/****************************************************************************
 * libs/libc/machine/sparc/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 <assert.h>
#include <stdlib.h>
#include <errno.h>
#include <debug.h>

#include <nuttx/elf.h>

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/****************************************************************************
 * Private Data
 ****************************************************************************/

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * 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(const Elf32_Ehdr *ehdr)
{
  /* Make sure it's an Sparc executable */

  if (ehdr->e_machine != EM_SPARC)
    {
      berr("ERROR: Not for Sparc: e_machine=%04x\n", ehdr->e_machine);
      return false;
    }

  /* Make sure that 32-bit objects are supported */

  if (ehdr->e_ident[EI_CLASS] != ELFCLASS32)
    {
      berr("ERROR: Need 32-bit objects: e_ident[EI_CLASS]=%02x\n",
           ehdr->e_ident[EI_CLASS]);
      return false;
    }

  /* Verify endian-ness */

#ifdef CONFIG_ENDIAN_BIG
  if (ehdr->e_ident[EI_DATA] != ELFDATA2MSB)
#else
  if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB)
#endif
    {
      berr("ERROR: Wrong endian-ness: e_ident[EI_DATA]=%02x\n",
           ehdr->e_ident[EI_DATA]);
      return false;
    }

  return true;
}

/****************************************************************************
 * Name: up_relocate and up_relocateadd
 *
 * Description:
 *   Perform on 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(const Elf32_Rel *rel, const Elf32_Sym *sym,
                uintptr_t addr, void *arch_data)
{
  unsigned int relotype;

  /* All relocations except NONE depend upon having valid symbol
   * information.
   */

  relotype = ELF32_R_TYPE(rel->r_info);
  if (sym == NULL && relotype != R_SPARC_NONE)
    {
      return -EINVAL;
    }

  berr("ERROR: Unsupported relocation: %u\n", relotype);

  return OK;
}

int up_relocateadd(const Elf32_Rela *rel, const Elf32_Sym *sym,
                   uintptr_t addr, void *arch_data)
{
  unsigned int relotype;
  uint32_t value;

  /* All relocations except NONE depend upon having valid symbol
   * information.
   */

  relotype = ELF32_R_TYPE(rel->r_info);
  if (sym == NULL)
    {
      if (relotype != R_SPARC_NONE)
        {
          return -EINVAL;
        }
    }
  else
    {
      value = sym->st_value + rel->r_addend;
    }

  /* Handle the relocation by relocation type */

  switch (relotype)
    {
    case R_SPARC_NONE:
      break;
    case R_SPARC_8:
        (*(uint8_t *)addr) = (uint8_t)value;
        break;

    case R_SPARC_16:
        (*(uint16_t *)addr) = (uint16_t)value;
        break;

    case R_SPARC_32:
        (*(uint32_t *)addr) = value;
        break;

    case R_SPARC_DISP8:
    case R_SPARC_DISP16:
    case R_SPARC_DISP32:
        (*(uint32_t *)addr) = value - addr;
        break;

    case R_SPARC_WDISP30:
        value  -= addr;
        (*(uint32_t *)addr) &= (~0x3fffffff);
        (*(uint32_t *)addr) |= (value >> 2) & 0x3fffffff;
        break;

    case R_SPARC_WDISP22:
        value  -= addr;
        (*(uint32_t *)addr) &= (~0x3fffff);
        (*(uint32_t *)addr) |= (value >> 2) & 0x3fffff;
        break;

    case R_SPARC_HI22:
        (*(uint32_t *)addr) &= (~0x3fffff);
        (*(uint32_t *)addr) |= (value >> 10) & 0x3fffff;
        break;

    case R_SPARC_22:
        (*(uint32_t *)addr) &= (~0x3fffff);
        (*(uint32_t *)addr) |= value & 0x3fffff;
        break;

    case R_SPARC_13:
        (*(uint32_t *)addr) &= (~0x1ffff);
        (*(uint32_t *)addr) |= value & 0x1ffff;
        break;

    case R_SPARC_LO10:
        (*(uint32_t *)addr) &= (~0x3ff);
        (*(uint32_t *)addr) |= value & 0x3ff;
        break;

    case R_SPARC_PC10:
        value  -= addr;
        (*(uint32_t *)addr) &= (~0x3ff);
        (*(uint32_t *)addr) |= value & 0x3ff;
        break;

    case R_SPARC_PC22:
        value  -= addr;
        (*(uint32_t *)addr) &= (~0x3fffff);
        (*(uint32_t *)addr) |= (value >> 10) & 0x3fffff;
        break;

    case R_SPARC_UA32:
    case R_SPARC_GLOB_DAT:
        (*(uint32_t *)addr) = value;
        break;

    case R_SPARC_JMP_SLOT:
        (*(uint32_t *)(addr + 1)) = OPCODE_SETHI_G1 | ((value >> 10) &
                                        0x3fffff);
        (*(uint32_t *)(addr + 2)) = OPCODE_JMP_G1 | (value & 0x3ff);
        break;

    default:
      berr("ERROR: RELA relocation %u not supported\n", relotype);
      return -EINVAL;
    }

  return OK;
}