* Fixing typo that caused infinite loop upon PKE MPG.

[binutils-gdb.git] / gdb / arm-xdep.c

/* Acorn Risc Machine host machine support.
   Copyright (C) 1988, 1989, 1991 Free Software Foundation, Inc.

This file is part of GDB.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "frame.h"
#include "inferior.h"
#include "arm-opcode.h"

#include <sys/param.h>
#include <sys/dir.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <sys/ptrace.h>
#include <machine/reg.h>

#define N_TXTADDR(hdr) 0x8000
#define N_DATADDR(hdr) (hdr.a_text + 0x8000)

#include "gdbcore.h"

#include <sys/user.h>           /* After a.out.h  */
#include <sys/file.h>
#include "gdb_stat.h"

#include <errno.h>

void
fetch_inferior_registers (regno)
     int regno;         /* Original value discarded */
{
  register unsigned int regaddr;
  char buf[MAX_REGISTER_RAW_SIZE];
  register int i;

  struct user u;
  unsigned int offset = (char *) &u.u_ar0 - (char *) &u;
  offset = ptrace (PT_READ_U, inferior_pid, (PTRACE_ARG3_TYPE) offset, 0)
      - KERNEL_U_ADDR;

  registers_fetched ();
  
  for (regno = 0; regno < 16; regno++)
    {
      regaddr = offset + regno * 4;
      *(int *)&buf[0] = ptrace (PT_READ_U, inferior_pid,
                                (PTRACE_ARG3_TYPE) regaddr, 0);
      if (regno == PC_REGNUM)
          *(int *)&buf[0] = GET_PC_PART(*(int *)&buf[0]);
      supply_register (regno, buf);
    }
  *(int *)&buf[0] = ptrace (PT_READ_U, inferior_pid,
                            (PTRACE_ARG3_TYPE) (offset + PC*4), 0);
  supply_register (PS_REGNUM, buf); /* set virtual register ps same as pc */

  /* read the floating point registers */
  offset = (char *) &u.u_fp_regs - (char *)&u;
  *(int *)buf = ptrace (PT_READ_U, inferior_pid, (PTRACE_ARG3_TYPE) offset, 0);
  supply_register (FPS_REGNUM, buf);
  for (regno = 16; regno < 24; regno++) {
      regaddr = offset + 4 + 12 * (regno - 16);
      for (i = 0; i < 12; i += sizeof(int))
          *(int *) &buf[i] = ptrace (PT_READ_U, inferior_pid,
                                     (PTRACE_ARG3_TYPE) (regaddr + i), 0);
      supply_register (regno, buf);
  }
}

/* Store our register values back into the inferior.
   If REGNO is -1, do this for all registers.
   Otherwise, REGNO specifies which register (so we can save time).  */

void
store_inferior_registers (regno)
     int regno;
{
  register unsigned int regaddr;
  char buf[80];

  struct user u;
  unsigned long value;
  unsigned int offset = (char *) &u.u_ar0 - (char *) &u;
  offset = ptrace (PT_READ_U, inferior_pid, (PTRACE_ARG3_TYPE) offset, 0)
      - KERNEL_U_ADDR;

  if (regno >= 0) {
      if (regno >= 16) return;
      regaddr = offset + 4 * regno;
      errno = 0;
      value = read_register(regno);
      if (regno == PC_REGNUM)
          value = SET_PC_PART(read_register (PS_REGNUM), value);
      ptrace (PT_WRITE_U, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, value);
      if (errno != 0)
        {
          sprintf (buf, "writing register number %d", regno);
          perror_with_name (buf);
        }
    }
  else for (regno = 0; regno < 15; regno++)
    {
      regaddr = offset + regno * 4;
      errno = 0;
      value = read_register(regno);
      if (regno == PC_REGNUM)
          value = SET_PC_PART(read_register (PS_REGNUM), value);
      ptrace (6, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, value);
      if (errno != 0)
        {
          sprintf (buf, "writing all regs, number %d", regno);
          perror_with_name (buf);
        }
    }
}
\f
/* Work with core dump and executable files, for GDB. 
   This code would be in corefile.c if it weren't machine-dependent. */

/* Structure to describe the chain of shared libraries used
   by the execfile.
   e.g. prog shares Xt which shares X11 which shares c. */

struct shared_library {
    struct exec_header header;
    char name[SHLIBLEN];
    CORE_ADDR text_start;       /* CORE_ADDR of 1st byte of text, this file */
    long data_offset;           /* offset of data section in file */
    int chan;                   /* file descriptor for the file */
    struct shared_library *shares; /* library this one shares */
};
static struct shared_library *shlib = 0;

/* Hook for `exec_file_command' command to call.  */

extern void (*exec_file_display_hook) ();
   
static CORE_ADDR unshared_text_start;

/* extended header from exec file (for shared library info) */

static struct exec_header exec_header;
\f
void
core_file_command (filename, from_tty)
     char *filename;
     int from_tty;
{
  int val;
  extern char registers[];

  /* Discard all vestiges of any previous core file
     and mark data and stack spaces as empty.  */

  if (corefile)
    free (corefile);
  corefile = 0;

  if (corechan >= 0)
    close (corechan);
  corechan = -1;

  data_start = 0;
  data_end = 0;
  stack_start = STACK_END_ADDR;
  stack_end = STACK_END_ADDR;

  /* Now, if a new core file was specified, open it and digest it.  */

  if (filename)
    {
      filename = tilde_expand (filename);
      make_cleanup (free, filename);
      
      if (have_inferior_p ())
        error ("To look at a core file, you must kill the program with \"kill\".");
      corechan = open (filename, O_RDONLY, 0);
      if (corechan < 0)
        perror_with_name (filename);
      /* 4.2-style (and perhaps also sysV-style) core dump file.  */
      {
        struct user u;

        unsigned int reg_offset, fp_reg_offset;

        val = myread (corechan, &u, sizeof u);
        if (val < 0)
          perror_with_name ("Not a core file: reading upage");
        if (val != sizeof u)
          error ("Not a core file: could only read %d bytes", val);

        /* We are depending on exec_file_command having been called
           previously to set exec_data_start.  Since the executable
           and the core file share the same text segment, the address
           of the data segment will be the same in both.  */
        data_start = exec_data_start;

        data_end = data_start + NBPG * u.u_dsize;
        stack_start = stack_end - NBPG * u.u_ssize;
        data_offset = NBPG * UPAGES;
        stack_offset = NBPG * (UPAGES + u.u_dsize);

        /* Some machines put an absolute address in here and some put
           the offset in the upage of the regs.  */
        reg_offset = (int) u.u_ar0;
        if (reg_offset > NBPG * UPAGES)
          reg_offset -= KERNEL_U_ADDR;
        fp_reg_offset = (char *) &u.u_fp_regs - (char *)&u;

        /* I don't know where to find this info.
           So, for now, mark it as not available.  */
        N_SET_MAGIC (core_aouthdr, 0);

        /* Read the register values out of the core file and store
           them where `read_register' will find them.  */

        {
          register int regno;

          for (regno = 0; regno < NUM_REGS; regno++)
            {
              char buf[MAX_REGISTER_RAW_SIZE];

              if (regno < 16)
                  val = lseek (corechan, reg_offset + 4 * regno, 0);
              else if (regno < 24)
                  val = lseek (corechan, fp_reg_offset + 4 + 12*(regno - 24), 0);
              else if (regno == 24)
                  val = lseek (corechan, fp_reg_offset, 0);
              else if (regno == 25)
                  val = lseek (corechan, reg_offset + 4 * PC, 0);
              if (val < 0
                  || (val = myread (corechan, buf, sizeof buf)) < 0)
                {
                  char * buffer = (char *) alloca (strlen (reg_names[regno])
                                                   + 30);
                  strcpy (buffer, "Reading register ");
                  strcat (buffer, reg_names[regno]);
                                                   
                  perror_with_name (buffer);
                }

              if (regno == PC_REGNUM)
                  *(int *)buf = GET_PC_PART(*(int *)buf);
              supply_register (regno, buf);
            }
        }
      }
      if (filename[0] == '/')
        corefile = savestring (filename, strlen (filename));
      else
        {
          corefile = concat (current_directory, "/", filename, NULL);
        }

      flush_cached_frames ();
      select_frame (get_current_frame (), 0);
      validate_files ();
    }
  else if (from_tty)
    printf ("No core file now.\n");
}

#if 0
/* Work with core dump and executable files, for GDB. 
   This code would be in corefile.c if it weren't machine-dependent. */

/* Structure to describe the chain of shared libraries used
   by the execfile.
   e.g. prog shares Xt which shares X11 which shares c. */

struct shared_library {
    struct exec_header header;
    char name[SHLIBLEN];
    CORE_ADDR text_start;       /* CORE_ADDR of 1st byte of text, this file */
    long data_offset;           /* offset of data section in file */
    int chan;                   /* file descriptor for the file */
    struct shared_library *shares; /* library this one shares */
};
static struct shared_library *shlib = 0;

/* Hook for `exec_file_command' command to call.  */

extern void (*exec_file_display_hook) ();
   
static CORE_ADDR unshared_text_start;

/* extended header from exec file (for shared library info) */

static struct exec_header exec_header;

void
exec_file_command (filename, from_tty)
     char *filename;
     int from_tty;
{
  int val;

  /* Eliminate all traces of old exec file.
     Mark text segment as empty.  */

  if (execfile)
    free (execfile);
  execfile = 0;
  data_start = 0;
  data_end -= exec_data_start;
  text_start = 0;
  unshared_text_start = 0;
  text_end = 0;
  exec_data_start = 0;
  exec_data_end = 0;
  if (execchan >= 0)
    close (execchan);
  execchan = -1;
  if (shlib) {
      close_shared_library(shlib);
      shlib = 0;
  }

  /* Now open and digest the file the user requested, if any.  */

  if (filename)
    {
      filename = tilde_expand (filename);
      make_cleanup (free, filename);

      execchan = openp (getenv ("PATH"), 1, filename, O_RDONLY, 0,
                        &execfile);
      if (execchan < 0)
        perror_with_name (filename);

      {
        struct stat st_exec;

#ifdef HEADER_SEEK_FD
        HEADER_SEEK_FD (execchan);
#endif
        
        val = myread (execchan, &exec_header, sizeof exec_header);
        exec_aouthdr = exec_header.a_exec;

        if (val < 0)
          perror_with_name (filename);

        text_start = 0x8000;

        /* Look for shared library if needed */
        if (exec_header.a_exec.a_magic & MF_USES_SL)
            shlib = open_shared_library(exec_header.a_shlibname, text_start);

        text_offset = N_TXTOFF (exec_aouthdr);
        exec_data_offset = N_TXTOFF (exec_aouthdr) + exec_aouthdr.a_text;

        if (shlib) {
            unshared_text_start = shared_text_end(shlib) & ~0x7fff;
            stack_start = shlib->header.a_exec.a_sldatabase;
            stack_end = STACK_END_ADDR;
        } else
            unshared_text_start = 0x8000;
        text_end = unshared_text_start + exec_aouthdr.a_text;

        exec_data_start = unshared_text_start + exec_aouthdr.a_text;
        exec_data_end = exec_data_start + exec_aouthdr.a_data;

        data_start = exec_data_start;
        data_end += exec_data_start;

        fstat (execchan, &st_exec);
        exec_mtime = st_exec.st_mtime;
      }

      validate_files ();
    }
  else if (from_tty)
    printf ("No exec file now.\n");

  /* Tell display code (if any) about the changed file name.  */
  if (exec_file_display_hook)
    (*exec_file_display_hook) (filename);
}
#endif

#if 0
/* Read from the program's memory (except for inferior processes).
   This function is misnamed, since it only reads, never writes; and
   since it will use the core file and/or executable file as necessary.

   It should be extended to write as well as read, FIXME, for patching files.

   Return 0 if address could be read, EIO if addresss out of bounds.  */

int
xfer_core_file (memaddr, myaddr, len)
     CORE_ADDR memaddr;
     char *myaddr;
     int len;
{
  register int i;
  register int val;
  int xferchan;
  char **xferfile;
  int fileptr;
  int returnval = 0;

  while (len > 0)
    {
      xferfile = 0;
      xferchan = 0;

      /* Determine which file the next bunch of addresses reside in,
         and where in the file.  Set the file's read/write pointer
         to point at the proper place for the desired address
         and set xferfile and xferchan for the correct file.

         If desired address is nonexistent, leave them zero.

         i is set to the number of bytes that can be handled
         along with the next address.

         We put the most likely tests first for efficiency.  */

      /* Note that if there is no core file
         data_start and data_end are equal.  */
      if (memaddr >= data_start && memaddr < data_end)
        {
          i = min (len, data_end - memaddr);
          fileptr = memaddr - data_start + data_offset;
          xferfile = &corefile;
          xferchan = corechan;
        }
      /* Note that if there is no core file
         stack_start and stack_end define the shared library data.  */
      else if (memaddr >= stack_start && memaddr < stack_end)
        {
            if (corechan < 0) {
                struct shared_library *lib;
                for (lib = shlib; lib; lib = lib->shares)
                    if (memaddr >= lib->header.a_exec.a_sldatabase &&
                        memaddr < lib->header.a_exec.a_sldatabase +
                          lib->header.a_exec.a_data)
                        break;
                if (lib) {
                    i = min (len, lib->header.a_exec.a_sldatabase +
                             lib->header.a_exec.a_data - memaddr);
                    fileptr = lib->data_offset + memaddr -
                        lib->header.a_exec.a_sldatabase;
                    xferfile = execfile;
                    xferchan = lib->chan;
                }
            } else {
                i = min (len, stack_end - memaddr);
                fileptr = memaddr - stack_start + stack_offset;
                xferfile = &corefile;
                xferchan = corechan;
            }
        }
      else if (corechan < 0
               && memaddr >= exec_data_start && memaddr < exec_data_end)
        {
          i = min (len, exec_data_end - memaddr);
          fileptr = memaddr - exec_data_start + exec_data_offset;
          xferfile = &execfile;
          xferchan = execchan;
        }
      else if (memaddr >= text_start && memaddr < text_end)
        {
            struct shared_library *lib;
            for (lib = shlib; lib; lib = lib->shares)
                if (memaddr >= lib->text_start &&
                    memaddr < lib->text_start + lib->header.a_exec.a_text)
                    break;
            if (lib) {
                i = min (len, lib->header.a_exec.a_text +
                         lib->text_start - memaddr);
                fileptr = memaddr - lib->text_start + text_offset;
                xferfile = &execfile;
                xferchan = lib->chan;
            } else {
                i = min (len, text_end - memaddr);
                fileptr = memaddr - unshared_text_start + text_offset;
                xferfile = &execfile;
                xferchan = execchan;
            }
        }
      else if (memaddr < text_start)
        {
          i = min (len, text_start - memaddr);
        }
      else if (memaddr >= text_end
               && memaddr < (corechan >= 0? data_start : exec_data_start))
        {
          i = min (len, data_start - memaddr);
        }
      else if (corechan >= 0
               && memaddr >= data_end && memaddr < stack_start)
        {
          i = min (len, stack_start - memaddr);
        }
      else if (corechan < 0 && memaddr >= exec_data_end)
        {
          i = min (len, - memaddr);
        }
      else if (memaddr >= stack_end && stack_end != 0)
        {
          i = min (len, - memaddr);
        }
      else
        {
          /* Address did not classify into one of the known ranges.
             This shouldn't happen; we catch the endpoints.  */
          fatal ("Internal: Bad case logic in xfer_core_file.");
        }

      /* Now we know which file to use.
         Set up its pointer and transfer the data.  */
      if (xferfile)
        {
          if (*xferfile == 0)
            if (xferfile == &execfile)
              error ("No program file to examine.");
            else
              error ("No core dump file or running program to examine.");
          val = lseek (xferchan, fileptr, 0);
          if (val < 0)
            perror_with_name (*xferfile);
          val = myread (xferchan, myaddr, i);
          if (val < 0)
            perror_with_name (*xferfile);
        }
      /* If this address is for nonexistent memory,
         read zeros if reading, or do nothing if writing.
         Actually, we never right.  */
      else
        {
          memset (myaddr, '\0', i);
          returnval = EIO;
        }

      memaddr += i;
      myaddr += i;
      len -= i;
    }
  return returnval;
}
#endif