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

[Tom Rini]

On Thu, Mar 15, 2012 at 1:46 PM, Wolfgang Denk <wd at denx.de> wrote:
> Dear Tom Rini,
>
> In message <20120315202316.GA6855 at bill-the-cat> you wrote:
>>
>> So, the (normally?) required to work toolchains are ELDK 5.1 and ELDK
>> 4.2.  5.1 is fine but with 4.2 (gcc 4.2.2) we get two warnings for every
>> file about interworking/thumb not being supported.  Further, the
>> resulting binary doesn't boot.
>>
>> However, is this really a problem?  I don't imagine folks using ELDK
>> 4.2-era tools on OMAP5, and I have a tough time imaging them using it
>> for OMAP4.
>
> 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?

> 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).

-- 
Tom