text: /****************************************************************************
   * arch/or1k/include/arch.h
   *
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.  The
   * ASF licenses this file to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance with the
   * License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
   * License for the specific language governing permissions and limitations
   * under the License.
   *
   ****************************************************************************/
  
  /* This file should never be included directly but, rather,
   * only indirectly through nuttx/arch.h
   */
  
  #ifndef __ARCH_OR1K_INCLUDE_ARCH_H
  #define __ARCH_OR1K_INCLUDE_ARCH_H
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  #ifndef __ASSEMBLY__
  #  include <stdint.h>
  #  include <nuttx/pgalloc.h>
  #  include <nuttx/addrenv.h>
  #endif
  
  /****************************************************************************
   * Pre-processor Definitions
   ****************************************************************************/
  
  #define IDLE_STACK ((uint32_t)&_ebss+CONFIG_IDLETHREAD_STACKSIZE-4)
  
  #ifdef CONFIG_ARCH_ADDRENV
  #if CONFIG_MM_PGSIZE != 4096
  #  error Only pages sizes of 4096 are currently supported (CONFIG_ARCH_ADDRENV)
  #endif
  
  /* Convert 4KiB pages to 1MiB sections */
  
  #  define __PG2SECT_SHIFT     (20 - MM_PGSHIFT)
  #  define __PG2SECT_MASK      ((1 << __PG2SECT_SHIFT) - 1)
  
  #  define ARCH_PG2SECT(p)     (((p) + __PG2SECT_MASK) >> __PG2SECT_SHIFT)
  #  define ARCH_SECT2PG(s)     ((s) << __PG2SECT_SHIFT)
  
  #  define ARCH_TEXT_NSECTS    ARCH_PG2SECT(CONFIG_ARCH_TEXT_NPAGES)
  #  define ARCH_DATA_NSECTS    ARCH_PG2SECT(CONFIG_ARCH_DATA_NPAGES)
  #  define ARCH_HEAP_NSECTS    ARCH_PG2SECT(CONFIG_ARCH_HEAP_NPAGES)
  
  #  ifdef CONFIG_MM_SHM
  #    define ARCH_SHM_NSECTS   ARCH_PG2SECT(ARCH_SHM_MAXPAGES)
  #  endif
  
  #  ifdef CONFIG_ARCH_STACK_DYNAMIC
  #    define ARCH_STACK_NSECTS ARCH_PG2SECT(CONFIG_ARCH_STACK_NPAGES)
  #  endif
  #endif /* CONFIG_ARCH_ADDRENV */
  
  /****************************************************************************
   * Inline functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: or1k_getsp
   ****************************************************************************/
  
  static inline uint32_t or1k_getsp(void)
  {
    uint32_t sp;
  
    __asm__
    (
      "\tmov %0, sp\n\t"
      : "=r"(sp)
    );
  
    return sp;
  }
  
  /****************************************************************************
   * Public Types
   ****************************************************************************/
  
  #ifdef CONFIG_ARCH_ADDRENV
  /* The task group resources are retained in a single structure, task_group_s
   * that is defined in the header file nuttx/include/nuttx/sched.h. The type
   * group_addrenv_t must be defined by platform specific logic in
   * nuttx/arch/<architecture>/include/arch.h.
   *
   * These tables would hold the physical address of the level 2 page tables.
   * All would be initially NULL and would not be backed up with physical
   * memory until mappings in the level 2 page table are required.
   */
  
  struct group_addrenv_s
  {
    /* Level 1 page table entries for each group section */
  
    FAR uintptr_t *text[ARCH_TEXT_NSECTS];
    FAR uintptr_t *data[ARCH_DATA_NSECTS];
  #ifdef CONFIG_BUILD_KERNEL
    FAR uintptr_t *heap[ARCH_HEAP_NSECTS];
  #ifdef CONFIG_MM_SHM
    FAR uintptr_t *shm[ARCH_SHM_NSECTS];
  #endif
  
    /* Initial heap allocation (in bytes).  This exists only provide an
     * indirect path for passing the size of the initial heap to the heap
     * initialization logic.  These operations are separated in time and
     * architecture.  REVISIT:  I would like a better way to do this.
     */
  
    size_t heapsize;
  #endif
  };
  
  typedef struct group_addrenv_s group_addrenv_t;
  
  /* This type is used when the OS needs to temporarily instantiate a
   * different address environment.  Used in the implementation of
   *
   *   int up_addrenv_select(group_addrenv_t addrenv, save_addrenv_t *oldenv);
   *   int up_addrenv_restore(save_addrenv_t oldenv);
   *
   * In this case, the saved valued in the L1 page table are returned
   */
  
  struct save_addrenv_s
  {
    FAR uint32_t text[ARCH_TEXT_NSECTS];
    FAR uint32_t data[ARCH_DATA_NSECTS];
  #ifdef CONFIG_BUILD_KERNEL
    FAR uint32_t heap[ARCH_HEAP_NSECTS];
  #ifdef CONFIG_MM_SHM
    FAR uint32_t shm[ARCH_SHM_NSECTS];
  #endif
  #endif
  };
  
  typedef struct save_addrenv_s save_addrenv_t;
  #endif
  
  /****************************************************************************
   * Public Data
   ****************************************************************************/
  
  /****************************************************************************
   * Public Function Prototypes
   ****************************************************************************/
  
  #ifdef __cplusplus
  #define EXTERN extern "C"
  extern "C"
  {
  #else
  #define EXTERN extern
  #endif
  
  #undef EXTERN
  #ifdef __cplusplus
  }
  #endif
  
  #endif /* __ARCH_OR1K_INCLUDE_ARCH_H */
  