Setting up standalone RetroArch on a Raspberry Pi 4

[anthonycaccese]

I recently worked through the steps to install a standalone version of RetroArch on my Raspberry Pi 4 that I could launch via the new 240-MP scripts module

I wrote up a gist for the steps that worked for me here:
https://gist.github.com/anthonycaccese/f040036665e53c2a15905f106bd1823f

Please keep these notes in mind:

• This is what worked for me and there may be better ways to do this =) (please let me know what's worked for you)
• I've only run this on Raspberry Pi 4 so I am not sure if it works on other Pi models
• I have not yet done any specific video output research for getting direct 240p output when playing a game in RA

What I like about this set up is RA and its settings are completely standalone and easy to launch with or without 240-MP (similar to how I use MPV)

I also have syncthing installed now so I can sync saves/states from RA on my other devices which is nice because I can easily continue a game now on my CRT or a handheld. I added details on how i set up syncthing here: https://github.com/anthonycaccese/240-MP/wiki/Syncthing if you are interested in doing something similar.

Here is a video walkthrough of my current set up:

A001_08171548_C015.mp4

[mkonji008]

Tested this and could get retroarch up and running using 240p on a pi4. i can force 240p through ssh while a game is running but only through ssh and after a game has been started.

You'll need to build "tvservice" from https://github.com/raspberrypi/userland.git with that you can run something like this should get you close.

#!/bin/bash

set -euo pipefail

INSTALL_USER="${SUDO_USER:-${USER}}"

if [[ "${EUID}" -ne 0 ]]; then
    echo "Run with sudo: sudo $0"
    exit 1
fi

TVSERVICE="/usr/local/bin/tvservice"
LIBDIR="/usr/local/lib/raspberry-userland"
MODEDIR="/usr/local/lib/240mp-prog"
MODE="${MODEDIR}/mode"
BUILD_DIR="/tmp/240mp-userland"

echo "Installing for: ${INSTALL_USER}"

# dependencies
apt-get update
apt-get install -y \
    git \
    cmake \
    build-essential \
    pkg-config \
    python3 \
    python3-dev \
    libdrm-dev \
    libudev-dev

# download userland
rm -rf "${BUILD_DIR}"

git clone --depth=1 \
    https://github.com/raspberrypi/userland.git \
    "${BUILD_DIR}"

cd "${BUILD_DIR}"

# build
./buildme --aarch64

# Find tvservice
FOUND_TVSERVICE=""

for candidate in \
    "${BUILD_DIR}/build/bin/tvservice" \
    "${BUILD_DIR}/build/host_applications/linux/apps/tvservice/tvservice" \
    "${BUILD_DIR}/host_applications/linux/apps/tvservice/tvservice" \
    "${BUILD_DIR}/output/opt/vc/bin/tvservice" \
    "${BUILD_DIR}/output/bin/tvservice"
do
    if [[ -x "${candidate}" ]]; then
        FOUND_TVSERVICE="${candidate}"
        break
    fi
done

if [[ -z "${FOUND_TVSERVICE}" ]]; then
    FOUND_TVSERVICE="$(find "${BUILD_DIR}" \
        -type f \
        -name tvservice \
        -perm -111 \
        2>/dev/null | head -n 1 || true)"
fi

if [[ -z "${FOUND_TVSERVICE}" ]]; then
    echo "ERROR: tvservice was not found."
    find "${BUILD_DIR}" -type f -name 'tvservice*' 2>/dev/null || true
    exit 1
fi

echo "found tvservice: ${FOUND_TVSERVICE}"

# install tvservice
mkdir -p "${LIBDIR}"
mkdir -p "$(dirname "${TVSERVICE}")"

install -m 0755 \
    "${FOUND_TVSERVICE}" \
    "${TVSERVICE}"

# install libraries
for lib in \
    libbcm_host.so \
    libvchiq_arm.so \
    libvcos.so
do
    FOUND_LIB="$(find "${BUILD_DIR}" \
        -type f \
        -name "${lib}*" \
        2>/dev/null | head -n 1 || true)"

    if [[ -n "${FOUND_LIB}" ]]; then
        echo "installing ${lib}"
        install -m 0755 \
            "${FOUND_LIB}" \
            "${LIBDIR}/${lib}"
    else
        echo "WARNING: ${lib} not found"
    fi
done

# configure libs
cat > /etc/ld.so.conf.d/raspberry-userland.conf <<EOF
${LIBDIR}
EOF

ldconfig

# mode helper
mkdir -p "${MODEDIR}"

cat > "${MODE}" <<'EOF'
#!/bin/bash

set -u

TVSERVICE="/usr/local/bin/tvservice"

case "${1:-}" in
    240p)
        echo "switching composite output to 240p"
        exec "${TVSERVICE}" -c "NTSC 4:3 P"
        ;;

    480i)
        echo "switching composite output to 480i"
        exec "${TVSERVICE}" -c "NTSC 4:3"
        ;;

    restore)
        echo "restoring 240-mp display mode: 480i"
        exec "${TVSERVICE}" -c "NTSC 4:3"
        ;;

    status)
        exec "${TVSERVICE}" -s
        ;;

    *)
        echo "Usage: $0 {240p|480i|restore|status}"
        exit 1
        ;;
esac
EOF

chmod 0755 "${MODE}"
chown root:root "${MODE}"

chmod 0755 /usr/local/lib
chmod 0755 "${MODEDIR}"

echo
echo "tvservice:"
ls -l "${TVSERVICE}"

echo
echo "libraries:"
ls -l "${LIBDIR}"

echo
echo "mode helper:"
ls -l "${MODE}"

echo
echo "dependencies:"
ldd "${TVSERVICE}" || true

echo
echo "current mode:"
"${TVSERVICE}" -s || true

echo
echo "testing 240p..."
"${MODE}" 240p

echo
echo "restoring 480i..."
"${MODE}" restore

echo
echo "final mode:"
"${MODE}" status

echo
echo "installed."
echo
echo "use:"
echo "  ${MODE} 240p"
echo "  ${MODE} 480i"
echo "  ${MODE} restore"
echo "  ${MODE} status"

That should enable you to pass something like /usr/local/lib/240mp-prog/mode 240p on the fly from a ssh session or from the retroarch.sh execute script. For it to appear correctly from here be sure to boot retroarch as you did before in 480i, load up a game then run /usr/local/lib/240mp-prog/mode 240p If you boot the menu in 240p like i had below it outputs on only half the display.

ex.

#!/bin/bash

MODE="/usr/local/lib/240mp-crt/mode"

cleanup()
{
    "$MODE" restore
}

# always restore 480i when ra exits
trap cleanup EXIT

# start ra first
retroarch "$@" &
RA_PID=$!

# give ra/240-mp time to finish
sleep 2

# switch the comp output to 240p
"$MODE" 240p

# wait for ra to exit
wait "$RA_PID"
RET=$?

exit "$RET"

Retroarch should boot into 240p at that point but weird things happen with the framebuffer after you launch a game and it gets squished.

It might be solvable by creating a custom resolution profile to boot the games and then let switchres handle 480i menus. I sat on this for a while thinking I'd get back to it but I never got around to it. I figured if it's something you still wanted pursue it might get you part of the way there.

Best of luck!

[anthonycaccese]

thank you for the details @mkonji008 ❤️

i've been busy the last few weeks so haven't been able to spend further time on this yet either. but when i am able to make time again your notes here are super helpful so thank you again.