Questions tagged [framebuffer]
related to Linux `fbdev` abstraction (a.k.a. Linux framebuffer), as well as to accessing the framebuffer (a part of video memory) in general
142
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What is the definitive (and simplest) way to use fbi on Raspberry OS Buster to display images automatically on startup?
I have made all sorts of modifications to my ACLs and even created a photos.service that starts fbi, but it only starts, and displays 1 image before the screen goes blank.
I have other processes (web ...
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Which service creates /dev/fb0 node?
I want to update the console-setup.service to detect screen resolution using fbset -s and adjust console font size accordingly. For fbset, I need /dev/fb0 to be present, but I don't know which service ...
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Buildroot and framebuffer
I am very new to embedded programming so please have some understanding if i sound dumb.
Recently i have built a linux kernel using buildroot tool.
These are the commands i used:
make ...
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78
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How to interpret linux frame buffer pseudo color palette
I am trying to write a custom pseudo color palette to use with linux frame buffer. To write color palette I use the fb_cmap structure and IOCTL call ioctl(fp,FBIOPUTCMAP,&ocmap); in my C code.
I ...
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Linux: re-enable display port after disabling by kernel command video=DP-1:d
Is it possible to re-enable an display that was disabled by kernel option video=DP-1:d ?
Background: I have a laptop (ux8402) that has two monitors by design and I do not want a second display on ...
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2
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876
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How can I get the number bytes to write per row for FrameBuffer?
Goal: I'm writing a very simple image viewer for framebuffer /dev/fb0 (something like fbi).
Current state:
My software takes the pixel resolution from /sys/class/graphics/fb0/virtual_size (such as ...
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2
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1
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TERM=fbterm causes box-drawing characters (by curses) get scrambled
I'm writing TUI software on fbterm using python-curses library.
To get full color in fbterm, I read it's man page and concluded I need to change environmental variable TERM to fbterm.
Man page: By ...
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1
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Video rom part of iomem usage
Given some x86_64 linux stock kernel running one single GPU embedded into whatever pci-e extension board.
cat-ing /proc/iomem, I can realize that some space is reserved in RAM and associated to the ...
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Relationship between framebuffer and a tty
A framebuffer is a device file which allows for a simplified interface to the screen.
For example running the below code on a RaspberryPi with a HDMI display connected:
cat /dev/urandom > /dev/fb1
...
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2
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1
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How to stream the linux framebuffer as video over http
I have an embedded linux system (yocto based) with a framebuffer UI (no X11) and a running web server.
Now I'm asking how to "mirror" the screen contents to a web page. Think of it like a ...
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Problems enabling HDMI screen framebuffer on startup for ts_calibrate
I'm running EGT on a SAMA5D4 Xplained board. It uses KMS for output to a HDMI screen. I've got a touchscreen that needs to be calibrated on the first use, I'm using ts_calibrate from tslib. I have a ...
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Debian text mode framebuffer issue - Kernel 5.14
I can't fix the startup issue I'm facing since I updated my Debian (bullseye) to backports distribution in order to get the Kernel 5.14
As per my researching it seems to be something related to the ...
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1
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471
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How do I write directly to video memory without xorg?
Kind of an odd question I know, but fifteen years ago I was able to use svgalib on some ancient version of Debian to draw directly to video memory without xorg.
To my dismay I see svgalib was pulled ...
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Frame buffer driver(altfb) not working with a 24 bit display
I am developing an embedded Linux system with a 24 bit LCD display. I use terasic linux-socfpga to compile the kernel and I want to use the altfb driver to show the desktop in LCD. For that, I copied ...
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260
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Low-Latency method to read Xorg or DRM framebuffer
I am trying to build an application that can measure the latency/processing time of graphics frameworks on Linux.
My idea is to implement simple programs that react to an input event (e.g. mouse click)...
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1
answer
514
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Got EOS from element "pipeline0" on gst fbdevsink
I'm trying to forward video file to the framebuffer on my device that has no X. I'm using gstreamer with fbdevsink plugin.
When I test it with
gst-launch-1.0 videotestsrc ! fbdevsink
it works ...
- 161
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736
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Alpine Linux: Disable switching into framebuffer mode at boot?
We are installing a custom version of Alpine Linux on several embedded elderly PC. The monitor is connected using VGA and may not report the supported resolutions correctly, hence the GPU may choose ...
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qt5 program with "-platform linuxfb" does not reset framebuffer when crashing
We have a qt5 program running under Alpine Linux v3.14 which uses a fragile legacy library which may cause the entire program to crash. Alpine Linux switches to framebuffer mode during start up. We ...
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How to hide firmware logo in GRUB?
I disabled the hidden menu feature of GRUB on Fedora 34 Workstation, which hides GRUB menu and lets the vendor logo remain on the screen during GRUB operation.
$ sudo grub2-editenv - unset ...
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how to not stretch the 4:3 (1024x768) resolution on a wide monitor (1920x1080)?
I need this because my dell notebook video card is only not freezing if I use nomodeset on grub.
But then, I am limited to 4:3 resolutions (right?).
So, I am looking for a way to not stretch the ...
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Is it possible to configure GRUB to remove UEFI vendor logo faster during boot?
I appreciate the flicker free boot feature of Fedora. However, I am a disappointed customer of my laptop manufacturer. I would like to see less of its logo, so that I could dwell less on my regrets. ...
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Write on /dev/fb0 has no effect on GUI console
I run X in this way
/usr/bin/X vt07 -retro
to have the GUI on console 7 and the gray grid as background.
On console 1 I write
while [ 1 ] ; do cat /dev/random > /dev/fb0; done
and I see the ...
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hwinfo --framebuffer shows nothing, can't change grub resolution
I am using a Lenovo Yoga C940 15" with Fedora 34. It has a 4K screen with an nvidia gtx1650 mobile card and integrated intel graphics. I wanted to change the resolution of the GRUB menu because ...
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Is it possible to access the "frame buffer" so I can change the properties of each pixel?
I don't know if my question is technically correct. Here is what I want to do,
I'm running linux with xorg. The colors on my screen is way too dull. Its not my hardware because when I had windows my ...
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2
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3k
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How can I enable TTY console?
I'm running Linux (Debian 10) on a Chromebook (Eve) using a stock Chrome OS kernel (4.4.x) with minor modifications. Everything runs (mostly) fine except that TTY console cannot be accessed via Ctrl+...
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Can't clear /dev/fb0
I have one of those 7" HDMI diplays from eBay, driving it with a Q1900 board running Ubuntu 20. I can write to the display using fbi:
sudo fbi -a -T 1 --noverbose -d /dev/fb0 -t 5 --blend 1000 &...
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3
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cannot run in framebuffer mode. Please specify busIDs
from my previous question empty screen after booting from live persistent usb, I am able after boot to access all files and folders, but the X-server is unable to load (so I get only to tty1). From ...
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Is it possible to run fb on one head and X on anohter, given one card connected to a TV and a monitor?
I would like to set up so that my computer's monitor is connected to it's VGA output, while having a framebuffer on the other head.
Both heads seem to share a card.
They work fine as part of the same ...
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0
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594
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Initializing framebuffer device without udev
I am trying to reduce boot time in a Raspberry Pi 4 using Yocto Linux. The system uses SysV init.
There is psplash that uses framebuffer, and Qt application that uses DRM/eglfs, displayed ...
- 291
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117
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X writing top of screen to random parts of framebuffer - Xorg problem?
I have an ASUS laptop with an SIS graphics card. The default Xorg generated when I installed Debian (well, technically Raspbian Desktop) was at 640x480, yet it can easily do better as it's a 1280x800 ...
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Cannot run in framebuffer mode. error help
I'm using ParrotSec and the system I normally used gave an error last night and I could not solve it.
I start normally, then wait, but the KDE does not start and the screen remains black. I pressed ...
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455
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How do I allocate memory for a framebuffer loadable kernel module (linux)
I'm writing a 'fake' framebuffer device so I can use my e-reader as an external screen for my raspberry pi. The e-reader part is working fine (https://github.com/llandsmeer/inkvt), but now I want to ...
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3
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2k
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Cannot force Debian to start in Framebuffer 640x480 resolution
In order to port an embedded project from an ARM target to Linux/x86, I have to create a Debian VM (I'm using Virtualbox right now) which starts in framebuffer mode with 640x480 resolution.
I used ...
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Debian10: No such file or directory: /dev/dri/card0
I'm installing Debian 10 but I cannot startx nor have a GUI. I think the problem is about some driver.
Here are the errors I've got in /var/log/Xorg.0.log :
[drm] Failed to open DRM device for pci:...
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3
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3k
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How to access and use Linux Frame Buffer without GTK?
I'd like to use /dev/fb0 or whichever other files are provided by the linux.
This in a system specific way as low as possible how to read/write/interpret those device files for GUI frame-buffer non-...
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Can gstreamer fbdevsink output to Xvfb virtual framebuffer? Which device to use?
I learned recently how to use Xvfb virtual Linux framebuffer:
https://www.raspberrypi.org/forums/viewtopic.php?f=66&t=261264
I want gstreamer fbdevsink output into a virtual framebuffer, but that ...
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1
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371
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Displaying a picture on the framebuffer while running a script created with dialog
I have setup scripts that use the dialog command. They are used to prepare embedded servers.
I'd like to display a picture on a edge while a dialog script is running. The problem is, that dialog by ...
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0
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684
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Xfbdev not found after including X (tinyx/kdrive) in Buildroot
I'm trying to add Xorg to an evaluation board for which I've already been provided with a working linux kernel. The evaluation board has an LCD display and I can confirm hardware & drivers are ...
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How do I get fb0 scanline length?
I am accessing /dev/fb0, the screen's frame buffer, in console mode, Debian 10, using a HP Envy Touchsmart laptop, using fwrite standard C function.
I read this page:
https://techoverflow.net/2015/06/...
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How can I display graphics on the screen from the kernel over the top of my X11/Wayland session?
I want to draw simple (2D bitmapped) graphics onto my screen (in response to (simple) external inputs) with the lowest latency possible (the order of tens of milliseconds) so I can empirically test ...
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1
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How can I prevent a TTY (e.g. /dev/tty1) from writing to the framebuffer (/dev/fb0)?
I'm running a Raspbian Buster server with no Xserver. I want to display wallpaper on a connected television but /dev/tty1 keeps over writing /dev/fb0 either with a blinking cursor or just refreshing ...
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How to prevent a particular terminal (e.g. /dev/tty1) from writing the cursor to framebuffer (e.g. /dev/fb0)
I'm running Raspbian Buster with no Xserver but attached to a television. I have a script that writes an image to the framebuffer from a timed systemd service.
The problem is /dev/tty1 is writing ...
- 443
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How to set a large stty size?(default 80x24)
I'm really not sure where is the problem, so I'm putting all message i think helpful here.
dmesg | grep drm
[ 0.316388] fb0: switching to cirrusdrmfb from EFI VGA
[ 0.316769] [drm] fb mappable ...
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763
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Struggling with display KMS options on Lenovo D330-10igm
I'm trying to replace the default Windows 10 installation with Linux on this hybrid tablet.
What I tried
First I tried with Ubuntu 18.04, blank screen, I thought about starting modifying the KMS ...
- 233
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376
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Accessing the full screen in console mode
I have a newly installed version Rockchip Debian running on a Libre Computer Renegade that I use solely in console mode. I am trying to get text to take up the entire screen and have managed to ...
- 109
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221
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Redirect all keyboard input to a detached screen session
I'm trying to build a headless system using a Raspberry Pi; I have two programs runnning on it, one to catch all the input from a barcode reader (a simple keyboard emulation device) and one to display ...
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408
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How do I vsync in bash (or the Linux framebuffer)?
I was trying to see how fast I could fill/swap on /dev/fb0 with something to the effect of:
while :; do head -c $SIZE /dev/erg > /dev/fb0; head -c $SIZE /dev/zero > /dev/fb0; done
(Where /dev/...
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100
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Display blacking out on boot (Macbook Linux)
(Please note that I am breaking this out as a separate question from this one I asked earlier: How exactly do the Linux display device files work?)
I have a Linux From Scratch system that I've built (...
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315
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How exactly do the Linux display device files work? [closed]
I don't really understand how the Linux display device files work and interact together. What files in the /dev tree need to go where and where do they need to connect/point to, in order to show a ...
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1
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mapping linux /dev/fb0 to DDR for displaying
I want to write a linux driver which maps my specified memory address space to /dev/fb0.
the driver should be specified by what part of linux? drm or frame buffer or server X or somthing else? Which ...
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