text: /****************************************************************************
   * libs/libc/machine/sim/arch_elf.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 <stdlib.h>
  #include <errno.h>
  #include <debug.h>
  
  #include <nuttx/elf.h>
  
  /****************************************************************************
   * Pre-processor Definitions
   ****************************************************************************/
  
  #define R_386_32        1
  #define R_386_PC32      2
  
  #define ELF_BITS        32
  #define ELF_ARCH        EM_386
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: up_checkarch
   *
   * Description:
   *   Given the ELF header in 'hdr', verify that the ELF file is appropriate
   *   for the current, configured architecture.  Every architecture that uses
   *   the ELF loader must provide this function.
   *
   * Input Parameters:
   *   hdr - The ELF header read from the ELF file.
   *
   * Returned Value:
   *   True if the architecture supports this ELF file.
   *
   ****************************************************************************/
  
  bool up_checkarch(FAR const Elf32_Ehdr *hdr)
  {
    return hdr->e_machine == EM_386 || hdr->e_machine == EM_486;
  }
  
  /****************************************************************************
   * Name: up_relocate and up_relocateadd
   *
   * Description:
   *   Perform an architecture-specific ELF relocation.  Every architecture
   *   that uses the ELF loader must provide this function.
   *
   * Input Parameters:
   *   rel - The relocation type
   *   sym - The ELF symbol structure containing the fully resolved value.
   *         There are a few relocation types for a few architectures that do
   *         not require symbol information.  For those, this value will be
   *         NULL.  Implementations of these functions must be able to handle
   *         that case.
   *   addr - The address that requires the relocation.
   *
   * Returned Value:
   *   Zero (OK) if the relocation was successful.  Otherwise, a negated errno
   *   value indicating the cause of the relocation failure.
   *
   ****************************************************************************/
  
  int up_relocate(FAR const Elf32_Rel *rel, FAR const Elf32_Sym *sym,
                  uintptr_t addr)
  {
    FAR uint32_t *ptr = (FAR uint32_t *)addr;
  
    /* All relocations depend upon having valid symbol information. */
  
    if (sym == NULL)
      {
        return -EINVAL;
      }
  
    /* Handle the relocation by relocation type */
  
    switch (ELF32_R_TYPE(rel->r_info))
      {
       case R_386_32:
         *ptr += sym->st_value;
         break;
  
       case R_386_PC32:
         *ptr += sym->st_value - (uint32_t)((uintptr_t)ptr);
         break;
  
       default:
         berr("ERROR: Unsupported type %u\n", ELF32_R_TYPE(rel->r_info));
         return -EINVAL;
      }
  
    return OK;
  }
  
  int up_relocateadd(FAR const Elf32_Rela *rel, FAR const Elf32_Sym *sym,
                     uintptr_t addr)
  {
    berr("ERROR: Not supported\n");
    return -ENOSYS;
  }
  