Johns release

gdb/standalone.c

@@ -0,0 +1,594 @@
+/* Interface to bare machine for GDB running as kernel debugger.
+   Copyright (C) 1986, 1989, 1991 Free Software Foundation, Inc.
+
+This file is part of GDB.
+
+GDB 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 1, or (at your option)
+any later version.
+
+GDB 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 GDB; see the file COPYING.  If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#if defined (SIGTSTP) && defined (SIGIO)
+#include <sys/time.h>
+#include <sys/resource.h>
+#endif /* SIGTSTP and SIGIO defined (must be 4.2) */
+
+#include "defs.h"
+#include "param.h"
+#include "signals.h"
+#include "symtab.h"
+#include "frame.h"
+#include "inferior.h"
+#include "wait.h"
+
+
+/* Random system calls, mostly no-ops to prevent link problems  */
+
+ioctl (desc, code, arg)
+{}
+
+int (* signal ()) ()
+{}
+
+kill ()
+{}
+
+getpid ()
+{
+  return 0;
+}
+
+sigsetmask ()
+{}
+
+chdir ()
+{}
+
+char *
+getwd (buf)
+     char *buf;
+{
+  buf[0] = '/';
+  buf[1] = 0;
+  return buf;
+}
+
+/* Used to check for existence of .gdbinit.  Say no.  */
+
+access ()
+{
+  return -1;
+}
+
+exit ()
+{
+  error ("Fatal error; restarting.");
+}
+
+/* Reading "files".  The contents of some files are written into kdb's
+   data area before it is run.  These files are used to contain the
+   symbol table for kdb to load, and the source files (in case the
+   kdb user wants to print them).  The symbols are stored in a file
+   named "kdb-symbols" in a.out format (except that all the text and
+   data have been stripped to save room).
+
+   The files are stored in the following format:
+   int     number of bytes of data for this file, including these four.
+   char[]  name of the file, ending with a null.
+   padding to multiple of 4 boundary.
+   char[]  file contents.  The length can be deduced from what was
+           specified before.  There is no terminating null here.
+
+   If the int at the front is zero, it means there are no more files.
+
+   Opening a file in kdb returns a nonzero value to indicate success,
+   but the value does not matter.  Only one file can be open, and only
+   for reading.  All the primitives for input from the file know
+   which file is open and ignore what is specified for the descriptor
+   or for the stdio stream.
+
+   Input with fgetc can be done either on the file that is open
+   or on stdin (which reads from the terminal through tty_input ()  */
+
+/* Address of data for the files stored in format described above.  */
+char *files_start;
+
+/* The file stream currently open:  */
+
+char *sourcebeg;		/* beginning of contents */
+int sourcesize;			/* size of contents */
+char *sourceptr;		/* current read pointer */
+int sourceleft;			/* number of bytes to eof */
+
+/* "descriptor" for the file now open.
+   Incremented at each close.
+   If specified descriptor does not match this,
+   it means the program is trying to use a closed descriptor.
+   We report an error for that.  */
+
+int sourcedesc;
+
+open (filename, modes)
+     char *filename;
+     int modes;
+{
+  register char *next;
+
+  if (modes)
+    {
+      errno = EROFS;
+      return -1;
+    }
+
+  if (sourceptr)
+    {
+      errno = EMFILE;
+      return -1;
+    }
+
+  for (next - files_start; * (int *) next;
+       next += * (int *) next)
+    {
+      if (!strcmp (next + 4, filename))
+	{
+	  sourcebeg = next + 4 + strlen (next + 4) + 1;
+	  sourcebeg = (char *) (((int) sourcebeg + 3) & (-4));
+	  sourceptr = sourcebeg;
+	  sourcesize = next + * (int *) next - sourceptr;
+	  sourceleft = sourcesize;
+	  return sourcedesc;
+	}
+    }
+  return 0;
+}
+
+close (desc)
+     int desc;
+{
+  sourceptr = 0;
+  sourcedesc++;
+  /* Don't let sourcedesc get big enough to be confused with stdin.  */
+  if (sourcedesc == 100)
+    sourcedesc = 5;
+}
+
+FILE *
+fopen (filename, modes)
+     char *filename;
+     char *modes;
+{
+  return (FILE *) open (filename, *modes == 'w');
+}
+
+FILE *
+fdopen (desc)
+     int desc;
+{
+  return (FILE *) desc;
+}
+
+fclose (desc)
+     int desc;
+{
+  close (desc);
+}
+
+fstat (desc, statbuf)
+     struct stat *statbuf;
+{
+  if (desc != sourcedesc)
+    {
+      errno = EBADF;
+      return -1;
+    }
+  statbuf->st_size = sourcesize;
+}
+
+myread (desc, destptr, size, filename)
+     int desc;
+     char *destptr;
+     int size;
+     char *filename;
+{
+  int len = min (sourceleft, size);
+
+  if (desc != sourcedesc)
+    {
+      errno = EBADF;
+      return -1;
+    }
+
+  bcopy (sourceptr, destptr, len);
+  sourceleft -= len;
+  return len;
+}
+
+int
+fread (bufp, numelts, eltsize, stream)
+{
+  register int elts = min (numelts, sourceleft / eltsize);
+  register int len = elts * eltsize;
+
+  if (stream != sourcedesc)
+    {
+      errno = EBADF;
+      return -1;
+    }
+
+  bcopy (sourceptr, bufp, len);
+  sourceleft -= len;
+  return elts;
+}
+
+int
+fgetc (desc)
+     int desc;
+{
+
+  if (desc == (int) stdin)
+    return tty_input ();
+
+  if (desc != sourcedesc)
+    {
+      errno = EBADF;
+      return -1;
+    }
+
+  if (sourceleft-- <= 0)
+    return EOF;
+  return *sourceptr++;
+}
+
+lseek (desc, pos)
+     int desc;
+     int pos;
+{
+
+  if (desc != sourcedesc)
+    {
+      errno = EBADF;
+      return -1;
+    }
+
+  if (pos < 0 || pos > sourcesize)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
+  sourceptr = sourcebeg + pos;
+  sourceleft = sourcesize - pos;
+}
+
+/* Output in kdb can go only to the terminal, so the stream
+   specified may be ignored.  */
+
+printf (a1, a2, a3, a4, a5, a6, a7, a8, a9)
+{
+  char buffer[1024];
+  sprintf (buffer, a1, a2, a3, a4, a5, a6, a7, a8, a9);
+  display_string (buffer);
+}
+
+fprintf (ign, a1, a2, a3, a4, a5, a6, a7, a8, a9)
+{
+  char buffer[1024];
+  sprintf (buffer, a1, a2, a3, a4, a5, a6, a7, a8, a9);
+  display_string (buffer);
+}
+
+fwrite (buf, numelts, size, stream)
+     register char *buf;
+     int numelts, size;
+{
+  register int i = numelts * size;
+  while (i-- > 0)
+    fputc (*buf++, stream);
+}
+
+fputc (c, ign)
+{
+  char buf[2];
+  buf[0] = c;
+  buf[1] = 0;
+  display_string (buf);
+}
+
+/* sprintf refers to this, but loading this from the
+   library would cause fflush to be loaded from it too.
+   In fact there should be no need to call this (I hope).  */
+
+_flsbuf ()
+{
+  error ("_flsbuf was actually called.");
+}
+
+fflush (ign)
+{
+}
+
+/* Entries into core and inflow, needed only to make things link ok.  */
+
+exec_file_command ()
+{}
+
+core_file_command ()
+{}
+
+char *
+get_exec_file (err)
+     int err;
+{
+  /* Makes one printout look reasonable; value does not matter otherwise.  */
+  return "run";
+}
+
+have_core_file_p ()
+{
+  return 0;
+}
+
+kill_command ()
+{
+  inferior_pid = 0;
+}
+
+terminal_inferior ()
+{}
+
+terminal_ours ()
+{}
+
+terminal_init_inferior ()
+{}
+
+write_inferior_register ()
+{}
+
+read_inferior_register ()
+{}
+
+read_memory (memaddr, myaddr, len)
+     CORE_ADDR memaddr;
+     char *myaddr;
+     int len;
+{
+  bcopy (memaddr, myaddr, len);
+}
+
+/* Always return 0 indicating success.  */
+
+write_memory (memaddr, myaddr, len)
+     CORE_ADDR memaddr;
+     char *myaddr;
+     int len;
+{
+  bcopy (myaddr, memaddr, len);
+  return 0;
+}
+
+static REGISTER_TYPE saved_regs[NUM_REGS];
+
+REGISTER_TYPE
+read_register (regno)
+     int regno;
+{
+  if (regno < 0 || regno >= NUM_REGS)
+    error ("Register number %d out of range.", regno);
+  return saved_regs[regno];
+}
+
+void
+write_register (regno, value)
+     int regno;
+     REGISTER_TYPE value;
+{
+  if (regno < 0 || regno >= NUM_REGS)
+    error ("Register number %d out of range.", regno);
+  saved_regs[regno] = value;
+}
+
+/* System calls needed in relation to running the "inferior".  */
+
+vfork ()
+{
+  /* Just appear to "succeed".  Say the inferior's pid is 1.  */
+  return 1;
+}
+
+/* These are called by code that normally runs in the inferior
+   that has just been forked.  That code never runs, when standalone,
+   and these definitions are so it will link without errors.  */
+
+ptrace ()
+{}
+
+setpgrp ()
+{}
+
+execle ()
+{}
+
+_exit ()
+{}
+
+/* Malloc calls these.  */
+
+malloc_warning (str)
+     char *str;
+{
+  printf ("\n%s.\n\n", str);
+}
+
+char *next_free;
+char *memory_limit;
+
+char *
+sbrk (amount)
+     int amount;
+{
+  if (next_free + amount > memory_limit)
+    return (char *) -1;
+  next_free += amount;
+  return next_free - amount;
+}
+
+/* Various ways malloc might ask where end of memory is.  */
+
+char *
+ulimit ()
+{
+  return memory_limit;
+}
+
+int
+vlimit ()
+{
+  return memory_limit - next_free;
+}
+
+getrlimit (addr)
+     struct rlimit *addr;
+{
+  addr->rlim_cur = memory_limit - next_free;
+}
+
+/* Context switching to and from program being debugged.  */
+
+/* GDB calls here to run the user program.
+   The frame pointer for this function is saved in
+   gdb_stack by save_frame_pointer; then we restore
+   all of the user program's registers, including PC and PS.  */
+
+static int fault_code;
+static REGISTER_TYPE gdb_stack;
+
+resume ()
+{
+  REGISTER_TYPE restore[NUM_REGS];
+
+  PUSH_FRAME_PTR;
+  save_frame_pointer ();
+
+  bcopy (saved_regs, restore, sizeof restore);
+  POP_REGISTERS;
+  /* Control does not drop through here!  */
+}
+
+save_frame_pointer (val)
+     CORE_ADDR val;
+{
+  gdb_stack = val;
+}
+
+/* Fault handlers call here, running in the user program stack.
+   They must first push a fault code,
+   old PC, old PS, and any other info about the fault.
+   The exact format is machine-dependent and is known only
+   in the definition of PUSH_REGISTERS.  */
+
+fault ()
+{
+  /* Transfer all registers and fault code to the stack
+     in canonical order: registers in order of GDB register number,
+     followed by fault code.  */
+  PUSH_REGISTERS;
+
+  /* Transfer them to saved_regs and fault_code.  */
+  save_registers ();
+
+  restore_gdb ();
+  /* Control does not reach here */
+}
+
+restore_gdb ()
+{
+  CORE_ADDR new_fp = gdb_stack;
+  /* Switch to GDB's stack  */
+  POP_FRAME_PTR;
+  /* Return from the function `resume'.  */
+}
+
+/* Assuming register contents and fault code have been pushed on the stack as
+   arguments to this function, copy them into the standard place
+   for the program's registers while GDB is running.  */
+
+save_registers (firstreg)
+     int firstreg;
+{
+  bcopy (&firstreg, saved_regs, sizeof saved_regs);
+  fault_code = (&firstreg)[NUM_REGS];
+}
+
+/* Store into the structure such as `wait' would return
+   the information on why the program faulted,
+   converted into a machine-independent signal number.  */
+
+static int fault_table[] = FAULT_TABLE;
+
+int
+wait (w)
+     WAITTYPE *w;
+{
+  WSETSTOP (*w, fault_table[fault_code / FAULT_CODE_UNITS]);
+  return inferior_pid;
+}
+
+/* Allocate a big space in which files for kdb to read will be stored.
+   Whatever is left is where malloc can allocate storage.
+
+   Initialize it, so that there will be space in the executable file
+   for it.  Then the files can be put into kdb by writing them into
+   kdb's executable file.  */
+
+/* The default size is as much space as we expect to be available
+   for kdb to use!  */
+
+#ifndef HEAP_SIZE
+#define HEAP_SIZE 400000
+#endif
+
+char heap[HEAP_SIZE] = {0};
+
+#ifndef STACK_SIZE
+#define STACK_SIZE 100000
+#endif
+
+int kdb_stack_beg[STACK_SIZE / sizeof (int)];
+int kdb_stack_end;
+
+_initialize_standalone ()
+{
+  register char *next;
+
+  /* Find start of data on files.  */
+
+  files_start = heap;
+
+  /* Find the end of the data on files.  */
+
+  for (next - files_start; * (int *) next;
+       next += * (int *) next)
+    {}
+
+  /* That is where free storage starts for sbrk to give out.  */
+  next_free = next;
+
+  memory_limit = heap + sizeof heap;
+}
+