Kernel-space ctypes.h support?

[Chris Johns]

On 14/09/2018 10:13, Joel Sherrill wrote:
> On Thu, Sep 13, 2018, 5:40 PM Chris Johns <chrisj at rtems.org
> <mailto:chrisj at rtems.org>> wrote:
>     On 14/09/2018 02:30, Joel Sherrill wrote:
>     > On Thu, Sep 13, 2018, 10:34 AM Sebastian Huber
>     > <sebastian.huber at embedded-brains.de
>     <mailto:sebastian.huber at embedded-brains.de>
>     <mailto:sebastian.huber at embedded-brains.de
>     <mailto:sebastian.huber at embedded-brains.de>>>
>     > wrote:
>     >     ----- Am 13. Sep 2018 um 14:07 schrieb joel joel at rtems.org
>     <mailto:joel at rtems.org>
>     >     <mailto:joel at rtems.org <mailto:joel at rtems.org>>:
>     >
>     >     > On Thu, Sep 13, 2018, 3:28 AM Sebastian Huber <
>     >     > sebastian.huber at embedded-brains.de
>     <mailto:sebastian.huber at embedded-brains.de>
>     >     <mailto:sebastian.huber at embedded-brains.de
>     <mailto:sebastian.huber at embedded-brains.de>>> wrote:
>     >     >
>     >     >> Hello,
>     >     >>
>     >     >> I test currently the tqm8xx BSP which worked fine until RTEMS 5. The
>     >     >> problem is that this BSP uses strtoul() to get some system
>     configuration
>     >     >> parameters from the boot loader. The Newlib used by RTEMS 5 has now
>     >     >> support for C locales in strtoul(). The C locale support needs an
>     >     >> executing thread with a valid Newlib reentrancy structure. This is
>     >     >> definitely not the case during bsp_start().
>     >     >>
>     >     >
>     >     > Why do we now longer have a global reentrancy structure to fall back on?
>     >
>     >     I think having a global reentrancy as a fall back just for the lowest
>     level
>     >     system start without an idle thread is a bit of overkill.
>     >
>     >     The heavy weight C local support which was recently introduced in
>     Newlib is
>     >     not really the right thing for the embedded systems I know.  There were
>     >     several complaints about this on the Newlib mailing list as well.  The
>     root
>     >     cause for this is the C standard. So, basically the C standard
>     strtoul() is
>     >     unsuitable for embedded systems. The FreeBSD (sys/kern/strtoul.c) and
>     Linux
>     >     (lib/kstrtox.c) kernel have their own implementations.
>     >
>     >
>     > FWIW the FACE Technical Standard does not include wide characters in ANY
>     profile
>     > as of Edition 3.0. None of the RTOS vendors knew of any avionics users. It
>     > wasn't viewed as a necessary feature. We could consider disabling it by
>     default.
>     >
> 
>     Is this something we could ot would want to control with newlib via a config
>     option?
> 
> 
> We don't turn on locale for h8, m32c and maybe not epiphany. I am pretty sure.it
> <http://sure.it> is an option. And should be a documented RSB option to turn it
> back on. Should be a size savings for most users.

We turn on or off as an option?

Chris