arch/nios2nommu/kernel/module.c

   1 /*  Kernel module help for Nios2.
   2     Copyright (C) 2004 Microtronix Datacom Ltd.
   3     Copyright (C) 2001,03  Rusty Russell
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18
  19     Written by Wentao Xu <xuwentao@microtronix.com>
  20 */
  21 #include <linux/moduleloader.h>
  22 #include <linux/elf.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/fs.h>
  25 #include <linux/string.h>
  26 #include <linux/kernel.h>
  27
  28 #if 0
  29 #define DEBUGP printk
  30 #else
  31 #define DEBUGP(fmt , ...)
  32 #endif
  33
  34 void *module_alloc(unsigned long size)
  35 {
  36         if (size == 0)
  37                 return NULL;
  38         return vmalloc(size);
  39 }
  40
  41
  42 /* Free memory returned from module_alloc */
  43 void module_free(struct module *mod, void *module_region)
  44 {
  45         vfree(module_region);
  46         /* FIXME: If module_region == mod->init_region, trim exception
  47            table entries. */
  48 }
  49
  50 /* We don't need anything special. */
  51 int module_frob_arch_sections(Elf_Ehdr *hdr,
  52                               Elf_Shdr *sechdrs,
  53                               char *secstrings,
  54                               struct module *mod)
  55 {
  56         return 0;
  57 }
  58
  59 int apply_relocate(Elf32_Shdr *sechdrs,
  60                    const char *strtab,
  61                    unsigned int symindex,
  62                    unsigned int relsec,
  63                    struct module *me)
  64 {
  65         printk(KERN_ERR "module %s: NO-ADD RELOCATION unsupported\n",
  66                me->name);
  67         return -ENOEXEC;
  68 }
  69
  70
  71 int apply_relocate_add (Elf32_Shdr *sechdrs, const char *strtab,
  72                         unsigned int symindex, unsigned int relsec,
  73                         struct module *mod)
  74 {
  75         unsigned int i;
  76         Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
  77
  78         DEBUGP ("Applying relocate section %u to %u\n", relsec,
  79                 sechdrs[relsec].sh_info);
  80
  81         for (i = 0; i < sechdrs[relsec].sh_size / sizeof (*rela); i++) {
  82                 /* This is where to make the change */
  83                 uint32_t word;
  84                 uint32_t *loc
  85                         = ((void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
  86                            + rela[i].r_offset);
  87                 /* This is the symbol it is referring to.  Note that all
  88                    undefined symbols have been resolved.  */
  89                 Elf32_Sym *sym
  90                         = ((Elf32_Sym *)sechdrs[symindex].sh_addr
  91                            + ELF32_R_SYM (rela[i].r_info));
  92                 uint32_t v = sym->st_value + rela[i].r_addend;
  93
  94                 switch (ELF32_R_TYPE (rela[i].r_info)) {
  95                 case R_NIOS2_NONE:
  96                         break;
  97
  98                 case R_NIOS2_BFD_RELOC_32:
  99                         *loc += v;
 100                         break;
 101
 102                 case R_NIOS2_PCREL16:
 103                         v -= (uint32_t)loc + 4;
 104                         if ((int32_t)v > 0x7fff ||
 105                                         (int32_t)v < -(int32_t)0x8000) {
 106                                 printk(KERN_ERR
 107                                        "module %s: relocation overflow\n",
 108                                        mod->name);
 109                                 return -ENOEXEC;
 110                         }
 111                         word = *loc;
 112                         *loc = ((((word >> 22) << 16) | (v & 0xffff)) << 6) | (word & 0x3f);
 113                         break;
 114
 115                 case R_NIOS2_CALL26:
 116                         if (v & 3) {
 117                                 printk(KERN_ERR
 118                                        "module %s: dangerous relocation\n",
 119                                        mod->name);
 120                                 return -ENOEXEC;
 121                         }
 122                         if ((v >> 28) != ((uint32_t)loc >> 28)) {
 123                                 printk(KERN_ERR
 124                                        "module %s: relocation overflow\n",
 125                                        mod->name);
 126                                 return -ENOEXEC;
 127                         }
 128                         *loc = (*loc & 0x3f) | ((v >> 2) << 6);
 129                         break;
 130
 131                 case R_NIOS2_HI16:
 132                         word = *loc;
 133                         *loc = ((((word >> 22) << 16) | ((v >>16) & 0xffff)) << 6) |
 134                                         (word & 0x3f);
 135                         break;
 136
 137                 case R_NIOS2_LO16:
 138                         word = *loc;
 139                         *loc = ((((word >> 22) << 16) | (v & 0xffff)) << 6) |
 140                                         (word & 0x3f);
 141                         break;
 142
 143                 case R_NIOS2_HIADJ16:
 144                         {
 145                                 Elf32_Addr word2;
 146
 147                                 word = *loc;
 148                                 word2 = ((v >> 16) + ((v >> 15) & 1)) & 0xffff;
 149                                 *loc = ((((word >> 22) << 16) | word2) << 6) |
 150                                                 (word & 0x3f);
 151                         }
 152                         break;
 153
 154                 default:
 155                         printk (KERN_ERR "module %s: Unknown reloc: %u\n",
 156                                 mod->name, ELF32_R_TYPE (rela[i].r_info));
 157                         return -ENOEXEC;
 158                 }
 159         }
 160
 161         return 0;
 162 }
 163
 164 int module_finalize(const Elf_Ehdr *hdr,
 165                     const Elf_Shdr *sechdrs,
 166                     struct module *me)
 167 {
 168         return 0;
 169 }
 170
 171 void module_arch_cleanup(struct module *mod)
 172 {
 173 }