03Retroarch

Install compilation dependencies and download the source from github

apt install git build-essential
apt build-dep retroarch
git clone https://github.com/libretro/retroarch

Compile and install

./configure
make -j$(nproc)
make install

Systemwide configuration file examples:

For an ATI card, with native resolutions.

/etc/retroarch.cfg

menu_driver = "rgui"
video_fullscreen = "true"
crt_switch_resolution = "4"
crt_switch_resolution_super = "1"
system_directory = "~/bios_files"
rgui_browser_directory = "~/ROMs"

For an INTEL card, with super resolutions.

/etc/retroarch.cfg

menu_driver = "rgui"
video_fullscreen = "true"
crt_switch_resolution = "4"
crt_switch_resolution_super = "2560"
system_directory = "~/bios_files"
rgui_browser_directory = "~/ROMs"

For an LCD monitor.

/etc/retroarch.cfg

menu_driver = "rgui"
video_fullscreen = "true"
crt_switch_resolution = "0"
system_directory = "~/bios_files"
rgui_browser_directory = "~/ROMs"

crt_switch_resolution="4" option needs an extra file. /etc/switchres.ini You can see all the options here