Subversion Repositories or1k_old

@c

@c  COPYRIGHT (c) 1988-2002.

@c  On-Line Applications Research Corporation (OAR).

@c  All rights reserved.

@c

@c  cputable.t,v 1.9 2002/01/17 21:47:46 joel Exp

@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 i386 version of the RTEMS CPU Dependent

Information Table contains the information required to interface

a Board Support Package and RTEMS on the i386.  This information

is provided to allow RTEMS to interoperate effectively with the

BSP.  The C structure definition is given here:

@example

@group

typedef struct @{

  void       (*pretasking_hook)( void );

  void       (*predriver_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   interrupt_segment;

  void        *interrupt_vector_table;

@} rtems_cpu_table;

@end group

@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 interrupt_segment

is the value of the selector which should be placed in a segment

register to access the Interrupt Descriptor Table.

@item interrupt_vector_table

is the base address of the Interrupt Descriptor Table relative to the

interrupt_segment.

@end table

The contents of the i386 Interrupt Descriptor Table

are discussed in  Intel's i386 User's Manual.  Structure

definitions for the i386 IDT is provided by including the file

rtems.h.