[Buildroot] Prelim RTAI integration help needed

[Thomas Petazzoni]

Hello Herman,

On Tue, 7 Sep 2010 08:44:45 +0200 (SAST)
Herman Theron <htheron at hmo.ac.za> wrote:

> I'm currently trying to integrate RTAI into buildroot (which is the
> last hurdle to use buildroot for our embedded data logging systems).
> I've got a basic setup compiling and would like to share it with the
> Buildroot community. I've attached rtai.mk which allows me to compile
> and install RTAI. This is still in infancy, and I would like to get
> help from the buildroot community. (Please note that this is the
> minimum requirements for my project, so a lot of stuff is disabled).

Great!

> There is some issues to get RTAI compiling under buildroot:
> 
> #1 You need to first build a linux kernel with an appropriate RTAI
> kernel patch. Then you can select RTAI and run make again.

In general, we currently don't really have a good common way of
handling stuff such as RTAI which require kernel patches, so the fact
that you're having issues with this does not surprise me.

> #2 When compiling any of the kernel modules, make complains of
> "unknown option: --sysroot" and exits with an error. I've found that
> by deleting all the "--sysroot=...." text in the corresponding
> makefiles, that I was then able to get the compiler going. In the
> makefile I have made use of the POST_CONFIGURE_HOOK to delete
> occurrences of "--sysroot" from the GNUmakefile that is giving an
> error. Question: is this the best way to do it? Any suggestions?

Which toolchain are you using ?

> #3 When installing to the staging area, RTAI expects
> $(STAGING_DIR)/usr/include/asm to be a symlink to
> $(STAGING_DIR)/usr/include/asm-i386 (for x86 architecture).
> Currently, $(STAGING_DIR)/usr/include is directory with .h files, and
> $(STAGING_DIR)/usr/include/asm-i386 is non-existent. I had to create
> $(STAGING_DIR)/usr/include/asm-i386 by hand, move the files from the
> "asm" directory to it, delete the "asm", create a softlink from "asm"
> to "asm-i386". Question, what will be the best way to handle this? In
> rtai.mk, a patch for RTAI? 

Again, which toolchain are you using ? The one generated by Buildroot ?
An external toolchain, and if so, which one ?

Regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com