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 "server.h"
  22 #include "bfd.h"
  23 #include "callback.h"           /* GDB simulator callback interface */
  24 #include "remote-sim.h"         /* GDB simulator interface */
  25
  26 extern int remote_debug;
  27
  28 extern host_callback default_callback;  /* in sim/common/callback.c */
  29
  30 static char my_registers[REGISTER_BYTES] __attribute__ ((aligned));
  31 char * registers = my_registers;
  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 mygeneric_load (bfd *loadfile_bfd)
  44 {
  45   asection *s;
  46
  47   for (s = loadfile_bfd->sections; s; s = s->next)
  48     {
  49       if (s->flags & SEC_LOAD)
  50         {
  51           bfd_size_type size;
  52
  53           size = bfd_get_section_size_before_reloc (s);
  54           if (size > 0)
  55             {
  56               char *buffer;
  57               bfd_vma lma;      /* use load address, not virtual address */
  58
  59               buffer = xmalloc (size);
  60               lma = s->lma;
  61
  62               /* Is this really necessary?  I guess it gives the user something
  63                  to look at during a long download.  */
  64               printf ("Loading section %s, size 0x%lx lma 0x%lx\n",
  65                       bfd_get_section_name (loadfile_bfd, s),
  66                       (unsigned long) size,
  67                       (unsigned long) lma);     /* chops high 32 bits.  FIXME!! */
  68
  69               bfd_get_section_contents (loadfile_bfd, s, buffer, 0, size);
  70
  71               write_inferior_memory (lma, buffer, size);
  72               free (buffer);
  73             }
  74         }
  75     }
  76
  77   printf ("Start address 0x%lx\n",
  78           (unsigned long) loadfile_bfd->start_address);
  79
  80   /* We were doing this in remote-mips.c, I suspect it is right
  81      for other targets too.  */
  82   /* write_pc (loadfile_bfd->start_address); *//* FIXME!! */
  83 }
  84
  85 int
  86 create_inferior (char *program, char **argv)
  87 {
  88   bfd *abfd;
  89   int pid = 0;
  90 #ifdef TARGET_BYTE_ORDER_SELECTABLE
  91   char **new_argv;
  92   int nargs;
  93 #endif
  94
  95   abfd = bfd_openr (program, 0);
  96   if (!abfd)
  97     {
  98       fprintf (stderr, "gdbserver: can't open %s: %s\n",
  99                program, bfd_errmsg (bfd_get_error ()));
 100       exit (1);
 101     }
 102
 103   if (!bfd_check_format (abfd, bfd_object))
 104     {
 105       fprintf (stderr, "gdbserver: unknown load format for %s: %s\n",
 106                program, bfd_errmsg (bfd_get_error ()));
 107       exit (1);
 108     }
 109
 110 #ifdef TARGET_BYTE_ORDER_SELECTABLE
 111   /* Add "-E big" or "-E little" to the argument list depending on the
 112      endianness of the program to be loaded.  */
 113   for (nargs = 0; argv[nargs] != NULL; nargs++)         /* count the args */
 114     ;
 115   new_argv = alloca (sizeof (char *) * (nargs + 3));    /* allocate new args */
 116   for (nargs = 0; argv[nargs] != NULL; nargs++)         /* copy old to new */
 117     new_argv[nargs] = argv[nargs];
 118   new_argv[nargs] = "-E";
 119   new_argv[nargs + 1] = bfd_big_endian (abfd) ? "big" : "little";
 120   new_argv[nargs + 2] = NULL;
 121   argv = new_argv;
 122 #endif
 123
 124   /* Create an instance of the simulator.  */
 125   default_callback.init (&default_callback);
 126   gdbsim_desc = sim_open (SIM_OPEN_STANDALONE, &default_callback, abfd, argv);
 127   if (gdbsim_desc == 0)
 128     exit (1);
 129
 130   /* Load the program into the simulator.  */
 131   if (abfd)
 132     if (sim_load (gdbsim_desc, program, NULL, 0) == SIM_RC_FAIL)
 133       mygeneric_load (abfd);
 134
 135   /* Create an inferior process in the simulator.  This initializes SP.  */
 136   sim_create_inferior (gdbsim_desc, abfd, argv, /* env */ NULL);
 137   sim_resume (gdbsim_desc, 1, 0);       /* execute one instr */
 138   return pid;
 139 }
 140
 141 /* Kill the inferior process.  Make us have no inferior.  */
 142
 143 void
 144 kill_inferior (void)
 145 {
 146   sim_close (gdbsim_desc, 0);
 147   default_callback.shutdown (&default_callback);
 148 }
 149
 150 /* Fetch one register.  */
 151
 152 static void
 153 fetch_register (int regno)
 154 {
 155   sim_fetch_register (gdbsim_desc, regno, &registers[REGISTER_BYTE (regno)],
 156                       REGISTER_RAW_SIZE (regno));
 157 }
 158
 159 /* Fetch all registers, or just one, from the child process.  */
 160
 161 void
 162 fetch_inferior_registers (int regno)
 163 {
 164   if (regno == -1 || regno == 0)
 165     for (regno = 0; regno < NUM_REGS /*-NUM_FREGS*/ ; regno++)
 166       fetch_register (regno);
 167   else
 168     fetch_register (regno);
 169 }
 170
 171 /* Store our register values back into the inferior.
 172    If REGNO is -1, do this for all registers.
 173    Otherwise, REGNO specifies which register (so we can save time).  */
 174
 175 void
 176 store_inferior_registers (int regno)
 177 {
 178   if (regno == -1)
 179     {
 180       for (regno = 0; regno < NUM_REGS; regno++)
 181         store_inferior_registers (regno);
 182     }
 183   else
 184     sim_store_register (gdbsim_desc, regno, &registers[REGISTER_BYTE (regno)],
 185                         REGISTER_RAW_SIZE (regno));
 186 }
 187
 188 /* Return nonzero if the given thread is still alive.  */
 189 int
 190 mythread_alive (int pid)
 191 {
 192   return 1;
 193 }
 194
 195 /* Wait for process, returns status */
 196
 197 unsigned char
 198 mywait (char *status)
 199 {
 200   int sigrc;
 201   enum sim_stop reason;
 202
 203   sim_stop_reason (gdbsim_desc, &reason, &sigrc);
 204   switch (reason)
 205     {
 206     case sim_exited:
 207       if (remote_debug)
 208         printf ("\nChild exited with retcode = %x \n", sigrc);
 209       *status = 'W';
 210       return sigrc;
 211
 212 #if 0
 213     case sim_stopped:
 214       if (remote_debug)
 215         printf ("\nChild terminated with signal = %x \n", sigrc);
 216       *status = 'X';
 217       return sigrc;
 218 #endif
 219
 220     default:                    /* should this be sim_signalled or sim_stopped?  FIXME!! */
 221       if (remote_debug)
 222         printf ("\nChild received signal = %x \n", sigrc);
 223       fetch_inferior_registers (0);
 224       *status = 'T';
 225       return (unsigned char) sigrc;
 226     }
 227 }
 228
 229 /* Resume execution of the inferior process.
 230    If STEP is nonzero, single-step it.
 231    If SIGNAL is nonzero, give it that signal.  */
 232
 233 void
 234 myresume (int step, int signo)
 235 {
 236   /* Should be using target_signal_to_host() or signal numbers in target.h
 237      to convert GDB signal number to target signal number.  */
 238   sim_resume (gdbsim_desc, step, signo);
 239 }
 240
 241 /* Copy LEN bytes from inferior's memory starting at MEMADDR
 242    to debugger memory starting at MYADDR.  */
 243
 244 void
 245 read_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len)
 246 {
 247   sim_read (gdbsim_desc, memaddr, myaddr, len);
 248 }
 249
 250 /* Copy LEN bytes of data from debugger memory at MYADDR
 251    to inferior's memory at MEMADDR.
 252    On failure (cannot write the inferior)
 253    returns the value of errno.  */
 254
 255 int
 256 write_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len)
 257 {
 258   sim_write (gdbsim_desc, memaddr, myaddr, len);        /* should check for error.  FIXME!! */
 259   return 0;
 260 }
 261
 262 void
 263 initialize_low (void)
 264 {
 265 }