Johns release

1 files changed, 366 insertions, 0 deletions

diff --git a/gdb/pyr-xdep.c b/gdb/pyr-xdep.c
new file mode 100644
index 0000000..5ba4a8d
--- /dev/null
+++ b/gdb/pyr-xdep.c
@@ -0,0 +1,366 @@
+/* Low level Pyramid interface to ptrace, for GDB when running under Unix.
+   Copyright (C) 1988, 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 "defs.h"
+#include "param.h"
+#include "frame.h"
+#include "inferior.h"
+
+#include <sys/param.h>
+#include <sys/dir.h>
+#include <signal.h>
+#include <sys/ioctl.h>
+/* #include <fcntl.h>  Can we live without this?  */
+
+#include "gdbcore.h"
+#include <sys/user.h>		/* After a.out.h  */
+#include <sys/file.h>
+#include <sys/stat.h>
+
+void
+fetch_inferior_registers ()
+{
+  register int regno, datum;
+  register unsigned int regaddr;
+  int reg_buf[NUM_REGS+1];
+  struct user u;
+  register int skipped_frames = 0;
+
+  registers_fetched ();
+  
+  for (regno = 0; regno < 64; regno++) {
+    reg_buf[regno] = ptrace (3, inferior_pid, regno, 0);
+    
+#if defined(PYRAMID_CONTROL_FRAME_DEBUGGING)
+    printf ("Fetching %s from inferior, got %0x\n",
+	    reg_names[regno],
+	    reg_buf[regno]);
+#endif /* PYRAMID_CONTROL_FRAME_DEBUGGING */
+    
+    if (reg_buf[regno] == -1 && errno == EIO) {
+      printf("fetch_interior_registers: fetching %s from inferior\n",
+	     reg_names[regno]);
+      errno = 0;
+    }
+    supply_register (regno, reg_buf+regno);
+  }
+  /* that leaves regs 64, 65, and 66 */
+  datum = ptrace (3, inferior_pid,
+		  ((char *)&u.u_pcb.pcb_csp) -
+		  ((char *)&u), 0);
+  
+  
+  
+  /* FIXME: Find the Current Frame Pointer (CFP). CFP is a global
+     register (ie, NOT windowed), that gets saved in a frame iff
+     the code for that frame has a prologue (ie, "adsf N").  If
+     there is a prologue, the adsf insn saves the old cfp in
+     pr13, cfp is set to sp, and N bytes of locals are allocated
+     (sp is decremented by n).
+     This makes finding CFP hard. I guess the right way to do it
+     is: 
+     - If this is the innermost frame, believe ptrace() or
+     the core area.
+     - Otherwise:
+     Find the first insn of the current frame.
+     - find the saved pc;
+     - find the call insn that saved it;
+     - figure out where the call is to;
+     - if the first insn is an adsf, we got a frame
+     pointer. */
+  
+  
+  /* Normal processors have separate stack pointers for user and
+     kernel mode. Getting the last user mode frame on such
+     machines is easy: the kernel context of the ptrace()'d
+     process is on the kernel stack, and the USP points to what
+     we want. But Pyramids only have a single cfp for both user and
+     kernel mode.  And processes being ptrace()'d have some
+     kernel-context control frames on their stack.
+     To avoid tracing back into the kernel context of an inferior,
+     we skip 0 or more contiguous control frames where the pc is
+     in the kernel. */ 
+  
+  while (1) {
+    register int inferior_saved_pc;
+    inferior_saved_pc = ptrace (1, inferior_pid, datum+((32+15)*4), 0);
+    if (inferior_saved_pc > 0) break;
+#if defined(PYRAMID_CONTROL_FRAME_DEBUGGING)
+    printf("skipping kernel frame %08x, pc=%08x\n", datum,
+	   inferior_saved_pc);
+#endif /* PYRAMID_CONTROL_FRAME_DEBUGGING */
+    skipped_frames++;
+    datum -= CONTROL_STACK_FRAME_SIZE;
+  }
+  
+  reg_buf[CSP_REGNUM] = datum;
+  supply_register(CSP_REGNUM, reg_buf+CSP_REGNUM);
+#ifdef  PYRAMID_CONTROL_FRAME_DEBUGGING
+  if (skipped_frames) {
+    fprintf (stderr,
+	     "skipped %d frames from %x to %x; cfp was %x, now %x\n",
+	     skipped_frames, reg_buf[CSP_REGNUM]);
+  }
+#endif /* PYRAMID_CONTROL_FRAME_DEBUGGING */
+}
+
+/* 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).  */
+
+store_inferior_registers (regno)
+     int regno;
+{
+  register unsigned int regaddr;
+  char buf[80];
+
+  if (regno >= 0)
+    {
+      if ((0 <= regno) && (regno < 64)) {
+	/*regaddr = register_addr (regno, offset);*/
+	regaddr = regno;
+	errno = 0;
+	ptrace (6, inferior_pid, regaddr, read_register (regno));
+	if (errno != 0)
+	  {
+	    sprintf (buf, "writing register number %d", regno);
+	    perror_with_name (buf);
+	  }
+      }
+    }
+  else
+    {
+      for (regno = 0; regno < NUM_REGS; regno++)
+	{
+	  /*regaddr = register_addr (regno, offset);*/
+	  regaddr = regno;
+	  errno = 0;
+	  ptrace (6, inferior_pid, regaddr, read_register (regno));
+	  if (errno != 0)
+	    {
+	      sprintf (buf, "writing all regs, number %d", regno);
+	      perror_with_name (buf);
+	    }
+	}
+}
+
+/*** Extensions to  core and dump files, for GDB. */
+
+extern unsigned int last_frame_offset;
+
+#ifdef PYRAMID_CORE
+
+/* Can't make definitions here static, since core.c needs them
+   to do bounds checking on the core-file areas. O well. */
+
+/* have two stacks: one for data, one for register windows. */
+extern CORE_ADDR reg_stack_start;
+extern CORE_ADDR reg_stack_end;
+
+/* need this so we can find the global registers: they never get saved. */
+CORE_ADDR global_reg_offset;
+static CORE_ADDR last_frame_address;
+CORE_ADDR last_frame_offset;
+
+
+/* Address in core file of start of register window stack area.
+   Don't know if is this any of meaningful, useful or necessary.   */
+extern int reg_stack_offset;
+
+#endif /* PYRAMID_CORE */  
+
+
+/* Work with core dump and executable files, for GDB. 
+   This code would be in core.c if it weren't machine-dependent. */
+
+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;
+
+#ifdef PYRAMID_CORE
+  reg_stack_start = CONTROL_STACK_ADDR;
+  reg_stack_end = CONTROL_STACK_ADDR;	/* this isn't strictly true...*/
+#endif /* PYRAMID_CORE */
+
+  /* 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 inferior 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;
+
+	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);
+	data_start = exec_data_start;
+
+	data_end = data_start + NBPG * u.u_dsize;
+	data_offset = NBPG * UPAGES;
+	stack_offset = NBPG * (UPAGES + u.u_dsize);
+
+	/* find registers in core file */
+#ifdef PYRAMID_PTRACE
+	stack_start = stack_end - NBPG * u.u_ussize;
+	reg_stack_offset = stack_offset + (NBPG *u.u_ussize);
+	reg_stack_end = reg_stack_start + NBPG * u.u_cssize;
+
+	last_frame_address = ((int) u.u_pcb.pcb_csp);
+	last_frame_offset = reg_stack_offset + last_frame_address
+		- CONTROL_STACK_ADDR ;
+	global_reg_offset = (char *)&u - (char *)&u.u_pcb.pcb_gr0 ;
+
+	/* skip any control-stack frames that were executed in the
+	   kernel. */
+
+	while (1) {
+	    char buf[4];
+	    val = lseek (corechan, last_frame_offset+(47*4), 0);
+	    if (val < 0)
+		    perror_with_name (filename);
+	    val = myread (corechan, buf, sizeof buf);
+	    if (val < 0)
+		    perror_with_name (filename);
+
+	    if (*(int *)buf >= 0)
+		    break;
+	    printf ("skipping frame %0x\n", last_frame_address);
+	    last_frame_offset -= CONTROL_STACK_FRAME_SIZE;
+	    last_frame_address -= CONTROL_STACK_FRAME_SIZE;
+	}
+	reg_offset = last_frame_offset;
+
+#if 1 || defined(PYRAMID_CONTROL_FRAME_DEBUGGING)
+	printf ("Control stack pointer = 0x%08x\n",
+		u.u_pcb.pcb_csp);
+	printf ("offset to control stack %d outermost frame %d (%0x)\n",
+	      reg_stack_offset, reg_offset, last_frame_address);
+#endif /* PYRAMID_CONTROL_FRAME_DEBUGGING */
+
+#else /* not PYRAMID_CORE */
+	stack_start = stack_end - NBPG * u.u_ssize;
+        reg_offset = (int) u.u_ar0 - KERNEL_U_ADDR;
+#endif /* not PYRAMID_CORE */
+
+#ifdef __not_on_pyr_yet
+	/* 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;
+#endif
+
+	/* 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 < 64; regno++)
+	    {
+	      char buf[MAX_REGISTER_RAW_SIZE];
+
+	      val = lseek (corechan, register_addr (regno, reg_offset), 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 (val < 0)
+		perror_with_name (filename);
+#ifdef PYRAMID_CONTROL_FRAME_DEBUGGING
+      printf ("[reg %s(%d), offset in file %s=0x%0x, addr =0x%0x, =%0x]\n",
+	      reg_names[regno], regno, filename,
+	      register_addr(regno, reg_offset),
+	      regno * 4 + last_frame_address,
+	      *((int *)buf));
+#endif /* PYRAMID_CONTROL_FRAME_DEBUGGING */
+	      supply_register (regno, buf);
+	    }
+	}
+      }
+      if (filename[0] == '/')
+	corefile = savestring (filename, strlen (filename));
+      else
+	{
+	  corefile = concat (current_directory, "/", filename);
+	}
+
+#if 1 || defined(PYRAMID_CONTROL_FRAME_DEBUGGING)
+      printf ("Providing CSP (%0x) as nominal address of current frame.\n",
+	      last_frame_address);
+#endif PYRAMID_CONTROL_FRAME_DEBUGGING
+      /* FIXME: Which of the following is correct? */
+#if 0
+      set_current_frame ( create_new_frame (read_register (FP_REGNUM),
+					    read_pc ()));
+#else
+      set_current_frame ( create_new_frame (last_frame_address,
+					    read_pc ()));
+#endif
+
+      select_frame (get_current_frame (), 0);
+      validate_files ();
+    }
+  else if (from_tty)
+    printf ("No core file now.\n");
+}