gdb/gdbserver/low-sim.c

   1 /* Low level interface to simulators, for the remote server for GDB.
   2    Copyright (C) 1995, 1996 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include "defs.h"
  22 #include "bfd.h"
  23 #include "server.h"
  24 #include "callback.h"           /* GDB simulator callback interface */
  25 #include "remote-sim.h"         /* GDB simulator interface */
  26
  27 extern int remote_debug;
  28
  29 extern host_callback default_callback;  /* in sim/common/callback.c */
  30
  31 char registers[REGISTER_BYTES] __attribute__ ((aligned));
  32
  33 int target_byte_order;          /* used by simulator */
  34
  35 /* We record the result of sim_open so we can pass it
  36    back to the other sim_foo routines.  */
  37 static SIM_DESC gdbsim_desc = 0;
  38
  39 /* This version of "load" should be usable for any simulator that
  40    does not support loading itself.  */
  41
  42 static void
  43 generic_load (loadfile_bfd)
  44      bfd *loadfile_bfd;
  45 {
  46   asection *s;
  47
  48   for (s = loadfile_bfd->sections; s; s = s->next)
  49     {
  50       if (s->flags & SEC_LOAD)
  51         {
  52           bfd_size_type size;
  53
  54           size = bfd_get_section_size_before_reloc (s);
  55           if (size > 0)
  56             {
  57               char *buffer;
  58               bfd_vma lma;      /* use load address, not virtual address */
  59
  60               buffer = xmalloc (size);
  61               lma = s->lma;
  62
  63               /* Is this really necessary?  I guess it gives the user something
  64                  to look at during a long download.  */
  65               printf ("Loading section %s, size 0x%lx lma 0x%lx\n",
  66                       bfd_get_section_name (loadfile_bfd, s),
  67                       (unsigned long) size,
  68                       (unsigned long) lma);     /* chops high 32 bits.  FIXME!! */
  69
  70               bfd_get_section_contents (loadfile_bfd, s, buffer, 0, size);
  71
  72               write_inferior_memory (lma, buffer, size);
  73               free (buffer);
  74             }
  75         }
  76     }
  77
  78   printf ("Start address 0x%lx\n",
  79           (unsigned long) loadfile_bfd->start_address);
  80
  81   /* We were doing this in remote-mips.c, I suspect it is right
  82      for other targets too.  */
  83   /* write_pc (loadfile_bfd->start_address); *//* FIXME!! */
  84 }
  85
  86 int
  87 create_inferior (program, argv)
  88      char *program;
  89      char **argv;
  90 {
  91   bfd *abfd;
  92   int pid = 0;
  93 #ifdef TARGET_BYTE_ORDER_SELECTABLE
  94   char **new_argv;
  95   int nargs;
  96 #endif
  97
  98   abfd = bfd_openr (program, 0);
  99   if (!abfd)
 100     {
 101       fprintf (stderr, "gdbserver: can't open %s: %s\n",
 102                program, bfd_errmsg (bfd_get_error ()));
 103       exit (1);
 104     }
 105
 106   if (!bfd_check_format (abfd, bfd_object))
 107     {
 108       fprintf (stderr, "gdbserver: unknown load format for %s: %s\n",
 109                program, bfd_errmsg (bfd_get_error ()));
 110       exit (1);
 111     }
 112
 113 #ifdef TARGET_BYTE_ORDER_SELECTABLE
 114   /* Add "-E big" or "-E little" to the argument list depending on the
 115      endianness of the program to be loaded.  */
 116   for (nargs = 0; argv[nargs] != NULL; nargs++)         /* count the args */
 117     ;
 118   new_argv = alloca (sizeof (char *) * (nargs + 3));    /* allocate new args */
 119   for (nargs = 0; argv[nargs] != NULL; nargs++)         /* copy old to new */
 120     new_argv[nargs] = argv[nargs];
 121   new_argv[nargs] = "-E";
 122   new_argv[nargs + 1] = bfd_big_endian (abfd) ? "big" : "little";
 123   new_argv[nargs + 2] = NULL;
 124   argv = new_argv;
 125 #endif
 126
 127   /* Create an instance of the simulator.  */
 128   default_callback.init (&default_callback);
 129   gdbsim_desc = sim_open (SIM_OPEN_STANDALONE, &default_callback, abfd, argv);
 130   if (gdbsim_desc == 0)
 131     exit (1);
 132
 133   /* Load the program into the simulator.  */
 134   if (abfd)
 135     if (sim_load (gdbsim_desc, program, NULL, 0) == SIM_RC_FAIL)
 136       generic_load (abfd);
 137
 138   /* Create an inferior process in the simulator.  This initializes SP.  */
 139   sim_create_inferior (gdbsim_desc, abfd, argv, /* env */ NULL);
 140   sim_resume (gdbsim_desc, 1, 0);       /* execute one instr */
 141   return pid;
 142 }
 143
 144 /* Kill the inferior process.  Make us have no inferior.  */
 145
 146 void
 147 kill_inferior ()
 148 {
 149   sim_close (gdbsim_desc, 0);
 150   default_callback.shutdown (&default_callback);
 151 }
 152
 153 /* Fetch one register.  */
 154
 155 static void
 156 fetch_register (regno)
 157      int regno;
 158 {
 159   sim_fetch_register (gdbsim_desc, regno, &registers[REGISTER_BYTE (regno)],
 160                       REGISTER_RAW_SIZE (regno));
 161 }
 162
 163 /* Fetch all registers, or just one, from the child process.  */
 164
 165 void
 166 fetch_inferior_registers (regno)
 167      int regno;
 168 {
 169   if (regno == -1 || regno == 0)
 170     for (regno = 0; regno < NUM_REGS /*-NUM_FREGS*/ ; regno++)
 171       fetch_register (regno);
 172   else
 173     fetch_register (regno);
 174 }
 175
 176 /* Store our register values back into the inferior.
 177    If REGNO is -1, do this for all registers.
 178    Otherwise, REGNO specifies which register (so we can save time).  */
 179
 180 void
 181 store_inferior_registers (regno)
 182      int regno;
 183 {
 184   if (regno == -1)
 185     {
 186       for (regno = 0; regno < NUM_REGS; regno++)
 187         store_inferior_registers (regno);
 188     }
 189   else
 190     sim_store_register (gdbsim_desc, regno, &registers[REGISTER_BYTE (regno)],
 191                         REGISTER_RAW_SIZE (regno));
 192 }
 193
 194 /* Return nonzero if the given thread is still alive.  */
 195 int
 196 mythread_alive (pid)
 197      int pid;
 198 {
 199   return 1;
 200 }
 201
 202 /* Wait for process, returns status */
 203
 204 unsigned char
 205 mywait (status)
 206      char *status;
 207 {
 208   int sigrc;
 209   enum sim_stop reason;
 210
 211   sim_stop_reason (gdbsim_desc, &reason, &sigrc);
 212   switch (reason)
 213     {
 214     case sim_exited:
 215       if (remote_debug)
 216         printf ("\nChild exited with retcode = %x \n", sigrc);
 217       *status = 'W';
 218       return sigrc;
 219
 220 #if 0
 221     case sim_stopped:
 222       if (remote_debug)
 223         printf ("\nChild terminated with signal = %x \n", sigrc);
 224       *status = 'X';
 225       return sigrc;
 226 #endif
 227
 228     default:                    /* should this be sim_signalled or sim_stopped?  FIXME!! */
 229       if (remote_debug)
 230         printf ("\nChild received signal = %x \n", sigrc);
 231       fetch_inferior_registers (0);
 232       *status = 'T';
 233       return (unsigned char) sigrc;
 234     }
 235 }
 236
 237 /* Resume execution of the inferior process.
 238    If STEP is nonzero, single-step it.
 239    If SIGNAL is nonzero, give it that signal.  */
 240
 241 void
 242 myresume (step, signo)
 243      int step;
 244      int signo;
 245 {
 246   /* Should be using target_signal_to_host() or signal numbers in target.h
 247      to convert GDB signal number to target signal number.  */
 248   sim_resume (gdbsim_desc, step, signo);
 249 }
 250
 251 /* Copy LEN bytes from inferior's memory starting at MEMADDR
 252    to debugger memory starting at MYADDR.  */
 253
 254 void
 255 read_inferior_memory (memaddr, myaddr, len)
 256      CORE_ADDR memaddr;
 257      char *myaddr;
 258      int len;
 259 {
 260   sim_read (gdbsim_desc, memaddr, myaddr, len);
 261 }
 262
 263 /* Copy LEN bytes of data from debugger memory at MYADDR
 264    to inferior's memory at MEMADDR.
 265    On failure (cannot write the inferior)
 266    returns the value of errno.  */
 267
 268 int
 269 write_inferior_memory (memaddr, myaddr, len)
 270      CORE_ADDR memaddr;
 271      char *myaddr;
 272      int len;
 273 {
 274   sim_write (gdbsim_desc, memaddr, myaddr, len);        /* should check for error.  FIXME!! */
 275   return 0;
 276 }
 277
 278 #if 0
 279 void
 280 initialize ()
 281 {
 282   inferior_pid = 0;
 283 }
 284
 285 int
 286 have_inferior_p ()
 287 {
 288   return inferior_pid != 0;
 289 }
 290 #endif