Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => A20 => Topic started by: Fra on May 23, 2022, 10:47:27 AM

Title: LCD 7CTS not recognized after u-boot building
Post by: Fra on May 23, 2022, 10:47:27 AM
Goodmoring you all,

I have an A20-Lime. I'm using Bullseye minimal from a flashed SD.
Evrything worked fine, LCD 7CTS and 10CTS worked fine, no problem of ehernet, so everything was good.
I cloned the "u-boot-olinuxino" directory from https://github.com/OLIMEX/u-boot-olinuxino , I enabled the "bmp command" thanks to menunconfig, rebuilt evrything with:
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- and written it to SD card thanks to:
sudo dd if=u-boot-sunxi-with-spl.bin of=/dev/mmcblk0 bs=1024 seek=8
After this, the board boot, but the LCD 7CTS (and also the 10CTS) remains blank and it is no more recognized.
Thanks to serial and ethernet connection I've tried setting it by
#olinuxino-displayand
#olinuxino-overlaybut it doesen't work.

If I use
export DISPLAY=:0
xrandr
it says:
Can't open display:0
I've also noticed that
=>olinuxino infocommand is no more recognized i the u-boot command shell.

Evryone know how to solve the prbolem of the unrecognized LCD? Or sombody can give me hints ho to resolve it?
Title: Re: LCD 7CTS not recognized after u-boot building
Post by: LubOlimex on May 25, 2022, 11:04:10 AM
Well, you need to use the defconfig for your A20 board not just the default one, use:

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- A20-OLinuXino-Lime2_defconfig

instead of the generic

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf-

All defconfigs can be found here:

https://github.com/OLIMEX/u-boot-olinuxino/tree/release-20220413/configs
Title: Re: LCD 7CTS not recognized after u-boot building
Post by: Fra on May 25, 2022, 12:13:52 PM
I've done it, but it doesn't work.

These are the passages that i've done:
git clone https://github.com/OLIMEX/u-boot-olinuxino
cd u-boot-olinuxino

I've taken the configuratoin thanks to:

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- A20-OLinuXino-Lime_defconfig
I've enabled the "bmp command", using

nano .config

then i recompiled and flashed the sd with:

make all
sudo dd if=u-boot-sunxi-with-spl.bin of=/dev/mmcblk0 bs=1024 seek=8
.

After reboot, the LCD remains off, even specifying it with:

#olinuxino-display
#olinuxino-overlay


Looking at the u-boot messaggess, it seems that it can't recognize the LCD. Probably it doesn't get the overlays file, but i don't know hw to fix it.
If u can help me


Title: Re: LCD 7CTS not recognized after u-boot building
Post by: Steen E on May 25, 2022, 06:08:34 PM
Hi there
I just browsed the forum, and has no experience, but perhaps the issue is the dd.1 cmd. The man-page says 'seek' is for the of-file and 'skip' is for the if-file, so maybe the ubuntu-lcd connection fails because you first start to write 8MB past the start of the lcd memory block?
(Skimmed from https://www.olimex.com/forum/index.php?topic=3066.msg33821#msg33821)
Title: Re: LCD 7CTS not recognized after u-boot building
Post by: Fra on May 26, 2022, 12:19:34 PM
It doesn't work.
If I use
sudo dd if=u-boot-sunxi-with-spl.bin of=/dev/mmcblk0 bs=1024 skip=8
reboot

The boards doesen't boot anymore (the green LED reamins off)  :(
Title: Re: LCD 7CTS not recognized after u-boot building
Post by: Steen E on May 29, 2022, 11:51:33 AM
Hi again

After rereading I can see that my attempt at explaining is completely wrong. The skip/seek parameter is important, and documented in the man-page. But I now realise (?) that your dd command writes to a flashcard.

I am not able to help you further, but I wish you the best of luck.
Title: Re: LCD 7CTS not recognized after u-boot building
Post by: LubOlimex on May 31, 2022, 10:35:20 AM
Try just A20-OLinuXino aka:

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- A20-OLinuXino_defconfig
Title: Re: LCD 7CTS not recognized after u-boot building
Post by: Fra on May 31, 2022, 04:12:54 PM
Using
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- A20-OLinuXino_defconfig
the LCD works and it is recognized.

Many thanks