[U-Boot-Custodians] SPL / TPL

Wolfgang Denk wd at denx.de
Mon Oct 14 08:18:42 UTC 2019

Dear Tom,

In message <20191010190807.GB6716 at bill-the-cat> you wrote:
> This last point here is what I'm also wondering about.  My gut is that
> README.TPL is more "old aspiration" than "what we have implemented".

It is not "aspiration", but documentation of how things are/were
intended to be used.

It is sad that we have not enough documentation, but it is even more
sad that existing documentation gats ignored.  What I finx really
disappointing is that we then start inventing new names to justify
the implementation errors.

> And, setting aside some of the back-and-forth jumps we can have, the
> flow is:
> ROM/etc -> Tiny Program Loader -> SPL -> U-Boot or Linux

Sorry, this is not acceptable, and it will not work.  Explaining TPL
as "tiny" may be applicable in some cases, but not always.  I think
there are use cases where size(SPL) < size(TPL) so this name makes
no sense for general use.

If you want to change the order from

	RBL -> SPL -> TPL -> U-Boot -> OS 

[ignoring falcon mode] into something else, you should completely
drop the names "SPL" and "TPL" which have a meaning attached (and
more than one interpretation), and use completely new names which
do not depend on properties as size.

As a lesson learned from history you should also chose names that do
not refer to execution order, as people tend to ignore that or they
change direction while counting from 1 to 3 :-( 

Best regards,

Wolfgang Denk

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Business is like a wheelbarrow. Nothing ever happens until you  start

More information about the U-Boot-Custodians mailing list