raspberry-pi-mixer/scripts/carla-build.sh

#!/bin/bash
# carla-build.sh — Build Carla plugin host from source for RPi4B (ARM Cortex-A72)
# Run on the Raspberry Pi 4B directly. Estimated build time: 30-60 min.
#
# Usage:
#   chmod +x carla-build.sh
#   ./carla-build.sh              # Build only
#   ./carla-build.sh --install    # Build + install to /usr/local
#   ./carla-build.sh --clean      # Clean and rebuild

set -euo pipefail

CARLA_VERSION="2.6.0-alpha1"
CARLA_REPO="https://github.com/falkTX/Carla.git"
CARLA_DIR="/tmp/carla-build"
INSTALL_PREFIX="/usr/local"
JOBS=$(nproc 2>/dev/null || echo 4)

# Cortex-A72 optimized flags for aarch64
# -march=armv8-a+crc+crypto covers baseline A72 features
# -mtune=cortex-a72 schedules for A72 pipeline
# -O3 -ffast-math: aggressive math (safe for audio)
A72_CFLAGS="-march=armv8-a+crc+crypto -mtune=cortex-a72 -O3 -ffast-math -fdata-sections -ffunction-sections -fvisibility=hidden"
A72_CXXFLAGS="-march=armv8-a+crc+crypto -mtune=cortex-a72 -O3 -ffast-math -fdata-sections -ffunction-sections -fvisibility=hidden -fvisibility-inlines-hidden"

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m'

log()  { echo -e "${GREEN}[carla-build]${NC} $*"; }
warn() { echo -e "${YELLOW}[carla-build] WARN:${NC} $*"; }
err()  { echo -e "${RED}[carla-build] ERROR:${NC} $*" >&2; exit 1; }

# ── Installation mode ──────────────────────────────────
INSTALL=false
CLEAN=false
while [[ $# -gt 0 ]]; do
    case "$1" in
        --install) INSTALL=true; shift ;;
        --clean)   CLEAN=true; shift ;;
        *)         echo "Unknown flag: $1"; exit 1 ;;
    esac
done

# ── Check platform ─────────────────────────────────────
ARCH=$(uname -m)
if [[ "$ARCH" != "aarch64" ]] && [[ "$ARCH" != "armv7l" ]]; then
    warn "Not running on ARM (detected $ARCH). Cross-compilation not supported by this script."
    warn "Run this script directly on the Raspberry Pi 4B."
fi

# ── Install build dependencies ─────────────────────────
log "Installing build dependencies..."
sudo apt update -qq
sudo apt install -y \
    build-essential \
    git \
    cmake \
    pkg-config \
    g++ \
    gcc \
    make \
    libasound2-dev \
    libjack-jackd2-dev \
    libpulse-dev \
    libsndfile1-dev \
    libx11-dev \
    libxcursor-dev \
    libxext-dev \
    libxrandr-dev \
    libfreetype6-dev \
    libfontconfig1-dev \
    libgl1-mesa-dev \
    liblo-dev \
    libmagic-dev \
    libfluidsynth-dev \
    libsmf-dev \
    python3-pyqt5 \
    python3-pyqt5.qtsvg \
    python3-rdflib \
    pyqt5-dev-tools \
    python3-dev \
    python3-liblo \
    qtbase5-dev \
    qtbase5-dev-tools \
    libfftw3-dev \
    librtmidi-dev \
    libzita-resampler-dev

# Optional: VST3 SDK (needed for VST3 plugin hosting)
# The VST3 SDK must be obtained separately from Steinberg.
# We check for it but don't error if absent.
VST3_SDK_DIR="/opt/vst3sdk"
VST3_AVAILABLE=false
if [ -d "$VST3_SDK_DIR" ]; then
    log "VST3 SDK found at $VST3_SDK_DIR"
    VST3_AVAILABLE=true
else
    warn "VST3 SDK not found at $VST3_SDK_DIR"
    warn "To add VST3 plugin hosting, download from:"
    warn "  https://github.com/steinbergmedia/vst3sdk.git"
    warn "  sudo git clone --recursive https://github.com/steinbergmedia/vst3sdk.git /opt/vst3sdk"
    warn "Continuing without VST3 support..."
fi

# ── Clone Carla ────────────────────────────────────────
if [ "$CLEAN" = true ] || [ ! -d "$CARLA_DIR" ]; then
    log "Cloning Carla repository..."
    rm -rf "$CARLA_DIR"
    git clone --depth 1 --branch main "$CARLA_REPO" "$CARLA_DIR"
fi

cd "$CARLA_DIR"

# ── Patch Makefile for ARM Cortex-A72 ─────────────────
log "Patching Carla Makefile for Cortex-A72 optimization..."

# Back up original
if [ ! -f source/Makefile.mk.orig ]; then
    cp source/Makefile.mk source/Makefile.mk.orig
fi

# Add ARM64 optimization flags after the ARM32 section
if ! grep -q "CPU_ARM64_OR_AARCH64" source/Makefile.mk; then
    sed -i '/^ifeq .*CPU_ARM_OR_AARCH64.*/,/^endif/{
        /^endif/{
            i\
\
ifeq ($(CPU_ARM64_OR_AARCH64),true)\
BASE_OPTS += -march=armv8-a+crc+crypto -mtune=cortex-a72\
endif
        }
    }' source/Makefile.mk
    log "Added ARM64 optimization block to Makefile.mk"
fi

# Check for features
log "Checking available features..."
make features 2>&1 | tee /tmp/carla-features.log || true

# ── Build Carla ────────────────────────────────────────
log "Building Carla (${JOBS} parallel jobs)..."
export CFLAGS="$A72_CFLAGS"
export CXXFLAGS="$A72_CXXFLAGS"

# Build with all available features
# NOOPT= removes CPU-specific flags so we can supply our own
# WITH_LTO=true enables link-time optimization for smaller/faster binary
make -j"$JOBS" \
    PREFIX="$INSTALL_PREFIX" \
    WITH_LTO=true \
    2>&1 | tee /tmp/carla-build.log

log "Carla build complete."

# ── Check build results ───────────────────────────────
if [ -f "source/frontend/carla" ]; then
    log "✓ Carla frontend binary built successfully."
else
    err "Carla frontend binary not found. Check /tmp/carla-build.log"
fi

# ── Install (optional) ─────────────────────────────────
if [ "$INSTALL" = true ]; then
    log "Installing Carla to $INSTALL_PREFIX..."
    sudo make install PREFIX="$INSTALL_PREFIX"
    sudo ldconfig

    # Verify installation
    if command -v carla >/dev/null 2>&1; then
        log "✓ Carla installed successfully: $(which carla)"
    else
        warn "Carla binary not on PATH. It may be in /usr/local/bin/carla"
    fi

    # Create desktop integration
    if [ -f "resources/carla.desktop" ]; then
        sudo cp resources/carla.desktop /usr/local/share/applications/
    fi
fi

# ── Output summary ─────────────────────────────────────
log ""
log "╔══════════════════════════════════════════════╗"
log "║   Carla Build Summary                         ║"
log "╚══════════════════════════════════════════════╝"
log ""
log "  Binary:      $CARLA_DIR/source/frontend/carla"
log "  Install:     $([ "$INSTALL" = true ] && echo "yes" || echo "no (use --install)")"
log "  Platform:    $ARCH (Cortex-A72 optimized)"
log "  Plugins:     LV2, LADSPA, DSSI, SF2/SFZ"
log "  VST3:        $([ "$VST3_AVAILABLE" = true ] && echo "yes" || echo "no (install VST3 SDK)")"
log "  JACK:        yes (ALSA backend)"
log "  OSC:         yes (liblo)"
log "  FluidSynth:  yes (SF2/SFZ)"
log ""
log "  Next steps:"
log "    1. Start JACK:    sudo audio-stack-start"
log "    2. Run Carla:     carla ./config/carla-default.carxp"
log "    3. Build NAM:     ./scripts/nam-build.sh"
log ""