I am developing an embedded application that will run on the framebuffer on the target device. Is it possible to develop and test such an application on a development machine (a standard desktop PC) without leaving X11?
I know there is a virtual framebuffer for Qt. I am looking to something similar to this, but not Qt-specific.
Note: This question is similar to this one, but not related to DirectFB.
Related
I have some question about linux desktop environment.
How linux shows its desktop environment on a screen. I mean where and how its GUI frames generates and send to lcd driver? is it at kernel level? does it have any relation to frame buffer (such fb0)?
Is it possible to access the Desktop GUI of linux and write it on frame buffer to show the window environment of linux?
I have searched a lot but did not find my main answer that how linux Desktop Environment is created and shown by monitor that have been known by drivers on linux.
thank you for your attention.
In Linux there's no internal desktop or anything like that. desktop environments are just regular applications just like other applications. almost all desktop environments at their lowest level interact with another GUI library (e.g Qt, GTK, ...). then all these GUI libraries interact with lower-level software called windowing system or display server or window server.
In Unix systems most used window system is X window system ( simply called as X or X11). almost any GUI library which supports Linux, it works with X.
Wayland is another windowing system which is growing and is supposed to be a good replacement for X, because X window system is too old and have many issues. but X is used almost everywhere in Linux and other Unix based operating systems.
So if you really want to know what's going on down there, you should know linux graphics stack. as i said desktop environments are just high level applications. from windowing system (like X) to lower-level libraries and modules (KMS, DRM, ...), are what you really looking for.
KMS (kernel mode setting) works with display controller and DRM (direct rendering manager) works with graphics card and GPU. (however it's really not as simple as i explained)
I am doing a project on OS. I am trying similar to AUTOMATE-IT app in android.
It's an app which automatically dims brightness, turn off WiFi when battery is low etc.
So I am trying something similar in Linux environment. I thought of using C language and thought of implementing the ideas as that app. Like reducing the brightness, turning off WiFi. But i just want to know whether it is possible to carry out in Linux operating system.
Like, are there any system calls or any other way to change the brightness or turn off WiFi using C program . Does Linux allows it?
I tried surfing over the web, but i couldn't get a proper idea, so I thought of asking here.
If it can be carried out, to what extent I can do in Linux ?
I'm currently putting together a project where my application will have a web based frontend and will be running on a microcontroller. In order to provide a friendly UI I would like my app UI to startup without showing any Unix screens, such as splash screen, login and BIOS. This is supposed to behave as an embedded system.
Since my app is browser dependent, I presume I'm going to need my Linux graphical desktop environment running in the background but the less I have running the better.
What is the best OS Rasberry PI for this purpose and how do I make it behave as an embedded system?
Thanks in advance.
regards,
ForeignerBR
Your solution could likely be the following:
Raspbian is the most supported operating system on the Pi at this time and most Linux Debian applications are on there. For speed Arch is the best (but has no GUI as standard).
You could then get it to login & start up into X11 automatically and then set it to launch up the web browser.
I would recommend chromium as you can start it up into a full screen Kiosk mode via the command line. So at boot it would show the command line and possibly the start of a GUI but once booted up should just display the browser.
Hope This Helps -
Ryan Walmmsley
I am developing a program similar to xbmc but only for movies. I was wondering if there is any very simple operating system that will basically just boot and run the program I am developing? Similar to what openelec does for XBMC. I can run it on windows but I want to be able to put it on a machine like raspberry pi without having to have a whole windows or linux OS.
I hope that makes sense.
Take a look at the rather slim linux distributions specialized in embedded systems, like firewalling distros and so on.
Then, if it is a graphical application you have to make sure you boot into runlevel 5 (graphics) and configure your application as login shell for the default user.
You might also be interested in two services the openSUSE project offers: the Open Build Service (OBS) and SUSE Studio:
OBS allows you to automatically get packages of your application built and packaged, ready for use in a number of wide spread distributions.
Studio allows you to go a step further and create a custom distribution for your own purpose: you can call it 'your' operating system, completely preconfigured for your purpose, with all requried software and your own application installed. You just have to download a CD image afterwards!
I'm looking for a really really small linux distribution or process of making my own that's sole purpose is to get an air application to launch full screen and stay there; Essentially I'm building a home kitchen computer that runs entirely as an AIR app.
I have looked into using windows xp; and windows xp embedded but they pose so many issues I figured I'd try modern linux.
I have also seen TinyCore Linux which looks interestingly small but not sure what issues that poses in regards to running AIR and "hardware" accelerated display. I've also thought about stripping down an Ubuntu installation but I'm sure somebody must have done this already; google is just failing me right now...
I'm also interested in running an "embedded" version of say android and running the air app on some arm-based hardware again; with just the AIR runtimes only - although this is less preferred as it's more complex.
I'm also hooking this up to a touch screen monitor (not yet arrived) so I'll need to hunt down or write some drivers for translating the touch events into something AIR can understand... (this was my main intention for using windows in that all the drivers will just work).
What I'm after
Minified Linux kernel with JUST the drivers for the box I need
X Display with accelerated graphics support (Doesn't have to be X if AIR can run on a frame buffer?)
Running a Full screen AIR application (simple enough)
Ability to write back to the filesystem (enough support for AIR)
SSH Access for remote control
Samba for updating the filesystem (easier to maintain the system)
Touch screen support (3M Ex III I think...)
Audio support
Don't need
Don't need any window manager or any other GUI tools unless required by AIR
Don't need any toolbars or file managers or anything; The AIR app is the "OS"
Don't need any package managers or repos
Don't need multi user or logging in; everything can just run as an unprivileged account
Don't need to
I don't mind hand crafting the filesystem and configs if that makes it easier; I'm mainly looking for a "filesystem" that is as tiny as possible that I can just plop my AIR app into and write some scripts to get it to start when the X server starts
Thanks,
Chris
Try an embedded Linux build system such as Buildroot. It can build an entire system from source, and be very lightweight. The basic system is less than 1 MB in size.
Ended up going with Tiny Core. Very tiny and quick to boot up. You can also write extensions for it and you don't have a persistent drive which allows you to just switch the thing off without worry that it's going to break something -- exactly what you need in a kitchen :-D.
My current plan is to:
Just set up a working version using Ubuntu as this is mostly supported by Adobe
Slowly strip it back and try and get as little things to start as possible on boot
Try building my own distro/package from source and selecting only the packages I need
Compile my own kernel with nearly everything turned off and just leave on the things I need