Re: EPICS on ARM (continued)

[Dirk Zimoch <dirk.zimoch@psi.ch>]

emmanuel_mayssat@lynceantech.com wrote:
> Rod, Dirk,
>
> I was able to compile and build the libs for my arm platform.
> To my surprise the catools (caget, etc) are not built (only the libs are)
> I don't need them for my iocs, but would be nice to have them for troubleshooting.
> (my arm linux is the etch debian version, i.e. in theory I could ssh to it and caget from
> it). What is the directive to build the <top>/bin/linux-arm_el ?
>
> Obviously the files are built on my linux x86_64 machine.
> But how does the arm access those files, i.e what is common practice?
> 1/ Do you nfs mount the partition on the arm and access the lib from there?
> 2/ Do you copy the files on the arm? scp, ftp, unison, etc...
> 3/ Do you nfs mount the arm and build on local machine?
>
> I would prefer my embedded system to be standalone. So 2 and 3 seem to make sense.
> But what do you/others do?
>
> Thanks,

I would implement 1 and 2. 1 is easier for development. Once you have 
implemented 1 then 2 is easy because you can copy locally on your arm 
system from nfs to local disk. I would use a symbolic link for iocBoot 
to switch between nfs and local disk. If you use automount for nfs, you 
don't even need to worry what happens to your nfs mounts when you run 
standalone and the server is not available. As long as you don't use the 
drive it will not be mounted. If your system supports the /net automount 
facility, it becomes very easy: just set the link to 
/net/servername/remotedir to boot from nfs.

If 2 makes sense depends on the size of the local disk. With tiny flash 
drives it becomes difficult. With modern solid state drives or even real 
hard disks, it is not a problem.

Normally I don't build on the local machine. But it depends. If it is 
large enough to have the compiler installed and you build locally, then 
your EPICS_HOST_ARCH is linux-arm* and it is not treated as a cross 
build. And you will automatically have caget etc.

In src/catools/Makefile you find:
LIBRARY_HOST += catools
PROD_HOST += caget camonitor cainfo caput

This builds caget etc only for the host, not for the cross targets.

To build the tools for all cross Linux IOCs, you may try to add:
LIBRARY_IOC_Linux += catools
PROD_IOC_Linux += caget camonitor cainfo caput

I don't know if that works. And I don't know if it is possible to enable 
this in one of the configure files instead of hacking in src. I guess 
that is is possible with some advanced Makefile programming.

Dirk