[PATCH 1/9] cpukit, testsuite: Add rtems_printf and rtems_printer support.

Gedare Bloom gedare at rtems.org
Tue May 24 15:38:37 UTC 2016

On Tue, May 24, 2016 at 1:13 AM, Chris Johns <chrisj at rtems.org> wrote:
> On 23/05/2016 22:37, Gedare Bloom wrote:
>> How does this affect user applications?
> It should not but if a user has an application that is using the plugin
> interface there is a struct name change. The previous struct ended in '_t'
> and that is reserved for POSIX plus the name included _printk_ and it is a
> plugin interface for printf, printk, fprintf and fiprintf (I think). The
> change for a user is simple and should be stable from here on.
That's what I thought.

> The rtems_printf interface can become a documented interface and we can
> maintain it. The previous interface was functionally fine and is pretty much
> as it was but it's user interface needed some rework, which is what I have
> done. For example there was no easy way to test if a plugin was present and
> if not present dropped all output.
OK, it makes sense.

> Going forward there is a benefit for small memory devices and there is a
> case for printf possibly mapping to rtems_vprintf for those BSPs. I am not
> yet sure how this would be managed but it could be via SYSINT and
> confdefs.h. Defining a stable way to manage this sort of things removes the
> need for users to handle it in their applications.
> Chris

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