source: rtems/doc/supplements/hppa1_1/cputable.t @ 9ec462aa

@c
@c  COPYRIGHT (c) 1988-1998.
@c  On-Line Applications Research Corporation (OAR).
@c  All rights reserved.
@c
@c  $Id$
@c

@chapter Processor Dependent Information Table

@section Introduction

Any highly processor dependent information required
to describe a processor to RTEMS is provided in the CPU
Dependent Information Table.  This table is not required for all
processors supported by RTEMS.  This chapter describes the
contents, if any, for a particular processor type.

@section 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:

@example
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;
@end example

@table @code
@item 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.

@item 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.

@item 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.

@item 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.

@item 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.

@item 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.

@item 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.

@item 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.

@item 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.

@item 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.

@item 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.

@item 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.

@end table