KDMcM
Posts: 11
Joined: Tue Dec 01, 2015 11:07 pm
Location: Redditch, England

Splash Screen

Wed Nov 14, 2018 5:43 pm

I use a Raspberry Pi for a control application. It doesn't run an X interface. My script (Python) runs automatically at boot using the systemctl method.

The machine's job is to display some measurements on an LCD screen, but it doesn't do anything until the Pi OS has finished booting. I understand the need for this: there are certain things the computer simply cannot do before the boot process is finished.

How can I find out what operations the machine is capable of at various stages of its boot process? More specifically, is it possible for me to program the GPIO ports or execute my Python script before the OS has finished booting?
Even more specifically, I wish to display a splash screen on the LCD indicating that the OS is booting and that the measurements will start in the next 20 or 30 seconds.

If I even had a few keywords I could Google it would be helpful. Part of my struggle is not knowing what the question is!!!

Thanks.

Aydan
Posts: 688
Joined: Fri Apr 13, 2012 11:48 am
Location: Germany, near Lake Constance

Re: Splash Screen

Thu Nov 15, 2018 1:49 pm


jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 23312
Joined: Sat Jul 30, 2011 7:41 pm

Re: Splash Screen

Thu Nov 15, 2018 2:24 pm

And this may help with GPIO settings on boot

https://www.raspberrypi.org/documentati ... xt/gpio.md
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
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tqhien
Posts: 33
Joined: Thu Feb 02, 2012 10:07 am

Re: Splash Screen

Thu Nov 15, 2018 3:19 pm

Hi,

I would go to Linux Embedded or build a custom Linux Kernel with buildroot : you keep only what you need, no extra module.

For splash screen, use this link that explain how to quickly show a splash screen : https://bootlin.com/blog/super-fast-linux-splashscreen/

You can start your app in 10 seconds, Python loading libraries take 5 more seconds...

DarkElvenAngel
Posts: 146
Joined: Tue Mar 20, 2018 9:53 pm

Re: Splash Screen

Wed Nov 21, 2018 2:54 am

tqhien wrote:
Thu Nov 15, 2018 3:19 pm
For splash screen, use this link that explain how to quickly show a splash screen : https://bootlin.com/blog/super-fast-linux-splashscreen/
I have a similar setup I've used this guide for a initrd boot splash. You need to install busybox and lzop's maximum compression is 6 not 9 like listed in The guild unless you compile it yourself.

The problem with using an initrd.img is kernel updates seem to break it.

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