[U-Boot] Porting to Broadcom BCM7038 (Hermes board)

Detlev Zundel dzu at denx.de
Thu Aug 20 13:18:07 CEST 2009


Hi Peter,

>     All the tasks you mention here are performed by U-Boot. U-Boot _is_
>     the boot loader.
>
> Right, I'm just having trouble getting to grips with the code flow, the start.S
> in the CPU is the initial entry point, at what point does that hand over to
> U-Boot? Any chance you could give me a brief overview of the code flow? In
> particular where the code I need to write fits in with the boot process, i.e.
> where I need to interface with U-Boot.
>
> Once I've got a better idea of how U-Boot boots, I should be able to get
> started at least.

Be sure to read the section "Implementation Internals" in the README.
Other than that, simply trace the flow (on a piece of paper) for a
comparable board, e.g. the "purple" board which seems to be pretty close
to what you have.

Another hint is that functions in U-Boot ending with _f are run from
flash, wherease functions ending in _r run already relocated from RAM.

I hope this gets you started.

Cheers
  Detlev

-- 
It's like manually inflatable airbags -- people will never
think to use it in time to actually get any help from it.
             -- Miles Bader in <20030607122005.GA1086 at gnu.org>
--
DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
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