shangon_mod_install.sh

#!/usr/bin/env bash

# Var for top level dir where we will build stuff
BUILD_DIR="${BUILD_DIR:-${HOME}/shangon}"

# Var for mame2003-plus-libretro target platform
MAME_PLATFORM="${MAME_PLATFORM:-rpi4}"
# Var for mame2003-plus-libretro git REMOTE repo URL
GIT_URL_MAME="${GIT_URL_MAME:-https://github.com/neildavis/mame2003-plus-libretro}"
# Var for mame2003-plus-libretro git repo branch
GIT_BRANCH_MAME="${GIT_BRANCH_MAME:-dev-nd}"
# Var for mame2003-plus-libretro git LOCAL repo dir
GIT_DIR_MAME="${GIT_DIR_MAME:-${BUILD_DIR}/mame2003-plus-libretro}"

# Var for alsa_volume_from_usb_hid git REMOTE repo URL
GIT_URL_ALSA_VOL_HID="${GIT_URL_ALSA_VOL_HID:-https://github.com/neildavis/alsa_volume_from_usb_hid.git}"
# Var for alsa_volume_from_usb_hid git repo branch
GIT_BRANCH_ALSA_VOL_HID="${GIT_BRANCH_ALSA_VOL_HID:-main}"
# Var for alsa_volume_from_usb_hid git LOCAL repo dir
GIT_DIR_ALSA_VOL_HID="${GIT_DIR_ALSA_VOL_HID:-${BUILD_DIR}/alsa_volume_from_usb_hid}"

# Var for RetroPie-Setup dir
RETROPIE_SETUP_DIR="${RETROPIE_SETUP_DIR:-${HOME}/RetroPie-Setup}"
# Var for where RetroPie stores libretro cores
LIBRETRO_CORES_DIR="${LIBRETRO_CORES_DIR:-/opt/retropie/libretrocores}"
# Debian verison file path
DEB_VERSION_FILE="/etc/debian_version"
# pigpiod systemd service config file
PIGPIOD_SYSTEMD_SERVICE_FILE="/lib/systemd/system/pigpiod.service"

# Func to clone or update a repo
# $1 = git remote URL, $2 = branch, $3 = dest dir
git_clone_or_pull() {
    echo "Git clone $1 at branch $2 into $3 ..."
    if [[ -d "$3" ]]; then
        # repo has already been cloned, just pull updates
        echo "Dir $3 already exists, pulling updates ..."
        cd $3
        git fetch
        git checkout -f "$2"
        git pull
    else
        # repo has not yet been cloned. clone it
        echo "Cloning $1 at branch $2 into $3 ..."
        git clone -b "$2" "$1" "$3"
    fi
}

# We don't want retroarch running whilst the update proceeds so kill it if its running
echo "Killing any instances of retroarch ..."
killall retroarch 2> /dev/null || true
sleep 1

# Let's get up to date!
echo "Updating OS ..."
# Buster is now legacy, so patch apt sources if we are on Buster
if [[ -f "$DEB_VERSION_FILE" ]]; then
    if grep -q "^10\." "$DEB_VERSION_FILE"; then
        echo "Debian 10 (Buster) detected. Buster is now 'legacy' - updating apt sources..."
        sudo sed -i 's/raspbian.raspberrypi.org/legacy.raspbian.org/g' /etc/apt/sources.list
        echo "apt sources update done."
    else
        echo "Debian version is not 10.x (Buster) Found: $(cat $DEB_VERSION_FILE). No apt sources changes made."
    fi
else
    echo "Error: Debian version file $DEB_VERSION_FILE not found."
    exit 1
fi
# Update package repos index
sudo apt update
# Update OS
sudo apt -y upgrade

# Install build tools and dependencies
echo "Installing build tools and dependencies ..."
sudo apt -y install build-essential git pigpio python3 python3-pip python3-venv python3-dev

# Patch pigpiod systemd config to start pigpiod daemon using PWM hw clock
echo "Ensuring pigpiod uses PWM clock ..."
sudo sed -i '/ExecStart=\/usr\/bin\/pigpiod -l/ { /-t 0/! s/$/ -t 0/ }' "$PIGPIOD_SYSTEMD_SERVICE_FILE"
echo "Reload systemd daemon config and enable & start pigpiod service..."
sudo systemctl daemon-reload
sudo systemctl enable pigpiod.service
sudo systemctl start pigpiod

# Use RetroPie-Setup to ensure that lr-mame2003 is NOT installed and lr-mame2003-plus IS installed
echo "Checking RetroPie libretro cores setup ..."
if [[ -d "${LIBRETRO_CORES_DIR}/lr-mame2003" ]]; then
    echo "lr-mame2003 core is installed in RetroPie. Removing ..."
    cd "${RETROPIE_SETUP_DIR}"
    sudo ./retropie_packages.sh lr-mame2003 remove 
else
    echo "lr-mame2003 core is NOT installed in RetroPie. Good!"
fi
if [[ ! -d "${LIBRETRO_CORES_DIR}/lr-mame2003-plus" ]]; then
    echo "lr-mame2003-plus core is NOT installed in RetroPie. Installing ..."
    cd "${RETROPIE_SETUP_DIR}"
    sudo ./retropie_packages.sh lr-mame2003-plus install_bin
    sudo ./retropie_packages.sh lr-mame2003-plus configure
else
    echo "lr-mame2003-plus core IS installed in RetroPie. Good!"
fi

# Start to build stuff. Make the dir where we will clone code and build stuff
mkdir -p "${BUILD_DIR}"

# Clone the alsa_volume_from_usb_hid repo
git_clone_or_pull "${GIT_URL_ALSA_VOL_HID}" "${GIT_BRANCH_ALSA_VOL_HID}" "${GIT_DIR_ALSA_VOL_HID}"
# Clone the mame2003-plus-libretro repo
git_clone_or_pull "${GIT_URL_MAME}" "${GIT_BRANCH_MAME}" "${GIT_DIR_MAME}"

# Build and install alsa_volume_from_usb_hid
echo "Building and installing alsa_volume_from_usb_hid ..."
cd "${GIT_DIR_ALSA_VOL_HID}"
make install

# Build the lrmame2003osvr outputs server
echo "Building lrmame2003osvr (outputs server)"
cd "${GIT_DIR_MAME}/outputs"
if [[ -f "$HOME/bin/lrmame2003osvr" ]]; then
    echo "Removing previous lrmame2003osvr install"
    make uninstall
fi
make ROMS=shangon install
# Start the outputs server
systemctl --user start lrmame2003osvr 2> /dev/null || true

# Build mame2003-plus-libretro core
echo "Building mame2003-plus-libretro.so ..."
cd "${GIT_DIR_MAME}"
make system_platform=unix platform="${MAME_PLATFORM}" -j$(nproc)

# Replace RetroPie version of mame2003-plus-libretro.so with the one we just built
echo "Replacing RetroPie installed version of mame2003_plus_libretro.so with modified version we built ..."
RETROPIE_MAME_2003_PLUS_LIB="${LIBRETRO_CORES_DIR}/lr-mame2003-plus/mame2003_plus_libretro.so"
RETROPIE_MAME_2003_PLUS_LIB_BAK="${RETROPIE_MAME_2003_PLUS_LIB}.bak"
# Create a backup and symlink to redirect the original lib to our built version
if [[ ! -L "${RETROPIE_MAME_2003_PLUS_LIB}" ]]; then
    # Backup the original
    if [[ ! -f "${RETROPIE_MAME_2003_PLUS_LIB_BAK}" ]]; then
        sudo mv "${RETROPIE_MAME_2003_PLUS_LIB}" "${RETROPIE_MAME_2003_PLUS_LIB_BAK}"
        echo "Made a backup of RetroPie installed version of mame2003_plus_libretro.so at ${RETROPIE_MAME_2003_PLUS_LIB_BAK}"
    fi
    sudo ln -fs "${GIT_DIR_MAME}/mame2003_plus_libretro.so" "${RETROPIE_MAME_2003_PLUS_LIB}"
    echo "Created symbolic link for mame2003_plus_libretro.so at ${RETROPIE_MAME_2003_PLUS_LIB}"
else
    echo "Symbolic link for mame2003_plus_libretro.so already exists at ${RETROPIE_MAME_2003_PLUS_LIB}"
fi