Linux or Android Based product How to

[ebclr]

I would like to make a product that is based on Linux or Android,  Basically, I would like that they don't  show any botting messages only some king of customized boot screen,  after that the system will execute my program, who will show the product screen, and interact with all hardware, when chose to power down, the system will also shut down without any typical Linux / Android, messages .

The question is where can I found information on how to do that? What are the common developer tools? Any tip for a good source of information for this kind of development

[MosherIV]

Hi

From memory (it has been more than 2 years since I was involved with Linux development) Linux does have capability to have a graphic boot screen loaded and shown. Never used it just came across the feature as I was examining the boot up process.

Just search for it. Then use the man pages for it or the brief documentation.

It may be dependant on the distribution, variant and version.

Good luck. I never got on with the documentation from Unix/Linux. It is a rabit hole, you just end up deeper and deeper having to read more and more stuff. Becomes more irrelevant to the task you are trying to accomplish but you need to plough through the garbage to find the 1 peice of information you need 

[jhpadjustable]

For Linux, there are two splash screens to worry about: one in the bootloader and one in userspace. The bootloader varies by platform. For das U-Boot, the video display typically isn't enabled unless explicitly called for in the bootloader script. You could just set the console to the serial port and absorb the extra second or so in boot time. In Ubuntu, the userspace startup/shutdown splash screen package is called Plymouth and it has a theming system for your use. At the end of the boot process, the system would usually start the display manager, which manages the life cycle of the X server and sets up the login prompt. Most of the common display managers allow you to set up an auto-login mode. From there, you can use a ~/.xinitrc or ~/.xsession file to start up your UI instead of the window manager, whether you've brought a Tcl/Tk script, an Electron app, or just a browser configured in kiosk mode.

A few minutes of googling worked for me finding the answers. Then again, I'm a salty old Unix admin and I used to be a lot more aggravated by eye candy than I am today. Learning how to turn these special effects off is helpful in knowing how to turn them on.

When you build your own Android image, you can change the source and therefore the user experience as you like. That was an intended benefit of Android's "open" development model, in fact. For early boot, see Linux, above.

[SiliconWizard]

For Linux, there also simply is the option of getting the boot process to be completely quiet (meaning nothing will be displayed on screen), which is a simple and effective alternative to bootsplash stuff, especially if the boot sequence is short (which is something I recommend anyway). The screen will remain black until the system has booted, you can then display a first image or your full GUI (if it loads fast) as the first thing the user will see. This is what I did on a small device based on an SBC. You'll have to customize your Linux install to shorten the boot sequence as much as you can. Keep it lightweight.

If the boot sequence exceeds like 2 or 3 s, then yes I agree a bootsplash screen would be recommended. Then again, depending on the device it's going to run on, you may be able to display some kind of image BEFORE the OS even starts booting, in which case it would be enough IMO, and then you'd make the Linux boot quiet as suggested above. This option, if available, may even be nicer than a Linux bootsplash, because with the latter, it would take a bit longer for a first image to appear on screen.

I personally don't recommend Android, as it looks like a gigantic PAIN to customize, and really doesn't seem that easy to write low-level stuff for (but my experience is limited with that, so someone that has done that extensively may be of more help.) Just saying that for me, Linux is much easier to deal with. YMMV.