[U-Boot] [PATCH] Add splash screen support via loading from flash

[Robert Winkler]

On Fri, May 31, 2013 at 12:49 AM, Wolfgang Denk <wd at denx.de> wrote:
>
> Dear Robert,
>
> In message <CAMDMJ5PJ_AqZaxTRdnvS8ju_SkVHV7zoDrBUyhgjt2jfr4Ok4Q at mail.gmail.com> you wrote:
> >
> > > >  board/boundary/nitrogen6x/nitrogen6x.c | 22 ++++++++++++++++++++++
> > > >  include/configs/nitrogen6x.h           | 11 ++++++++++-
> > > >  2 files changed, 32 insertions(+), 1 deletion(-)
> > >
> > > Could you please explain why you need custom code here?
> >
> > I originally tried to use the CONFIG_SPLASH_SCREEN_PREPARE functionality.
> > After some frustration, I figured out that without CONFIG_LCD, it is never
> > actually called.
> > http://git.denx.de/?p=u-boot/u-boot-imx.git;a=blob;f=common/stdio.c;h=5d5117c0ed838195a2caad7c28c128247771cd92;hb=HEAD#l216
> >
> > It does seem odd that there are 2 totally different paths and the other
> > splash screen related macros are used in both but the prepare function is
> > only called in the LCD case.
>
> OK, so this is a bug that needs to be fixed - but for all boards.
>
> > Since we use CONFIG_VIDEO and not CONFIG_LCD, this seemed to be the best,
> > or at least the least invasive, solution.
>
> No, this is definitely not the "best" solution, as it keeps the bug,
> so the next one who tries to do what you are doing will run into it
> again.
>
>
> Pleast let's fix the problem at the cause.
>
> Please fix the video code to also run splash_screen_prepare() at the
> appropriate place.  While you are at it, please also replace this
> construct
>
>         1071 #ifdef CONFIG_SPLASH_SCREEN_PREPARE
>         1072 static inline int splash_screen_prepare(void)
>         1073 {
>         1074         return board_splash_screen_prepare();
>         1075 }
>         1076 #else
>         1077 static inline int splash_screen_prepare(void)
>         1078 {
>         1079         return 0;
>         1080 }
>         1081 #endif
>
> (in "common/lcd.c") and use a "weak" function for
> splash_screen_prepare().  board_splash_screen_prepare() is no longer
> needed, then (the boards can provide their own implementation of
> splash_screen_prepare()).


I'm not quite clear on how it should be.

So if I were just fixing lcd.c to use a weak function it would look like this:
#ifdef CONFIG_SPLASH_SCREEN_PREPARE
int __splash_screen_prepare(void)
{
    return 0;
}

int splash_screen_prepare(void)
    __attribute__ ((weak, alias("__splash_screen_prepare")));
#endif

But it'd also have to go in cfb_console.c.  Is it possible for a board
to ever use both CONFIG_LCD and CONFIG_VIDEO and if ?

Also are prototypes necessary?  Looking at cfb_console for example
weak functions I see a prototype for video_set_lut in video_fb.h but I
can't find any for board_video_skip.


>
>
> Thanks.
>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
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Thanks,

Robert Winkler