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

   1 /* Copyright (C) 1998-2021 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    <https://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 /* The main work is done in the generic function.  */
  28 #define LIBC_START_MAIN generic_start_main
  29 #define LIBC_START_DISABLE_INLINE
  30 #define LIBC_START_MAIN_AUXVEC_ARG
  31 #define MAIN_AUXVEC_ARG
  32 #define INIT_MAIN_ARGS
  33 #include <csu/libc-start.c>
  34
  35 struct startup_info
  36   {
  37     void *sda_base;
  38     int (*main) (int, char **, char **, void *);
  39     int (*init) (int, char **, char **, void *);
  40     void (*fini) (void);
  41   };
  42
  43 int
  44 __libc_start_main (int argc, char **argv,
  45                    char **ev,
  46                    ElfW (auxv_t) * auxvec,
  47                    void (*rtld_fini) (void),
  48                    struct startup_info *stinfo,
  49                    char **stack_on_entry)
  50 {
  51   /* the PPC SVR4 ABI says that the top thing on the stack will
  52      be a NULL pointer, so if not we assume that we're being called
  53      as a statically-linked program by Linux...  */
  54   if (*stack_on_entry != NULL)
  55     {
  56       char **temp;
  57       /* ...in which case, we have argc as the top thing on the
  58          stack, followed by argv (NULL-terminated), envp (likewise),
  59          and the auxiliary vector.  */
  60       /* 32/64-bit agnostic load from stack */
  61       argc = *(long int *) stack_on_entry;
  62       argv = stack_on_entry + 1;
  63       ev = argv + argc + 1;
  64 #ifdef HAVE_AUX_VECTOR
  65       temp = ev;
  66       while (*temp != NULL)
  67         ++temp;
  68       auxvec = (ElfW (auxv_t) *)++ temp;
  69 #endif
  70       rtld_fini = NULL;
  71     }
  72
  73   for (ElfW (auxv_t) * av = auxvec; av->a_type != AT_NULL; ++av)
  74     switch (av->a_type)
  75       {
  76       /* For the static case, we also need _dl_hwcap, _dl_hwcap2 and
  77          _dl_platform, so we can call
  78          __tcb_parse_hwcap_and_convert_at_platform ().  */
  79 #ifndef SHARED
  80       case AT_HWCAP:
  81         _dl_hwcap = (unsigned long int) av->a_un.a_val;
  82         break;
  83       case AT_HWCAP2:
  84         _dl_hwcap2 = (unsigned long int) av->a_un.a_val;
  85         break;
  86       case AT_PLATFORM:
  87         _dl_platform = (void *) av->a_un.a_val;
  88         break;
  89 #endif
  90       }
  91
  92   /* Initialize hwcap/hwcap2 and platform data so it can be copied to
  93      the TCB later in __libc_setup_tls (). (static case only).  */
  94 #ifndef SHARED
  95   __tcb_parse_hwcap_and_convert_at_platform ();
  96 #endif
  97
  98   return generic_start_main (stinfo->main, argc, argv, auxvec,
  99                              stinfo->init, stinfo->fini, rtld_fini,
 100                              stack_on_entry);
 101 }