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video mode bootloader and after kernel is loaded ?


arhi

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Hi guy's, trying to get my hdmi screen to work on some board (not really relevant but board is orangepi on and lcd is "7inch hdmi lcd (c), usb capacitive touch screen, 1024x600, rev 2.1" - the box it came in states brand is "waveshare") with armbian and I'm having issues. I don't care too much of getting screen to work "ideally", having txt console working is all I need. When I turn the board on I see everything properly, background is, as expected black, letters are white + some colors, it starts the booting process, looks for mmc controller, ethernet etc etc.. then it finds the kernel and start loading it and then - puf, the screen is gone... depending on what h3disp option I use I get different behaviors (from going slowly all white to filling slowly screen white from corner pixel by pixel..) but not a single option gave me visible picture (when I connect some big "normal" monitor I see the console).

 

So, the "pre kernel" screen is visible, is there any way I can configure armbian to keep "that" hdmi output after kernel boots up?

 

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Experimental mainline image (currently without support) will do just that... Legacy image unfortunately doesn't support this resolution because it is not standard. However, it can be added by patching a kernel. Which way do you want to go?

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On 4/13/2017 at 10:49 PM, jernej said:

Which way do you want to go?

Good question :D

 

I would like to understand how "just keeping the same resolution that is set by the bootloader after kernel loads" is a problem :D.. it's not relevant to my current issue, just my curiosity and wanting to know more about linux internals :D as the way I get it when arm boots up it will load the bootloader (u-boot ?) from the sd card that will init the screen and load the kernel.. I assumed the kernel and the bootloader from the same repo are maintained by same team so that they support same resolutions :D

 

Back to the question at hand, I think patching the kernel is more interesting to me as I'd like to figure out how to recompile the kernel for these embedded systems (lot of experience with linux on PC, no experience with linux on embeded systems, arm .. at all).

 

This what I have:


Welcome to ARMBIAN 5.25 stable Debian GNU/Linux 8 (jessie) 3.4.113-sun8i
System load:   0.88             Up time:       33 sec
Memory usage:  16 % of 494Mb    IP:            192.168.90.61
CPU temp:      44°C
Usage of /:    20% of 7.2G

Last login: Sat Apr  1 22:59:03 2017 from 192.168.89.6
root@orangepione:~# uname -a
Linux orangepione 3.4.113-sun8i #10 SMP PREEMPT Thu Feb 23 19:55:00 CET 2017 armv7l GNU/Linux
root@orangepione:~#

 

Any links to "what to patch it with and how to compile the darn thing" :D

 

I just started going trough

and https://docs.armbian.com/Developer-Guide_Build-Preparation/

and looks like I'll have to get ubuntu on some of the boxes (I use mostly redhat myself), that's not the big deal, but I don't see with what to patch the kernel to get this resolution issue solved :D

 

thanks

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I compiled and booted the "experimental" image (could not find with what to patch kernel to get display working) and yey, the display works :) .. now I just hope it's stable enough for the few simple tasks I need it to do :D

 

thanks

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