Screens that use HDMI should work out of the box you may need to configure the resolution in RaspberryOS Bookworm you can do this by editing the kernel commandline ``` sudo nano /boot/firmware/cmdline.txt ``` !!! warning "Important" Do not add newlines to the file, it must be 1 line with the options separated by spaces for example: ``` video=1920x1080 ``` more complex example: ``` video=HDMI-A-1:1920x1080M@60,rotate=90,reflect_x ``` ???+ "Find the identifier use xrandr" on a terminal run: ```sh DISPLAY=:0 xrandr ``` it will output something like: ``` Screen 0: minimum 320 x 200, current 1024 x 600, maximum 8192 x 8192 HDMI-1 connected primary 1024x600+0+0 (normal left inverted right x axis y axis) 800mm x 450mm ``` in this case the identifier is HDMI-1 and a simple cmdline arg would be something like: `video=HDMI-1:1024x600@60` Valid mode specifiers: ``` x[M][R][-][@][i][m][eDd] ``` options on brackets are optional | Option | Description | |-----------------|----------------------------------------------------------------------------------------| | M | Calculate timings using [CVT](https://en.wikipedia.org/wiki/Coordinated_Video_Timings) | | R | CVT reduced blanking (refresh rate must be 60Hz) | | - | Bits per pixel, A.K.A. BitDepth usuallly 24 | | @ | acceptable refresh rates are 50, 60, 70 or 85 Hz only | | e | Force enable | | D | Force enable Digital mode | | d | Disable | For more info read [modedb default video mode support](https://docs.kernel.org/fb/modedb.html)