should a vendor layer override the base "u-boot" recipe?

["Robert P. J. Day" <rpjday@crashcourse.ca>]

  sort of a policy question but i'm working with a vendor layer from
STMicroelectronics ("ST"), and that layer provides ST's version of
u-boot -- a recipe named "u-boot-stm32mp". fair enough, and they also
have an include file that makes that recipe the preferred provider:

  PREFERRED_PROVIDER_virtual/bootloader ??= "u-boot-stm32mp"

so, ideally, someone would not define their recipes to refer to u-boot
explicitly, but to virtual/bootloader.

  but i decided to build the "base" (OE) u-boot recipe just as a
baseline, and ran:

  $ bitbake u-boot

and was surprised that nothing further was done, and i noticed that it
tried to build ST's recipe, and then i noticed this:

  PREFERRED_PROVIDER_u-boot ??= "u-boot-stm32mp"

is that normal behaviour from a vendor? does that not mean i can't
even try to build OE's version of u-boot because ST's setting above
will hijack the recipe name?

  is this considered normal vendor behaviour?

rday