[U-Boot-Users] Changing u-boot relocation scheme

[Robert Schwebel]

On Wed, Jul 23, 2008 at 10:39:00AM -0700, vb wrote:
> While this relocation is seamless for u-boot in its released form, it
> becomes a pain each time a module needs to be added (not necessarily
> for following release to the Open Source community, for instance used
> for inhouse installations which include tens of thousand units for
> some companies). If these added modules were not written in position
> independent manner (namely, using structures with multiple stage
> indirect pointers interleaved with data), the effort to make these
> modules work in u-boot is very exhausting.

Note that in U-Boot-v2 we have loadable module support; code can
EXPORT_SYMBOL() "public" APIs to other components, which, for example,
can be such custom modules. The mechanism was invented for the scenario
you describe above.

It comes for a cost (footprint), but the overhead is not so big as one
might think. You can play around with the feature by building the
"sandbox" target, which is a user-mode-u-boot (port of u-boot to Linux
userspace).

rsc
-- 
 Dipl.-Ing. Robert Schwebel | http://www.pengutronix.de
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