[PATCH 01/14] bloblist: Update the tag numbering

Julius Werner jwerner at chromium.org
Fri Jul 28 23:56:05 CEST 2023

> Ok, but if we do that we need to be careful with the standard.  Things
> like BLOBLISTT_U_BOOT_VIDEO dont feel U-Boot specific.

The idea behind the Transfer List tag allocation policy is low
friction allocation and organically emerging standards. You're not
supposed to need to have big up-front debates about how exactly e.g. a
video info descriptor should look like or whether it can be shared
with other projects. Projects are just supposed to add what they need
in the moment, in whatever format they prefer, and can call it
something specific to that project to begin with (e.g. U_BOOT_VIDEO).

Then, later, if other projects feel that this is a good format that
would be worthwhile to reuse, they can just start using it. Just
because it says U_BOOT or the ID number is close to the number for
other U-Boot descriptors doesn't mean that it's not appropriate to be
used anywhere else as long as the same structure with the same meaning
makes sense there. If we eventually find that a bunch of different
projects are all using this tag and it has become a de facto standard,
we can also change the name to drop the U_BOOT (or different projects
can even use different names for the same thing, that doesn't really
matter as long as the ID and format matches). Or, if U-Boot eventually
finds that this structure doesn't work well for them anymore they can
just allocate a new U_BOOT_VIDEO2 and stop using the old one (or
rename the old one to U_BOOT_VIDEO_DEPRECATED and call a new ID with a
new format U_BOOT_VIDEO).

Basically, the idea here is that upfront "perfect" design by committee
tends to not work well for these things anyway and the friction it
adds would be too much of a barrier to adoption. So it's better to not
even try, just let everyone allocate what they want, and then later
see what tends to work out well in practice and where there are
opportunities for tag sharing between projects.

More information about the U-Boot mailing list