Removing blank screen between Boot Splash screen and boot animation

[Shivanand Naik]

Hi,
I am working on NVidia tegra 3 platform  and working on Jelly Bean 4.1.2r1 release of AOSP. I am trying to customize boot splash screen along with boot animation. I want to provide an effect that the splash screen and boot animation are one part. Currently I observed on most of the android devices available in market, that the screen goes blank after splash screen and before starting boot animation. The splash screen is loaded by bootloader and the boot animation is in the form of ZIP file stored in /system partition. The surface flinger loads the animation from zip file.

I browsed the code in surface flinger to locate the place where the screen is cleared out after splash screen. I think if I can avoid clearing of the screen, then the boot animation will be started immediately after splash screen without a blank effect in between.

Any pointers on which part of surface flinger is doing this?

Cheers
Shivanand

[Maninder Singh]

Hi,
   As per my knowledge the splash image is loaded to the frame buffer by the booloader.Now as soon as the booting process is completed and the kernel starts,a new framebuffer allocation takes place and the frame buffer memory is cleared.It is done by the kernel's frame buffer driver of the respective chipset.Now there are two cases.One is when the frame buffer RAM address used by the bootloader is same as the frame buffer RAM address used by the kernel.The other is when they are different.If in your case it is same then u will find the code in ur frame buffer driver where there is a reset of the frame buffer contents by a memset operation most probably.And if they are same there u will find the code for new frame buffer allocation in ur frame buffer driver.This reset operation is mainly done by the driver in order to prevent any garbage from being displayed on the screen.So I think surface flinger has nothing to do with it.This is the logic behind this.But how this logic is implemented depends completely on the respective chipset vendor and accordingly the code shall vary.

Regards
Maninder

[Syed Mohammed, Khasim]

To add to Maninder's input. Also check if you are turning off/on the display controller in Linux driver, if there is another off/on of the controller or reset of the controller then comment that out. Just do all the necessary configurations in the bootloader itself.

Regards,

Khasim

--
--
unsubscribe: android-porti...@googlegroups.com
website: http://groups.google.com/group/android-porting
 
---
You received this message because you are subscribed to the Google Groups "android-porting" group.
To unsubscribe from this group and stop receiving emails from it, send an email to android-porti...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

[Abbas A. Elmas]

Hi Shivanand,

Did you success on removing blank effect by avoiding clear before bootanimation? if so how? or how far did you try?

thanks in advance,

Abbas