[U-Boot-Users] software FP yada yada yada

[Robert Schwebel]

Hi Ulf,

On Fri, Oct 13, 2006 at 06:44:07AM +0200, Ulf Samuelsson wrote:
> I quite often work with customers which has little or no experience
> with Linux but still wants to start using this for new embedded
> systems

Well, I know that it's a common habit of customers out there to expect
that with Linux everything works with a click, one doesn't have to learn
anything, wants all the features and it shoudl be free of cost of
course. Nevertheless, the knowledge has to be somewhere, and until
something goes wrong there are OSS projects out there which do both -
conserving the knowledge and providing a one-click solution.

> My goal is to have a customer download a file, decompress it and type
> make.  After that, everything needed to install a demo on a target
> should be ready.

We do similar things for our customers' OSELAS.BSP()s. Do you know
PTXdist? It was heavily inspired by buildroot when it started in 2002,
although had a menuconfig frontend from the beginning and recently
evolved into something which is really powerful for that kind of project
work.

> I have choosen to use "buildroot" as the framework for this.
> 
> Buildroot will build the toolchain as part of the build process, so
> there is no need to download and install a toolchain.  Avoiding extra
> steps like this has high value to me.

Well, you probably don't want to build the toolchain every time you
build your rootfs. With PTXdist, building toolchains is just another
"project", and "projects" are being built with "ptxdist go" once they
have been defined by somebody.

> It is going to be very complicated to use buildroot with two
> toolchains and there is of course nothing in buildroot which installs
> ELDK as the toolset.

IMHO there is no need for two toolchains. Do your processors have
hardware floating point? If not, build everything with a softfloat
toolchain. We do that all the time and it works like a charm, up to
gcc-4.2 previews.

> I do want to have u-boot built as part of the buildroot make process.

With PTXdist, you could simply define an u-boot packet in your project.

> Since most combinations of gcc/binutils fail it is much easier to use
> a NWFPE version of the compiler also for U-boot.

I can imagine only one reason at this moment to use hardware floating
point toolchains on ARMs without harware float units: Java. The kaffe vm
has still no jit support which works with softfloat/vfp. 

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