gdb/arm-xdep.c

   1 /* Acorn Risc Machine host machine support.
   2    Copyright (C) 1988, 1989, 1991 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #include "defs.h"
  21 #include "frame.h"
  22 #include "inferior.h"
  23 #include "arm-opcode.h"
  24
  25 #include <sys/param.h>
  26 #include <sys/dir.h>
  27 #include <signal.h>
  28 #include <sys/ioctl.h>
  29 #include <sys/ptrace.h>
  30 #include <machine/reg.h>
  31
  32 #define N_TXTADDR(hdr) 0x8000
  33 #define N_DATADDR(hdr) (hdr.a_text + 0x8000)
  34
  35 #include "gdbcore.h"
  36
  37 #include <sys/user.h>           /* After a.out.h  */
  38 #include <sys/file.h>
  39 #include <sys/stat.h>
  40
  41 #include <errno.h>
  42
  43 void
  44 fetch_inferior_registers (regno)
  45      int regno;         /* Original value discarded */
  46 {
  47   register unsigned int regaddr;
  48   char buf[MAX_REGISTER_RAW_SIZE];
  49   register int i;
  50
  51   struct user u;
  52   unsigned int offset = (char *) &u.u_ar0 - (char *) &u;
  53   offset = ptrace (PT_READ_U, inferior_pid, (PTRACE_ARG3_TYPE) offset, 0)
  54       - KERNEL_U_ADDR;
  55
  56   registers_fetched ();
  57
  58   for (regno = 0; regno < 16; regno++)
  59     {
  60       regaddr = offset + regno * 4;
  61       *(int *)&buf[0] = ptrace (PT_READ_U, inferior_pid,
  62                                 (PTRACE_ARG3_TYPE) regaddr, 0);
  63       if (regno == PC_REGNUM)
  64           *(int *)&buf[0] = GET_PC_PART(*(int *)&buf[0]);
  65       supply_register (regno, buf);
  66     }
  67   *(int *)&buf[0] = ptrace (PT_READ_U, inferior_pid,
  68                             (PTRACE_ARG3_TYPE) (offset + PC*4), 0);
  69   supply_register (PS_REGNUM, buf); /* set virtual register ps same as pc */
  70
  71   /* read the floating point registers */
  72   offset = (char *) &u.u_fp_regs - (char *)&u;
  73   *(int *)buf = ptrace (PT_READ_U, inferior_pid, (PTRACE_ARG3_TYPE) offset, 0);
  74   supply_register (FPS_REGNUM, buf);
  75   for (regno = 16; regno < 24; regno++) {
  76       regaddr = offset + 4 + 12 * (regno - 16);
  77       for (i = 0; i < 12; i += sizeof(int))
  78           *(int *) &buf[i] = ptrace (PT_READ_U, inferior_pid,
  79                                      (PTRACE_ARG3_TYPE) (regaddr + i), 0);
  80       supply_register (regno, buf);
  81   }
  82 }
  83
  84 /* Store our register values back into the inferior.
  85    If REGNO is -1, do this for all registers.
  86    Otherwise, REGNO specifies which register (so we can save time).  */
  87
  88 void
  89 store_inferior_registers (regno)
  90      int regno;
  91 {
  92   register unsigned int regaddr;
  93   char buf[80];
  94
  95   struct user u;
  96   unsigned long value;
  97   unsigned int offset = (char *) &u.u_ar0 - (char *) &u;
  98   offset = ptrace (PT_READ_U, inferior_pid, (PTRACE_ARG3_TYPE) offset, 0)
  99       - KERNEL_U_ADDR;
 100
 101   if (regno >= 0) {
 102       if (regno >= 16) return;
 103       regaddr = offset + 4 * regno;
 104       errno = 0;
 105       value = read_register(regno);
 106       if (regno == PC_REGNUM)
 107           value = SET_PC_PART(read_register (PS_REGNUM), value);
 108       ptrace (PT_WRITE_U, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, value);
 109       if (errno != 0)
 110         {
 111           sprintf (buf, "writing register number %d", regno);
 112           perror_with_name (buf);
 113         }
 114     }
 115   else for (regno = 0; regno < 15; regno++)
 116     {
 117       regaddr = offset + regno * 4;
 118       errno = 0;
 119       value = read_register(regno);
 120       if (regno == PC_REGNUM)
 121           value = SET_PC_PART(read_register (PS_REGNUM), value);
 122       ptrace (6, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, value);
 123       if (errno != 0)
 124         {
 125           sprintf (buf, "writing all regs, number %d", regno);
 126           perror_with_name (buf);
 127         }
 128     }
 129 }
 130 \f
 131 /* Work with core dump and executable files, for GDB.
 132    This code would be in core.c if it weren't machine-dependent. */
 133
 134 /* Structure to describe the chain of shared libraries used
 135    by the execfile.
 136    e.g. prog shares Xt which shares X11 which shares c. */
 137
 138 struct shared_library {
 139     struct exec_header header;
 140     char name[SHLIBLEN];
 141     CORE_ADDR text_start;       /* CORE_ADDR of 1st byte of text, this file */
 142     long data_offset;           /* offset of data section in file */
 143     int chan;                   /* file descriptor for the file */
 144     struct shared_library *shares; /* library this one shares */
 145 };
 146 static struct shared_library *shlib = 0;
 147
 148 /* Hook for `exec_file_command' command to call.  */
 149
 150 extern void (*exec_file_display_hook) ();
 151
 152 static CORE_ADDR unshared_text_start;
 153
 154 /* extended header from exec file (for shared library info) */
 155
 156 static struct exec_header exec_header;
 157 \f
 158 void
 159 core_file_command (filename, from_tty)
 160      char *filename;
 161      int from_tty;
 162 {
 163   int val;
 164   extern char registers[];
 165
 166   /* Discard all vestiges of any previous core file
 167      and mark data and stack spaces as empty.  */
 168
 169   if (corefile)
 170     free (corefile);
 171   corefile = 0;
 172
 173   if (corechan >= 0)
 174     close (corechan);
 175   corechan = -1;
 176
 177   data_start = 0;
 178   data_end = 0;
 179   stack_start = STACK_END_ADDR;
 180   stack_end = STACK_END_ADDR;
 181
 182   /* Now, if a new core file was specified, open it and digest it.  */
 183
 184   if (filename)
 185     {
 186       filename = tilde_expand (filename);
 187       make_cleanup (free, filename);
 188
 189       if (have_inferior_p ())
 190         error ("To look at a core file, you must kill the inferior with \"kill\".");
 191       corechan = open (filename, O_RDONLY, 0);
 192       if (corechan < 0)
 193         perror_with_name (filename);
 194       /* 4.2-style (and perhaps also sysV-style) core dump file.  */
 195       {
 196         struct user u;
 197
 198         unsigned int reg_offset, fp_reg_offset;
 199
 200         val = myread (corechan, &u, sizeof u);
 201         if (val < 0)
 202           perror_with_name ("Not a core file: reading upage");
 203         if (val != sizeof u)
 204           error ("Not a core file: could only read %d bytes", val);
 205
 206         /* We are depending on exec_file_command having been called
 207            previously to set exec_data_start.  Since the executable
 208            and the core file share the same text segment, the address
 209            of the data segment will be the same in both.  */
 210         data_start = exec_data_start;
 211
 212         data_end = data_start + NBPG * u.u_dsize;
 213         stack_start = stack_end - NBPG * u.u_ssize;
 214         data_offset = NBPG * UPAGES;
 215         stack_offset = NBPG * (UPAGES + u.u_dsize);
 216
 217         /* Some machines put an absolute address in here and some put
 218            the offset in the upage of the regs.  */
 219         reg_offset = (int) u.u_ar0;
 220         if (reg_offset > NBPG * UPAGES)
 221           reg_offset -= KERNEL_U_ADDR;
 222         fp_reg_offset = (char *) &u.u_fp_regs - (char *)&u;
 223
 224         /* I don't know where to find this info.
 225            So, for now, mark it as not available.  */
 226         N_SET_MAGIC (core_aouthdr, 0);
 227
 228         /* Read the register values out of the core file and store
 229            them where `read_register' will find them.  */
 230
 231         {
 232           register int regno;
 233
 234           for (regno = 0; regno < NUM_REGS; regno++)
 235             {
 236               char buf[MAX_REGISTER_RAW_SIZE];
 237
 238               if (regno < 16)
 239                   val = lseek (corechan, reg_offset + 4 * regno, 0);
 240               else if (regno < 24)
 241                   val = lseek (corechan, fp_reg_offset + 4 + 12*(regno - 24), 0);
 242               else if (regno == 24)
 243                   val = lseek (corechan, fp_reg_offset, 0);
 244               else if (regno == 25)
 245                   val = lseek (corechan, reg_offset + 4 * PC, 0);
 246               if (val < 0
 247                   || (val = myread (corechan, buf, sizeof buf)) < 0)
 248                 {
 249                   char * buffer = (char *) alloca (strlen (reg_names[regno])
 250                                                    + 30);
 251                   strcpy (buffer, "Reading register ");
 252                   strcat (buffer, reg_names[regno]);
 253
 254                   perror_with_name (buffer);
 255                 }
 256
 257               if (regno == PC_REGNUM)
 258                   *(int *)buf = GET_PC_PART(*(int *)buf);
 259               supply_register (regno, buf);
 260             }
 261         }
 262       }
 263       if (filename[0] == '/')
 264         corefile = savestring (filename, strlen (filename));
 265       else
 266         {
 267           corefile = concat (current_directory, "/", filename, NULL);
 268         }
 269
 270       set_current_frame ( create_new_frame (read_register (FP_REGNUM),
 271                                             read_pc ()));
 272       select_frame (get_current_frame (), 0);
 273       validate_files ();
 274     }
 275   else if (from_tty)
 276     printf ("No core file now.\n");
 277 }