like you say long time ago you need to do (wiki batocera)
cp /etc/X11/xinit/xinitrc ~/.xinitrc
and edit .xinitrc with (make copy/paste) :
#!/bin/sh
#hide mouse cursor
unclutter –noevents -b
systemsetting=“python /usr/lib/python2.7/site-packages/configgen/settings/batoceraSettings.py”
#set the keyboard
settings_lang=“$systemsetting -command load -key system.language
”
#not always true (en_US for us), but it’s really better than always english
map_name=$(echo $settings_lang | cut -c 1-2)
setxkbmap “${map_name}”
#disable dpms to prevent screen from blanking
xset -dpms
xset s off
#environment
export HOME=/userdata/system
export LC_ALL=“${settings_lang}.UTF-8”
export LANG=${LC_ALL}
#because of xinerama breaking es, enable only one screen at a time
settings_output=“$systemsetting -command load -key global.videooutput
”
batocera-resolution setOutput “${settings_output}” # empty or invalid values defaults to the first valid
#dpi override for nvidia gpus
settings_output=“$systemsetting -command load -key global.dpi
”
[ ! -z “${settings_output}” ] && batocera-resolution setDPI “${settings_output}”
#####################
###CUSTOMISATIONS ###
#to customize your display, you can copy this file to ~/.xinitrc and then modify it
#rotate the screen
#xrandr -o left
#xrandr -o right
xrandr -o inverted
#change the resolution
#xrandr -s 640×480
#change the resolution and the Hz
#xrandr -s 640×480 -r 60
#adding new modeline for monitor 60Hz
xrandr –newmode “640×480-31khz” 27.216 640 717 760 864 480 485 491 525 -hsync -vsync
#put this new resolution and new frequency into output DVI-0.
xrandr –addmode DVI-0 “640×480-31khz”
#put this new resolution and new frequency into output DVI-0.
xrandr –output DVI-0 –mode “640×480-31khz”
#####################
#####################
#set user desired resolution
#nice workaround for displays which tell X11 to use strange resolutions
settings_output=“$systemsetting -command load -key global.videomode
”
[ ! -z “${settings_output}” ] && batocera-resolution setMode “${settings_output}”
batocera-resolution minTomaxResolution
#allow coredumps for ES
ulimit -H -c unlimited
ulimit -S -c unlimited emulationstation
cd /userdata # es needs a PWD
openbox –config-file /etc/openbox/rc.xml –startup “emulationstation –windowed”
Stéphane