[PATCH 1/3] score: Add MicroBlaze port

Alex White alex.white at oarcorp.com
Fri Oct 1 05:43:56 UTC 2021


From: Joel Sherrill <joel at rtems.org>

---
 .../gdbmbsim/startup/_hw_exception_handler.S  |   38 +
 cpukit/score/cpu/microblaze/cpu.c             |  168 +++
 cpukit/score/cpu/microblaze/rtems/asm.h       |  125 ++
 cpukit/score/cpu/microblaze/rtems/score/cpu.h | 1263 +++++++++++++++++
 .../cpu/microblaze/rtems/score/microblaze.h   |   70 +
 5 files changed, 1664 insertions(+)
 create mode 100644 c/src/lib/libbsp/microblaze/gdbmbsim/startup/_hw_exception_handler.S
 create mode 100644 cpukit/score/cpu/microblaze/cpu.c
 create mode 100644 cpukit/score/cpu/microblaze/rtems/asm.h
 create mode 100644 cpukit/score/cpu/microblaze/rtems/score/cpu.h
 create mode 100644 cpukit/score/cpu/microblaze/rtems/score/microblaze.h

diff --git a/c/src/lib/libbsp/microblaze/gdbmbsim/startup/_hw_exception_handler.S b/c/src/lib/libbsp/microblaze/gdbmbsim/startup/_hw_exception_handler.S
new file mode 100644
index 0000000000..bb729ca33b
--- /dev/null
+++ b/c/src/lib/libbsp/microblaze/gdbmbsim/startup/_hw_exception_handler.S
@@ -0,0 +1,38 @@
+/* Copyright (c) 2001, 2009 Xilinx, Inc.  All rights reserved. 
+   
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions are
+   met:
+   
+   1.  Redistributions source code must retain the above copyright notice,
+   this list of conditions and the following disclaimer. 
+   
+   2.  Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution. 
+   
+   3.  Neither the name of Xilinx nor the names of its contributors may be
+   used to endorse or promote products derived from this software without
+   specific prior written permission. 
+   
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS "AS
+   IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+   TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+   PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+   HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+   TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+  
+*/
+
+	.text
+	.globl _hw_exception_handler    # HW Exception Handler Label 
+	.align 2
+	
+	_hw_exception_handler:
+	rted    r17, 0
+	nop
diff --git a/cpukit/score/cpu/microblaze/cpu.c b/cpukit/score/cpu/microblaze/cpu.c
new file mode 100644
index 0000000000..27dd69b9fb
--- /dev/null
+++ b/cpukit/score/cpu/microblaze/cpu.c
@@ -0,0 +1,168 @@
+/*
+ *  MicroBlaze CPU Dependent Source
+ *
+ *  COPYRIGHT (c) 1989-2011.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id: cpu.c,v 1.24 2010/03/27 15:02:26 joel Exp $
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/system.h>
+#include <rtems/score/isr.h>
+#include <rtems/score/wkspace.h>
+
+/*  _CPU_Initialize
+ *
+ *  This routine performs processor dependent initialization.
+ *
+ *  INPUT PARAMETERS: NONE
+ *
+ *  NO_CPU Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+
+void _CPU_Initialize(void)
+{
+  /*
+   *  If there is not an easy way to initialize the FP context
+   *  during Context_Initialize, then it is usually easier to
+   *  save an "uninitialized" FP context here and copy it to
+   *  the task's during Context_Initialize.
+   */
+
+  /* FP context initialization support goes here */
+}
+
+/*PAGE
+ *
+ *  _CPU_ISR_Get_level
+ *
+ *  NO_CPU Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+
+uint32_t   _CPU_ISR_Get_level( void )
+{
+  /*
+   *  This routine returns the current interrupt level.
+   */
+
+  return 0;
+}
+
+/*PAGE
+ *
+ *  _CPU_ISR_install_raw_handler
+ *
+ *  NO_CPU Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+
+void _CPU_ISR_install_raw_handler(
+  uint32_t    vector,
+  proc_ptr    new_handler,
+  proc_ptr   *old_handler
+)
+{
+  /*
+   *  This is where we install the interrupt handler into the "raw" interrupt
+   *  table used by the CPU to dispatch interrupt handlers.
+   */
+}
+
+/*PAGE
+ *
+ *  _CPU_ISR_install_vector
+ *
+ *  This kernel routine installs the RTEMS handler for the
+ *  specified vector.
+ *
+ *  Input parameters:
+ *    vector      - interrupt vector number
+ *    old_handler - former ISR for this vector number
+ *    new_handler - replacement ISR for this vector number
+ *
+ *  Output parameters:  NONE
+ *
+ *
+ *  NO_CPU Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+
+void _CPU_ISR_install_vector(
+  uint32_t    vector,
+  proc_ptr    new_handler,
+  proc_ptr   *old_handler
+)
+{
+   *old_handler = _ISR_Vector_table[ vector ];
+
+   /*
+    *  If the interrupt vector table is a table of pointer to isr entry
+    *  points, then we need to install the appropriate RTEMS interrupt
+    *  handler for this vector number.
+    */
+
+   _CPU_ISR_install_raw_handler( vector, new_handler, old_handler );
+
+   /*
+    *  We put the actual user ISR address in '_ISR_vector_table'.  This will
+    *  be used by the _ISR_Handler so the user gets control.
+    */
+
+    _ISR_Vector_table[ vector ] = new_handler;
+}
+
+/*PAGE
+ *
+ *  _CPU_Install_interrupt_stack
+ *
+ *  NO_CPU Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+
+void _CPU_Install_interrupt_stack( void )
+{
+}
+
+/*PAGE
+ *
+ *  _CPU_Thread_Idle_body
+ *
+ *  NOTES:
+ *
+ *  1. This is the same as the regular CPU independent algorithm.
+ *
+ *  2. If you implement this using a "halt", "idle", or "shutdown"
+ *     instruction, then don't forget to put it in an infinite loop.
+ *
+ *  3. Be warned. Some processors with onboard DMA have been known
+ *     to stop the DMA if the CPU were put in IDLE mode.  This might
+ *     also be a problem with other on-chip peripherals.  So use this
+ *     hook with caution.
+ *
+ *  NO_CPU Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+
+void *_CPU_Thread_Idle_body( uintptr_t ignored )
+{
+
+  for( ; ; )
+    /* insert your "halt" instruction here */ ;
+  return NULL;
+}
diff --git a/cpukit/score/cpu/microblaze/rtems/asm.h b/cpukit/score/cpu/microblaze/rtems/asm.h
new file mode 100644
index 0000000000..13609d2d70
--- /dev/null
+++ b/cpukit/score/cpu/microblaze/rtems/asm.h
@@ -0,0 +1,125 @@
+/**
+ * @file rtems/asm.h
+ *
+ *  This include file attempts to address the problems
+ *  caused by incompatible flavors of assemblers and
+ *  toolsets.  It primarily addresses variations in the
+ *  use of leading underscores on symbols and the requirement
+ *  that register names be preceded by a %.
+ */
+
+/*
+ *  NOTE: The spacing in the use of these macros
+ *        is critical to them working as advertised.
+ *
+ *  COPYRIGHT:
+ *
+ *  This file is based on similar code found in newlib available
+ *  from ftp.cygnus.com.  The file which was used had no copyright
+ *  notice.  This file is freely distributable as long as the source
+ *  of the file is noted.  This file is:
+ *
+ *  COPYRIGHT (c) 1994-2006.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  $Id: asm.h,v 1.16 2006/01/16 15:12:12 joel Exp $
+ */
+
+#ifndef _RTEMS_ASM_H
+#define _RTEMS_ASM_H
+
+/*
+ *  Indicate we are in an assembly file and get the basic CPU definitions.
+ */
+
+#ifndef ASM
+#define ASM
+#endif
+#include <rtems/score/cpuopts.h>
+#include <rtems/score/no_cpu.h>
+
+#ifndef __USER_LABEL_PREFIX__
+/**
+ *  Recent versions of GNU cpp define variables which indicate the
+ *  need for underscores and percents.  If not using GNU cpp or
+ *  the version does not support this, then you will obviously
+ *  have to define these as appropriate.
+ *
+ *  This symbol is prefixed to all C program symbols.
+ */
+#define __USER_LABEL_PREFIX__ _
+#endif
+
+#ifndef __REGISTER_PREFIX__
+/**
+ *  Recent versions of GNU cpp define variables which indicate the
+ *  need for underscores and percents.  If not using GNU cpp or
+ *  the version does not support this, then you will obviously
+ *  have to define these as appropriate.
+ *
+ *  This symbol is prefixed to all register names.
+ */
+#define __REGISTER_PREFIX__
+#endif
+
+#include <rtems/concat.h>
+
+/** Use the right prefix for global labels.  */
+#define SYM(x) CONCAT1 (__USER_LABEL_PREFIX__, x)
+
+/** Use the right prefix for registers.  */
+#define REG(x) CONCAT1 (__REGISTER_PREFIX__, x)
+
+/*
+ *  define macros for all of the registers on this CPU
+ *
+ *  EXAMPLE:     #define d0 REG (d0)
+ */
+
+/*
+ *  Define macros to handle section beginning and ends.
+ */
+
+
+/** This macro is used to denote the beginning of a code declaration. */
+#define BEGIN_CODE_DCL .text
+/** This macro is used to denote the end of a code declaration. */
+#define END_CODE_DCL
+/** This macro is used to denote the beginning of a data declaration section. */
+#define BEGIN_DATA_DCL .data
+/** This macro is used to denote the end of a data declaration section. */
+#define END_DATA_DCL
+/** This macro is used to denote the beginning of a code section. */
+#define BEGIN_CODE .text
+/** This macro is used to denote the end of a code section. */
+#define END_CODE
+/** This macro is used to denote the beginning of a data section. */
+#define BEGIN_DATA
+/** This macro is used to denote the end of a data section. */
+#define END_DATA
+/** This macro is used to denote the beginning of the
+ *  unitialized data section.
+ */
+#define BEGIN_BSS
+/** This macro is used to denote the end of the unitialized data section.  */
+#define END_BSS
+/** This macro is used to denote the end of the assembly file.  */
+#define END
+
+/**
+ *  This macro is used to declare a public global symbol.
+ *
+ *  @note This must be tailored for a particular flavor of the C compiler.
+ *  They may need to put underscores in front of the symbols.
+ */
+#define PUBLIC(sym) .globl SYM (sym)
+
+/**
+ *  This macro is used to prototype a public global symbol.
+ *
+ *  @note This must be tailored for a particular flavor of the C compiler.
+ *  They may need to put underscores in front of the symbols.
+ */
+#define EXTERN(sym) .globl SYM (sym)
+
+#endif
diff --git a/cpukit/score/cpu/microblaze/rtems/score/cpu.h b/cpukit/score/cpu/microblaze/rtems/score/cpu.h
new file mode 100644
index 0000000000..4947045c2c
--- /dev/null
+++ b/cpukit/score/cpu/microblaze/rtems/score/cpu.h
@@ -0,0 +1,1263 @@
+/**
+ * @file rtems/score/cpu.h
+ */
+
+/*
+ *  This include file contains information pertaining to the XXX
+ *  processor.
+ *
+ *  @note This file is part of a porting template that is intended
+ *  to be used as the starting point when porting RTEMS to a new
+ *  CPU family.  The following needs to be done when using this as
+ *  the starting point for a new port:
+ *
+ *  + Anywhere there is an XXX, it should be replaced
+ *    with information about the CPU family being ported to.
+ *
+ *  + At the end of each comment section, there is a heading which
+ *    says "Port Specific Information:".  When porting to RTEMS,
+ *    add CPU family specific information in this section
+ */
+
+/*
+ *  COPYRIGHT (c) 1989-2008.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id: cpu.h,v 1.35 2010/10/21 22:14:20 joel Exp $
+ */
+
+#ifndef _RTEMS_SCORE_CPU_H
+#define _RTEMS_SCORE_CPU_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <rtems/score/types.h>
+#include <rtems/score/microblaze.h>
+
+/* conditional compilation parameters */
+
+/**
+ *  Should the calls to @ref _Thread_Enable_dispatch be inlined?
+ *
+ *  If TRUE, then they are inlined.
+ *  If FALSE, then a subroutine call is made.
+ *
+ *  This conditional is an example of the classic trade-off of size
+ *  versus speed.  Inlining the call (TRUE) typically increases the
+ *  size of RTEMS while speeding up the enabling of dispatching.
+ *
+ *  @note In general, the @ref _Thread_Dispatch_disable_level will
+ *  only be 0 or 1 unless you are in an interrupt handler and that
+ *  interrupt handler invokes the executive.]  When not inlined
+ *  something calls @ref _Thread_Enable_dispatch which in turns calls
+ *  @ref _Thread_Dispatch.  If the enable dispatch is inlined, then
+ *  one subroutine call is avoided entirely.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_INLINE_ENABLE_DISPATCH       FALSE
+
+/**
+ *  Should the body of the search loops in _Thread_queue_Enqueue_priority
+ *  be unrolled one time?  In unrolled each iteration of the loop examines
+ *  two "nodes" on the chain being searched.  Otherwise, only one node
+ *  is examined per iteration.
+ *
+ *  If TRUE, then the loops are unrolled.
+ *  If FALSE, then the loops are not unrolled.
+ *
+ *  The primary factor in making this decision is the cost of disabling
+ *  and enabling interrupts (_ISR_Flash) versus the cost of rest of the
+ *  body of the loop.  On some CPUs, the flash is more expensive than
+ *  one iteration of the loop body.  In this case, it might be desirable
+ *  to unroll the loop.  It is important to note that on some CPUs, this
+ *  code is the longest interrupt disable period in RTEMS.  So it is
+ *  necessary to strike a balance when setting this parameter.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_UNROLL_ENQUEUE_PRIORITY      TRUE
+
+/**
+ *  Does RTEMS manage a dedicated interrupt stack in software?
+ *
+ *  If TRUE, then a stack is allocated in @ref _ISR_Handler_initialization.
+ *  If FALSE, nothing is done.
+ *
+ *  If the CPU supports a dedicated interrupt stack in hardware,
+ *  then it is generally the responsibility of the BSP to allocate it
+ *  and set it up.
+ *
+ *  If the CPU does not support a dedicated interrupt stack, then
+ *  the porter has two options: (1) execute interrupts on the
+ *  stack of the interrupted task, and (2) have RTEMS manage a dedicated
+ *  interrupt stack.
+ *
+ *  If this is TRUE, @ref CPU_ALLOCATE_INTERRUPT_STACK should also be TRUE.
+ *
+ *  Only one of @ref CPU_HAS_SOFTWARE_INTERRUPT_STACK and
+ *  @ref CPU_HAS_HARDWARE_INTERRUPT_STACK should be set to TRUE.  It is
+ *  possible that both are FALSE for a particular CPU.  Although it
+ *  is unclear what that would imply about the interrupt processing
+ *  procedure on that CPU.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_HAS_SOFTWARE_INTERRUPT_STACK FALSE
+
+/**
+ *  Does the CPU follow the simple vectored interrupt model?
+ *
+ *  If TRUE, then RTEMS allocates the vector table it internally manages.
+ *  If FALSE, then the BSP is assumed to allocate and manage the vector
+ *  table
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_SIMPLE_VECTORED_INTERRUPTS TRUE
+
+/**
+ *  Does this CPU have hardware support for a dedicated interrupt stack?
+ *
+ *  If TRUE, then it must be installed during initialization.
+ *  If FALSE, then no installation is performed.
+ *
+ *  If this is TRUE, @ref CPU_ALLOCATE_INTERRUPT_STACK should also be TRUE.
+ *
+ *  Only one of @ref CPU_HAS_SOFTWARE_INTERRUPT_STACK and
+ *  @ref CPU_HAS_HARDWARE_INTERRUPT_STACK should be set to TRUE.  It is
+ *  possible that both are FALSE for a particular CPU.  Although it
+ *  is unclear what that would imply about the interrupt processing
+ *  procedure on that CPU.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_HAS_HARDWARE_INTERRUPT_STACK TRUE
+
+/**
+ *  Does RTEMS allocate a dedicated interrupt stack in the Interrupt Manager?
+ *
+ *  If TRUE, then the memory is allocated during initialization.
+ *  If FALSE, then the memory is allocated during initialization.
+ *
+ *  This should be TRUE is CPU_HAS_SOFTWARE_INTERRUPT_STACK is TRUE.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_ALLOCATE_INTERRUPT_STACK TRUE
+
+/**
+ *  Does the RTEMS invoke the user's ISR with the vector number and
+ *  a pointer to the saved interrupt frame (1) or just the vector
+ *  number (0)?
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_ISR_PASSES_FRAME_POINTER 0
+
+/**
+ *  @def CPU_HARDWARE_FP
+ *
+ *  Does the CPU have hardware floating point?
+ *
+ *  If TRUE, then the RTEMS_FLOATING_POINT task attribute is supported.
+ *  If FALSE, then the RTEMS_FLOATING_POINT task attribute is ignored.
+ *
+ *  If there is a FP coprocessor such as the i387 or mc68881, then
+ *  the answer is TRUE.
+ *
+ *  The macro name "NO_CPU_HAS_FPU" should be made CPU specific.
+ *  It indicates whether or not this CPU model has FP support.  For
+ *  example, it would be possible to have an i386_nofp CPU model
+ *  which set this to false to indicate that you have an i386 without
+ *  an i387 and wish to leave floating point support out of RTEMS.
+ */
+
+/**
+ *  @def CPU_SOFTWARE_FP
+ *
+ *  Does the CPU have no hardware floating point and GCC provides a
+ *  software floating point implementation which must be context
+ *  switched?
+ *
+ *  This feature conditional is used to indicate whether or not there
+ *  is software implemented floating point that must be context
+ *  switched.  The determination of whether or not this applies
+ *  is very tool specific and the state saved/restored is also
+ *  compiler specific.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#if ( NO_CPU_HAS_FPU == 1 )
+#define CPU_HARDWARE_FP     TRUE
+#else
+#define CPU_HARDWARE_FP     FALSE
+#endif
+#define CPU_SOFTWARE_FP     FALSE
+
+/**
+ *  Are all tasks RTEMS_FLOATING_POINT tasks implicitly?
+ *
+ *  If TRUE, then the RTEMS_FLOATING_POINT task attribute is assumed.
+ *  If FALSE, then the RTEMS_FLOATING_POINT task attribute is followed.
+ *
+ *  So far, the only CPUs in which this option has been used are the
+ *  HP PA-RISC and PowerPC.  On the PA-RISC, The HP C compiler and
+ *  gcc both implicitly used the floating point registers to perform
+ *  integer multiplies.  Similarly, the PowerPC port of gcc has been
+ *  seen to allocate floating point local variables and touch the FPU
+ *  even when the flow through a subroutine (like vfprintf()) might
+ *  not use floating point formats.
+ *
+ *  If a function which you would not think utilize the FP unit DOES,
+ *  then one can not easily predict which tasks will use the FP hardware.
+ *  In this case, this option should be TRUE.
+ *
+ *  If @ref CPU_HARDWARE_FP is FALSE, then this should be FALSE as well.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_ALL_TASKS_ARE_FP     TRUE
+
+/**
+ *  Should the IDLE task have a floating point context?
+ *
+ *  If TRUE, then the IDLE task is created as a RTEMS_FLOATING_POINT task
+ *  and it has a floating point context which is switched in and out.
+ *  If FALSE, then the IDLE task does not have a floating point context.
+ *
+ *  Setting this to TRUE negatively impacts the time required to preempt
+ *  the IDLE task from an interrupt because the floating point context
+ *  must be saved as part of the preemption.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_IDLE_TASK_IS_FP      FALSE
+
+/**
+ *  Should the saving of the floating point registers be deferred
+ *  until a context switch is made to another different floating point
+ *  task?
+ *
+ *  If TRUE, then the floating point context will not be stored until
+ *  necessary.  It will remain in the floating point registers and not
+ *  disturned until another floating point task is switched to.
+ *
+ *  If FALSE, then the floating point context is saved when a floating
+ *  point task is switched out and restored when the next floating point
+ *  task is restored.  The state of the floating point registers between
+ *  those two operations is not specified.
+ *
+ *  If the floating point context does NOT have to be saved as part of
+ *  interrupt dispatching, then it should be safe to set this to TRUE.
+ *
+ *  Setting this flag to TRUE results in using a different algorithm
+ *  for deciding when to save and restore the floating point context.
+ *  The deferred FP switch algorithm minimizes the number of times
+ *  the FP context is saved and restored.  The FP context is not saved
+ *  until a context switch is made to another, different FP task.
+ *  Thus in a system with only one FP task, the FP context will never
+ *  be saved or restored.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_USE_DEFERRED_FP_SWITCH       TRUE
+
+/**
+ *  Does this port provide a CPU dependent IDLE task implementation?
+ *
+ *  If TRUE, then the routine @ref _CPU_Thread_Idle_body
+ *  must be provided and is the default IDLE thread body instead of
+ *  @ref _CPU_Thread_Idle_body.
+ *
+ *  If FALSE, then use the generic IDLE thread body if the BSP does
+ *  not provide one.
+ *
+ *  This is intended to allow for supporting processors which have
+ *  a low power or idle mode.  When the IDLE thread is executed, then
+ *  the CPU can be powered down.
+ *
+ *  The order of precedence for selecting the IDLE thread body is:
+ *
+ *    -#  BSP provided
+ *    -#  CPU dependent (if provided)
+ *    -#  generic (if no BSP and no CPU dependent)
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_PROVIDES_IDLE_THREAD_BODY    TRUE
+
+/**
+ *  Does the stack grow up (toward higher addresses) or down
+ *  (toward lower addresses)?
+ *
+ *  If TRUE, then the grows upward.
+ *  If FALSE, then the grows toward smaller addresses.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_STACK_GROWS_UP               TRUE
+
+/**
+ *  The following is the variable attribute used to force alignment
+ *  of critical RTEMS structures.  On some processors it may make
+ *  sense to have these aligned on tighter boundaries than
+ *  the minimum requirements of the compiler in order to have as
+ *  much of the critical data area as possible in a cache line.
+ *
+ *  The placement of this macro in the declaration of the variables
+ *  is based on the syntactically requirements of the GNU C
+ *  "__attribute__" extension.  For example with GNU C, use
+ *  the following to force a structures to a 32 byte boundary.
+ *
+ *      __attribute__ ((aligned (32)))
+ *
+ *  @note Currently only the Priority Bit Map table uses this feature.
+ *        To benefit from using this, the data must be heavily
+ *        used so it will stay in the cache and used frequently enough
+ *        in the executive to justify turning this on.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_STRUCTURE_ALIGNMENT
+
+/**
+ *  @defgroup CPUEndian Processor Dependent Endianness Support
+ *
+ *  This group assists in issues related to processor endianness.
+ */
+
+/**
+ *  @ingroup CPUEndian
+ *  Define what is required to specify how the network to host conversion
+ *  routines are handled.
+ *
+ *  @note @a CPU_BIG_ENDIAN and @a CPU_LITTLE_ENDIAN should NOT have the
+ *  same values.
+ *
+ *  @see CPU_LITTLE_ENDIAN
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_BIG_ENDIAN                           TRUE
+
+/**
+ *  @ingroup CPUEndian
+ *  Define what is required to specify how the network to host conversion
+ *  routines are handled.
+ *
+ *  @note @ref CPU_BIG_ENDIAN and @ref CPU_LITTLE_ENDIAN should NOT have the
+ *  same values.
+ *
+ *  @see CPU_BIG_ENDIAN
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_LITTLE_ENDIAN                        FALSE
+
+/**
+ *  @ingroup CPUInterrupt
+ *  The following defines the number of bits actually used in the
+ *  interrupt field of the task mode.  How those bits map to the
+ *  CPU interrupt levels is defined by the routine @ref _CPU_ISR_Set_level.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_MODES_INTERRUPT_MASK   0x00000001
+
+/*
+ *  Processor defined structures required for cpukit/score.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+
+/* may need to put some structures here.  */
+
+/**
+ * @defgroup CPUContext Processor Dependent Context Management
+ *
+ *  From the highest level viewpoint, there are 2 types of context to save.
+ *
+ *     -# Interrupt registers to save
+ *     -# Task level registers to save
+ *
+ *  Since RTEMS handles integer and floating point contexts separately, this
+ *  means we have the following 3 context items:
+ *
+ *     -# task level context stuff::  Context_Control
+ *     -# floating point task stuff:: Context_Control_fp
+ *     -# special interrupt level context :: CPU_Interrupt_frame
+ *
+ *  On some processors, it is cost-effective to save only the callee
+ *  preserved registers during a task context switch.  This means
+ *  that the ISR code needs to save those registers which do not
+ *  persist across function calls.  It is not mandatory to make this
+ *  distinctions between the caller/callee saves registers for the
+ *  purpose of minimizing context saved during task switch and on interrupts.
+ *  If the cost of saving extra registers is minimal, simplicity is the
+ *  choice.  Save the same context on interrupt entry as for tasks in
+ *  this case.
+ *
+ *  Additionally, if gdb is to be made aware of RTEMS tasks for this CPU, then
+ *  care should be used in designing the context area.
+ *
+ *  On some CPUs with hardware floating point support, the Context_Control_fp
+ *  structure will not be used or it simply consist of an array of a
+ *  fixed number of bytes.   This is done when the floating point context
+ *  is dumped by a "FP save context" type instruction and the format
+ *  is not really defined by the CPU.  In this case, there is no need
+ *  to figure out the exact format -- only the size.  Of course, although
+ *  this is enough information for RTEMS, it is probably not enough for
+ *  a debugger such as gdb.  But that is another problem.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+
+/**
+ *  @ingroup CPUContext Management
+ *  This defines the minimal set of integer and processor state registers
+ *  that must be saved during a voluntary context switch from one thread
+ *  to another.
+ */
+typedef struct {
+    /** This field is a hint that a port will have a number of integer
+     *  registers that need to be saved at a context switch.
+     */
+    uint32_t   some_integer_register;
+    /** This field is a hint that a port will have a number of system
+     *  registers that need to be saved at a context switch.
+     */
+    uint32_t   some_system_register;
+
+    /** This field is a hint that a port will have a register that
+     *  is the stack pointer.
+     */
+    uint32_t   stack_pointer;
+} Context_Control;
+
+/**
+ *  @ingroup CPUContext Management
+ *
+ *  This macro returns the stack pointer associated with @a _context.
+ *
+ *  @param[in] _context is the thread context area to access
+ *
+ *  @return This method returns the stack pointer.
+ */
+#define _CPU_Context_Get_SP( _context ) \
+  (_context)->stack_pointer
+
+/**
+ *  @ingroup CPUContext Management
+ *  This defines the complete set of floating point registers that must
+ *  be saved during any context switch from one thread to another.
+ */
+typedef struct {
+    /** FPU registers are listed here */
+    double      some_float_register;
+} Context_Control_fp;
+
+/**
+ *  @ingroup CPUContext Management
+ *  This defines the set of integer and processor state registers that must
+ *  be saved during an interrupt.  This set does not include any which are
+ *  in @ref Context_Control.
+ */
+typedef struct {
+    /** This field is a hint that a port will have a number of integer
+     *  registers that need to be saved when an interrupt occurs or
+     *  when a context switch occurs at the end of an ISR.
+     */
+    uint32_t   special_interrupt_register;
+} CPU_Interrupt_frame;
+
+/**
+ *  This variable is optional.  It is used on CPUs on which it is difficult
+ *  to generate an "uninitialized" FP context.  It is filled in by
+ *  @ref _CPU_Initialize and copied into the task's FP context area during
+ *  @ref _CPU_Context_Initialize.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+SCORE_EXTERN Context_Control_fp  _CPU_Null_fp_context;
+
+/**
+ *  @defgroup CPUInterrupt Processor Dependent Interrupt Management
+ *
+ *  On some CPUs, RTEMS supports a software managed interrupt stack.
+ *  This stack is allocated by the Interrupt Manager and the switch
+ *  is performed in @ref _ISR_Handler.  These variables contain pointers
+ *  to the lowest and highest addresses in the chunk of memory allocated
+ *  for the interrupt stack.  Since it is unknown whether the stack
+ *  grows up or down (in general), this give the CPU dependent
+ *  code the option of picking the version it wants to use.
+ *
+ *  @note These two variables are required if the macro
+ *        @ref CPU_HAS_SOFTWARE_INTERRUPT_STACK is defined as TRUE.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+
+/*
+ *  Nothing prevents the porter from declaring more CPU specific variables.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+
+/* XXX: if needed, put more variables here */
+
+/**
+ *  @ingroup CPUContext
+ *  The size of the floating point context area.  On some CPUs this
+ *  will not be a "sizeof" because the format of the floating point
+ *  area is not defined -- only the size is.  This is usually on
+ *  CPUs with a "floating point save context" instruction.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_CONTEXT_FP_SIZE sizeof( Context_Control_fp )
+
+/**
+ *  Amount of extra stack (above minimum stack size) required by
+ *  MPCI receive server thread.  Remember that in a multiprocessor
+ *  system this thread must exist and be able to process all directives.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_MPCI_RECEIVE_SERVER_EXTRA_STACK 0
+
+/**
+ *  @ingroup CPUInterrupt
+ *  This defines the number of entries in the @ref _ISR_Vector_table managed
+ *  by RTEMS.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_INTERRUPT_NUMBER_OF_VECTORS      32
+
+/**
+ *  @ingroup CPUInterrupt
+ *  This defines the highest interrupt vector number for this port.
+ */
+#define CPU_INTERRUPT_MAXIMUM_VECTOR_NUMBER  (CPU_INTERRUPT_NUMBER_OF_VECTORS - 1)
+
+/**
+ *  @ingroup CPUInterrupt
+ *  This is defined if the port has a special way to report the ISR nesting
+ *  level.  Most ports maintain the variable @a _ISR_Nest_level.
+ */
+#define CPU_PROVIDES_ISR_IS_IN_PROGRESS FALSE
+
+/**
+ *  @ingroup CPUContext
+ *  Should be large enough to run all RTEMS tests.  This ensures
+ *  that a "reasonable" small application should not have any problems.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_STACK_MINIMUM_SIZE          (1024*4)
+
+/**
+ *  CPU's worst alignment requirement for data types on a byte boundary.  This
+ *  alignment does not take into account the requirements for the stack.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_ALIGNMENT              8
+
+/**
+ *  This number corresponds to the byte alignment requirement for the
+ *  heap handler.  This alignment requirement may be stricter than that
+ *  for the data types alignment specified by @ref CPU_ALIGNMENT.  It is
+ *  common for the heap to follow the same alignment requirement as
+ *  @ref CPU_ALIGNMENT.  If the @ref CPU_ALIGNMENT is strict enough for
+ *  the heap, then this should be set to @ref CPU_ALIGNMENT.
+ *
+ *  @note  This does not have to be a power of 2 although it should be
+ *         a multiple of 2 greater than or equal to 2.  The requirement
+ *         to be a multiple of 2 is because the heap uses the least
+ *         significant field of the front and back flags to indicate
+ *         that a block is in use or free.  So you do not want any odd
+ *         length blocks really putting length data in that bit.
+ *
+ *         On byte oriented architectures, @ref CPU_HEAP_ALIGNMENT normally will
+ *         have to be greater or equal to than @ref CPU_ALIGNMENT to ensure that
+ *         elements allocated from the heap meet all restrictions.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_HEAP_ALIGNMENT         CPU_ALIGNMENT
+
+/**
+ *  This number corresponds to the byte alignment requirement for memory
+ *  buffers allocated by the partition manager.  This alignment requirement
+ *  may be stricter than that for the data types alignment specified by
+ *  @ref CPU_ALIGNMENT.  It is common for the partition to follow the same
+ *  alignment requirement as @ref CPU_ALIGNMENT.  If the @ref CPU_ALIGNMENT is
+ *  strict enough for the partition, then this should be set to
+ *  @ref CPU_ALIGNMENT.
+ *
+ *  @note  This does not have to be a power of 2.  It does have to
+ *         be greater or equal to than @ref CPU_ALIGNMENT.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_PARTITION_ALIGNMENT    CPU_ALIGNMENT
+
+/**
+ *  This number corresponds to the byte alignment requirement for the
+ *  stack.  This alignment requirement may be stricter than that for the
+ *  data types alignment specified by @ref CPU_ALIGNMENT.  If the
+ *  @ref CPU_ALIGNMENT is strict enough for the stack, then this should be
+ *  set to 0.
+ *
+ *  @note This must be a power of 2 either 0 or greater than @ref CPU_ALIGNMENT.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define CPU_STACK_ALIGNMENT        0
+
+/*
+ *  ISR handler macros
+ */
+
+/**
+ *  @ingroup CPUInterrupt
+ *  Support routine to initialize the RTEMS vector table after it is allocated.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define _CPU_Initialize_vectors()
+
+/**
+ *  @ingroup CPUInterrupt
+ *  Disable all interrupts for an RTEMS critical section.  The previous
+ *  level is returned in @a _isr_cookie.
+ *
+ *  @param[out] _isr_cookie will contain the previous level cookie
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define _CPU_MSR_GET( _msr_value ) \
+  do { \
+    _msr_value = 0; \
+    __asm__ volatile ("mfs %0, rmsr" : "=&r" ((_msr_value)) : "0" ((_msr_value))); \
+  } while (0)
+
+#define _CPU_MSR_SET( _msr_value ) \
+{ __asm__ volatile ("mts rmsr, %0" : "=&r" ((_msr_value)) : "0" ((_msr_value))); }
+
+#define _CPU_ISR_Disable( _isr_cookie ) \
+  { \
+    unsigned int _new_msr;  \
+    _CPU_MSR_GET(_isr_cookie); \
+    _new_msr = _isr_cookie & ~0x02; \
+    _CPU_MSR_SET(_new_msr); \
+  }
+
+/**
+ *  @ingroup CPUInterrupt
+ *  Enable interrupts to the previous level (returned by _CPU_ISR_Disable).
+ *  This indicates the end of an RTEMS critical section.  The parameter
+ *  @a _isr_cookie is not modified.
+ *
+ *  @param[in] _isr_cookie contain the previous level cookie
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define _CPU_ISR_Enable( _isr_cookie )  \
+  { \
+    _CPU_MSR_SET(_isr_cookie); \
+  }
+
+/**
+ *  @ingroup CPUInterrupt
+ *  This temporarily restores the interrupt to @a _isr_cookie before immediately
+ *  disabling them again.  This is used to divide long RTEMS critical
+ *  sections into two or more parts.  The parameter @a _isr_cookie is not
+ *  modified.
+ *
+ *  @param[in] _isr_cookie contain the previous level cookie
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define _CPU_ISR_Flash( _isr_cookie ) \
+  { \
+    unsigned int _new_msr;  \
+    _CPU_MSR_SET(_isr_cookie); \
+    _new_msr = _isr_cookie & ~0x02; \
+    _CPU_MSR_SET(_new_msr); \
+  }
+
+/**
+ *  @ingroup CPUInterrupt
+ *
+ *  This routine and @ref _CPU_ISR_Get_level
+ *  Map the interrupt level in task mode onto the hardware that the CPU
+ *  actually provides.  Currently, interrupt levels which do not
+ *  map onto the CPU in a generic fashion are undefined.  Someday,
+ *  it would be nice if these were "mapped" by the application
+ *  via a callout.  For example, m68k has 8 levels 0 - 7, levels
+ *  8 - 255 would be available for bsp/application specific meaning.
+ *  This could be used to manage a programmable interrupt controller
+ *  via the rtems_task_mode directive.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define _CPU_ISR_Set_level( new_level ) \
+  { \
+  }
+
+/**
+ *  @ingroup CPUInterrupt
+ *  Return the current interrupt disable level for this task in
+ *  the format used by the interrupt level portion of the task mode.
+ *
+ *  @note This routine usually must be implemented as a subroutine.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+uint32_t   _CPU_ISR_Get_level( void );
+
+/* end of ISR handler macros */
+
+/* Context handler macros */
+
+/**
+ *  @ingroup CPUContext
+ *  Initialize the context to a state suitable for starting a
+ *  task after a context restore operation.  Generally, this
+ *  involves:
+ *
+ *     - setting a starting address
+ *     - preparing the stack
+ *     - preparing the stack and frame pointers
+ *     - setting the proper interrupt level in the context
+ *     - initializing the floating point context
+ *
+ *  This routine generally does not set any unnecessary register
+ *  in the context.  The state of the "general data" registers is
+ *  undefined at task start time.
+ *
+ *  @param[in] _the_context is the context structure to be initialized
+ *  @param[in] _stack_base is the lowest physical address of this task's stack
+ *  @param[in] _size is the size of this task's stack
+ *  @param[in] _isr is the interrupt disable level
+ *  @param[in] _entry_point is the thread's entry point.  This is
+ *         always @a _Thread_Handler
+ *  @param[in] _is_fp is TRUE if the thread is to be a floating
+ *        point thread.  This is typically only used on CPUs where the
+ *        FPU may be easily disabled by software such as on the SPARC
+ *        where the PSR contains an enable FPU bit.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define _CPU_Context_Initialize( _the_context, _stack_base, _size, \
+                                 _isr, _entry_point, _is_fp ) \
+  { \
+  }
+
+/**
+ *  This routine is responsible for somehow restarting the currently
+ *  executing task.  If you are lucky, then all that is necessary
+ *  is restoring the context.  Otherwise, there will need to be
+ *  a special assembly routine which does something special in this
+ *  case.  For many ports, simply adding a label to the restore path
+ *  of @ref _CPU_Context_switch will work.  On other ports, it may be
+ *  possibly to load a few arguments and jump to the restore path. It will
+ *  not work if restarting self conflicts with the stack frame
+ *  assumptions of restoring a context.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define _CPU_Context_Restart_self( _the_context ) \
+   _CPU_Context_restore( (_the_context) );
+
+/**
+ *  @ingroup CPUContext
+ *  The purpose of this macro is to allow the initial pointer into
+ *  a floating point context area (used to save the floating point
+ *  context) to be at an arbitrary place in the floating point
+ *  context area.
+ *
+ *  This is necessary because some FP units are designed to have
+ *  their context saved as a stack which grows into lower addresses.
+ *  Other FP units can be saved by simply moving registers into offsets
+ *  from the base of the context area.  Finally some FP units provide
+ *  a "dump context" instruction which could fill in from high to low
+ *  or low to high based on the whim of the CPU designers.
+ *
+ *  @param[in] _base is the lowest physical address of the floating point
+ *         context area
+ *  @param[in] _offset is the offset into the floating point area
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define _CPU_Context_Fp_start( _base, _offset ) \
+   ( (void *) _Addresses_Add_offset( (_base), (_offset) ) )
+
+/**
+ *  This routine initializes the FP context area passed to it to.
+ *  There are a few standard ways in which to initialize the
+ *  floating point context.  The code included for this macro assumes
+ *  that this is a CPU in which a "initial" FP context was saved into
+ *  @a _CPU_Null_fp_context and it simply copies it to the destination
+ *  context passed to it.
+ *
+ *  Other floating point context save/restore models include:
+ *    -# not doing anything, and
+ *    -# putting a "null FP status word" in the correct place in the FP context.
+ *
+ *  @param[in] _destination is the floating point context area
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define _CPU_Context_Initialize_fp( _destination ) \
+  { \
+   *(*(_destination)) = _CPU_Null_fp_context; \
+  }
+
+/* end of Context handler macros */
+
+/* Fatal Error manager macros */
+
+/**
+ *  This routine copies _error into a known place -- typically a stack
+ *  location or a register, optionally disables interrupts, and
+ *  halts/stops the CPU.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#define _CPU_Fatal_halt( _error ) \
+  { \
+  }
+
+/* end of Fatal Error manager macros */
+
+/* Bitfield handler macros */
+
+/**
+ *  @defgroup CPUBitfield Processor Dependent Bitfield Manipulation
+ *
+ *  This set of routines are used to implement fast searches for
+ *  the most important ready task.
+ */
+
+/**
+ *  @ingroup CPUBitfield
+ *  This definition is set to TRUE if the port uses the generic bitfield
+ *  manipulation implementation.
+ */
+#define CPU_USE_GENERIC_BITFIELD_CODE TRUE
+
+/**
+ *  @ingroup CPUBitfield
+ *  This definition is set to TRUE if the port uses the data tables provided
+ *  by the generic bitfield manipulation implementation.
+ *  This can occur when actually using the generic bitfield manipulation
+ *  implementation or when implementing the same algorithm in assembly
+ *  language for improved performance.  It is unlikely that a port will use
+ *  the data if it has a bitfield scan instruction.
+ */
+#define CPU_USE_GENERIC_BITFIELD_DATA TRUE
+
+/**
+ *  @ingroup CPUBitfield
+ *  This routine sets @a _output to the bit number of the first bit
+ *  set in @a _value.  @a _value is of CPU dependent type
+ *  @a Priority_bit_map_Control.  This type may be either 16 or 32 bits
+ *  wide although only the 16 least significant bits will be used.
+ *
+ *  There are a number of variables in using a "find first bit" type
+ *  instruction.
+ *
+ *    -# What happens when run on a value of zero?
+ *    -# Bits may be numbered from MSB to LSB or vice-versa.
+ *    -# The numbering may be zero or one based.
+ *    -# The "find first bit" instruction may search from MSB or LSB.
+ *
+ *  RTEMS guarantees that (1) will never happen so it is not a concern.
+ *  (2),(3), (4) are handled by the macros @ref _CPU_Priority_Mask and
+ *  @ref _CPU_Priority_bits_index.  These three form a set of routines
+ *  which must logically operate together.  Bits in the _value are
+ *  set and cleared based on masks built by @ref _CPU_Priority_Mask.
+ *  The basic major and minor values calculated by @ref _Priority_Major
+ *  and @ref _Priority_Minor are "massaged" by @ref _CPU_Priority_bits_index
+ *  to properly range between the values returned by the "find first bit"
+ *  instruction.  This makes it possible for @ref _Priority_Get_highest to
+ *  calculate the major and directly index into the minor table.
+ *  This mapping is necessary to ensure that 0 (a high priority major/minor)
+ *  is the first bit found.
+ *
+ *  This entire "find first bit" and mapping process depends heavily
+ *  on the manner in which a priority is broken into a major and minor
+ *  components with the major being the 4 MSB of a priority and minor
+ *  the 4 LSB.  Thus (0 << 4) + 0 corresponds to priority 0 -- the highest
+ *  priority.  And (15 << 4) + 14 corresponds to priority 254 -- the next
+ *  to the lowest priority.
+ *
+ *  If your CPU does not have a "find first bit" instruction, then
+ *  there are ways to make do without it.  Here are a handful of ways
+ *  to implement this in software:
+ *
+ at verbatim
+      - a series of 16 bit test instructions
+      - a "binary search using if's"
+      - _number = 0
+        if _value > 0x00ff
+          _value >>=8
+          _number = 8;
+
+        if _value > 0x0000f
+          _value >=8
+          _number += 4
+
+        _number += bit_set_table[ _value ]
+ at endverbatim
+
+ *    where bit_set_table[ 16 ] has values which indicate the first
+ *      bit set
+ *
+ *  @param[in] _value is the value to be scanned
+ *  @param[in] _output is the first bit set
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+
+#if (CPU_USE_GENERIC_BITFIELD_CODE == FALSE)
+#define _CPU_Bitfield_Find_first_bit( _value, _output ) \
+  { \
+    (_output) = 0;   /* do something to prevent warnings */ \
+  }
+#endif
+
+/* end of Bitfield handler macros */
+
+/**
+ *  This routine builds the mask which corresponds to the bit fields
+ *  as searched by @ref _CPU_Bitfield_Find_first_bit.  See the discussion
+ *  for that routine.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#if (CPU_USE_GENERIC_BITFIELD_CODE == FALSE)
+
+#define _CPU_Priority_Mask( _bit_number ) \
+  ( 1 << (_bit_number) )
+
+#endif
+
+/**
+ *  @ingroup CPUBitfield
+ *  This routine translates the bit numbers returned by
+ *  @ref _CPU_Bitfield_Find_first_bit into something suitable for use as
+ *  a major or minor component of a priority.  See the discussion
+ *  for that routine.
+ *
+ *  @param[in] _priority is the major or minor number to translate
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+#if (CPU_USE_GENERIC_BITFIELD_CODE == FALSE)
+
+#define _CPU_Priority_bits_index( _priority ) \
+  (_priority)
+
+#endif
+
+/* end of Priority handler macros */
+
+/* functions */
+
+/**
+ *  This routine performs CPU dependent initialization.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+void _CPU_Initialize(void);
+
+/**
+ *  @ingroup CPUInterrupt
+ *  This routine installs a "raw" interrupt handler directly into the
+ *  processor's vector table.
+ *
+ *  @param[in] vector is the vector number
+ *  @param[in] new_handler is the raw ISR handler to install
+ *  @param[in] old_handler is the previously installed ISR Handler
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+void _CPU_ISR_install_raw_handler(
+  uint32_t    vector,
+  proc_ptr    new_handler,
+  proc_ptr   *old_handler
+);
+
+/**
+ *  @ingroup CPUInterrupt
+ *  This routine installs an interrupt vector.
+ *
+ *  @param[in] vector is the vector number
+ *  @param[in] new_handler is the RTEMS ISR handler to install
+ *  @param[in] old_handler is the previously installed ISR Handler
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+void _CPU_ISR_install_vector(
+  uint32_t    vector,
+  proc_ptr    new_handler,
+  proc_ptr   *old_handler
+);
+
+/**
+ *  @ingroup CPUInterrupt
+ *  This routine installs the hardware interrupt stack pointer.
+ *
+ *  @note  It need only be provided if @ref CPU_HAS_HARDWARE_INTERRUPT_STACK
+ *         is TRUE.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+void _CPU_Install_interrupt_stack( void );
+
+/**
+ *  This routine is the CPU dependent IDLE thread body.
+ *
+ *  @note  It need only be provided if @ref CPU_PROVIDES_IDLE_THREAD_BODY
+ *         is TRUE.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+void *_CPU_Thread_Idle_body( uintptr_t ignored );
+
+/**
+ *  @ingroup CPUContext
+ *  This routine switches from the run context to the heir context.
+ *
+ *  @param[in] run points to the context of the currently executing task
+ *  @param[in] heir points to the context of the heir task
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+void _CPU_Context_switch(
+  Context_Control  *run,
+  Context_Control  *heir
+);
+
+/**
+ *  @ingroup CPUContext
+ *  This routine is generally used only to restart self in an
+ *  efficient manner.  It may simply be a label in @ref _CPU_Context_switch.
+ *
+ *  @param[in] new_context points to the context to be restored.
+ *
+ *  @note May be unnecessary to reload some registers.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+void _CPU_Context_restore(
+  Context_Control *new_context
+) RTEMS_COMPILER_NO_RETURN_ATTRIBUTE;
+
+/**
+ *  @ingroup CPUContext
+ *  This routine saves the floating point context passed to it.
+ *
+ *  @param[in] fp_context_ptr is a pointer to a pointer to a floating
+ *  point context area
+ *
+ *  @return on output @a *fp_context_ptr will contain the address that
+ *  should be used with @ref _CPU_Context_restore_fp to restore this context.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+void _CPU_Context_save_fp(
+  Context_Control_fp **fp_context_ptr
+);
+
+/**
+ *  @ingroup CPUContext
+ *  This routine restores the floating point context passed to it.
+ *
+ *  @param[in] fp_context_ptr is a pointer to a pointer to a floating
+ *  point context area to restore
+ *
+ *  @return on output @a *fp_context_ptr will contain the address that
+ *  should be used with @ref _CPU_Context_save_fp to save this context.
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+void _CPU_Context_restore_fp(
+  Context_Control_fp **fp_context_ptr
+);
+
+/**
+ *  @ingroup CPUEndian
+ *  The following routine swaps the endian format of an unsigned int.
+ *  It must be static because it is referenced indirectly.
+ *
+ *  This version will work on any processor, but if there is a better
+ *  way for your CPU PLEASE use it.  The most common way to do this is to:
+ *
+ *     swap least significant two bytes with 16-bit rotate
+ *     swap upper and lower 16-bits
+ *     swap most significant two bytes with 16-bit rotate
+ *
+ *  Some CPUs have special instructions which swap a 32-bit quantity in
+ *  a single instruction (e.g. i486).  It is probably best to avoid
+ *  an "endian swapping control bit" in the CPU.  One good reason is
+ *  that interrupts would probably have to be disabled to ensure that
+ *  an interrupt does not try to access the same "chunk" with the wrong
+ *  endian.  Another good reason is that on some CPUs, the endian bit
+ *  endianness for ALL fetches -- both code and data -- so the code
+ *  will be fetched incorrectly.
+ *
+ *  @param[in] value is the value to be swapped
+ *  @return the value after being endian swapped
+ *
+ *  Port Specific Information:
+ *
+ *  XXX document implementation including references if appropriate
+ */
+static inline uint32_t CPU_swap_u32(
+  uint32_t value
+)
+{
+  uint32_t byte1, byte2, byte3, byte4, swapped;
+
+  byte4 = (value >> 24) & 0xff;
+  byte3 = (value >> 16) & 0xff;
+  byte2 = (value >> 8)  & 0xff;
+  byte1 =  value        & 0xff;
+
+  swapped = (byte1 << 24) | (byte2 << 16) | (byte3 << 8) | byte4;
+  return swapped;
+}
+
+/**
+ *  @ingroup CPUEndian
+ *  This routine swaps a 16 bir quantity.
+ *
+ *  @param[in] value is the value to be swapped
+ *  @return the value after being endian swapped
+ */
+#define CPU_swap_u16( value ) \
+  (((value&0xff) << 8) | ((value >> 8)&0xff))
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/cpukit/score/cpu/microblaze/rtems/score/microblaze.h b/cpukit/score/cpu/microblaze/rtems/score/microblaze.h
new file mode 100644
index 0000000000..06f79aadea
--- /dev/null
+++ b/cpukit/score/cpu/microblaze/rtems/score/microblaze.h
@@ -0,0 +1,70 @@
+/*  
+ *  This file sets up basic CPU dependency settings based on
+ *  compiler settings.  For example, it can determine if
+ *  floating point is available.  This particular implementation
+ *  is specified to the NO CPU port.
+ *
+ *  COPYRIGHT (c) 1989-2011.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id: no_cpu.h,v 1.9 2009/12/02 09:48:25 ralf Exp $
+ *
+ */
+
+#ifndef _RTEMS_SCORE_NO_CPU_H
+#define _RTEMS_SCORE_NO_CPU_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ *  This file contains the information required to build
+ *  RTEMS for a particular member of the NO CPU family.
+ *  It does this by setting variables to indicate which
+ *  implementation dependent features are present in a particular
+ *  member of the family.
+ *
+ *  This is a good place to list all the known CPU models
+ *  that this port supports and which RTEMS CPU model they correspond
+ *  to.
+ */
+
+#if defined(rtems_multilib)
+/*
+ *  Figure out all CPU Model Feature Flags based upon compiler
+ *  predefines.
+ */
+
+#define CPU_MODEL_NAME  "rtems_multilib"
+#define NOCPU_HAS_FPU     1
+
+#else
+/* if defined(__MICROBLAZE__) */
+
+#define CPU_MODEL_NAME  "MicroBlaze"
+#define NOCPU_HAS_FPU     1
+
+/*
+#else
+
+#error "Unsupported CPU Model"
+*/
+
+#endif
+
+/*
+ *  Define the name of the CPU family.
+ */
+
+#define CPU_NAME "MicroBlaze CPU"
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTEMS_SCORE_NO_CPU_H */
-- 
2.27.0



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