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