[U-Boot] [RFC] Multiple binaries per U-Boot target

[Albert ARIBAUD <albert.u.boot@aribaud.net>]

Hi Simon,

On Fri, 19 Jul 2013 10:53:33 -0600, Simon Glass <sjg@chromium.org>
wrote:

> Hi,
> 
> On Fri, Jul 19, 2013 at 9:27 AM, Sascha Silbe <t-uboot@infra-silbe.de>wrote:
> 
> > Albert ARIBAUD <albert.u.boot@aribaud.net> writes:
> >
> > > Although, with recent proposals like the TPL one:
> > >
> > > http://permalink.gmane.org/gmane.comp.boot-loaders.u-boot/164432
> > >
> > > ... I am toying with the idea of a more generic build mechanism which
> > > would allow a target to specify as many binaries as it needs, each with
> > > its own configuration.
> >
> > FWIW, I like the idea. Apart from streamlining the current code, it
> > would allow building custom chains of bootloaders. One thing I could use
> > for development would be a minimal stage that can load one of two
> > "normal" / full-blown U-Boot versions, similar to dual BIOS support on
> > modern x86 PCs. All devices I work with can be un-bricked reasonably
> > easily, but for most of them it either requires manual interaction
> > (e.g. the push-button for UART boot on CuBox) or prevents "normal" boots
> > (e.g. removing the SD card on Wandboard so that it boots via USB
> > _instead_ of from SD card).
> >
> > In addition, it would allow customising SPL features without having to
> > introduce more special code.
> >
> 
> We actually use something like this in Chrome OS. Right now we are working
> on a 'small' U-Boot which is not SPL but has no commands (they are compiled
> out by a CONFIG option which I will post one day). This will involve two
> complete runs of the U-Boot Makefile - one to create each version of
> U-Boot. It would be great if this could be handled automatically in the
> same build.

My idea is that any 'component' needed in at least one 'binary' would
be compiled once, and then linked as many times as there would be
binaries needing it, all in one single makefile invocation.

> Regards,
> Simon

Amicalement,
-- 
Albert.