source: rtems/doc/supplements/powerpc/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 PowerPC version of the RTEMS CPU Dependent
Information Table is given by the C structure definition is
shown below:

@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 */

  unsigned32   clicks_per_usec;       /* Timer clicks per microsecond */
  void       (*spurious_handler)(
                unsigned32 vector, CPU_Interrupt_frame *);
  boolean      exceptions_in_RAM;     /* TRUE if in RAM */

#if defined(ppc403)
  unsigned32   serial_per_sec;        /* Serial clocks per second */
  boolean      serial_external_clock;
  boolean      serial_xon_xoff;
  boolean      serial_cts_rts;
  unsigned32   serial_rate;
  unsigned32   timer_average_overhead; /* in ticks */
  unsigned32   timer_least_valid;   /* Least valid number from timer */
#endif
@};
@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 clicks_per_usec
is the number of decrementer interupts that occur each microsecond.

@item spurious_handler
is the address of the
routine which is invoked when a spurious interrupt occurs.

@item exceptions_in_RAM
indicates whether the exception vectors are located in RAM or ROM.  If 
they are located in RAM dynamic vector installation occurs, otherwise
it does not.

@item serial_per_sec
is a PPC403 specific field which specifies the number of clock
ticks per second for the PPC403 serial timer.

@item serial_rate
is a PPC403 specific field which specifies the baud rate for the
PPC403 serial port.

@item serial_external_clock
is a PPC403 specific field which indicates whether or not to mask in a 0x2 into
the Input/Output Configuration Register (IOCR) during initialization of the
PPC403 console.  (NOTE: This bit is defined as "reserved" 6-12?)

@item serial_xon_xoff
is a PPC403 specific field which indicates whether or not
XON/XOFF flow control is supported for the PPC403 serial port.

@item serial_cts_rts
is a PPC403 specific field which indicates whether or not to set the 
least significant bit of the Input/Output Configuration Register
(IOCR) during initialization of the PPC403 console.  (NOTE: This
bit is defined as "reserved" 6-12?)

@item timer_average_overhead
is a PPC403 specific field which specifies the average number of overhead ticks that occur on the PPC403 timer.

@item timer_least_valid
is a PPC403 specific field which specifies the maximum valid PPC403 timer value.

@end table