[U-Boot] DM_VIDEO and splash screen functionality

[Igor Opaniuk <igor.opaniuk@gmail.com>]

Hi Anatolij,

On Tue, May 28, 2019 at 3:31 PM Anatolij Gustschin <agust@denx.de> wrote:
>
> Hi Igor,
>
> On Tue, 28 May 2019 13:35:13 +0300
> Igor Opaniuk igor.opaniuk at gmail.com wrote:
>
> > Hi all,
> >
> > Just a clarifying question:
> > I assume a splash screen functionality from common/splash.c and
> > common/splash_source.c is marked as deprecated and is not going to be
> > used anymore alongside with DM_VIDEO enabled, right?
>
> no, this is still used with DM_VIDEO enabled. This splash image
> loading code is for pre-loading the bitmap (file) from configurable
> storage source before drawing it (see also doc/README.splashprepare).
>
> The bitmap drawing code is currently at 3 different locations,
> depending on the board and/or video driver configuration:
>  common/lcd.c
>  drivers/video/cfb_console.c (!DM_VIDEO)
>  drivers/video/video_bmp.c (DM_VIDEO)

Actually I meant the difference in behavior I'm observing between
DM_VIDEO enabled drivers and legacy ones.
For example, for legacy lcd video stack drawing of boot logo is a part
of initialization process, where
the main condition is a sane value of env("splashimage"):
lcd_init() (common/lcd.c:245) -> lcd_clear() -> lcd_splash() ->
bmp_display(addr, x, y)

Also I'm observing the same behavior for cfb_console (also with the
same check if env("splashimage") is defined):
cfg_video_init(cfb_console.c:2018) -> video_logo() ->video_display_bitmap()

But for DM_VIDEO enabled drivers there is no any signs of invocation
of bmp_display()/other wrappers during
the overall initialization  (I've followed all possible paths starting
from stdio_add_devices()), and probing of
of DM_VIDEO enabled drivers are deferred till I explicitly invoke
something like `bmp` command), so
I assumed that not adding the same check for env("splashimage") and
further bmp_display() invocation was done for
some purpose (for example, to deprecate and remove splash.c
functionality in the future).

>
> We will most probably remove cfb_console when all remaining users
> are converted to DM_VIDEO. lcd.c can co-exist with DM_VIDEO enabled
> drivers and is still used for some boards. Maybe we will drop it as
> well, unless LCD console for older boards with limited resources must
> be supported.
>
> > I understand that the same result can be achieved (showing a boot
> > logo) using CONFIG_PREBOOT define and with an invocation of something
> > like "bmp display <addr>" in "preboot" env variable, but just wanted
> > to know if splashscreen legacy stuff (common/splash.c) is going to be
> > somehow integrated into the new video stack in the future.
>
> Yes, you can load the .bmp file to memory first via commands in "preboot"
> and display it with "bmp" command then. But it would be better to
> implement it in common way reusable for other boards and independent
> of "preboot" configuration. We already have the necessary functions
> splash_screen_prepare() and bmp_display(). The first loads the file
> to memory address defined in "splashimage" env variable. This address
> can be passed to bmp_display(). We can add a common function which
> checks "splashimage" and sets it if not defined, then calls prepare/
> display functions. No other integration is required.

Yeah, this was my initial point that it doesn't work now and there is no such
function for DM_VIDEO configurations. I just assumed that following steps from
doc/README.splashprepare, adding CONFIG_SPLASH_SOURCE define
and providing proper values for splashsource/splashimage env vars
should make a deal, but
obviously it doesn't.

I'll send a patch if don't mind.

>
> --
> Anatolij

Thanks for your reply!

-- 
Best regards - Freundliche Grüsse - Meilleures salutations

Igor Opaniuk

mailto: igor.opaniuk at gmail.com
skype: igor.opanyuk
+380 (93) 836 40 67
http://ua.linkedin.com/in/iopaniuk