arch/sh64/kernel/module.c

   1 /*  Kernel module help for sh64.
   2
   3     This program is free software; you can redistribute it and/or modify
   4     it under the terms of the GNU General Public License as published by
   5     the Free Software Foundation; either version 2 of the License, or
   6     (at your option) any later version.
   7
   8     This program is distributed in the hope that it will be useful,
   9     but WITHOUT ANY WARRANTY; without even the implied warranty of
  10     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11     GNU General Public License for more details.
  12
  13     You should have received a copy of the GNU General Public License
  14     along with this program; if not, write to the Free Software
  15     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  16
  17     Copyright 2004 SuperH (UK) Ltd
  18     Author: Richard Curnow
  19
  20     Based on the sh version, and on code from the sh64-specific parts of
  21     modutils, originally written by Richard Curnow and Ben Gaster.
  22
  23 */
  24 #include <linux/moduleloader.h>
  25 #include <linux/elf.h>
  26 #include <linux/vmalloc.h>
  27 #include <linux/fs.h>
  28 #include <linux/string.h>
  29 #include <linux/kernel.h>
  30
  31 #if 0
  32 #define DEBUGP printk
  33 #else
  34 #define DEBUGP(fmt...)
  35 #endif
  36
  37 void *module_alloc(unsigned long size)
  38 {
  39         if (size == 0)
  40                 return NULL;
  41         return vmalloc(size);
  42 }
  43
  44
  45 /* Free memory returned from module_alloc */
  46 void module_free(struct module *mod, void *module_region)
  47 {
  48         vfree(module_region);
  49         /* FIXME: If module_region == mod->init_region, trim exception
  50            table entries. */
  51 }
  52
  53 /* We don't need anything special. */
  54 int module_frob_arch_sections(Elf_Ehdr *hdr,
  55                               Elf_Shdr *sechdrs,
  56                               char *secstrings,
  57                               struct module *mod)
  58 {
  59         return 0;
  60 }
  61
  62 int apply_relocate_add(Elf32_Shdr *sechdrs,
  63                    const char *strtab,
  64                    unsigned int symindex,
  65                    unsigned int relsec,
  66                    struct module *me)
  67 {
  68         unsigned int i;
  69         Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
  70         Elf32_Sym *sym;
  71         Elf32_Addr relocation;
  72         uint32_t *location;
  73         int align;
  74         int is_shmedia;
  75
  76         DEBUGP("Applying relocate section %u to %u\n", relsec,
  77                sechdrs[relsec].sh_info);
  78         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
  79                 /* This is where to make the change */
  80                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
  81                         + rel[i].r_offset;
  82                 /* This is the symbol it is referring to.  Note that all
  83                    undefined symbols have been resolved.  */
  84                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
  85                         + ELF32_R_SYM(rel[i].r_info);
  86                 relocation = sym->st_value + rel[i].r_addend;
  87                 align = (int)location & 3;
  88
  89                 /* For text addresses, bit2 of the st_other field indicates
  90                  * whether the symbol is SHmedia (1) or SHcompact (0).  If
  91                  * SHmedia, the LSB of the symbol needs to be asserted
  92                  * for the CPU to be in SHmedia mode when it starts executing
  93                  * the branch target. */
  94                 is_shmedia = (sym->st_other & 4) ? 1 : 0;
  95                 if (is_shmedia) {
  96                         relocation |= 1;
  97                 }
  98
  99                 switch (ELF32_R_TYPE(rel[i].r_info)) {
 100                 case R_SH_DIR32:
 101                         DEBUGP("R_SH_DIR32 @%08lx = %08lx\n", (unsigned long) location, (unsigned long) relocation);
 102                         *location += relocation;
 103                         break;
 104                 case R_SH_REL32:
 105                         DEBUGP("R_SH_REL32 @%08lx = %08lx\n", (unsigned long) location, (unsigned long) relocation);
 106                         relocation -= (Elf32_Addr) location;
 107                         *location += relocation;
 108                         break;
 109                 case R_SH_IMM_LOW16:
 110                         DEBUGP("R_SH_IMM_LOW16 @%08lx = %08lx\n", (unsigned long) location, (unsigned long) relocation);
 111                         *location = (*location & ~0x3fffc00) |
 112                                 ((relocation & 0xffff) << 10);
 113                         break;
 114                 case R_SH_IMM_MEDLOW16:
 115                         DEBUGP("R_SH_IMM_MEDLOW16 @%08lx = %08lx\n", (unsigned long) location, (unsigned long) relocation);
 116                         *location = (*location & ~0x3fffc00) |
 117                                 (((relocation >> 16) & 0xffff) << 10);
 118                         break;
 119                 case R_SH_IMM_LOW16_PCREL:
 120                         DEBUGP("R_SH_IMM_LOW16_PCREL @%08lx = %08lx\n", (unsigned long) location, (unsigned long) relocation);
 121                         relocation -= (Elf32_Addr) location;
 122                         *location = (*location & ~0x3fffc00) |
 123                                 ((relocation & 0xffff) << 10);
 124                         break;
 125                 case R_SH_IMM_MEDLOW16_PCREL:
 126                         DEBUGP("R_SH_IMM_MEDLOW16_PCREL @%08lx = %08lx\n", (unsigned long) location, (unsigned long) relocation);
 127                         relocation -= (Elf32_Addr) location;
 128                         *location = (*location & ~0x3fffc00) |
 129                                 (((relocation >> 16) & 0xffff) << 10);
 130                         break;
 131                 default:
 132                         printk(KERN_ERR "module %s: Unknown relocation: %u\n",
 133                                me->name, ELF32_R_TYPE(rel[i].r_info));
 134                         return -ENOEXEC;
 135                 }
 136         }
 137         return 0;
 138 }
 139
 140 int apply_relocate(Elf32_Shdr *sechdrs,
 141                        const char *strtab,
 142                        unsigned int symindex,
 143                        unsigned int relsec,
 144                        struct module *me)
 145 {
 146         printk(KERN_ERR "module %s: REL RELOCATION unsupported\n",
 147                me->name);
 148         return -ENOEXEC;
 149 }
 150
 151 int module_finalize(const Elf_Ehdr *hdr,
 152                     const Elf_Shdr *sechdrs,
 153                     struct module *me)
 154 {
 155         return 0;
 156 }
 157
 158 void module_arch_cleanup(struct module *mod)
 159 {
 160 }
 161