[U-Boot] [PATCH v2 06/22] Add generic spl infrastructure

Wolfgang Denk
2011-05-15T19:48:59Z

Dear Aneesh V,

In message <1305472900-4004-7-git-send-email-aneesh@ti.com> you wrote:
> Define a new type of SPL that is not tied to any particular media.
> - Create a top level directory 'spl' that has a structure similar
> to the existing 'nand_spl'
> - Make necessary changes to top-level Makefile to build such an spl
>
> Rationale for this approach:
> - There may be SPLs(like the OMAP x-loader) that support booting from
> multiple media.
> - Also, there is no harm in keeping SPLs specific to a particular media
> also under this directory. In fact it makes sense to merge all the
> different spl directories into this one.

Thanks a lot for addressing this. This is an area that has long been
on my mind, and I'm really happy to see someone starting to work on
this.

In addition to booting from different types of media, I see at least
two more topics that scould and should addressed by this work:

- Get rid of xloader. I cannot see any good reasons why we need it,
i. e. which functions if performs that cannot be as well (and
eventually even more efficiently) be performed in the U-Boot SPL
code.

- Become more flexible regarding the kind of second stage payload.
It is definitely very powerful and convenient during development to
be able to load U-Boot with all it's capabilities as payload of the
SPL, but then, except for image size and parameter passing, there is
little or no difference to loading a Linux kernel directly instead
(and actually this is what most of the super-fast booting approaches
do). If done right, we may even have the flexibility to do both,
just by providing different images as payload.

> Signed-off-by: Aneesh V <aneesh@ti.com>
> ---
> This patch generates 1 checkpatch warning due to declaration
> of DECLARE_GLOBAL_DATA_PTR. This is un-avoidable
> ---
> Makefile | 24 ++++++++++++++++++++++++
> arch/arm/include/asm/global_data.h | 5 +++++
> 2 files changed, 29 insertions(+), 0 deletions(-)

Here the commit message and the implementation do not agree. You
wrote "Create a top level directory 'spl'" - but I don't see any of
that here?

I think this should be split into a separate patch series, and care
should be taken that commit messages and implementaiton match.

Best regards,

Wolfgang Denk

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