Re: Building RedBoot for SH3 targets with new toolchain

[John Dallaway <john@dallaway.org.uk>]

Hi Jifl

Jonathan Larmour wrote:

> The sh.ld linker script does have the necessary SECTION_eh_frame define.
> But older SH targets have not been updated to use it. In fact the only
> one that does is the sh4_202_md. Something to note down for after the
> code freeze.

Hmm, yes. There will be many targets on other architectures that also
need their .ldi files updating.

> In a slight change of plan, I think I'll wait until you're finished
> looking at all the targets before starting even the SH cygwin build -
> given the recent report it seems like it may be wise to rebuild all the
> cygwin tools with statically linked GMP and MPFR. I have no desire to
> rebuild them all more than once, so let's wait to see if your
> experiments show up more issues down to the tools.

You should find that re-spinning on Cygwin takes no more effort than on
Linux. Of course, elapsed time is another matter entirely!

With Cygwin, it is generally preferable to take advantage of shared DLLs
wherever possible to reduce application load times and overall memory
footprint. This is especially true for parallel builds (eg "make -j2").
FYI, the latest Cygwin-hosted tools are also dependent on Cygwin intl
and iconv DLLs for internationalisation.

I am aware of several members of the eCos community that are using the
current Cygwin-hosted toolchains with no reported problems. We also have
the flexibility of releasing updated toolchains independently of our
eCos releases should this prove necessary in the future.

Taking all these things into account, plus the desire to avoid further
delays to the eCos 3.0 release, I think it preferable to stick with the
stock mpfr and gmp DLLs for the Cygwin-hosted toolchains. We must
document the need to install the relevant Cygwin packages though, and
add an entry to the FAQ.

John Dallaway