RTEMS 4.9.4 On-Line Library

Interrupt Manager Directives Allowed from an ISR

RTEMS C User's Guide

6.3.2: Directives Allowed from an ISR

Using the interrupt manager ensures that RTEMS knows when a directive is being called from an ISR. The ISR may then use system calls to synchronize itself with an application task. The synchronization may involve messages, events or signals being passed by the ISR to the desired task. Directives invoked by an ISR must operate only on objects which reside on the local node. The following is a list of RTEMS system calls that may be made from an ISR:

Task Management
Although it is acceptable to operate on the RTEMS_SELF task (e.g. the currently executing task), while in an ISR, this will refer to the interrupted task. Most of the time, it is an application implementation error to use RTEMS_SELF from an ISR.
- rtems_task_get_note
- rtems_task_set_note
- rtems_task_suspend
- rtems_task_resume
Interrupt Management
- rtems_interrupt_enable
- rtems_interrupt_disable
- rtems_interrupt_flash
- rtems_interrupt_is_in_progress
- rtems_interrupt_catch
Message, Event, and Signal Management
- rtems_message_queue_send
- rtems_message_queue_urgent
- rtems_event_send
- rtems_signal_send
Semaphore Management
- rtems_semaphore_release
Dual-Ported Memory Management
- rtems_port_external_to_internal
- rtems_port_internal_to_external
IO Management
The following services are safe to call from an ISR if and only if the device driver service invoked is also safe. The IO Manager itself is safe but the invoked driver entry point may or may not be.
- rtems_io_initialize
- rtems_io_open
- rtems_io_close
- rtems_io_read
- rtems_io_write
- rtems_io_control
Fatal Error Management
- rtems_fatal_error_occurred
Multiprocessing
- rtems_multiprocessing_announce

RTEMS C User's Guide