[U-Boot] [PATCH v4 0/6] Enable Thumb build for ARM platforms

[Tom Rini]

On Thu, Mar 15, 2012 at 10:01:50PM +0100, Wolfgang Denk wrote:
> Dear Tom Rini,
> 
> In message <CA+M6bXkBodKLkkqFseqo=BeNuL62W-MUSgsTEYgV4WLEvf1GtA at mail.gmail.com> you wrote:
> >
> > > I don't consider it a big problem (just a bit sad) if  ELDK 4.2 cannot
> > > be used for building these.  However, I think it is not acceptable
> > > tobuild known-to-be-broken images.  If the tool chain is too old, this
> > > shall result in a clear error message and abort of the build.
> > 
> > Is an #error in a common omap4/5 file sufficient or does it need to be
> > sooner than that?
> 
> If it can be tested there, it can probably also tested before we start
> building at all?

I suspect no just because the kernel does this in
<linux/compiler-gcc[45].h>

> > > Why is thumb mode needed for these boards?  Just because of image
> > > size?
> > 
> > Basically, yes.  Without thumb mode we're very close (and sometimes
> > spilling over) the size limit.  Thumb takes us away from that and is a
> > small speed increase (due to smaller sized files).
> 
> size limit means size limit for the SPL due to limitations of the ROM
> boot loader resp. the available RAM size?

On OMAP4 we have (after a quick peek around) 56KB SRAM but we only have
40KB of that as non-secure SRAM for use by SPL.

-- 
Tom