sysdeps/unix/sysv/linux/powerpc/libc-start.c

   1 /* Copyright (C) 1998-2019 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <stdlib.h>
  19 #include <unistd.h>
  20 #include <ldsodefs.h>
  21 #include <sysdep.h>
  22
  23 #ifndef SHARED
  24 #include <hwcapinfo.h>
  25 #endif
  26
  27 int __cache_line_size attribute_hidden;
  28 /* The main work is done in the generic function.  */
  29 #define LIBC_START_MAIN generic_start_main
  30 #define LIBC_START_DISABLE_INLINE
  31 #define LIBC_START_MAIN_AUXVEC_ARG
  32 #define MAIN_AUXVEC_ARG
  33 #define INIT_MAIN_ARGS
  34 #include <csu/libc-start.c>
  35
  36 struct startup_info
  37   {
  38     void *sda_base;
  39     int (*main) (int, char **, char **, void *);
  40     int (*init) (int, char **, char **, void *);
  41     void (*fini) (void);
  42   };
  43
  44 int
  45 __libc_start_main (int argc, char **argv,
  46                    char **ev,
  47                    ElfW (auxv_t) * auxvec,
  48                    void (*rtld_fini) (void),
  49                    struct startup_info *stinfo,
  50                    char **stack_on_entry)
  51 {
  52   /* the PPC SVR4 ABI says that the top thing on the stack will
  53      be a NULL pointer, so if not we assume that we're being called
  54      as a statically-linked program by Linux...  */
  55   if (*stack_on_entry != NULL)
  56     {
  57       char **temp;
  58       /* ...in which case, we have argc as the top thing on the
  59          stack, followed by argv (NULL-terminated), envp (likewise),
  60          and the auxiliary vector.  */
  61       /* 32/64-bit agnostic load from stack */
  62       argc = *(long int *) stack_on_entry;
  63       argv = stack_on_entry + 1;
  64       ev = argv + argc + 1;
  65 #ifdef HAVE_AUX_VECTOR
  66       temp = ev;
  67       while (*temp != NULL)
  68         ++temp;
  69       auxvec = (ElfW (auxv_t) *)++ temp;
  70 #endif
  71       rtld_fini = NULL;
  72     }
  73
  74   /* Initialize the __cache_line_size variable from the aux vector.  For the
  75      static case, we also need _dl_hwcap, _dl_hwcap2 and _dl_platform, so we
  76      can call __tcb_parse_hwcap_and_convert_at_platform ().  */
  77   for (ElfW (auxv_t) * av = auxvec; av->a_type != AT_NULL; ++av)
  78     switch (av->a_type)
  79       {
  80       case AT_DCACHEBSIZE:
  81         __cache_line_size = av->a_un.a_val;
  82         break;
  83 #ifndef SHARED
  84       case AT_HWCAP:
  85         _dl_hwcap = (unsigned long int) av->a_un.a_val;
  86         break;
  87       case AT_HWCAP2:
  88         _dl_hwcap2 = (unsigned long int) av->a_un.a_val;
  89         break;
  90       case AT_PLATFORM:
  91         _dl_platform = (void *) av->a_un.a_val;
  92         break;
  93 #endif
  94       }
  95
  96   /* Initialize hwcap/hwcap2 and platform data so it can be copied to
  97      the TCB later in __libc_setup_tls (). (static case only).  */
  98 #ifndef SHARED
  99   __tcb_parse_hwcap_and_convert_at_platform ();
 100 #endif
 101
 102   return generic_start_main (stinfo->main, argc, argv, auxvec,
 103                              stinfo->init, stinfo->fini, rtld_fini,
 104                              stack_on_entry);
 105 }