l4/pkg/uclibc/lib/contrib/uclibc/ldso/ldso/c6x/dl-startup.h

   1 /* Copyright (C) 2010 Texas Instruments Incorporated
   2  * Contributed by Mark Salter <msalter@redhat.com>
   3  *
   4  * Borrowed heavily from frv arch:
   5  * Copyright (C) 2003 Red Hat, Inc.
   6  *
   7  * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
   8  */
   9
  10 #undef DL_START
  11 #define DL_START(X)   \
  12 int  \
  13 _dl_start (unsigned placeholder, \
  14            struct elf32_dsbt_loadmap *dl_boot_progmap, \
  15            struct elf32_dsbt_loadmap *dl_boot_ldsomap, \
  16            Elf32_Dyn *dl_boot_ldso_dyn_pointer,        \
  17            X)
  18
  19 /*
  20  * On entry, the kernel has set up the stack thusly:
  21  *
  22  *      0(sp)                   pad0
  23  *      4(sp)                   pad1
  24  *      8(sp)                   argc
  25  *      12(sp)                  argv[0]
  26  *      ...
  27  *      (4*(argc+3))(sp)        NULL
  28  *      (4*(argc+4))(sp)        envp[0]
  29  *      ...
  30  *                              NULL
  31  *
  32  * Register values are unspecified, except:
  33  *
  34  *      B4  --> executable loadmap address
  35  *      A6  --> interpreter loadmap address
  36  *      B6  --> dynamic section address
  37  *      B14 --> our DP setup by kernel
  38  *
  39  * NB: DSBT index is always 0 for the executable
  40  *     and 1 for the interpreter
  41  */
  42
  43 __asm__("       .text\n"
  44         ".globl _start\n"
  45         "_start:\n"
  46         "          B .S2                _dl_start\n"
  47         "          STW .D2T2            B14, *+B14[1]\n"
  48         "          ADD .D1X             B15,8,A8\n"
  49         "          ADDKPC .S2           ret_from_dl,B3,2\n"
  50         "ret_from_dl:\n"
  51         "          B .S2X               A4\n"
  52         " ||       LDW .D2T2            *+B14[0],B14\n"
  53         "          ADDKPC .S2           __dl_fini,B0,0\n"
  54         "          MV .S1X              B0,A4\n"
  55         "          NOP\n"
  56         "          NOP\n"
  57         "          NOP\n"
  58         "__dl_fini:\n"
  59         "          LDW .D2T2            *+B14[1],B14\n"
  60         "          NOP          4\n"
  61         "          LDW .D2T1            *+B14($GOT(_dl_fini)), A0\n"
  62         "          NOP          4\n"
  63         "          BNOP .S2X            A0, 5\n");
  64
  65 __asm__("       .text\n"
  66         "__c6x_cache_sync:\n"
  67         "          MVK .S2              330,B0\n"
  68         "          SWE\n"
  69         "          NOP\n"
  70         "          BNOP .S2             B3,5\n"
  71         "          NOP\n"
  72         "          NOP\n"
  73         "          NOP\n"
  74         "          NOP\n"
  75         "\n"
  76 );
  77
  78 /*
  79  * Get a pointer to the argv array.  On many platforms this can be just
  80  * the address of the first argument, on other platforms we need to
  81  * do something a little more subtle here.
  82  */
  83 #define GET_ARGV(ARGVP, ARGS) ARGVP = (((unsigned long*) ARGS) + 1)
  84
  85 struct elf32_dsbt_loadmap;
  86
  87 /*
  88  * Here is a macro to perform a relocation.  This is only used when
  89  * bootstrapping the dynamic loader.  RELP is the relocation that we
  90  * are performing, REL is the pointer to the address we are relocating.
  91  * SYMBOL is the symbol involved in the relocation, and LOAD is the
  92  * load address.
  93  */
  94 #define PERFORM_BOOTSTRAP_RELOC(RELP,REL,SYMBOL,LOAD,SYMTAB) \
  95         switch(ELF32_R_TYPE((RELP)->r_info)){                           \
  96         case R_C6000_ABS_L16:                                           \
  97             {                                                           \
  98                     unsigned int opcode = *(REL);                       \
  99                     unsigned int v = (SYMBOL) + (RELP)->r_addend;       \
 100                     opcode &= ~0x7fff80;                                \
 101                     opcode |= ((v & 0xffff) << 7);                      \
 102                     *(REL) = opcode;                                    \
 103             }                                                           \
 104             break;                                                      \
 105         case R_C6000_ABS_H16:                                           \
 106             {                                                           \
 107                     unsigned int opcode = *(REL);                       \
 108                     unsigned int v = (SYMBOL) + (RELP)->r_addend;       \
 109                     opcode &= ~0x7fff80;                                \
 110                     opcode |= ((v >> 9) & 0x7fff80);                    \
 111                     *(REL) = opcode;                                    \
 112             }                                                           \
 113             break;                                                      \
 114         case R_C6000_ABS32:                                             \
 115             *(REL) = (SYMBOL) + (RELP)->r_addend;                       \
 116             break;                                                      \
 117         default:                                                        \
 118           _dl_exit(1);                                                  \
 119         }
 120
 121 extern void __c6x_cache_sync(unsigned long start, unsigned long end)
 122   attribute_hidden;