There is no standard configuration option to rotate the framebuffer by 90 or 270 degrees (a transpose, or reflection in the line y = x).
Any rotation that is only a combination of horizontal or vertical flips can be achieved.
The original legacy display stack had a slightly nasty hack that triggered a recomposition to memory with transpose at 60Hz to produce a rotated buffer that could be displayed.
With the shift to using the kernel for display composition, there is no easy way to replicate that. That's true of the majority of Linux display drivers.
There are some configuration options that give userspace an indication of the display orientation, but it is then up to the display client to do something useful with that information. The easiest is probably via the video= entry on the kernel command line, adding a "panel_orientation" value (eg "video=HDMI-A-1:1920x1080@60,panel_orientation=left_side_up"). See https://www.kernel.org/doc/html/latest/fb/modedb.html for the full list of options, and it gets inserted at the start of /boot/firmware/cmdline.txt.
I have no idea if Pico-8 or Picotron will look at that data though.
Any rotation that is only a combination of horizontal or vertical flips can be achieved.
The original legacy display stack had a slightly nasty hack that triggered a recomposition to memory with transpose at 60Hz to produce a rotated buffer that could be displayed.
With the shift to using the kernel for display composition, there is no easy way to replicate that. That's true of the majority of Linux display drivers.
There are some configuration options that give userspace an indication of the display orientation, but it is then up to the display client to do something useful with that information. The easiest is probably via the video= entry on the kernel command line, adding a "panel_orientation" value (eg "video=HDMI-A-1:1920x1080@60,panel_orientation=left_side_up"). See https://www.kernel.org/doc/html/latest/fb/modedb.html for the full list of options, and it gets inserted at the start of /boot/firmware/cmdline.txt.
I have no idea if Pico-8 or Picotron will look at that data though.
Statistics: Posted by 6by9 — Mon Jul 21, 2025 2:28 pm