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authorSebastian Huber <sebastian.huber@embedded-brains.de>2018-07-18 08:14:09 +0200
committerSebastian Huber <sebastian.huber@embedded-brains.de>2018-07-19 07:36:54 +0200
commitefd581f875a22276add4b85c56282ce7d9a94881 (patch)
tree794bd2d00f918d3e41293f819feecc7871ce2f52 /cpu-supplement
parent4c2ca04c478b9c76932e9d87ca9a8b07354d4cf5 (diff)
downloadrtems-docs-efd581f875a22276add4b85c56282ce7d9a94881.tar.bz2
cpu-supplement: Update interrupt stack paragraph
Close #3459.
Diffstat (limited to 'cpu-supplement')
-rw-r--r--cpu-supplement/port.rst24
1 files changed, 14 insertions, 10 deletions
diff --git a/cpu-supplement/port.rst b/cpu-supplement/port.rst
index dec91a7..bf1de3e 100644
--- a/cpu-supplement/port.rst
+++ b/cpu-supplement/port.rst
@@ -222,9 +222,9 @@ switches to this dedicated stack. On architectures without hardware support
for a dedicated interrupt stack which is separate from those of the tasks,
RTEMS will support switching to a dedicated stack for interrupt processing.
-Without a dedicated interrupt stack, every task in the system MUST have enough
+Without a dedicated interrupt stack, every task in the system must have enough
stack space to accommodate the worst case stack usage of that particular task
-and the interrupt service routines COMBINED. By supporting a dedicated
+and the interrupt service routines combined. By supporting a dedicated
interrupt stack, RTEMS significantly lowers the stack requirements for each
task.
@@ -232,16 +232,20 @@ A nested interrupt is processed similarly with the exception that since the CPU
is already executing on the interrupt stack, there is no need to switch to the
interrupt stack.
-In some configurations, RTEMS allocates the interrupt stack from the Workspace
-Area. The amount of memory allocated for the interrupt stack is user
-configured and based upon the ``confdefs.h`` parameter
+The interrupt stacks (one for each configured processor) are statically
+allocated by the application configuration via ``<rtems/confdefs.h>`` in the
+special section ``.rtemsstack``. This enables an optimal placement of the
+interrupt stacks by the Board Support Package (BSP), e.g. a fast on-chip
+memory. The amount of memory allocated for each interrupt stack is user
+configured and based upon the ``<rtems/confdefs.h>`` parameter
``CONFIGURE_INTERRUPT_STACK_SIZE``. This parameter is described in detail in
-the Configuring a System chapter of the User's Guide. On configurations in
-which RTEMS allocates the interrupt stack, during the initialization process,
-RTEMS will also install its interrupt stack. In other configurations, the
-interrupt stack is allocated and installed by the Board Support Package (BSP).
+the Configuring a System chapter of the User's Guide. Since interrupts are
+disabled during the sequential system initialization and the
+``_Thread_Start_multitasking()`` function does not return to the caller each
+interrupt stack may be used for the initialization stack on the corresponding
+processor.
-In each of the architecture specific chapters, this section discesses the
+In each of the architecture specific chapters, this section discusses the
interrupt response and control mechanisms of the architecture as they pertain
to RTEMS.