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

[Simon Glass]

Hi Albert,

On Fri, Jul 19, 2013 at 12:12 PM, Albert ARIBAUD
<albert.u.boot at aribaud.net>wrote:

> Hi Simon,
>
> On Fri, 19 Jul 2013 10:53:33 -0600, Simon Glass <sjg at chromium.org>
> wrote:
>
> > Hi,
> >
> > On Fri, Jul 19, 2013 at 9:27 AM, Sascha Silbe <t-uboot at infra-silbe.de
> >wrote:
> >
> > > Albert ARIBAUD <albert.u.boot at 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.
>

That would be excellent!

Regards,
Simon