tcploader/wii/elf.c

   1 /*
   2  * Copyright (c) 2001 William L. Pitts
   3  * Modifications (c) 2004 Felix Domke
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms are freely
   7  * permitted provided that the above copyright notice and this
   8  * paragraph and the following disclaimer are duplicated in all
   9  * such forms.
  10  *
  11  * This software is provided "AS IS" and without any express or
  12  * implied warranties, including, without limitation, the implied
  13  * warranties of merchantability and fitness for a particular
  14  * purpose.
  15  */
  16
  17 #include <stdio.h>
  18 #include <string.h>
  19
  20 #include <gccore.h>
  21
  22 #include "elf_abi.h"
  23
  24 /* ======================================================================
  25  * Determine if a valid ELF image exists at the given memory location.
  26  * First looks at the ELF header magic field, the makes sure that it is
  27  * executable and makes sure that it is for a PowerPC.
  28  * ====================================================================== */
  29 s32 valid_elf_image (void *addr)
  30 {
  31         Elf32_Ehdr *ehdr; /* Elf header structure pointer */
  32
  33         ehdr = (Elf32_Ehdr *) addr;
  34
  35         if (!IS_ELF (*ehdr))
  36                 return 0;
  37
  38         if (ehdr->e_type != ET_EXEC)
  39                 return -1;
  40
  41         if (ehdr->e_machine != EM_PPC)
  42                 return -1;
  43
  44         return 1;
  45 }
  46
  47
  48 /* ======================================================================
  49  * A very simple elf loader, assumes the image is valid, returns the
  50  * entry point address.
  51  * ====================================================================== */
  52 u32 load_elf_image (void *addr)
  53 {
  54         Elf32_Ehdr *ehdr;
  55         Elf32_Shdr *shdr;
  56         u8 *strtab = 0;
  57         u8 *image;
  58         int i;
  59
  60         ehdr = (Elf32_Ehdr *) addr;
  61         /* Find the section header string table for output info */
  62         shdr = (Elf32_Shdr *) (addr + ehdr->e_shoff +
  63                                (ehdr->e_shstrndx * sizeof (Elf32_Shdr)));
  64
  65         if (shdr->sh_type == SHT_STRTAB)
  66                 strtab = (u8 *) (addr + shdr->sh_offset);
  67
  68         /* Load each appropriate section */
  69         for (i = 0; i < ehdr->e_shnum; ++i) {
  70                 shdr = (Elf32_Shdr *) (addr + ehdr->e_shoff +
  71                                        (i * sizeof (Elf32_Shdr)));
  72
  73                 if (!(shdr->sh_flags & SHF_ALLOC)
  74                    || shdr->sh_addr == 0 || shdr->sh_size == 0) {
  75                         continue;
  76                 }
  77
  78                 shdr->sh_addr &= 0x3FFFFFFF;
  79                 shdr->sh_addr |= 0x80000000;
  80
  81                 if (strtab) {
  82                         printf ("%sing section %s @ 0x%08x (0x%08x bytes)\n",
  83                                 (shdr->sh_type == SHT_NOBITS) ?
  84                                         "clear" : "load",
  85                                 &strtab[shdr->sh_name],
  86                                 (u32) shdr->sh_addr,
  87                                 (u32) shdr->sh_size);
  88                 }
  89
  90                 if (shdr->sh_type == SHT_NOBITS) {
  91                         memset ((void *) shdr->sh_addr, 0, shdr->sh_size);
  92                 } else {
  93                         image = (u8 *) addr + shdr->sh_offset;
  94                         memcpy ((void *) shdr->sh_addr,
  95                                 (const void *) image,
  96                                 shdr->sh_size);
  97                 }
  98                 DCFlushRangeNoSync ((void *) shdr->sh_addr, shdr->sh_size);
  99         }
 100
 101         return (ehdr->e_entry & 0x3FFFFFFF) | 0x80000000;
 102 }
 103