBA/GbaConsole.cpp

@@ -354,6 +354,11 @@ void GbaConsole::ProcessEndOfFrame()
 {
 	_controlManager->UpdateControlDevices();
 	_controlManager->UpdateInputState();
+	// RetroPlug: GbaControlManager::UpdateInputState() has been modified to
+	// skip the BaseControlManager::UpdateInputState() clobbering call (which
+	// would wipe SetBitValue from the host) but still refresh _state.
+	// ActiveKeys from the controller bits, so the CPU's read of $4000130
+	// sees host-driven button changes.
 }
 
 BaseControlManager* GbaConsole::GetControlManager()

deps/mesen/Core/GBA/GbaControlManager.cpp

@@ -23,7 +23,15 @@ GbaControlManagerState& GbaControlManager::GetState()
 
 void GbaControlManager::UpdateInputState()
 {
-	BaseControlManager::UpdateInputState();
+	// RetroPlug: BaseControlManager::UpdateInputState() calls
+	// device->ClearState() + SetStateFromInput() on every poll, which
+	// reads from host KeyMappings and would wipe any bits the host set
+	// via SetBitValue. The host (CLI script / JS bridge / DAW plugin)
+	// is the source of truth for input; Mesen's keyboard-polling path
+	// is unused. Skip the base call and just refresh the ActiveKeys
+	// cache from the controller's current bits so the CPU's read of
+	// $4000130 sees host-driven button changes.
+	//BaseControlManager::UpdateInputState();
 	_state.ActiveKeys = (ReadController(0) | (ReadController(1) << 8));
 	CheckForIrq();
 }

examples/scripts/gba_smoke.json

@@ -0,0 +1,18 @@
+{
+  "systems": [
+    {
+      "rom": "resources/roms/nanoloop287d.gba",
+      "bios_path": "build/firmware/gba_bios.bin"
+    }
+  ],
+  "duration_ms": 8000,
+  "sample_rate": 44100,
+  "block_size": 1024,
+  "out_wav": "/tmp/gba-smoke.wav",
+  "events": [
+    { "at_ms": 2000, "screenshot": "boot",       "system": 0 },
+    { "at_ms": 4000, "tap": "Start", "system": 0, "hold_ms": 80 },
+    { "at_ms": 6000, "screenshot": "post_start", "system": 0 },
+    { "at_ms": 7500, "screenshot": "final",      "system": 0 }
+  ]
+}

src/PluginJsBridge.cpp

@@ -20,6 +20,8 @@ extern "C" {
 #include "system/InputTypes.hpp"
 #include "system/RomFormat.hpp"
 #include "system/SystemBase.hpp"
+#include "system/mesen/GbaConfig.hpp"
+#include "system/mesen/GbaSystem.hpp"
 #include "system/mesen/MesenConfig.hpp"
 #include "system/mesen/MesenSystem.hpp"
 #include "system/sameboy/SameBoyConfig.hpp"
@@ -178,19 +180,17 @@ SystemBase* PluginJsBridge::buildSystemFromPath(const std::string& path) {
         return nullptr;
     }
 
-    // Content-based dispatch: iNES magic → MesenSystem, Game Boy Nintendo
-    // logo → SameBoySystem, anything else → reject. Matching by magic bytes
-    // (not extension) means a mislabelled ROM still goes to the right
-    // backend, and totally unrelated files (a .sh script, a JPEG, …)
-    // surface as "rom-error" instead of being executed as instructions
-    // by whichever backend caught them. The pre-detector code fell through
-    // to SameBoy for anything not ending in `.nes`, which produced a stream
-    // of "Wrote XX to YYYY (RAM Mirror)" log spam from the GB CPU
-    // executing garbage.
+    // Content-based dispatch: iNES magic → MesenSystem, GBA Nintendo logo
+    // at $0004 → GbaSystem, Game Boy Nintendo logo at $0104 → SameBoySystem,
+    // anything else → reject. Matching by magic bytes (not extension) means
+    // a mislabelled ROM still goes to the right backend, and totally
+    // unrelated files (a .sh script, a JPEG, …) surface as "rom-error"
+    // instead of being executed as instructions by whichever backend caught
+    // them.
     const RomFormat fmt = detectRomFormat(bytes);
     if (fmt == RomFormat::Unknown) {
         std::fprintf(stderr,
-            "buildSystemFromPath: '%s' is not a recognised Game Boy or NES ROM\n",
+            "buildSystemFromPath: '%s' is not a recognised Game Boy, NES, or GBA ROM\n",
             path.c_str());
         emitRomEvent(engine, "rom-error", path);
         return nullptr;
@@ -207,6 +207,20 @@ SystemBase* PluginJsBridge::buildSystemFromPath(const std::string& path) {
         return sys.release();
     }
 
+    if (fmt == RomFormat::Gba) {
+        GbaSystemConfig cfg;
+        cfg.romPath = path;
+        // BIOS lookup: pass through anything the host has dropped into the
+        // build firmware dir. If absent, GbaSystem falls back to HLE
+        // (Mesen-zeroed boot ROM) and most non-trivial ROMs will hang on
+        // their first BIOS SWI. Plumbing a UI-side BIOS picker is a
+        // follow-up.
+        cfg.biosPath = "build/firmware/gba_bios.bin";
+        auto sys = std::make_unique<GbaSystem>(id, cfg, std::move(bytes));
+        sys->onActivate(sr);
+        return sys.release();
+    }
+
     SameBoyConfig cfg;
     cfg.romPath  = path;
     cfg.model    = SameBoyModel::CgbC;

src/project/Project.cpp

@@ -7,6 +7,7 @@
 
 #include "rfl/Variant.hpp"
 
+#include "system/mesen/GbaSystem.hpp"
 #include "system/mesen/MesenSystem.hpp"
 #include "system/sameboy/SameBoySystem.hpp"
 
@@ -76,6 +77,22 @@ SystemId Project::addSystem(const SystemConfig& config) {
         return id;
     }
 
+    if (const auto* gb = rfl::get_if<GbaSystemConfig>(&config.variant())) {
+        std::vector<std::uint8_t> rom = gb->romBytes.bytes();
+        if (rom.empty())
+            rom = slurpFile(gb->romPath);
+        if (rom.empty()) {
+            std::fprintf(stderr, "[Project] no ROM bytes/path for GBA id=%u path='%s'\n",
+                         id, gb->romPath.c_str());
+            return 0;
+        }
+        auto sys = std::make_unique<GbaSystem>(id, *gb, std::move(rom));
+        systems_.push_back(std::move(sys));
+        config_.systems.push_back(*gb);
+        rebuildLinkGroups();
+        return id;
+    }
+
     return 0;
 }
 

src/system/InputTypes.hpp

@@ -39,3 +39,26 @@ enum class NesButton : std::uint8_t {
     Start  = 7,
     Count  = 8,
 };
+
+// GBA buttons. The shared 8 names keep the position-aligned wire bytes used
+// across all kinds (Right=0..Start=7) so the CLI script parser, JS bridge,
+// and any other "name → button" path can stay system-agnostic. L and R are
+// GBA-only and live at the end of the table.
+//
+// Note: Mesen's own GbaController::Buttons enum has a different order
+// (Up=0, Down=1, Left=2, Right=3, Start=4, Select=5, B=6, A=7, L=8, R=9 —
+// see deps/mesen/Core/GBA/Input/GbaController.h). GbaSystem::pressButton
+// does the explicit remap from this wire byte to Mesen's native enum.
+enum class GbaButton : std::uint8_t {
+    Right  = 0,
+    Left   = 1,
+    Up     = 2,
+    Down   = 3,
+    A      = 4,
+    B      = 5,
+    Select = 6,
+    Start  = 7,
+    L      = 8,
+    R      = 9,
+    Count  = 10,
+};