Building RTEMS hello world image using CMake

[Pavel Pisa]

Hello Chris and others,

On Sunday 13 of March 2016 22:28:14 Chris Johns wrote:
> On 13/03/2016 1:53 AM, Gedare Bloom wrote:
> > If this works for you, and you are sufficiently interested, it would
> > be useful to provide CMake example for the examples-v2.git repository
> > for others to benefit.
>
> I am not sure about adding this to examples-v2.git. I would prefer it to
> be a waf only build system. I am not sure if make support is still
> present and working but it will go once Makefile.inc goes as it is not
> supported in the new RTEMS waf build system.

please, consider to keep/add some mechanism, rule etc.
to export Makefile.inc equivalent content to some file
in /opt/rtems/arch/bsp directory in easily readable form
(make, shell assignments or some other sed parsable format).

I could try to find how to do that when I find time to
switch to 4.12 and WAF. I think, that it is so minimal
information and it worth to be archived/documented with
installed BSP anyway and if it is in easily readable form
then it is better.

I see future when this information is not stored and easily
readable from installed libraries tree, as a real problem,
so I vote to not cut support for other make systems
for applications. How you propose to maintain for
example Microwindows and other libraries in future?
If these libraries are rewritten to WAF build then
each time when mainline is changed it would require
to analyze and update WAF based fork. May it be that
it stay to be solved by RSB. But again forcing every project
and application to be build through RSB is not win either.

Some mechanism to build Automake and Autoconf based projects
should to be considered as well or option to build broad range
of POSIX compliant packages against RTEMS would be complicated
too. I do not use Autoconf/Automake for RTEMS projects now
but it is thing which should be taken into account.

From my projects perspective, it would be real problem
to rewrite set of my projects which contains consistent
build system over many git submodules where many libraries
and even whole application compile to Linux userspace, Linux kernel,
RTEMS, Windows and many bare metal targets. I have about 30
automake-like fragments which are over 20kB long in my
largest project build for RTEMS. It needs to be maintained
for RTEMS-4.10 for long time due testing and instrument certification
but I want to keep run it against RTEMS development version
to catch problems and regressions in time. When I rewrite
all that fragments to the WAF then I have to keep WAF
in sync with other stuff which counts hundreds (may it be 500)
such make fragments and their total length is in hundreds kB.
So thinking about rewrite and forking is really nightmare
dream for me. For sure, I would look how to implement some hack
to extract required information to file as I do for Linux modules
build for example but it is not ideal solution.

So I hope and vote for some Makefile.inc alternative
to be available even in future RTEMS versions.

Best wishes,

             Pavel