Replacing cape overlays

Hi!

I own a BB-VIEW-43 cape:
http://at.farnell.com/element14/bb-view-43/4-3inch-lcd-display-cape-for-beaglebone/dp/2364756#

By requesting "BB-BONE-LCD4-01" the cape manager loads the dtbo from
the cape's eeprom.
The cape is not using PWM for backlight but a plain gpio LED.
For whatever reasons the dtbo within the eeprom configures this LED
with a heartbeat trigger which is very annoying and needs fixing while
bootup.

What is the best way to fix that? How can I overlay the overlay? :wink:

My trivial approach was using the dts file from the cape sources
and creating a 02 version of the dtbo.
But of course the shipped dts sources does not match the shipped binary.
GPL violation?

It's actually worse then that, "BB-BONE-LCD4-01" = 16bit lcd display,
while the "BB-VIEW-43" is a 24bit..

Start with 3.8: ( am33x-v3.8 )

from:
https://github.com/RobertCNelson/bb-kernel/

Then from the patch.sh script, uncomment this function call:

https://github.com/RobertCNelson/bb-kernel/blob/am33x-v3.8/patch.sh#L1134

#bb_view_lcd -> bb_view_lcd

Then run:

./build_deb.sh

and install the *.deb to the board.

If you still have time, return the "BB-VIEW-43" and pick up a 4D
Systems 4 inch lcd..

Regards,

Hmmm, does this mean that the BB-VIEW-43's eeprom contains a completely
broken devicetree overlay? :frowning:

Thanks,
//richard

The eeprom only contains the "BB-BONE-LCD4-01" identifer... The
device tree overlay is built-into the kernel binary..

The BB-View-43, swapped the red/blue color channels, so there's a hack
for 3.8 to fix that..

https://github.com/RobertCNelson/bb-kernel/blob/am33x-v3.8/patches/bb_view_lcd/0002-sitara_red_blue_swap_workaround.patch

Regards,

Hi!

I own a BB-VIEW-43 cape:
http://at.farnell.com/element14/bb-view-43/4-3inch-lcd-display-cape-for-beaglebone/dp/2364756#

By requesting "BB-BONE-LCD4-01" the cape manager loads the dtbo from
the cape's eeprom.

It's actually worse then that, "BB-BONE-LCD4-01" = 16bit lcd display,
while the "BB-VIEW-43" is a 24bit..

The eeprom only contains the "BB-BONE-LCD4-01" identifer... The
device tree overlay is built-into the kernel binary..

Ahhh, it is in the kernel binary. Thanks for pointing this out.
I was about to ask why it works even when the file is not present in /lib/firmware/

The BB-View-43, swapped the red/blue color channels, so there's a hack
for 3.8 to fix that..

https://github.com/RobertCNelson/bb-kernel/blob/am33x-v3.8/patches/bb_view_lcd/0002-sitara_red_blue_swap_workaround.patch

Yeah, but setting to 24bits depth in xorg.conf also does the trick, no kernel patching needed.

Thanks,
//richard