OpenRISC: Module support
Jonas Bonn [Sat, 4 Jun 2011 19:35:19 +0000 (22:35 +0300)]
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

arch/openrisc/kernel/module.c [new file with mode: 0644]

diff --git a/arch/openrisc/kernel/module.c b/arch/openrisc/kernel/module.c
new file mode 100644 (file)
index 0000000..10ff50f
--- /dev/null
@@ -0,0 +1,72 @@
+/*
+ * OpenRISC module.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/moduleloader.h>
+#include <linux/elf.h>
+
+int apply_relocate_add(Elf32_Shdr *sechdrs,
+                      const char *strtab,
+                      unsigned int symindex,
+                      unsigned int relsec,
+                      struct module *me)
+{
+       unsigned int i;
+       Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
+       Elf32_Sym *sym;
+       uint32_t *location;
+       uint32_t value;
+
+       pr_debug("Applying relocate section %u to %u\n", relsec,
+                sechdrs[relsec].sh_info);
+       for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
+               /* This is where to make the change */
+               location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+                       + rel[i].r_offset;
+
+               /* This is the symbol it is referring to.  Note that all
+                  undefined symbols have been resolved.  */
+               sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
+                       + ELF32_R_SYM(rel[i].r_info);
+               value = sym->st_value + rel[i].r_addend;
+
+               switch (ELF32_R_TYPE(rel[i].r_info)) {
+               case R_OR32_32:
+                       *location = value;
+                       break;
+               case R_OR32_CONST:
+                       location = (uint16_t *)location + 1;
+                       *((uint16_t *)location) = (uint16_t) (value);
+                       break;
+               case R_OR32_CONSTH:
+                       location = (uint16_t *)location + 1;
+                       *((uint16_t *)location) = (uint16_t) (value >> 16);
+                       break;
+               case R_OR32_JUMPTARG:
+                       value -= (uint32_t)location;
+                       value >>= 2;
+                       value &= 0x03ffffff;
+                       value |= *location & 0xfc000000;
+                       *location = value;
+                       break;
+               default:
+                       pr_err("module %s: Unknown relocation: %u\n",
+                              me->name, ELF32_R_TYPE(rel[i].r_info));
+                       break;
+               }
+       }
+
+       return 0;
+}