[PATCH] c-user: Document CONFIGURE_DIRTY_MEMORY

Gedare Bloom gedare at rtems.org
Mon Feb 10 12:23:41 UTC 2020


Looks good, thank you

On Mon, Feb 10, 2020 at 2:32 AM Sebastian Huber
<sebastian.huber at embedded-brains.de> wrote:
>
> Close #3843.
> ---
>  c-user/configuring_a_system.rst | 36 +++++++++++++++++++++++++++++++++++-
>  1 file changed, 35 insertions(+), 1 deletion(-)
>
> diff --git a/c-user/configuring_a_system.rst b/c-user/configuring_a_system.rst
> index 81bc9bb..00584c1 100644
> --- a/c-user/configuring_a_system.rst
> +++ b/c-user/configuring_a_system.rst
> @@ -425,6 +425,38 @@ General System Configuration
>  This section defines the general system configuration options supported by
>  ``<rtems/confdefs.h>``.
>
> +.. index:: CONFIGURE_DIRTY_MEMORY
> +
> +.. _CONFIGURE_DIRTY_MEMORY:
> +
> +CONFIGURE_DIRTY_MEMORY
> +----------------------
> +
> +CONSTANT:
> +    ``CONFIGURE_DIRTY_MEMORY``
> +
> +DATA TYPE:
> +    Boolean feature macro.
> +
> +RANGE:
> +    Defined or undefined.
> +
> +DEFAULT VALUE:
> +    By default, the memory used by the RTEMS Workspace and the C Program Heap
> +    is uninitialized memory.
> +
> +DESCRIPTION:
> +    This macro indicates whether RTEMS should dirty the memory used by the
> +    RTEMS Workspace and the C Program Heap as part of its initialization.  If
> +    defined, the memory areas are dirtied with a ``0xCF`` byte pattern.
> +    Otherwise, they are not.
> +
> +NOTES:
> +    Dirtying memory can add significantly to system boot time.  It may assist
> +    in finding code that assumes memory starts set to zero.  In case
> +    :ref:`CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY` is also defined, then the
> +    memory is first dirtied and then zeroed.
> +
>  .. index:: CONFIGURE_EXTRA_TASK_STACKS
>  .. index:: memory for task tasks
>
> @@ -1006,7 +1038,9 @@ DESCRIPTION:
>
>  NOTES:
>      Zeroing memory can add significantly to system boot time. It is not
> -    necessary for RTEMS but is often assumed by support libraries.
> +    necessary for RTEMS but is often assumed by support libraries.  In case
> +    :ref:`CONFIGURE_DIRTY_MEMORY` is also defined, then the memory is first
> +    dirtied and then zeroed.
>
>  Classic API Configuration
>  =========================
> --
> 2.16.4
>
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