# 23.3. Operations¶

## 23.3.1. Announcing a Fatal Error¶

The _Terminate() internal error handler is invoked when the application or the executive itself determines that a fatal error has occurred or a final system state is reached (for example after rtems_fatal() or exit()).

The first action of the internal error handler is to call the fatal extension of the user extensions. For the initial extensions the following conditions are required

• a valid stack pointer and enough stack space,

• a valid code memory, and

For the initial extensions the read-write data (including .bss segment) is not required on single processor configurations. In SMP configurations, however, the read-write data must be initialized since this function must determine the state of the other processors and request them to shut-down if necessary.

Non-initial extensions require in addition valid read-write data. The board support package (BSP) may install an initial extension that performs a system reset. In this case the non-initial extensions will be not called.

The fatal extensions are called with three parameters:

• the fatal source,

• a legacy parameter which is always set to false, and

• an error code with a fatal source dependent content.

Once all fatal extensions executed, the system state is set to SYSTEM_STATE_TERMINATED.

The final step is to call the CPU port specific _CPU_Fatal_halt().