From 05a5366469ee4ee7776f70dceea631ea57a63b19 Mon Sep 17 00:00:00 2001 From: Sebastian Huber Date: Mon, 22 Oct 2018 14:22:45 +0200 Subject: c-user: Modify CONFIGURE_INTERRUPT_STACK_SIZE Use CPU_STACK_MINIMUM_SIZE instead of CONFIGURE_MINIMUM_TASK_STACK_SIZE to set the default value. Clarify documentation. Update #3480. --- c-user/configuring_a_system.rst | 41 +++++++++++++++++++++++++++++------------ 1 file changed, 29 insertions(+), 12 deletions(-) (limited to 'c-user') diff --git a/c-user/configuring_a_system.rst b/c-user/configuring_a_system.rst index 3e44239..d9f65a4 100644 --- a/c-user/configuring_a_system.rst +++ b/c-user/configuring_a_system.rst @@ -1656,6 +1656,10 @@ NOTES: :ref:`CONFIGURE_MINIMUM_POSIX_THREAD_STACK_SIZE ` configuration option. + In releases before RTEMS 5.1 the ``CONFIGURE_MINIMUM_TASK_STACK_SIZE`` was + used to define the default value of :ref:`CONFIGURE_INTERRUPT_STACK_SIZE + `. + .. index:: CONFIGURE_INTERRUPT_STACK_SIZE .. index:: interrupt stack size @@ -1668,27 +1672,40 @@ CONSTANT: ``CONFIGURE_INTERRUPT_STACK_SIZE`` DATA TYPE: - Unsigned integer (``uint32_t``). + Unsigned integer. RANGE: Positive. DEFAULT VALUE: - The default value is CONFIGURE_MINIMUM_TASK_STACK_SIZE, which is the - minimum interrupt stack size. + The default value is ``BSP_INTERRUPT_STACK_SIZE`` in case it is defined, + otherwise the default value is ``CPU_STACK_MINIMUM_SIZE``. DESCRIPTION: - ``CONFIGURE_INTERRUPT_STACK_SIZE`` is set to the size of the interrupt - stack. The interrupt stack size is often set by the BSP but since this - memory may be allocated from the RTEMS Workspace, it must be accounted for. + The ``CONFIGURE_INTERRUPT_STACK_SIZE`` configuration option defines the + size of an interrupt stack in bytes. NOTES: - In some BSPs, changing this constant does NOT change the size of the - interrupt stack, only the amount of memory reserved for it. - - Patches which result in this constant only being used in memory - calculations when the interrupt stack is intended to be allocated from the - RTEMS Workspace would be welcomed by the RTEMS Project. + The interrupt stack size must be aligned according to + ``CPU_INTERRUPT_STACK_ALIGNMENT``. + + There is one interrupt stack available for each configured processor + (:ref:`CONFIGURE_MAXIMUM_PROCESSORS `). The + interrupt stack areas are statically allocated in a special linker section + (``.rtemsstack.interrupt``). The placement of this linker section is + BSP-specific. + + Some BSPs use the interrupt stack as the initialization stack which is used + to perform the sequential system initialization before the multithreading + is started. + + The interrupt stacks are covered by the :ref:`stack checker + `. However, using a too small interrupt + stack size may still result in undefined behaviour. + + In releases before RTEMS 5.1 the default value was + :ref:`CONFIGURE_MINIMUM_TASK_STACK_SIZE + ` instead of ``CPU_STACK_MINIMUM_SIZE``. .. index:: CONFIGURE_EXTRA_TASK_STACKS .. index:: memory for task tasks -- cgit v1.2.3