Johns release

1 files changed, 357 insertions, 0 deletions

diff --git a/gdb/i386-xdep.c b/gdb/i386-xdep.c
new file mode 100644
index 0000000..dddf22d
--- /dev/null
+++ b/gdb/i386-xdep.c
@@ -0,0 +1,357 @@
+/* Intel 386 stuff.
+   Copyright (C) 1988, 1989 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 "gdbcore.h"
+
+#ifdef USG
+#include <sys/types.h>
+#endif
+
+#include <sys/param.h>
+#include <sys/dir.h>
+#include <signal.h>
+#include <sys/user.h>
+#include <sys/ioctl.h>
+#include <fcntl.h>
+
+#include <sys/file.h>
+#include <sys/stat.h>
+
+#include <sys/reg.h>
+
+/* this table must line up with REGISTER_NAMES in m-i386.h */
+/* symbols like 'EAX' come from <sys/reg.h> */
+static int regmap[] = 
+{
+  EAX, ECX, EDX, EBX,
+  UESP, EBP, ESI, EDI,
+  EIP, EFL, CS, SS,
+  DS, ES, FS, GS,
+};
+
+/* blockend is the value of u.u_ar0, and points to the
+ * place where GS is stored
+ */
+i386_register_u_addr (blockend, regnum)
+{
+#if 0
+  /* this will be needed if fp registers are reinstated */
+  /* for now, you can look at them with 'info float'
+   * sys5 wont let you change them with ptrace anyway
+   */
+  if (regnum >= FP0_REGNUM && regnum <= FP7_REGNUM) 
+    {
+      int ubase, fpstate;
+      struct user u;
+      ubase = blockend + 4 * (SS + 1) - KSTKSZ;
+      fpstate = ubase + ((char *)&u.u_fpstate - (char *)&u);
+      return (fpstate + 0x1c + 10 * (regnum - FP0_REGNUM));
+    } 
+  else
+#endif
+    return (blockend + 4 * regmap[regnum]);
+  
+}
+
+/* This is broken for cross debugging.  Possible solutions are:
+
+1.  Don't worry about whether the thing compiles for cross-debugging.
+Go ahead and call them from i386-tdep.c.
+1a.  Same thing but use some macros in xm-i386.h so that gdb will
+compile for cross-debugging but just give an error (or some such behavior)
+when you attempt to convert floats.
+
+2.  Write a portable (in the sense of running on any machine; it would
+always be for i387 floating-point formats) extended<->double converter
+(which just deals with the values as arrays of char).
+
+3.  Assume the host machine has *some* IEEE chip.  However, IEEE does
+not standardize formats for extended floats (387 is 10 bytes, 68881 is
+12 bytes), so this won't work.  */
+
+i387_to_double (from, to)
+     char *from;
+     char *to;
+{
+  long *lp;
+  /* push extended mode on 387 stack, then pop in double mode
+   *
+   * first, set exception masks so no error is generated -
+   * number will be rounded to inf or 0, if necessary 
+   */
+  asm ("pushl %eax"); 		/* grab a stack slot */
+  asm ("fstcw (%esp)");		/* get 387 control word */
+  asm ("movl (%esp),%eax");	/* save old value */
+  asm ("orl $0x3f,%eax");		/* mask all exceptions */
+  asm ("pushl %eax");
+  asm ("fldcw (%esp)");		/* load new value into 387 */
+  
+  asm ("movl 8(%ebp),%eax");
+  asm ("fldt (%eax)");		/* push extended number on 387 stack */
+  asm ("fwait");
+  asm ("movl 12(%ebp),%eax");
+  asm ("fstpl (%eax)");		/* pop double */
+  asm ("fwait");
+  
+  asm ("popl %eax");		/* flush modified control word */
+  asm ("fnclex");			/* clear exceptions */
+  asm ("fldcw (%esp)");		/* restore original control word */
+  asm ("popl %eax");		/* flush saved copy */
+}
+
+double_to_i387 (from, to)
+     char *from;
+     char *to;
+{
+  /* push double mode on 387 stack, then pop in extended mode
+   * no errors are possible because every 64-bit pattern
+   * can be converted to an extended
+   */
+  asm ("movl 8(%ebp),%eax");
+  asm ("fldl (%eax)");
+  asm ("fwait");
+  asm ("movl 12(%ebp),%eax");
+  asm ("fstpt (%eax)");
+  asm ("fwait");
+}
+
+struct env387 
+{
+  unsigned short control;
+  unsigned short r0;
+  unsigned short status;
+  unsigned short r1;
+  unsigned short tag;
+  unsigned short r2;
+  unsigned long eip;
+  unsigned short code_seg;
+  unsigned short opcode;
+  unsigned long operand;
+  unsigned short operand_seg;
+  unsigned short r3;
+  unsigned char regs[8][10];
+};
+
+static
+print_387_control_word (control)
+unsigned short control;
+{
+  printf ("control 0x%04x: ", control);
+  printf ("compute to ");
+  switch ((control >> 8) & 3) 
+    {
+    case 0: printf ("24 bits; "); break;
+    case 1: printf ("(bad); "); break;
+    case 2: printf ("53 bits; "); break;
+    case 3: printf ("64 bits; "); break;
+    }
+  printf ("round ");
+  switch ((control >> 10) & 3) 
+    {
+    case 0: printf ("NEAREST; "); break;
+    case 1: printf ("DOWN; "); break;
+    case 2: printf ("UP; "); break;
+    case 3: printf ("CHOP; "); break;
+    }
+  if (control & 0x3f) 
+    {
+      printf ("mask:");
+      if (control & 0x0001) printf (" INVALID");
+      if (control & 0x0002) printf (" DENORM");
+      if (control & 0x0004) printf (" DIVZ");
+      if (control & 0x0008) printf (" OVERF");
+      if (control & 0x0010) printf (" UNDERF");
+      if (control & 0x0020) printf (" LOS");
+      printf (";");
+    }
+  printf ("\n");
+  if (control & 0xe080) printf ("warning: reserved bits on 0x%x\n",
+				control & 0xe080);
+}
+
+static
+print_387_status_word (status)
+     unsigned short status;
+{
+  printf ("status 0x%04x: ", status);
+  if (status & 0xff) 
+    {
+      printf ("exceptions:");
+      if (status & 0x0001) printf (" INVALID");
+      if (status & 0x0002) printf (" DENORM");
+      if (status & 0x0004) printf (" DIVZ");
+      if (status & 0x0008) printf (" OVERF");
+      if (status & 0x0010) printf (" UNDERF");
+      if (status & 0x0020) printf (" LOS");
+      if (status & 0x0040) printf (" FPSTACK");
+      printf ("; ");
+    }
+  printf ("flags: %d%d%d%d; ",
+	  (status & 0x4000) != 0,
+	  (status & 0x0400) != 0,
+	  (status & 0x0200) != 0,
+	  (status & 0x0100) != 0);
+  
+  printf ("top %d\n", (status >> 11) & 7);
+}
+
+static
+print_387_status (status, ep)
+     unsigned short status;
+     struct env387 *ep;
+{
+  int i;
+  int bothstatus;
+  int top;
+  int fpreg;
+  unsigned char *p;
+  
+  bothstatus = ((status != 0) && (ep->status != 0));
+  if (status != 0) 
+    {
+      if (bothstatus)
+	printf ("u: ");
+      print_387_status_word (status);
+    }
+  
+  if (ep->status != 0) 
+    {
+      if (bothstatus)
+	printf ("e: ");
+      print_387_status_word (ep->status);
+    }
+  
+  print_387_control_word (ep->control);
+  printf ("last exception: ");
+  printf ("opcode 0x%x; ", ep->opcode);
+  printf ("pc 0x%x:0x%x; ", ep->code_seg, ep->eip);
+  printf ("operand 0x%x:0x%x\n", ep->operand_seg, ep->operand);
+  
+  top = (ep->status >> 11) & 7;
+  
+  printf ("regno  tag  msb              lsb  value\n");
+  for (fpreg = 7; fpreg >= 0; fpreg--) 
+    {
+      double val;
+      
+      printf ("%s %d: ", fpreg == top ? "=>" : "  ", fpreg);
+      
+      switch ((ep->tag >> (fpreg * 2)) & 3) 
+	{
+	case 0: printf ("valid "); break;
+	case 1: printf ("zero  "); break;
+	case 2: printf ("trap  "); break;
+	case 3: printf ("empty "); break;
+	}
+      for (i = 9; i >= 0; i--)
+	printf ("%02x", ep->regs[fpreg][i]);
+      
+      i387_to_double (ep->regs[fpreg], (char *)&val);
+      printf ("  %g\n", val);
+    }
+  if (ep->r0)
+    printf ("warning: reserved0 is 0x%x\n", ep->r0);
+  if (ep->r1)
+    printf ("warning: reserved1 is 0x%x\n", ep->r1);
+  if (ep->r2)
+    printf ("warning: reserved2 is 0x%x\n", ep->r2);
+  if (ep->r3)
+    printf ("warning: reserved3 is 0x%x\n", ep->r3);
+}
+
+#ifndef U_FPSTATE
+#define U_FPSTATE(u) u.u_fpstate
+#endif
+
+i386_float_info ()
+{
+  struct user u; /* just for address computations */
+  int i;
+  /* fpstate defined in <sys/user.h> */
+  struct fpstate *fpstatep;
+  char buf[sizeof (struct fpstate) + 2 * sizeof (int)];
+  unsigned int uaddr;
+  char fpvalid;
+  unsigned int rounded_addr;
+  unsigned int rounded_size;
+  extern int corechan;
+  int skip;
+  
+  uaddr = (char *)&u.u_fpvalid - (char *)&u;
+  if (have_inferior_p()) 
+    {
+      unsigned int data;
+      unsigned int mask;
+      
+      rounded_addr = uaddr & -sizeof (int);
+      data = ptrace (3, inferior_pid, rounded_addr, 0);
+      mask = 0xff << ((uaddr - rounded_addr) * 8);
+      
+      fpvalid = ((data & mask) != 0);
+    } 
+  else 
+    {
+      if (lseek (corechan, uaddr, 0) < 0)
+	perror ("seek on core file");
+      if (myread (corechan, &fpvalid, 1) < 0) 
+	perror ("read on core file");
+      
+    }
+  
+  if (fpvalid == 0) 
+    {
+      printf ("no floating point status saved\n");
+      return;
+    }
+  
+  uaddr = (char *)&U_FPSTATE(u) - (char *)&u;
+  if (have_inferior_p ()) 
+    {
+      int *ip;
+      
+      rounded_addr = uaddr & -sizeof (int);
+      rounded_size = (((uaddr + sizeof (struct fpstate)) - uaddr) +
+		      sizeof (int) - 1) / sizeof (int);
+      skip = uaddr - rounded_addr;
+      
+      ip = (int *)buf;
+      for (i = 0; i < rounded_size; i++) 
+	{
+	  *ip++ = ptrace (3, inferior_pid, rounded_addr, 0);
+	  rounded_addr += sizeof (int);
+	}
+    } 
+  else 
+    {
+      if (lseek (corechan, uaddr, 0) < 0)
+	perror_with_name ("seek on core file");
+      if (myread (corechan, buf, sizeof (struct fpstate)) < 0) 
+	perror_with_name ("read from core file");
+      skip = 0;
+    }
+  
+  fpstatep = (struct fpstate *)(buf + skip);
+  print_387_status (fpstatep->status, (struct env387 *)fpstatep->state);
+}
+