text: /****************************************************************************
   * arch/x86_64/src/intel64/up_map_region.c
   *
   * 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.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <debug.h>
  #include <nuttx/irq.h>
  
  #include "up_arch.h"
  #include "up_internal.h"
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: up_map_region
   *
   * Description:
   *   Map a memory region as 1:1 by MMU
   *
   ****************************************************************************/
  
  int up_map_region(void *base, int size, int flags)
  {
    uint64_t bb;
    uint64_t num_of_pages;
    uint64_t entry;
    uint64_t curr;
    int i;
  
    /* Round to page boundary */
  
    bb = (uint64_t)base & ~(PAGE_SIZE - 1);
  
    /* Increase size if the base address is rounded off */
  
    size += (uint64_t)base - bb;
    num_of_pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
  
    if (bb > 0xffffffff)
      {
        return -1;  /* Only < 4GB can be mapped */
      }
  
    curr = bb;
    for (i = 0; i < num_of_pages; i++)
      {
        entry = (curr >> 12) & 0x7ffffff;
  
        pt[entry] = curr | flags;
        curr += PAGE_SIZE;
      }
  
    return 0;
  }
  