3 ms·
>Another answer I found said no modern operating system will let you access the framebuffer directly. BUT LUCKILY THAT’S WRONG. I don't know why this works for
by nemothekid 6y ago
>Another answer I found said no modern operating system will let you access the framebuffer directly. BUT LUCKILY THAT’S WRONG.
I don't know why this works for OP, but my understanding is that the original assertion is true. Writing/Reading directly from fb0 does not work on my machine.
- karatinversion 6y agoDid you try what OP did to fix this for himself – i.e. > sudo adduser seena video
- nemothekid 6y agoNo, it's not that I'm having a permission issue - /dev/fb0 simply returns all 0 on my machine.
- nitrogen 6y agoDo you have any other framebuffer devices or multiple GPUs? Or proprietary video drivers? Note: I was part of a small group that worked on a framebuffer utility library around 2002ish, but haven't used it much since apart from configuring embedded devices.
- therein 6y agoI'm getting the following: $ sudo hexdump -C /dev/fb0 00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 0000e000 aa aa aa 00 aa aa aa 00 aa aa aa 00 aa aa aa 00 |................| * 0000e020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 0000f000 aa aa aa 00 aa aa aa 00 aa aa aa 00 aa aa aa 00 |................| * 0000f020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00300000 `*` for repeating lines.
- Jasper_ 6y agoYou can't do it from an X11 session, which uses DRM/KMS instead of fbdev, hence you will get the compatibility fbdev buffer, which will be all 0s. You need to be VT switched away (hit Ctrl+Alt+F3 or similar).