[U-Boot] confused ... how do some CONFIG settings "implicitly" set others?

[Wolfgang Denk]

Dear "Robert P. J. Day",

In message <alpine.LFD.2.00.0911200826340.27923 at localhost> you wrote:
> 
>   reading http://www.denx.de/wiki/view/DULG/UBootSplashScreen, and i
> see:
> 
> "To enable splash screen support, you have to add a "#define
> CONFIG_SPLASH_SCREEN" to your board configuration file. This will also
> implicitly enable U-Boot Bitmap Support."
> 
>   "implicitly"?  how does that work?  from what i can see in
> define2mk.sed, the transformation is straightforward and there are no
> dependencies or selects as in the kernel Kconfig structure.  how does
> setting splash screen implicitly set bitmap support?  what am i
> missing?

Simple. The relevant parts of the code use

	#if defined(CONFIG_CMD_BMP) || defined(CONFIG_SPLASH_SCREEN)

so they get selected when CONFIG_CMD_BMP and/or CONFIG_SPLASH_SCREEN
is defined.

Best regards,

Wolfgang Denk

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