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

[Stefano Babic]

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.

>     - 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.

Best regards,
Stefano Babic


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