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RTEMS 4.6.6 On-Line Library


Processor Dependent Information Table CPU Dependent Information Table

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7.2: CPU Dependent Information Table

The PA-RISC version of the RTEMS CPU Dependent Information Table contains the information required to interface a Board Support Package and RTEMS on the PA-RISC. This information is provided to allow RTEMS to interoperate effectively with the BSP. The C structure definition is given here:

typedef struct {
  void       (*pretasking_hook)( void );
  void       (*predriver_hook)( void );
  void       (*postdriver_hook)( void );
  void       (*idle_task)( void );
  boolean      do_zero_of_workspace;
  unsigned32   idle_task_stack_size;
  unsigned32   interrupt_stack_size;
  unsigned32   extra_mpci_receive_server_stack;
  void *     (*stack_allocate_hook)( unsigned32 );
  void       (*stack_free_hook)( void * );
  /* end of fields required on all CPUs */

  hppa_rtems_isr_entry spurious_handler;

      /* itimer_clicks_per_microsecond is for the Clock driver */
  unsigned32   itimer_clicks_per_microsecond;
}   rtems_cpu_table;
pretasking_hook
is the address of the user provided routine which is invoked once RTEMS APIs are initialized. This routine will be invoked before any system tasks are created. Interrupts are disabled. This field may be NULL to indicate that the hook is not utilized.
predriver_hook
is the address of the user provided routine that is invoked immediately before the the device drivers and MPCI are initialized. RTEMS initialization is complete but interrupts and tasking are disabled. This field may be NULL to indicate that the hook is not utilized.
postdriver_hook
is the address of the user provided routine that is invoked immediately after the the device drivers and MPCI are initialized. RTEMS initialization is complete but interrupts and tasking are disabled. This field may be NULL to indicate that the hook is not utilized.
idle_task
is the address of the optional user provided routine which is used as the system's IDLE task. If this field is not NULL, then the RTEMS default IDLE task is not used. This field may be NULL to indicate that the default IDLE is to be used.
do_zero_of_workspace
indicates whether RTEMS should zero the Workspace as part of its initialization. If set to TRUE, the Workspace is zeroed. Otherwise, it is not.
idle_task_stack_size
is the size of the RTEMS idle task stack in bytes. If this number is less than MINIMUM_STACK_SIZE, then the idle task's stack will be MINIMUM_STACK_SIZE in byte.
interrupt_stack_size
is the size of the RTEMS allocated interrupt stack in bytes. This value must be at least as large as MINIMUM_STACK_SIZE.
extra_mpci_receive_server_stack
is the extra stack space allocated for the RTEMS MPCI receive server task in bytes. The MPCI receive server may invoke nearly all directives and may require extra stack space on some targets.
stack_allocate_hook
is the address of the optional user provided routine which allocates memory for task stacks. If this hook is not NULL, then a stack_free_hook must be provided as well.
stack_free_hook
is the address of the optional user provided routine which frees memory for task stacks. If this hook is not NULL, then a stack_allocate_hook must be provided as well.
spurious_handler
is the address of the optional user provided routine which is invoked when a spurious external interrupt occurs. A spurious interrupt is one for which no handler is installed.
itimer_clicks_per_microsecond
is the number of countdowns in the on-CPU timer which corresponds to a microsecond. This is a function of the clock speed of the CPU being used.


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