/*      $NetBSD: self_reloc.c,v 1.1 2017/01/24 11:09:14 nonaka Exp $    */

/*-
* Copyright (c) 2008-2010 Rui Paulo <[email protected]>
* 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 of 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/

#include <sys/types.h>
#include <sys/exec_elf.h>

#include <efi.h>

void self_reloc(Elf_Addr, Elf_Dyn *);

#if defined(__aarch64__)
#define USE_RELA
#endif

/*
* A simple elf relocator.
*/
void
self_reloc(Elf_Addr baseaddr, Elf_Dyn *dynamic)
{
       Elf_Word relsz, relent;
       Elf_Addr *newaddr;
       Elf_Rel *rel = NULL;
       Elf_Dyn *dynp;

       /*
        * Find the relocation address, its size and the relocation entry.
        */
       relsz = 0;
       relent = 0;
       for (dynp = dynamic; dynp->d_tag != DT_NULL; dynp++) {
               switch (dynp->d_tag) {
               case DT_REL:
               case DT_RELA:
                       rel = (Elf_Rel *)(dynp->d_un.d_ptr + baseaddr);
                       break;
               case DT_RELSZ:
               case DT_RELASZ:
                       relsz = dynp->d_un.d_val;
                       break;
               case DT_RELENT:
               case DT_RELAENT:
                       relent = dynp->d_un.d_val;
                       break;
               default:
                       break;
               }
       }

       /*
        * Perform the actual relocation.
        */
       for (; relsz > 0; relsz -= relent) {
               switch (ELF_R_TYPE(rel->r_info)) {
               case R_TYPE(NONE):
                       /* No relocation needs be performed. */
                       break;

               case R_TYPE(RELATIVE):
                       /* Address relative to the base address. */
                       newaddr = (Elf_Addr *)(rel->r_offset + baseaddr);
                       *newaddr += baseaddr;
#ifdef USE_RELA
                       /* Add the addend when the ABI uses them */
                       *newaddr += ((Elf_Rela *)rel)->r_addend;
#endif
                       break;
               default:
                       /* XXX: do we need other relocations ? */
                       break;
               }
               rel = (Elf_Rel *) ((char *) rel + relent);
       }
}