etheling/00_enable_kmsdrm.sh Secret

## 00_enable_kmsdrm.sh
#!/bin/bash

##
## Configure RetroPie to run under Linux KMS/DRM mode on Ubuntu 20.04 LTS.
## Supports only Intel (and virtual) framebuffers. Specifically nVidia and
## Radeon based systems are not properly set up by this script.
##
## Optional post-install setup-script (set __has_kms to enable) for
## https://github.com/MizterB/RetroPie-Setup-Ubuntu/blob/master/retropie_setup_ubuntu.sh
## and install this script to ~/optional_scripts/post_install before running ./retropie_setup_ubuntu.sh

## Control behaviour of script
__XRES="1920"          # target X & Y resolution (1080p)
__YRES="1080"

#__FB_DEV="/dev/fb0"   # set to skip i915 detection
#__KOPT_VIDEO=...      # set to skip resolution probing
#__KEEP_SPLASH=1       # set to keep plymouth/splash

__SLEEP=2              # delay between tasks

## TODO:
## - Enable early KMS start (https://wiki.archlinux.org/index.php/Kernel_mode_setting#Early_KMS_start)
## - Support radeon, maybe nvidia
## - Consider https://wiki.archlinux.org/index.php/intel_graphics#Enable_GuC_/_HuC_firmware_loading
## - Warn nvidia or radeon cards are found

##
USER="$SUDO_USER"
USER_HOME="/home/$USER"
if [ -z $SCRIPT_DIR ]; then
    SCRIPT_DIR=$(dirname $(realpath $0))
fi

# Backup system config file(s) before modifications (Eth)
function backupFile() {
    if [ ! -f "$1" ] ; then
	echo "-> backupFile: $1 does not exist. Not creating $1.orig"
	return
    fi
    if [ ! -f "$1.orig" ]; then
	echo "-> Backing up $1 -> $1.orig"
	cp $1 $1.orig
    else
	echo "-> backupFile: $1.orig already exists (and cowardly refusing to overwrite)"
    fi
}

##
function install_kmsdrm_depends() {
    echo "--------------------------------------------------------------------------------"
    echo "| install_kmsdrm_depends: TBD"
    echo "--------------------------------------------------------------------------------"

    apt-get install -y fbset

    echo -e "FINISHED install_kmsdrm_depends \n\n"
    sleep $__SLEEP
}

## Set FB_DEV, and set FB_i915 if i915 found
function is_it_i915_fb() {
    echo "--------------------------------------------------------------------------------"
    echo "| find_i915_fb: TBD"
    echo "--------------------------------------------------------------------------------"

    ## TODO: early exit if FB_DEV is set

    local __fb="null"
    local __tmp_fb="/dev/fb0"

    ## Assumes single display setup; one display ought to be enough for anybody...
    if [ ! $(cat /proc/fb | wc -l) -eq 1 ]; then
	echo "WARNING: More than one framebuffer found. This may produce unexpected results."
    fi

    ## https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/deployment_guide/s2-proc-fb
    echo "-> Probe /proc/fb to find if we have intel i915 framebuffer"
    __fb=$(cat /proc/fb | grep i915drmfb)
    if [ ! $? -eq 0 ]; then
	echo "-> Cannot find i915 framebuffer. Available framebuffers / displays are:"
	ls -l /dev/fb*
	cat /proc/fb
	lshw -c display -short
	FB_DEV=$__tmp_fb
	echo "-> Using /dev/fb0 for configuration"

    else
	export FB_DEV="/dev/fb$(echo $__fb | cut -d' ' -f1)"
	FB_i915=1
	echo "-> Found i915drmfb. Framebuffer device is $FB_DEV ($__fb)"
    fi

    ## Test that ($FB_DEV) is FB that we're (propably) looking at...
    fbset -fb $FB_DEV > /dev/null 2>&1
    if [ ! $? -eq 0 ]; then
	echo "ERROR: cannot verify that $FB_DEV is usable. Reverting back to $__tmp_fb"
	unset FB_i915
	export FB_DEV=$__tmp_fb
    fi

    echo -e "FINISHED is_it_i915_fb \n\n"
    sleep $__SLEEP
}


# Useful for getting systems with max resolution less than 1080p configured
function find_fb_max_resolution() {
    echo "--------------------------------------------------------------------------------"
    echo "| Detect if framebuffer supports ${__XRES}x${__YRES}, if not try to determine"
    echo "| usable resolution (using $FB_DEV)"
    echo "--------------------------------------------------------------------------------"

    local __fb=$FB_DEV
    local __x=$__XRES
    local __y=$__YRES

    echo "/proc/fb: "
    cat /proc/fb
    fbset -fb $__fb -s

    ## Test if we can set 1080p
    echo "-> Testing if we can set framebuffer $__fb to $__XRES x $__YRES resolution"
    fbset --test -fb $__fb -xres $__XRES -yres $__YRES -match
    if [ ! $? -eq 0 ]; then
	## Note: on VMs we might get lower then max, but on real hw, expectation is max supported (assuming kernel supports hw)
	echo "-> 1080p does not appear to be supported by $__fb. Getting current resolution."
	local __tempres=`sudo fbset -fb $__fb -s | sed -n -e 's/^.*geometry //p'`
	__XRES=`echo $__tempres | cut -d' ' -f1`
	__YRES=`echo $__tempres | cut -d' ' -f2`
	## double check that what we got can be set
	fbset --test -fb $__fb -xres $__XRES  -yres $__YRES -match
	if [ ! $? -eq 0 ]; then
	    echo "ERROR: cannot determine appropriate resolution. Falling back to 1920x1080."
	    echo "       It is likely you will experience resolution issues"
	    __XRES=$__x
	    __YRES=$__y
	fi
    	## TODO: test if we ended up with larger than 1080p for some reason
    fi
    echo "-> Using $__XRES x $__YRES for X and framebuffer default resolutions"

    echo -e "FINISHED find_fb_max_resolution \n\n"
    sleep $__SLEEP
}


## Build video= kernel boot option string. Assumes only one connected display; falls back
## to generic form if multiple connected displays
function build_kernel_video_option() {
    echo "--------------------------------------------------------------------------------"
    echo "| Construct video= kernel boot option from /sys/class/drm/card*"
    echo "--------------------------------------------------------------------------------"

    local __card="null"

    # determine video= parameter(s)
    echo "-> List of output ports under /sys/class/drm/*:"
    for p in /sys/class/drm/*/status; do con=${p%/status}; echo -n "${con#*/card?-}: "; cat $p; done
    if [ ! $(cat /sys/class/drm/*/status | grep -w "connected" | wc -l) -eq 1 ]; then
	__KOPT_VIDEO="video=${__XRES}x${__YRES}"
	echo "WARNING: multiple (or zero) connected displays found. This is untested setup."
	echo "         Falling back to generic $__KOPT_VIDEO kernel parameter."
	return
    fi

    for i in /sys/class/drm/*/status ; do
	cat $i | grep -w 'connected' > /dev/null
	if [ $? -eq 0 ]; then
	    __card=$i
	    break
	fi
    done
    #echo $CARD | cut -d'/' -f5 | cut -d'-' -f2-
    __KOPT_VIDEO="video=$(echo $__card | cut -d'/' -f5 | cut -d'-' -f2-):${__XRES}x${__YRES}"

    echo "-> Kernel video boot option: ${__KOPT_VIDEO}"

    echo -e "FINISHED build_kernel_video_option \n\n"
    sleep $__SLEEP
}

# Sets the GRUB graphics mode
# URL: https://www.gnu.org/software/grub/manual/grub/html_node/gfxmode.html
function update_grub_resolution() {
    if [[ -z "$1" ]]; then
        MODES="auto"
    else
        MODES="$1,auto"
    fi
    echo "--------------------------------------------------------------------------------"
    echo "| Changing the GRUB graphics mode to '$MODES' and adds"
    echo "| GRUB_GFXPAYLOAD_LINUX=\"keep\" to minimize display mode switching"
    echo "--------------------------------------------------------------------------------"

    local __ggpl=""

    grep GRUB_GFXPAYLOAD_LINUX /etc/default/grub > /dev/null 2>&1
    if [ ! $? -eq 0 ]; then
	__ggpl="\\nGRUB_GFXPAYLOAD_LINUX=\"keep\""
    fi
    sed -i "s/GRUB_GFXMODE=.*/GRUB_GFXMODE=${MODES}${__ggpl}/g" "/etc/default/grub"
    update-grub

    egrep "(GRUB_GFXMODE|GRUB_GFXPAYLOAD)" /etc/default/grub

    echo -e "FINISHED update_grub_resolution \n\n"
    sleep $__SLEEP
}

# Eth:
# Sets FB resolution using video= kernel boot parameter
function set_kernel_fb_resolution() {
    echo "--------------------------------------------------------------------------------"
    echo "| Adding video=${__XRES}x${__YRES} kernel parameter to /etc/default/grub"
    echo "--------------------------------------------------------------------------------"
    backupFile /etc/default/grub

    if [ -z $__KOPT_VIDEO ]; then
	build_kernel_video_option
    fi

    local __KOPT_MS=""
    if [ ! -z $FB_i915 ]; then
	## https://wiki.archlinux.org/index.php/Intel_graphics
	__KOPT_MS="i915.modeset=1 "
	echo "-> FB_i915 set. Adding option $__KOPT_MS"

    fi

    ## https://retropie.org.uk/forum/topic/18810/retropie-installation-on-ubuntu-server-x64-18-04-1/161
    sed -i "s/GRUB_CMDLINE_LINUX_DEFAULT=\"[^\"]*/& ${__KOPT_MS}${__KOPT_VIDEO}/" /etc/default/grub
    update-grub
    grep "GRUB_CMDLINE_LINUX_DEFAULT" /etc/default/grub

    echo -e "FINISHED set_kernel_fb_resolution \n\n"
    sleep $__SLEEP
}

# Eth:
function install_xorgconf() {
    XORGCONF="/etc/X11/xorg.conf"
    echo " "
    echo "+-------------------------------------------------------------------------------"
    echo "| Install $XORGCONF to set default X11 resolution to match"
    echo "| console resoluton (${__XRES}x${__YRES}) to avoid mode switches during boot"
    echo "+-------------------------------------------------------------------------------"

    backupFile $XORGCONF

    cat << EOF > $XORGCONF
## Sets X startup resolution to $__XRES x $__YRES as to avoid modeswitch
## https://wiki.ubuntu.com/X/Config/Resolution
Section "Monitor"
        Identifier      "Configured Monitor"
EndSection

Section "Screen"
        Identifier      "Default Screen"
        Monitor         "Configured Monitor"
        Device          "Configured Video Device"
           SubSection "Display"
                Virtual $__XRES $__YRES
           EndSubSection
EndSection

Section "Device"
        Identifier      "Configured Video Device"
EndSection
EOF
    chown root:root $XORGCONF
    #rw-r--r--
    chmod 644 $XORGCONF

    echo -e "FINISHED xorg_conf \n\n"
    sleep $__SLEEP
}

## .xsession that supports launching openbox, or a port; resolution set via /etc/X11/...
function rewrite_xsession() {
    echo "--------------------------------------------------------------------------------"
    echo "| FIXME: Update .xsession"
    echo "--------------------------------------------------------------------------------"
    backupFile $USER_HOME/.xsession

    cat << EOF > $USER_HOME/.xsession
## Support launching openbox and full screen games via RetroPie ports

## document xrandr output \$XRANDR_LOG
XRANDR_LOG=/dev/shm/xrand_modes.log
xrandr --version >> \$XRANDR_LOG 2>&1
xrandr >> \$XRANDR_LOG 2>&1

# Disable screen blanking (only happens outside of EmulationStation)
# This prevents the display from doing any ‘screen blanking’ due to inactivity
xset s off && xset -dpms

if [ ! -f /dev/shm/portruncommand.sh ] ; then
    exec openbox-session
else
    ## don't exec; we want to return & exit
    /dev/shm/portruncommand.sh
fi
EOF

    echo -e "FINISHED rewrite_xsession \n\n"
    sleep $__SLEEP
}

## Eth: Start emulationstation as soon as user is logged in
function enable_autostart_emulationstation() {
    echo "--------------------------------------------------------------------------------"
    echo "| Enabling autostart of EmulationStation in KMS/DRM mode via .bash_profile"
    echo "--------------------------------------------------------------------------------"
    backupFile $USER_HOME/.bash_profile

    sed -i '/startx/a\    emulationstation' $USER_HOME/.bash_profile
    sed -i '/startx/a\    # dont exec emulationstation: otherwise ES gets restarted on exit (F4)' $USER_HOME/.bash_profile
    sed -i 's/.*startx/#&/' $USER_HOME/.bash_profile

    chown $USER:$USER $USER_HOME/.bash_profile

    echo -e "FINISHED enable_autostart_emulationstation \n\n"
    sleep $__SLEEP
}

function disable_plymouth_splash() {
    echo "--------------------------------------------------------------------------------"
    echo "| Disable Plymouth theme by removing splash from /etc/default/grub"
    echo "--------------------------------------------------------------------------------"
    backupFile /etc/default/grub
    ## TODO: purge plymouth?

    ## TODO: etc/default/grub *should* not have other lines with 'splash'....but
    sed -i 's/\<splash\>//g' /etc/default/grub
    update-grub

    echo -n "-> Updated /etc/default/grub:GRUB_CMDLINE_LINUX_DEFAULT:"
    grep "GRUB_CMDLINE_LINUX_DEFAULT" /etc/default/grub

    echo -e "FINISHED disable_plymouth_splash \n\n"
    sleep $__SLEEP
}

function fix_quirks_kmsdrm() {
    echo "--------------------------------------------------------------------------------"
    echo "| Fixing any known quirks for KMS/DRM mode"
    echo "--------------------------------------------------------------------------------"

    echo " "
    echo "+-------------------------------------------------------------------------------"
    echo "| Add rpie user to the input group to allow /dev/input/* access"
    echo "| (needed for KSM/DRM mode with linxuraw/udev access"
    echo "+-------------------------------------------------------------------------------"
    ## https://github.com/libretro/RetroArch/issues/5033
    ## done already in helpers.sh: echo 'SUBSYSTEM=="input", GROUP="input", MODE="0660"' > /etc/udev/rules.d/99-input.rules
    usermod -a -G input $USER

    FBSET=`which fbset`
    echo " "
    echo "+-------------------------------------------------------------------------------"
    echo "| Allow $FBSET to be executed by non-root users"
    echo "| (used by /opt/retropie/supplementary/runcommand/runcommand.sh)"
    echo "+-------------------------------------------------------------------------------"
    ## https://stackoverflow.com/questions/53052294/managing-linux-framebufferfb0-permission-in-low-level-c-graphics-code
    usermod -a -G video $USER
    chgrp video /usr/bin/fbset
    chmod g+s $FBSET

    echo " "
    echo "+-------------------------------------------------------------------------------"
    echo "| Update /opt/retropie/config/all/retroarch.cfg to use audio_driver = alsa"
    echo "| (needed by KMS/DRM)"
    echo "+-------------------------------------------------------------------------------"
    cp -fv /opt/retropie/configs/all/retroarch.cfg /opt/retropie/configs/all/retroarch.cfg.orig
    sed -i '/# audio_driver =/c\audio_driver = \"alsa\"' /opt/retropie/configs/all/retroarch.cfg

    echo -e "FINISHED fix_quirks_kmsdrm \n\n"
    sleep $__SLEEP
}

# Install latest stock libsdl2
function install_local_libsdl2_with_kmsdrm() {
    echo "--------------------------------------------------------------------------------"
    echo "| Install local libsdl2 with KMS/DRM enabled"
    echo "--------------------------------------------------------------------------------"

    echo "-> Remove (possible) hold on libsdl2-dev package"
    dpkg --list | grep sdl2
    ## unhold all packages. But because this is fresh install, onluy libsdl2-dev should be on hold if installed by retropie
    ## https://askubuntu.com/questions/164587/how-can-you-unhold-remove-a-hold-on-a-package
    apt-mark unhold $(apt-mark showhold)

    echo "-> Install depends. Most/all should be installed already."
    apt-get install -y libasound2-dev libudev-dev libibus-1.0-dev libdbus-1-dev fcitx-libs-dev libsndio-dev libsamplerate0-dev libpulse-dev libwayland-dev libdrm-dev libgbm-dev

    #git clone https://github.com/RetroPie/SDL-mirror "retropie-2.0.10"
    #cd retropie-2.0.10
    # for some reason git clone https://github.com/RetroPie/SDL-mirror "retropie-2.0.10" version doesn't work

    echo "-> Get latest version of libsdl2"
    cd $USER_HOME


    ## sha1sum of SDL2-2.0.12.tar.gz from libsdl.org on 20201015 - do at least minimal effort
    ## to check that we're getting what we're expecting (https://www.gnupg.org/download/integrity_check.html)

    #local __SHA1SUM="e8ba91bf5eb438dbcf1fedf0530a1bcbe30d3bb6"
    #wget https://www.libsdl.org/release/SDL2-2.0.12.tar.gz

    local __LIBSDL2="SDL2-2.0.14"
    local __SDL2VER=$(echo ${__LIBSDL2} | cut -d- -f2)
    local __SHA1SUM="212b17d988c417a1a905ab09c50d1845cc48ddb7"
    wget https://www.libsdl.org/release/${__LIBSDL2}.tar.gz
    local __SHA1SUMNEW=`sha1sum ./${__LIBSDL2}.tar.gz | cut -d' ' -f1`

    if [ "$__SHA1SUM" != "$__SHA1SUMNEW" ]; then
	echo "ERROR: sha1sum of downloaded file doesn't match with previously recorded value."
	echo "ERROR: make sure ${__LIBSDL2}.tar.gz has not been tampered with. Aborting."
	exit 1
    fi

    tar zxf ${__LIBSDL2}.tar.gz
    cd ${__LIBSDL2}
    ./configure --enable-video-kmsdrm --prefix=/usr/local/lib/libsdl2-${__SDL2VER}
    make -j`grep -c ^processor /proc/cpuinfo`
    make install

    echo "-> Add local libsdl2 to ld.so.cache. Current versions of SDL2 are:"
    ldconfig -p | grep SDL
    echo "-> cat /etc/ld.so.conf.d/x86_64-linux-gnu.conf for library paths/search order"
    cat /etc/ld.so.conf.d/x86_64-linux-gnu.conf
    ## FIXME: read in first uncommented line and use that (should be /usr/local/lib/x86_64-linux-gnu on 20.04)
    mkdir -p /usr/local/lib/x86_64-linux-gnu
    echo "-> symlink to installed .so and rebuild ld.so.cache"
    ln -s /usr/local/lib/libsdl2-${__SDL2VER}/lib/libSDL2-2.0.so.0 /usr/local/lib/x86_64-linux-gnu
    ldconfig
    echo "-> ld.so.cache entries for libsdl2:"
    ldconfig -p | grep SDL
    echo "-> test that retroarch uses this copy"
    ldd /opt/retropie/emulators/retroarch/bin/retroarch  | grep libSDL2

    cd $USER_HOME
    mv -v ${__LIBSDL2} RetroPie-Setup/
    mv -v ${__LIBSDL2}.tar.gz RetroPie-Setup/

    echo -e "FINISHED install_local_libsdl2_with_kmsdrm \n\n"
    sleep $__SLEEP

}


function disable_es_openbox_autostart() {
    echo "--------------------------------------------------------------------------------"
    echo "| disable ES start from ~/.config/openbox/autostart as it is now laucnhed"
    echo "| from ~/.bash_profile"
    echo "--------------------------------------------------------------------------------"

    backupFile $USER_HOME/.config/openbox/autostart
    sed -i 's/.*autostart/#&/' $USER_HOME/.config/openbox/autostart

    ## TODO: maybe don't disable unclutter
    sed -i 's/.*unclutter/#&/' $USER_HOME/.config/openbox/autostart

    echo -e "FINISHED disable_es_openbox_autostart \n\n"
    sleep $__SLEEP
}

function normalize_gnome_terminal() {
    echo "--------------------------------------------------------------------------------"
    echo "| Comment out gnome terminal modifications from ~/.bash_profile"
    echo "--------------------------------------------------------------------------------"

    backupFile $USER_HOME/.bash_profile
    sed -i 's/.*gsettings/#&/' $USER_HOME/.bash_profile

    mv -v $USER_HOME/.config/openbox/rc.xml $USER_HOME/.config/openbox/rc.xml.retropie

    echo -e "FINISHED normalize_gnome_terminal \n\n"
    sleep $__SLEEP
}


function are_we_root() {
    # Make sure the user is running the script via sudo
    if [ -z "$SUDO_USER" ]; then
	echo "This script requires sudo privileges. Please run with: sudo $0"
	exit 1
    fi
    # Don't allow the user to run this script from the root account. RetroPie doesn't like this.
    if [[ "$SUDO_USER" == root ]]; then
	echo "This script cannot be run by the root user.  Please run as normal user using sudo."
	exit 1
    fi
}

### 1,2,3,...
if [ ! -z $__has_kms ]; then
    are_we_root
    echo "KMS/DRM setup activated."
    echo ""
    echo "Configure RetroPie to run under Linux KMS/DRM mode on Ubuntu 20.04 LTS."
    echo "Supports only Intel (and virtual) framebuffers. Specifically nVidia and"
    echo "Radeon based systems are not properly set up by this script."

    install_kmsdrm_depends

    is_it_i915_fb                # Find if we have i915 FB
    find_fb_max_resolution # Find if FB can support 1080p; if not try to find lower working resolution
    update_grub_resolution "${__XRES}x${__YRES}x32,1920x1440x32"
    set_kernel_fb_resolution    # Sets kernel video=
    install_xorgconf            # create /etc/X11/xorg.conf (match FB resolution)
    fix_quirks_kmsdrm

    install_local_libsdl2_with_kmsdrm

    ## Roll back / modify changes
    enable_autostart_emulationstation
    rewrite_xsession
    disable_es_openbox_autostart
    normalize_gnome_terminal
    if [ -z $__KEEP_SPLASH]; then
	disable_plymouth_splash
    fi

else
    echo "-> __has_kms is not set. Skipping KMS/DRM setup."
fi

## retropie_setup_ubuntu.sh
#! /bin/bash
# https://github.com/MizterB/RetroPie-Setup-Ubuntu/blob/master/retropie_setup_ubuntu.sh

## Optional features (Eth:)
export __has_kms=1                  # if set, setup to run in KMS mode (Intel only)

# Computed variables
USER="$SUDO_USER"
USER_HOME="/home/$USER"
SCRIPT_PATH="$(realpath $0)"
SCRIPT_DIR="$(dirname $SCRIPT_PATH)"
SCRIPT_FILE="$(basename $SCRIPT_PATH)"
LOG_FILE="$SCRIPT_DIR/$(basename $0 .sh)-$(date +"%Y%m%d_%H%M%S").log"
OPTIONAL_SCRIPT_DIR="$SCRIPT_DIR/optional_scripts"

# Global setting for APT recommended packages - leave blank for now.
# It's a little more bloated, but we can't get a clean boot without it.
#APT_RECOMMENDS="–no-install-recommends"
APT_RECOMMENDS=

# Minimal depedencies to install RetroPie on Ubuntu
RETROPIE_DEPENDS=(
    xorg openbox pulseaudio alsa-utils menu libglib2.0-bin python3-xdg
    at-spi2-core libglib2.0-bin dbus-x11 git dialog unzip xmlstarlet joystick
    triggerhappy
    # Eth: needed if building retroarch with __has_kms set (ideally should be in
    # in retroarch.sh, but maybe it's more robust to add it here)
    libdrm-dev
)

# Helpful packages to improve usability
#--------------------------------------------------------------------------------
# openssh-server      Remote administration, copy/paste
# xdg-utils           Eliminates 'xdg-screensaver not found' error
# unclutter           Hides mouse cursor when not being used
# inxi                Queries video driver information
#--------------------------------------------------------------------------------
EXTRA_TOOLS=(
    openssh-server xdg-utils unclutter inxi
)


# Output to both console and log file
function enable_logging() {
    echo "--------------------------------------------------------------------------------"
    echo "| Saving console output to '$LOG_FILE'"
    echo "--------------------------------------------------------------------------------"
    touch $LOG_FILE
    exec > >(tee $LOG_FILE) 2>&1
    sleep 2
}


# Install RetroPie dependencies
function install_retropie_dependencies() {
    echo "--------------------------------------------------------------------------------"
    echo "| Updating OS packages and installing RetroPie dependencies"
    echo "--------------------------------------------------------------------------------"
    apt-get update && apt-get -y upgrade
    apt-get install -y $APT_RECOMMENDS ${RETROPIE_DEPENDS[@]}
    echo -e "FINISHED install_retropie_dependencies \n\n"
    sleep 2
}

## Eth:
function patch_systemsh_kmsdrm() {
    # https://retropie.org.uk/forum/topic/28159/update-retroarch-sh-to-enable-kms-drm-on-x11-platform/4
    echo "-> __has_kms= set. Enabling KMS/DRM support in RetroPie."
    echo "-> patch RetroPie-Setup/scriptmodules/system.sh to enable both x11 and kms on x86"
    SYSTEMSH="$USER_HOME/RetroPie-Setup/scriptmodules/system.sh"
    cat << EOF >> $SYSTEMSH.patch
518c518,519
<         __platform_flags+=(kms)
---
>  	## modify non-default path to contain x11 (and kms)
>         __platform_flags+=(x11 kms)
EOF
	cp -v $SYSTEMSH $SYSTEMSH.orig
	patch $SYSTEMSH $SYSTEMSH.patch

}

# Install RetroPie
function install_retropie() {
    echo "--------------------------------------------------------------------------------"
    echo "| Installing RetroPie"
    echo "--------------------------------------------------------------------------------"
    # Get Retropie Setup script and perform an install of same packages
    # used in the RetroPie image (as applicable)
    # See https://github.com/RetroPie/RetroPie-Setup/blob/master/scriptmodules/admin/image.sh
    cd $USER_HOME
    git clone --depth=1 https://github.com/RetroPie/RetroPie-Setup.git

    ## Eth:
    if [ ! -z $__has_kms ]; then
	# https://retropie.org.uk/forum/topic/28159/update-retroarch-sh-to-enable-kms-drm-on-x11-platform/4
	patch_systemsh_kmsdrm
    fi

    $USER_HOME/RetroPie-Setup/retropie_packages.sh setup basic_install
    $USER_HOME/RetroPie-Setup/retropie_packages.sh bluetooth depends
    $USER_HOME/RetroPie-Setup/retropie_packages.sh usbromservice
    $USER_HOME/RetroPie-Setup/retropie_packages.sh samba depends
    $USER_HOME/RetroPie-Setup/retropie_packages.sh samba install_shares
    $USER_HOME/RetroPie-Setup/retropie_packages.sh splashscreen default
    $USER_HOME/RetroPie-Setup/retropie_packages.sh splashscreen enable
    $USER_HOME/RetroPie-Setup/retropie_packages.sh xpad

    chown -R $USER:$USER $USER_HOME/RetroPie-Setup

    echo -e "FINISHED install_retropie \n\n"
    sleep 2
}


# Install RetroArch shaders from official repository
function install_retroarch_shaders() {
    echo "--------------------------------------------------------------------------------"
    echo "| Remove the RPi shaders installed by RetroPie-Setup and replace with"
    echo "| RetroArch (merge of common & GLSL, and new Slang) shaders from Libretro"
    echo "--------------------------------------------------------------------------------"

    # Cleanup pi shaders installed by RetroPie-Setup
    rm -rf /opt/retropie/configs/all/retroarch/shaders
    mkdir -p /opt/retropie/configs/all/retroarch/shaders
    # Install common shaders from Libretro repository
    git clone --depth=1 https://github.com/libretro/common-shaders.git /tmp/common-shaders
    cp -r /tmp/common-shaders/* /opt/retropie/configs/all/retroarch/shaders/
    rm -rf /tmp/common-shaders
    # Install GLSL shaders from Libretro repository
    git clone --depth=1 https://github.com/libretro/glsl-shaders.git /tmp/glsl-shaders
    cp -r /tmp/glsl-shaders/* /opt/retropie/configs/all/retroarch/shaders/
    rm -rf /tmp/glsl-shaders

    # Install Slang shaders from Libretro repository (for use with Vulkan, glcore, ..)
    # https://www.libretro.com/index.php/category/slang/
    git clone --depth=1 https://github.com/libretro/slang-shaders.git /tmp/slang-shaders
    ##mkdir -vp /opt/retropie/configs/all/retroarch/shaders-slang ; # MERGE INSTEAD
    cp -r /tmp/slang-shaders/* /opt/retropie/configs/all/retroarch/shaders/
    rm -rf /tmp/slang-shaders

    # Remove git repository from shader dir
    rm -rf /opt/retropie/configs/all/retroarch/shaders/.git
    ##rm -rf /opt/retropie/configs/all/retroarch/slang-shaders/.git

    chown -R $USER:$USER /opt/retropie/configs
    echo -e "FINISHED install_retroarch_shaders \n\n"
    sleep 2
}


# Create file in sudoers.d directory and disable password prompt
function disable_sudo_password() {
    echo "--------------------------------------------------------------------------------"
    echo "| Disabling the sudo password prompt"
    echo "--------------------------------------------------------------------------------"
    echo "$USER ALL=(ALL) NOPASSWD:ALL" | sudo tee /etc/sudoers.d/$USER-no-password-prompt
    chmod 0440 /etc/sudoers.d/$USER-no-password-prompt
    echo -e "FINISHED disable_sudo_password \n\n"
    sleep 2
}


# Install latest Intel video drivers
function install_latest_intel_drivers() {
    echo "--------------------------------------------------------------------------------"
    echo "| Installing the latest Intel video drivers from 'ppa:ubuntu-x-swat/updates'"
    echo "| This may throw errors on a new release if this PPA does not supportit yet (OK)."
    echo "--------------------------------------------------------------------------------"
    add-apt-repository -y ppa:ubuntu-x-swat/updates
    apt-get update && apt-get -y upgrade
    echo -e "FINISHED install_latest_intel_drivers \n\n"
    sleep 2
}


# Install the latest Nvidia video drivers
function install_latest_nvidia_drivers() {
    echo "--------------------------------------------------------------------------------"
    echo "- Installing the latest Nvidia video drivers"
    echo "--------------------------------------------------------------------------------"
    apt-get install -y $APT_RECOMMENDS ubuntu-drivers-common
    add-apt-repository -y ppa:graphics-drivers/ppa
    ubuntu-drivers autoinstall
    echo -e "FINISHED install_latest_nvidia_drivers \n\n"
    sleep 2
}


# Install MESA Vulkan drivers
function install_vulkan() {
    echo "--------------------------------------------------------------------------------"
    echo "| Installing Vulkan video drivers"
    echo "--------------------------------------------------------------------------------"
    apt-get install -y $APT_RECOMMENDS mesa-vulkan-drivers
    echo -e "FINISHED install_vulkan \n\n"
    sleep 2
}


# Enable Plymouth Splash Screen
function enable_plymouth_theme() {
    if [[ -z "$1" ]]; then
        echo "--------------------------------------------------------------------------------"
        echo "| Skipping Plymouth boot splash because no theme name was provided"
        echo "--------------------------------------------------------------------------------"
        echo -e "Skipped\n\n"
        return 255
    fi
    PLYMOUTH_THEME=$1
    echo "--------------------------------------------------------------------------------"
    echo "| Installing Plymouth boot splash and enabling theme '$PLYMOUTH_THEME'"
    echo "--------------------------------------------------------------------------------"
    apt-get install -y $APT_RECOMMENDS plymouth plymouth-themes plymouth-x11
    rm -rf /tmp/plymouth-themes
    git clone --depth=1 https://github.com/HerbFargus/plymouth-themes.git /tmp/plymouth-themes
    mv /tmp/plymouth-themes/* /usr/share/plymouth/themes/
    update-alternatives --install /usr/share/plymouth/themes/default.plymouth default.plymouth /usr/share/plymouth/themes/$PLYMOUTH_THEME/$PLYMOUTH_THEME.plymouth 10
    update-alternatives --set default.plymouth /usr/share/plymouth/themes/$PLYMOUTH_THEME/$PLYMOUTH_THEME.plymouth
    update-initramfs -u
    echo -e "FINISHED enable_plymouth_theme \n\n"
    sleep 2
}


# Hide Boot Messages
function hide_boot_messages() {
    echo "--------------------------------------------------------------------------------"
    echo "| Hiding boot messages"
    echo "--------------------------------------------------------------------------------"
    # Hide kernel messages and blinking cursor via GRUB
    sed -i 's/GRUB_CMDLINE_LINUX_DEFAULT=".*"/GRUB_CMDLINE_LINUX_DEFAULT="quiet splash vt.global_cursor_default=0"/g' /etc/default/grub
    update-grub

    # Hide fsck messages after Plymouth splash
    echo 'FRAMEBUFFER=y' > /etc/initramfs-tools/conf.d/splash
    update-initramfs -u

    # Remove cloud-init to suppress its boot messages
    apt-get purge cloud-init -y
    rm -rf /etc/cloud/ /var/lib/cloud/

    # Disable motd
    touch $USER_HOME/.hushlogin
    chown $USER:$USER $USER_HOME/.hushlogin
    echo -e "FINISHED hide_boot_messages \n\n"
    sleep 2
}


# Change the default runlevel to multi-user
# This disables GDM from loading at boot (new for 20.04)
function enable_runlevel_multiuser () {
    echo "--------------------------------------------------------------------------------"
    echo "| Enabling the 'multi-user' runlevel"
    echo "--------------------------------------------------------------------------------"
    systemctl set-default multi-user
    echo -e "FINISHED enable_runlevel_multiuser \n\n"
    sleep 2
}


# Configure user to autologin at the terminal
function enable_autologin_tty() {
    echo "--------------------------------------------------------------------------------"
    echo "| Enabling autologin to terminal"
    echo "--------------------------------------------------------------------------------"
    mkdir -p /etc/systemd/system/getty@tty1.service.d
    cat << EOF >> /etc/systemd/system/getty@tty1.service.d/override.conf
[Service]
ExecStart=
ExecStart=-/sbin/agetty --skip-login --noissue --autologin $USER %I \$TERM
Type=idle
EOF
    echo -e "FINISHED enable_autologin_tty \n\n"
    sleep 2
}


# Start X as soon as autologin is complete
function enable_autostart_xwindows() {
    echo "--------------------------------------------------------------------------------"
    echo "| Enabling autostart of X Windows"
    echo "--------------------------------------------------------------------------------"
    # Create a .xsession file to launch OpenBox when startx is called
    echo 'exec openbox-session' >> $USER_HOME/.xsession
    chown $USER:$USER $USER_HOME/.xsession

    # Add startx to .bash_profile
    cat << EOF >> $USER_HOME/.bash_profile
if [[ -z \$DISPLAY ]] && [[ \$(tty) = /dev/tty1 ]]; then
    exec startx -- >/dev/null 2>&1
fi
EOF
    chown $USER:$USER $USER_HOME/.bash_profile
    echo -e "FINISHED enable_autostart_xwindows \n\n"
    sleep 2
}


# Hide Openbox Windows and reduce visibility of terminal
function hide_openbox_windows() {
    echo "--------------------------------------------------------------------------------"
    echo "| Hiding window decorations in OpenBox"
    echo "--------------------------------------------------------------------------------"
    # Reduce the visibility of the gnome terminal by prepending these settings in the bash profile
    GNOME_TERMINAL_SETTINGS='dbus-launch gsettings set org.gnome.Terminal.Legacy.Profile:/org/gnome/terminal/legacy/profiles:/:b1dcc9dd-5262-4d8d-a863-c897e6d979b9/'
    cat << EOF >> $USER_HOME/.bash_profile
$GNOME_TERMINAL_SETTINGS use-theme-colors false
$GNOME_TERMINAL_SETTINGS use-theme-transparency false
$GNOME_TERMINAL_SETTINGS foreground-color '#FFFFFF'
$GNOME_TERMINAL_SETTINGS background-color '#000000'
$GNOME_TERMINAL_SETTINGS cursor-blink-mode 'off'
$GNOME_TERMINAL_SETTINGS scrollbar-policy 'never'
$GNOME_TERMINAL_SETTINGS audible-bell 'false'
gsettings set org.gnome.Terminal.Legacy.Settings default-show-menubar false
EOF
    chown $USER:$USER $USER_HOME/.bash_profile

    # Further reduce the visibility of windows (terminal) by modifying the OpenBox config
    mkdir -p $USER_HOME/.config/openbox
    cp /etc/xdg/openbox/rc.xml $USER_HOME/.config/openbox/rc.xml
    cat << EOF > /tmp/rc.xml.applications
        <application class="*">
            <fullscreen>yes</fullscreen>
            <iconic>no</iconic>
            <layer>below</layer>
            <decor>no</decor>
            <maximized>true</maximized>
        </application>
EOF
    sed -i '/<applications>/r /tmp/rc.xml.applications' $USER_HOME/.config/openbox/rc.xml
    rm /tmp/rc.xml.applications
    sed -e 's/<keepBorder>yes<\/keepBorder>/<keepBorder>no<\/keepBorder>/g' -i $USER_HOME/.config/openbox/rc.xml
    chown -R $USER:$USER $USER_HOME/.config
    echo -e "FINISHED hide_openbox_xwindows \n\n"
    sleep 2
}


# Autostart OpenBox Applications
function autostart_openbox_apps() {
    echo "--------------------------------------------------------------------------------"
    echo "| Enabling OpenBox autostart applications and RetroPie autostart.sh"
    echo "--------------------------------------------------------------------------------"
    # OpenBox autostarts unclutter, then passes off to the RetroPie autostart
    mkdir -p $USER_HOME/.config/openbox
    echo 'unclutter -idle 0.01 -root' >> $USER_HOME/.config/openbox/autostart
    echo '/opt/retropie/configs/all/autostart.sh' >> $USER_HOME/.config/openbox/autostart
    chown -R $USER:$USER $USER_HOME/.config
    # Create RetroPie autostart
    mkdir -p /opt/retropie/configs/all
    touch /opt/retropie/configs/all/autostart.sh
    chmod +x /opt/retropie/configs/all/autostart.sh
    chown -R $USER:$USER /opt/retropie/configs
    cat << EOF > /opt/retropie/configs/all/autostart.sh
#! /bin/bash

gnome-terminal --full-screen --hide-menubar -- emulationstation --no-splash         # RPSU_End autostart_openbox_apps
EOF
    echo -e "FINISHED autostart_openbox_apps \n\n"
    sleep 2
}


# Install and configure extra tools
function install_extra_tools() {
    echo "--------------------------------------------------------------------------------"
    echo "| Installing the following tools to improve usability:"
    echo "| ${EXTRA_TOOLS[@]}"
    echo "--------------------------------------------------------------------------------"
    apt-get update
    apt-get install -y $APT_RECOMMENDS ${EXTRA_TOOLS[@]}

    # Configure 'inxi' if it was installed
    if [[ -x "$(command -v inxi)" ]]; then
        echo "--------------------------------------------------------------------------------"
        echo "| Enabling updates on the 'inxi' package", which is
        echo "| used for checking hardware and system information"
        echo "| Command 'inxi -G' is useful for querying video card driver versions"
        echo "--------------------------------------------------------------------------------"
        sed -i 's/B_ALLOW_UPDATE=false/B_ALLOW_UPDATE=true/g' /etc/inxi.conf
        inxi -U
    fi

    echo -e "FINISHED install_extra_tools \n\n"
    sleep 2
}


# Install and configure extra tools
function fix_quirks() {
    echo "--------------------------------------------------------------------------------"
    echo "| Fixing any known quirks"
    echo "--------------------------------------------------------------------------------"

    # XDG_RUNTIME_DIR
    echo "--------------------------------------------------------------------------------"
    echo "| Remove 'error: XDG_RUNTIME_DIR not set in the environment' CLI error"
    echo "| when exiting Retroarch from the RetroPie Setup screen within ES"
    echo "| by creating a file in sudoers.d directory to keep environment variable"
    echo "--------------------------------------------------------------------------------"
    echo 'Defaults	env_keep +="XDG_RUNTIME_DIR"' | sudo tee /etc/sudoers.d/keep-xdg-environment-variable
    chmod 0440 /etc/sudoers.d/keep-xdg-environment-variable
    echo -e "\n"

    # Screen blanking
    echo "--------------------------------------------------------------------------------"
    echo "| Disable screen blanking (only happens outside of EmulationStation)"
    echo "| This prevents the display from doing any ‘screen blanking’ due to inactivity"
    echo "--------------------------------------------------------------------------------"
    sed -i '1 i\xset s off && xset -dpms' $USER_HOME/.xsession
    echo -e "\n"

    echo -e "FINISHED fix_quirks \n\n"
    sleep 2
}


# Add the ability to change screen resolution in autostart.sh
function set_resolution_xwindows() {
    echo "--------------------------------------------------------------------------------"
    echo "| Adding the ability to override the default display resolution"
    echo "| from the '/opt/retropie/config/all/autostart.sh' script."
    echo "| Update the PREFERRED_RESOLUTION variable inside the script to change this value."
    echo "| If not valid, it will gracefully revert to the display's preferred resolution."
    echo "| This is typically helpful for improving performance by lowering resolution on 4K displays"
    echo "--------------------------------------------------------------------------------"
    cat << EOF >> /tmp/set_resolution_xwindows

# RPSU_START set_resolution_xwindows
# Update the next line to customize the display resolution
# If will fall back to the display's preferred resolution, if the custom value is invalid
PREFERRED_RESOLUTION=1920x1080
if [[ ! -z \$PREFERRED_RESOLUTION ]]; then
    current_resolution=\$(xrandr --display :0 | awk 'FNR==1{split(\$0,a,", "); print a[2]}' | awk '{gsub("current ","");gsub(" x ", "x");print}')
    connected_display=\$(xrandr --display :0 | grep " connected " | awk '{ print \$1 }')
    if \$(xrandr --display :0 | grep -q \$PREFERRED_RESOLUTION); then
        xrandr --display :0 --output \$connected_display --mode \$PREFERRED_RESOLUTION &
    else
        echo "\$PREFERRED_RESOLUTION is not available on \$connected_display.  Remaining at default resolution of \$current_resolution."
    fi
fi
# RPSU_END set_resolution_xwindows

EOF
    # Insert into autostart.sh after the 1st line (after shebang)
    sed -i '1r /tmp/set_resolution_xwindows' "/opt/retropie/configs/all/autostart.sh"
    rm /tmp/set_resolution_xwindows
    echo -e "FINISHED set_resolution_xwindows \n\n"
    sleep 2
}


# Sets the GRUB graphics mode
# Takes a valid mode string as a argument, such as "1920x1080x32"
# If none is provided, a default of 'auto' will be used
function set_resolution_grub() {
    if [[ -z "$1" ]]; then
        MODES="auto"
    else
        MODES="$1,auto"
    fi
    echo "--------------------------------------------------------------------------------"
    echo "| Changing the GRUB graphics mode to '$MODE'"
    echo "| If this mode is incompatible with your system, GRUB will fall back to 'auto' mode"
    echo "| Run 'vbeinfo' (legacy, pre-18.04) or 'videoinfo' (UEFI) from the GRUB command line"
    echo "| to see the supported modes"
    echo "| This value, 'GRUB_GFXMODE', can be edited in /etc/default/grub"
    echo "--------------------------------------------------------------------------------"
    sed -i "s/#GRUB_GFXMODE=.*/GRUB_GFXMODE=$MODES/g" "/etc/default/grub"
    update-grub
    echo -e "Done\n\n"
    sleep 2
    echo -e "FINISHED set_resolution_grub \n\n"
}


# Run any optional scripts that the user has provided
function run_optional_scripts() {
    SCRIPT_PATH=$1
    # If a specific file is provided, just run that
    if [[ -f $SCRIPT_PATH ]]; then
        SCRIPT_FILE_PATH=$SCRIPT_PATH
        echo "--------------------------------------------------------------------------------"
        echo "| Running optional script at $SCRIPT_FILE_PATH"
        echo "--------------------------------------------------------------------------------"
        echo -e "\n"
        source "$SCRIPT_FILE_PATH"
        sleep 2
    # Otherwise, run all scripts in the provided directory
    else
        echo "--------------------------------------------------------------------------------"
        echo "| Running any optional scripts found in $SCRIPT_PATH"
        echo "--------------------------------------------------------------------------------"
        ls "$SCRIPT_PATH" | sort -n | while read SCRIPT_FILE; do
            SCRIPT_FILE_PATH="$SCRIPT_PATH/$SCRIPT_FILE"
            if [[ -f $SCRIPT_FILE_PATH ]] && [[ $SCRIPT_FILE_PATH != *README* ]]; then
                echo -e "\n"
                source "$SCRIPT_FILE_PATH"
                sleep 2
            fi
        done
    fi
    echo -e "\n\n"
    echo -e "FINISHED run_optional_scripts \n\n"
}


# Repair any permissions that might have been incorrectly set
function repair_permissions() {
    echo "--------------------------------------------------------------------------------"
    echo "| Repairing file & folder permissions underneath $USER_HOME"
    echo "| by changing owner to $USER on all files and directories under $USER_HOME"
    echo "--------------------------------------------------------------------------------"
    chown -R $USER:$USER $USER_HOME/
    echo -e "FINISHED repair_permissions \n\n"
    sleep 2
}


# Remove unneeded packages
function remove_unneeded_packages() {
    echo "--------------------------------------------------------------------------------"
    echo "| Autoremoving any unneeded packages"
    echo "--------------------------------------------------------------------------------"
    apt-get update && apt-get -y upgrade
    apt-get -y autoremove
    echo -e "FINISHED remove_unneeded_packages \n\n"
    sleep 2
}

# Prompt user for reboot
function prompt_for_reboot() {
    read -p "Reboot the system now? (y/n) " -n 1 -r
    echo
    if [[ $REPLY =~ ^[Yy]$ ]]; then
        reboot
    fi
}


# Final message to user
function complete_install() {
    RUNTIME=$SECONDS
    echo "--------------------------------------------------------------------------------"
    echo "| Installation complete"
    echo "| Runtime: $(($RUNTIME / 60)) minutes and $(($RUNTIME % 60)) seconds"
    echo "| Output has been logged to '$LOG_FILE'"
    echo "--------------------------------------------------------------------------------"
    ## Eth:
    #prompt_for_reboot
}

# Make sure the user is running the script via sudo
if [ -z "$SUDO_USER" ]; then
    echo "This script requires sudo privileges. Please run with: sudo $0"
    exit 1
fi
# Don't allow the user to run this script from the root account. RetroPie doesn't like this.
if [[ "$SUDO_USER" == root ]]; then
    echo "This script cannot be run by the root user.  Please run as normal user using sudo."
    exit 1
fi

#--------------------------------------------------------------------------------
#| INSTALLATION SCRIPT
#--------------------------------------------------------------------------------
# If no arguments are provided
if [[ -z "$1" ]]; then

    #-- Log this script's output
    enable_logging
    run_optional_scripts "$OPTIONAL_SCRIPT_DIR/pre_install"
    #-- Basic RetroPie install
    install_retropie_dependencies
    install_retropie
    install_retroarch_shaders
    disable_sudo_password
    #-- Common video drivers
    install_latest_intel_drivers
    install_latest_nvidia_drivers
    install_vulkan
    #-- Hide text and boot directly into EmulationStation
    enable_plymouth_theme "retropie-pacman"       # See https://github.com/HerbFargus/plymouth-themes.git for other theme names
    hide_boot_messages
    enable_runlevel_multiuser
    enable_autologin_tty
    enable_autostart_xwindows
    hide_openbox_windows
    autostart_openbox_apps
    #-- Additional customizations
    install_extra_tools
    fix_quirks
    #-- OPTIONAL STEPS (comment/change as needed)
    #   These are helpful for improving 4k performance and user experience
    set_resolution_xwindows "1920x1080"          # Run 'xrandr --display :0' when a X Windows session is running to the supported resolutions
    set_resolution_grub "1920x1080x32"           # Run 'vbeinfo' (legacy, pre 18.04) or 'videoinfo' (UEFI) from the GRUB command line to see the supported modes
    run_optional_scripts "$OPTIONAL_SCRIPT_DIR/post_install"
    #-- Final cleanup
    repair_permissions
    remove_unneeded_packages
    complete_install

# If function names are provided as arguments, just run those functions
# (then restore perms and clean up)
else
    enable_logging
    for call_function in "$@"; do
        $call_function
    done
    repair_permissions
    complete_install
fi
	#!/bin/bash

	##
	## Configure RetroPie to run under Linux KMS/DRM mode on Ubuntu 20.04 LTS.
	## Supports only Intel (and virtual) framebuffers. Specifically nVidia and
	## Radeon based systems are not properly set up by this script.
	##
	## Optional post-install setup-script (set __has_kms to enable) for
	## https://github.com/MizterB/RetroPie-Setup-Ubuntu/blob/master/retropie_setup_ubuntu.sh
	## and install this script to ~/optional_scripts/post_install before running ./retropie_setup_ubuntu.sh

	## Control behaviour of script
	__XRES="1920" # target X & Y resolution (1080p)
	__YRES="1080"

	#__FB_DEV="/dev/fb0" # set to skip i915 detection
	#__KOPT_VIDEO=... # set to skip resolution probing
	#__KEEP_SPLASH=1 # set to keep plymouth/splash

	__SLEEP=2 # delay between tasks

	## TODO:
	## - Enable early KMS start (https://wiki.archlinux.org/index.php/Kernel_mode_setting#Early_KMS_start)
	## - Support radeon, maybe nvidia
	## - Consider https://wiki.archlinux.org/index.php/intel_graphics#Enable_GuC_/_HuC_firmware_loading
	## - Warn nvidia or radeon cards are found

	##
	USER="$SUDO_USER"
	USER_HOME="/home/$USER"
	if [ -z $SCRIPT_DIR ]; then
	SCRIPT_DIR=$(dirname $(realpath $0))
	fi

	# Backup system config file(s) before modifications (Eth)
	function backupFile() {
	if [ ! -f "$1" ] ; then
	echo "-> backupFile: $1 does not exist. Not creating $1.orig"
	return
	fi
	if [ ! -f "$1.orig" ]; then
	echo "-> Backing up $1 -> $1.orig"
	cp $1 $1.orig
	else
	echo "-> backupFile: $1.orig already exists (and cowardly refusing to overwrite)"
	fi
	}

	##
	function install_kmsdrm_depends() {
	echo "--------------------------------------------------------------------------------"
	echo "\| install_kmsdrm_depends: TBD"
	echo "--------------------------------------------------------------------------------"

	apt-get install -y fbset

	echo -e "FINISHED install_kmsdrm_depends \n\n"
	sleep $__SLEEP
	}

	## Set FB_DEV, and set FB_i915 if i915 found
	function is_it_i915_fb() {
	echo "--------------------------------------------------------------------------------"
	echo "\| find_i915_fb: TBD"
	echo "--------------------------------------------------------------------------------"

	## TODO: early exit if FB_DEV is set

	local __fb="null"
	local __tmp_fb="/dev/fb0"

	## Assumes single display setup; one display ought to be enough for anybody...
	if [ ! $(cat /proc/fb \| wc -l) -eq 1 ]; then
	echo "WARNING: More than one framebuffer found. This may produce unexpected results."
	fi

	## https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/deployment_guide/s2-proc-fb
	echo "-> Probe /proc/fb to find if we have intel i915 framebuffer"
	__fb=$(cat /proc/fb \| grep i915drmfb)
	if [ ! $? -eq 0 ]; then
	echo "-> Cannot find i915 framebuffer. Available framebuffers / displays are:"
	ls -l /dev/fb*
	cat /proc/fb
	lshw -c display -short
	FB_DEV=$__tmp_fb
	echo "-> Using /dev/fb0 for configuration"

	else
	export FB_DEV="/dev/fb$(echo $__fb \| cut -d' ' -f1)"
	FB_i915=1
	echo "-> Found i915drmfb. Framebuffer device is $FB_DEV ($__fb)"
	fi

	## Test that ($FB_DEV) is FB that we're (propably) looking at...
	fbset -fb $FB_DEV > /dev/null 2>&1
	if [ ! $? -eq 0 ]; then
	echo "ERROR: cannot verify that $FB_DEV is usable. Reverting back to $__tmp_fb"
	unset FB_i915
	export FB_DEV=$__tmp_fb
	fi

	echo -e "FINISHED is_it_i915_fb \n\n"
	sleep $__SLEEP
	}


	# Useful for getting systems with max resolution less than 1080p configured
	function find_fb_max_resolution() {
	echo "--------------------------------------------------------------------------------"
	echo "\| Detect if framebuffer supports ${__XRES}x${__YRES}, if not try to determine"
	echo "\| usable resolution (using $FB_DEV)"
	echo "--------------------------------------------------------------------------------"

	local __fb=$FB_DEV
	local __x=$__XRES
	local __y=$__YRES

	echo "/proc/fb: "
	cat /proc/fb
	fbset -fb $__fb -s

	## Test if we can set 1080p
	echo "-> Testing if we can set framebuffer $__fb to $__XRES x $__YRES resolution"
	fbset --test -fb $__fb -xres $__XRES -yres $__YRES -match
	if [ ! $? -eq 0 ]; then
	## Note: on VMs we might get lower then max, but on real hw, expectation is max supported (assuming kernel supports hw)
	echo "-> 1080p does not appear to be supported by $__fb. Getting current resolution."
	local __tempres=`sudo fbset -fb $__fb -s \| sed -n -e 's/^.*geometry //p'`
	__XRES=`echo $__tempres \| cut -d' ' -f1`
	__YRES=`echo $__tempres \| cut -d' ' -f2`
	## double check that what we got can be set
	fbset --test -fb $__fb -xres $__XRES -yres $__YRES -match
	if [ ! $? -eq 0 ]; then
	echo "ERROR: cannot determine appropriate resolution. Falling back to 1920x1080."
	echo " It is likely you will experience resolution issues"
	__XRES=$__x
	__YRES=$__y
	fi
	## TODO: test if we ended up with larger than 1080p for some reason
	fi
	echo "-> Using $__XRES x $__YRES for X and framebuffer default resolutions"

	echo -e "FINISHED find_fb_max_resolution \n\n"
	sleep $__SLEEP
	}


	## Build video= kernel boot option string. Assumes only one connected display; falls back
	## to generic form if multiple connected displays
	function build_kernel_video_option() {
	echo "--------------------------------------------------------------------------------"
	echo "\| Construct video= kernel boot option from /sys/class/drm/card*"
	echo "--------------------------------------------------------------------------------"

	local __card="null"

	# determine video= parameter(s)
	echo "-> List of output ports under /sys/class/drm/*:"
	for p in /sys/class/drm//status; do con=${p%/status}; echo -n "${con#/card?-}: "; cat $p; done
	if [ ! $(cat /sys/class/drm/*/status \| grep -w "connected" \| wc -l) -eq 1 ]; then
	__KOPT_VIDEO="video=${__XRES}x${__YRES}"
	echo "WARNING: multiple (or zero) connected displays found. This is untested setup."
	echo " Falling back to generic $__KOPT_VIDEO kernel parameter."
	return
	fi

	for i in /sys/class/drm/*/status ; do
	cat $i \| grep -w 'connected' > /dev/null
	if [ $? -eq 0 ]; then
	__card=$i
	break
	fi
	done
	#echo $CARD \| cut -d'/' -f5 \| cut -d'-' -f2-
	__KOPT_VIDEO="video=$(echo $__card \| cut -d'/' -f5 \| cut -d'-' -f2-):${__XRES}x${__YRES}"

	echo "-> Kernel video boot option: ${__KOPT_VIDEO}"

	echo -e "FINISHED build_kernel_video_option \n\n"
	sleep $__SLEEP
	}

	# Sets the GRUB graphics mode
	# URL: https://www.gnu.org/software/grub/manual/grub/html_node/gfxmode.html
	function update_grub_resolution() {
	if [[ -z "$1" ]]; then
	MODES="auto"
	else
	MODES="$1,auto"
	fi
	echo "--------------------------------------------------------------------------------"
	echo "\| Changing the GRUB graphics mode to '$MODES' and adds"
	echo "\| GRUB_GFXPAYLOAD_LINUX=\"keep\" to minimize display mode switching"
	echo "--------------------------------------------------------------------------------"

	local __ggpl=""

	grep GRUB_GFXPAYLOAD_LINUX /etc/default/grub > /dev/null 2>&1
	if [ ! $? -eq 0 ]; then
	__ggpl="\\nGRUB_GFXPAYLOAD_LINUX=\"keep\""
	fi
	sed -i "s/GRUB_GFXMODE=.*/GRUB_GFXMODE=${MODES}${__ggpl}/g" "/etc/default/grub"
	update-grub

	egrep "(GRUB_GFXMODE\|GRUB_GFXPAYLOAD)" /etc/default/grub

	echo -e "FINISHED update_grub_resolution \n\n"
	sleep $__SLEEP
	}

	# Eth:
	# Sets FB resolution using video= kernel boot parameter
	function set_kernel_fb_resolution() {
	echo "--------------------------------------------------------------------------------"
	echo "\| Adding video=${__XRES}x${__YRES} kernel parameter to /etc/default/grub"
	echo "--------------------------------------------------------------------------------"
	backupFile /etc/default/grub

	if [ -z $__KOPT_VIDEO ]; then
	build_kernel_video_option
	fi

	local __KOPT_MS=""
	if [ ! -z $FB_i915 ]; then
	## https://wiki.archlinux.org/index.php/Intel_graphics
	__KOPT_MS="i915.modeset=1 "
	echo "-> FB_i915 set. Adding option $__KOPT_MS"

	fi

	## https://retropie.org.uk/forum/topic/18810/retropie-installation-on-ubuntu-server-x64-18-04-1/161
	sed -i "s/GRUB_CMDLINE_LINUX_DEFAULT=\"[^\"]*/& ${__KOPT_MS}${__KOPT_VIDEO}/" /etc/default/grub
	update-grub
	grep "GRUB_CMDLINE_LINUX_DEFAULT" /etc/default/grub

	echo -e "FINISHED set_kernel_fb_resolution \n\n"
	sleep $__SLEEP
	}

	# Eth:
	function install_xorgconf() {
	XORGCONF="/etc/X11/xorg.conf"
	echo " "
	echo "+-------------------------------------------------------------------------------"
	echo "\| Install $XORGCONF to set default X11 resolution to match"
	echo "\| console resoluton (${__XRES}x${__YRES}) to avoid mode switches during boot"
	echo "+-------------------------------------------------------------------------------"

	backupFile $XORGCONF

	cat << EOF > $XORGCONF
	## Sets X startup resolution to $__XRES x $__YRES as to avoid modeswitch
	## https://wiki.ubuntu.com/X/Config/Resolution
	Section "Monitor"
	Identifier "Configured Monitor"
	EndSection

	Section "Screen"
	Identifier "Default Screen"
	Monitor "Configured Monitor"
	Device "Configured Video Device"
	SubSection "Display"
	Virtual $__XRES $__YRES
	EndSubSection
	EndSection

	Section "Device"
	Identifier "Configured Video Device"
	EndSection
	EOF
	chown root:root $XORGCONF
	#rw-r--r--
	chmod 644 $XORGCONF

	echo -e "FINISHED xorg_conf \n\n"
	sleep $__SLEEP
	}

	## .xsession that supports launching openbox, or a port; resolution set via /etc/X11/...
	function rewrite_xsession() {
	echo "--------------------------------------------------------------------------------"
	echo "\| FIXME: Update .xsession"
	echo "--------------------------------------------------------------------------------"
	backupFile $USER_HOME/.xsession

	cat << EOF > $USER_HOME/.xsession
	## Support launching openbox and full screen games via RetroPie ports

	## document xrandr output \$XRANDR_LOG
	XRANDR_LOG=/dev/shm/xrand_modes.log
	xrandr --version >> \$XRANDR_LOG 2>&1
	xrandr >> \$XRANDR_LOG 2>&1

	# Disable screen blanking (only happens outside of EmulationStation)
	# This prevents the display from doing any ‘screen blanking’ due to inactivity
	xset s off && xset -dpms

	if [ ! -f /dev/shm/portruncommand.sh ] ; then
	exec openbox-session
	else
	## don't exec; we want to return & exit
	/dev/shm/portruncommand.sh
	fi
	EOF

	echo -e "FINISHED rewrite_xsession \n\n"
	sleep $__SLEEP
	}

	## Eth: Start emulationstation as soon as user is logged in
	function enable_autostart_emulationstation() {
	echo "--------------------------------------------------------------------------------"
	echo "\| Enabling autostart of EmulationStation in KMS/DRM mode via .bash_profile"
	echo "--------------------------------------------------------------------------------"
	backupFile $USER_HOME/.bash_profile

	sed -i '/startx/a\ emulationstation' $USER_HOME/.bash_profile
	sed -i '/startx/a\ # dont exec emulationstation: otherwise ES gets restarted on exit (F4)' $USER_HOME/.bash_profile
	sed -i 's/.*startx/#&/' $USER_HOME/.bash_profile

	chown $USER:$USER $USER_HOME/.bash_profile

	echo -e "FINISHED enable_autostart_emulationstation \n\n"
	sleep $__SLEEP
	}

	function disable_plymouth_splash() {
	echo "--------------------------------------------------------------------------------"
	echo "\| Disable Plymouth theme by removing splash from /etc/default/grub"
	echo "--------------------------------------------------------------------------------"
	backupFile /etc/default/grub
	## TODO: purge plymouth?

	## TODO: etc/default/grub should not have other lines with 'splash'....but
	sed -i 's/\<splash\>//g' /etc/default/grub
	update-grub

	echo -n "-> Updated /etc/default/grub:GRUB_CMDLINE_LINUX_DEFAULT:"
	grep "GRUB_CMDLINE_LINUX_DEFAULT" /etc/default/grub

	echo -e "FINISHED disable_plymouth_splash \n\n"
	sleep $__SLEEP
	}

	function fix_quirks_kmsdrm() {
	echo "--------------------------------------------------------------------------------"
	echo "\| Fixing any known quirks for KMS/DRM mode"
	echo "--------------------------------------------------------------------------------"

	echo " "
	echo "+-------------------------------------------------------------------------------"
	echo "\| Add rpie user to the input group to allow /dev/input/* access"
	echo "\| (needed for KSM/DRM mode with linxuraw/udev access"
	echo "+-------------------------------------------------------------------------------"
	## https://github.com/libretro/RetroArch/issues/5033
	## done already in helpers.sh: echo 'SUBSYSTEM=="input", GROUP="input", MODE="0660"' > /etc/udev/rules.d/99-input.rules
	usermod -a -G input $USER

	FBSET=`which fbset`
	echo " "
	echo "+-------------------------------------------------------------------------------"
	echo "\| Allow $FBSET to be executed by non-root users"
	echo "\| (used by /opt/retropie/supplementary/runcommand/runcommand.sh)"
	echo "+-------------------------------------------------------------------------------"
	## https://stackoverflow.com/questions/53052294/managing-linux-framebufferfb0-permission-in-low-level-c-graphics-code
	usermod -a -G video $USER
	chgrp video /usr/bin/fbset
	chmod g+s $FBSET

	echo " "
	echo "+-------------------------------------------------------------------------------"
	echo "\| Update /opt/retropie/config/all/retroarch.cfg to use audio_driver = alsa"
	echo "\| (needed by KMS/DRM)"
	echo "+-------------------------------------------------------------------------------"
	cp -fv /opt/retropie/configs/all/retroarch.cfg /opt/retropie/configs/all/retroarch.cfg.orig
	sed -i '/# audio_driver =/c\audio_driver = \"alsa\"' /opt/retropie/configs/all/retroarch.cfg

	echo -e "FINISHED fix_quirks_kmsdrm \n\n"
	sleep $__SLEEP
	}

	# Install latest stock libsdl2
	function install_local_libsdl2_with_kmsdrm() {
	echo "--------------------------------------------------------------------------------"
	echo "\| Install local libsdl2 with KMS/DRM enabled"
	echo "--------------------------------------------------------------------------------"

	echo "-> Remove (possible) hold on libsdl2-dev package"
	dpkg --list \| grep sdl2
	## unhold all packages. But because this is fresh install, onluy libsdl2-dev should be on hold if installed by retropie
	## https://askubuntu.com/questions/164587/how-can-you-unhold-remove-a-hold-on-a-package
	apt-mark unhold $(apt-mark showhold)

	echo "-> Install depends. Most/all should be installed already."
	apt-get install -y libasound2-dev libudev-dev libibus-1.0-dev libdbus-1-dev fcitx-libs-dev libsndio-dev libsamplerate0-dev libpulse-dev libwayland-dev libdrm-dev libgbm-dev

	#git clone https://github.com/RetroPie/SDL-mirror "retropie-2.0.10"
	#cd retropie-2.0.10
	# for some reason git clone https://github.com/RetroPie/SDL-mirror "retropie-2.0.10" version doesn't work

	echo "-> Get latest version of libsdl2"
	cd $USER_HOME


	## sha1sum of SDL2-2.0.12.tar.gz from libsdl.org on 20201015 - do at least minimal effort
	## to check that we're getting what we're expecting (https://www.gnupg.org/download/integrity_check.html)

	#local __SHA1SUM="e8ba91bf5eb438dbcf1fedf0530a1bcbe30d3bb6"
	#wget https://www.libsdl.org/release/SDL2-2.0.12.tar.gz

	local __LIBSDL2="SDL2-2.0.14"
	local __SDL2VER=$(echo ${__LIBSDL2} \| cut -d- -f2)
	local __SHA1SUM="212b17d988c417a1a905ab09c50d1845cc48ddb7"
	wget https://www.libsdl.org/release/${__LIBSDL2}.tar.gz
	local __SHA1SUMNEW=`sha1sum ./${__LIBSDL2}.tar.gz \| cut -d' ' -f1`

	if [ "$__SHA1SUM" != "$__SHA1SUMNEW" ]; then
	echo "ERROR: sha1sum of downloaded file doesn't match with previously recorded value."
	echo "ERROR: make sure ${__LIBSDL2}.tar.gz has not been tampered with. Aborting."
	exit 1
	fi

	tar zxf ${__LIBSDL2}.tar.gz
	cd ${__LIBSDL2}
	./configure --enable-video-kmsdrm --prefix=/usr/local/lib/libsdl2-${__SDL2VER}
	make -j`grep -c ^processor /proc/cpuinfo`
	make install

	echo "-> Add local libsdl2 to ld.so.cache. Current versions of SDL2 are:"
	ldconfig -p \| grep SDL
	echo "-> cat /etc/ld.so.conf.d/x86_64-linux-gnu.conf for library paths/search order"
	cat /etc/ld.so.conf.d/x86_64-linux-gnu.conf
	## FIXME: read in first uncommented line and use that (should be /usr/local/lib/x86_64-linux-gnu on 20.04)
	mkdir -p /usr/local/lib/x86_64-linux-gnu
	echo "-> symlink to installed .so and rebuild ld.so.cache"
	ln -s /usr/local/lib/libsdl2-${__SDL2VER}/lib/libSDL2-2.0.so.0 /usr/local/lib/x86_64-linux-gnu
	ldconfig
	echo "-> ld.so.cache entries for libsdl2:"
	ldconfig -p \| grep SDL
	echo "-> test that retroarch uses this copy"
	ldd /opt/retropie/emulators/retroarch/bin/retroarch \| grep libSDL2

	cd $USER_HOME
	mv -v ${__LIBSDL2} RetroPie-Setup/
	mv -v ${__LIBSDL2}.tar.gz RetroPie-Setup/

	echo -e "FINISHED install_local_libsdl2_with_kmsdrm \n\n"
	sleep $__SLEEP

	}


	function disable_es_openbox_autostart() {
	echo "--------------------------------------------------------------------------------"
	echo "\| disable ES start from ~/.config/openbox/autostart as it is now laucnhed"
	echo "\| from ~/.bash_profile"
	echo "--------------------------------------------------------------------------------"

	backupFile $USER_HOME/.config/openbox/autostart
	sed -i 's/.*autostart/#&/' $USER_HOME/.config/openbox/autostart

	## TODO: maybe don't disable unclutter
	sed -i 's/.*unclutter/#&/' $USER_HOME/.config/openbox/autostart

	echo -e "FINISHED disable_es_openbox_autostart \n\n"
	sleep $__SLEEP
	}

	function normalize_gnome_terminal() {
	echo "--------------------------------------------------------------------------------"
	echo "\| Comment out gnome terminal modifications from ~/.bash_profile"
	echo "--------------------------------------------------------------------------------"

	backupFile $USER_HOME/.bash_profile
	sed -i 's/.*gsettings/#&/' $USER_HOME/.bash_profile

	mv -v $USER_HOME/.config/openbox/rc.xml $USER_HOME/.config/openbox/rc.xml.retropie

	echo -e "FINISHED normalize_gnome_terminal \n\n"
	sleep $__SLEEP
	}


	function are_we_root() {
	# Make sure the user is running the script via sudo
	if [ -z "$SUDO_USER" ]; then
	echo "This script requires sudo privileges. Please run with: sudo $0"
	exit 1
	fi
	# Don't allow the user to run this script from the root account. RetroPie doesn't like this.
	if [[ "$SUDO_USER" == root ]]; then
	echo "This script cannot be run by the root user. Please run as normal user using sudo."
	exit 1
	fi
	}

	### 1,2,3,...
	if [ ! -z $__has_kms ]; then
	are_we_root
	echo "KMS/DRM setup activated."
	echo ""
	echo "Configure RetroPie to run under Linux KMS/DRM mode on Ubuntu 20.04 LTS."
	echo "Supports only Intel (and virtual) framebuffers. Specifically nVidia and"
	echo "Radeon based systems are not properly set up by this script."

	install_kmsdrm_depends

	is_it_i915_fb # Find if we have i915 FB
	find_fb_max_resolution # Find if FB can support 1080p; if not try to find lower working resolution
	update_grub_resolution "${__XRES}x${__YRES}x32,1920x1440x32"
	set_kernel_fb_resolution # Sets kernel video=
	install_xorgconf # create /etc/X11/xorg.conf (match FB resolution)
	fix_quirks_kmsdrm

	install_local_libsdl2_with_kmsdrm

	## Roll back / modify changes
	enable_autostart_emulationstation
	rewrite_xsession
	disable_es_openbox_autostart
	normalize_gnome_terminal
	if [ -z $__KEEP_SPLASH]; then
	disable_plymouth_splash
	fi

	else
	echo "-> __has_kms is not set. Skipping KMS/DRM setup."
	fi