feat: Intel HDA audio driver, audio streaming syscalls, userspace Music app, fixes and improvements, rudimentary Bluetooth support

kernel/src/Api/Audio.hpp

@@ -0,0 +1,90 @@
+/*
+    * Audio.hpp
+    * Audio syscall implementations
+    * Routes audio to Intel HDA or Bluetooth A2DP based on handle
+    * Copyright (c) 2026 Daniel Hammer
+*/
+
+#pragma once
+#include <cstdint>
+#include <Drivers/Audio/IntelHda.hpp>
+#include <Drivers/USB/Bluetooth/Bluetooth.hpp>
+#include <Drivers/USB/Bluetooth/A2dp.hpp>
+
+#include "Syscall.hpp"
+
+namespace Montauk {
+
+    // Audio handle convention:
+    //   0x00 - 0x0F : Intel HDA handles
+    //   0x100       : Bluetooth A2DP audio output
+
+    static constexpr int AUDIO_HANDLE_BT = 0x100;
+
+    static int64_t Sys_AudioOpen(uint32_t sampleRate, uint8_t channels, uint8_t bitsPerSample) {
+        // If HDA is available, use it (primary output)
+        if (Drivers::Audio::IntelHda::IsInitialized()) {
+            return (int64_t)Drivers::Audio::IntelHda::Open(sampleRate, channels, bitsPerSample);
+        }
+
+        // Fallback: try Bluetooth audio if available
+        if (Drivers::USB::Bluetooth::IsInitialized()) {
+            auto state = Drivers::USB::Bluetooth::A2dp::GetState();
+            if (state == Drivers::USB::Bluetooth::A2dp::State::Open ||
+                state == Drivers::USB::Bluetooth::A2dp::State::Streaming ||
+                state == Drivers::USB::Bluetooth::A2dp::State::Configured) {
+                Drivers::USB::Bluetooth::A2dp::ConfigureStream(sampleRate, channels, bitsPerSample);
+                Drivers::USB::Bluetooth::A2dp::StartStream();
+                return AUDIO_HANDLE_BT;
+            }
+        }
+
+        return -1;
+    }
+
+    static int64_t Sys_AudioClose(int handle) {
+        if (handle == AUDIO_HANDLE_BT) {
+            Drivers::USB::Bluetooth::A2dp::StopStream();
+            return 0;
+        }
+        Drivers::Audio::IntelHda::Close(handle);
+        return 0;
+    }
+
+    static int64_t Sys_AudioWrite(int handle, const uint8_t* data, uint32_t size) {
+        if (handle == AUDIO_HANDLE_BT) {
+            return (int64_t)Drivers::USB::Bluetooth::A2dp::WriteAudio(data, size);
+        }
+        return (int64_t)Drivers::Audio::IntelHda::Write(handle, data, size);
+    }
+
+    static int64_t Sys_AudioCtl(int handle, int cmd, int value) {
+        if (handle == AUDIO_HANDLE_BT) {
+            switch (cmd) {
+                case AUDIO_CTL_SET_VOLUME:
+                    Drivers::USB::Bluetooth::A2dp::SetVolume(value);
+                    return 0;
+                case AUDIO_CTL_GET_VOLUME:
+                    return Drivers::USB::Bluetooth::A2dp::GetVolume();
+                case AUDIO_CTL_PAUSE:
+                    if (value) Drivers::USB::Bluetooth::A2dp::StopStream();
+                    else Drivers::USB::Bluetooth::A2dp::StartStream();
+                    return 0;
+                case AUDIO_CTL_GET_OUTPUT:
+                    return 1;  // Bluetooth
+                default:
+                    return -1;
+            }
+        }
+
+        // Additional control commands for audio routing
+        if (cmd == AUDIO_CTL_GET_OUTPUT) return 0;  // HDA
+        if (cmd == AUDIO_CTL_BT_STATUS) {
+            if (!Drivers::USB::Bluetooth::IsInitialized()) return 0;
+            return (int64_t)Drivers::USB::Bluetooth::A2dp::GetState();
+        }
+
+        return (int64_t)Drivers::Audio::IntelHda::Control(handle, cmd, value);
+    }
+
+};