[U-Boot] Help with exporting memory power management info in u-boot

[Wolfgang Denk]

Dear Ankita Garg,

In message <20110530063940.GB16331 at in.ibm.com> you wrote:
> 
> In this regard, we want some help from the u-boot community on designing
> the interfaces. Further, we would like to collaborate with all the SoCs
> that have support for managing memory power on their boards, so we could
> design a generic interface that can be exploited by all.

Could you please be so kind and explain which of such functionality
you envision to see in ore expect from U-Boot?

I understand why all thisi s a very important topic for an operating
system like Linux.

But U-Boot is a boot loader.  It is being used mainly in two different
environments or usage modes:

1) First, U-Boot is a powerful tool for board bringup and for software
   development purposes.  In this environment, power consumption is
   usually the least of your concerns.  Instead, we focus on
   simplicity and robustness.

2) Second, U-Boot is (sometimes) an inevitable intermediate step when
   booting an operating system.  In this mode, whole purpose of U-Boot
   is to get it's job done and then get out of the way as quickly as
   possible.

So in real-world applications we may see a few ten, or maybe in worst
case up to a few hundred milliseconds of U-Boot runtime compared to
hours, days and often weeks and months of run time of the respective
operating system.


Keeping this in mind, which are the parts of memory power management
that are important for the U-Boot context?

Thanks.


Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
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
It's not an optical illusion, it just looks like one.   -- Phil White