ldso/ldso/powerpc/dl-startup.h

   1 /* Any assmbly language/system dependent hacks needed to setup boot1.c so it
   2  * will work as expected and cope with whatever platform specific wierdness is
   3  * needed for this architecture.  */
   4
   5 /* Overrive the default _dl_boot function, and replace it with a bit of asm.
   6  * Then call the real _dl_boot function, which is now named _dl_boot2. */
   7
   8 asm("" \
   9 "       .text\n"                        \
  10 "       .globl  _dl_boot\n"             \
  11 "_dl_boot:\n"                           \
  12 "       mr      3,1\n"          \
  13 "       li      4,0\n"                  \
  14 "       addi    1,1,-16\n"              \
  15 "       stw     4,0(1)\n"               \
  16 "       bl      _dl_boot2\n"            \
  17 ".previous\n"                           \
  18 );
  19
  20 #define DL_BOOT(X) static void __attribute_used__ _dl_boot2(X)
  21
  22 /*
  23  * Get a pointer to the argv array.  On many platforms this can be just
  24  * the address if the first argument, on other platforms we need to
  25  * do something a little more subtle here.
  26  */
  27 #define GET_ARGV(ARGVP, ARGS) ARGVP = (((unsigned long*) ARGS)+1)
  28
  29 /*
  30  * Here is a macro to perform a relocation.  This is only used when
  31  * bootstrapping the dynamic loader.  RELP is the relocation that we
  32  * are performing, REL is the pointer to the address we are relocating.
  33  * SYMBOL is the symbol involved in the relocation, and LOAD is the
  34  * load address.
  35  */
  36 #define PERFORM_BOOTSTRAP_RELOC(RELP,REL,SYMBOL,LOAD,SYMTAB) \
  37         {int type=ELF32_R_TYPE((RELP)->r_info);         \
  38          Elf32_Addr finaladdr=(SYMBOL)+(RELP)->r_addend;\
  39         if (type==R_PPC_RELATIVE) {                     \
  40                 *REL=(Elf32_Word)(LOAD)+(RELP)->r_addend;\
  41         } else if (type==R_PPC_JMP_SLOT) {              \
  42                 Elf32_Sword delta=finaladdr-(Elf32_Word)(REL);\
  43                 *REL=OPCODE_B(delta);                   \
  44         } else if (type==R_PPC_ADDR32) {                \
  45                 *REL=finaladdr;                         \
  46         } else {                                        \
  47           _dl_exit(100+ELF32_R_TYPE((RELP)->r_info));   \
  48         }                                               \
  49         PPC_DCBST(REL); PPC_SYNC; PPC_ICBI(REL);        \
  50         }
  51 /*
  52  * Transfer control to the user's application, once the dynamic loader
  53  * is done.  This routine has to exit the current function, then
  54  * call the _dl_elf_main function.
  55  */
  56
  57 /*
  58  * Use "b"(Address base register) operand for %1 since "b" excludes
  59  * r0 which is important for the addi instruction in this case.
  60  */
  61 #define START()         \
  62         __asm__ volatile ( \
  63                     "addi 1,%1,0\n\t" \
  64                     "mtlr %0\n\t" \
  65                     "blrl\n\t"  \
  66                     : : "r" (_dl_elf_main), "b" (args))
  67
  68
  69