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

[Robert Winkler]

Stefano

On Tue, Jun 4, 2013 at 7:30 AM, Eric Nelson
<eric.nelson at boundarydevices.com> wrote:
> Hi Stefano,
>
>
> On 06/04/2013 07:15 AM, Stefano Babic wrote:
>>
>> Hi Eric,
>>
>> On 04/06/2013 15:55, Eric Nelson wrote:
>>>
>>> Hi Stefano,
>>>
>>> On 06/04/2013 06:44 AM, Stefano Babic wrote:
>>>>
>>>> Hi Robert,
>>>>
>>>> On 03/06/2013 18:34, Robert Winkler wrote:
>>>>
>>>>>> Which is the advantage instead of using the "preboot" variable setting
>>>>>> CONFIG_PREBOOT ? It does pretty the same and you can move the whole
>>>>>> script outside of board code.
>>>>>
>>>>>
>>>>> The preboot command is run too late.  It looks like it is run in
>>>>> main_loop but U-Boot looks for the splash image
>>>>> at the address in the splashimage variable in board_init_r ->
>>>>> stdio_init -> drv_lcd_init or drv_video_init (depending on
>>>>> whether you have CONFIG_LCD or CONFIG_VIDEO).
>>>>
>>>>
>>>> You are describing a bug - then it should be fixed globally, not only
>>>> for this board.
>>>>
>>>
>>> What's the bug?
>>>      - preboot being called too late, or
>>
>>
>> preboot is not called too late. The behavior is correct and wanted, as
>> the name says, and the variable is evaluated during the main loop before
>> booting. My suggestion comes because it is possible to implement a
>> splashscreen (even if the name can be misleading..), setting preboot to
>> something like "nand read <address> <offset>;bmp display <address>".
>> In your case (with a bmp image), it could be:
>>         "preboot=if sf probe ; then " \
>>                 "sf read ${splashimage} c2000 ${splashsize} ; bmp display
>> ${splashimage}; fi\0"
>>
>> The behavior is exactly as the subject in the patch, the delay is from
>> power-on until main loop is called. It can be on some boards acceptable,
>> sometimes not.
>>
>
> Gotcha. This method doesn't involve splash_screen_prepare() though.
>
> It also will blink the display since the splash screen will paint
> after the the compiled-in logo case.
>
> http://git.denx.de/u-boot.git/?p=u-boot.git;a=blob;f=common/lcd.c#l1085
>
>
>>>      - splash_screen_prepare() being called too early
>>>
>>> It seems that having splash_screen_prepare() called early
>>> makes sense, because stdout could be set to include VGA
>>> and having access to stdout is very useful in preboot
>>> commands.
>>
>>
>> You mention that it does not work, and then I assume that it is a bug,
>> because an image should be displayed. But again, if it does not work,
>> the issue is related to the video subsystem and should be fixed there
>> and not in board code - this is my point.
>>
Yes, as Eric mentioned I submitted a patch yesterday which fixes
splash screen prepare not working
with CONFIG_VIDEO and will submit a separate patch to add the function
to nitrogen6x.c once that goes through.

The only difference is that we won't call it in board_video_skip in
nitrogen6x.c, it'll be called in
drv_video_init similar to the way it is called in lcd_logo from drv_lcd_init.

Another thing that Eric pointed out that is a difference between
PREBOOT and SPLASH_SCREEN_PREPARE
is the former will always run but the latter will only run if there's
a display which is preferable.

If I had submitted the fix first instead of just working around the
bug I would probably have saved
some confusion.  Sorry about that.

>
> This works with Robert's latest patch, which implements
> splash_screen_prepare() for boards that use cfb_console.
>
> It just wasn't implemented there.
>
> Regards,
>
>
> Eric
>