gdb/z8k-tdep.c - third_party/binutils-gdb - Git at Google

 /* Target-machine dependent code for Zilog Z8000, for GDB.
    Copyright (C) 1992, 1993, 1994 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.  */

 /*
    Contributed by Steve Chamberlain
    sac@cygnus.com
  */

 #include "defs.h"
 #include "frame.h"
 #include "obstack.h"
 #include "symtab.h"
 #include "gdbcmd.h"
 #include "gdbtypes.h"
 #include "dis-asm.h"
 #include "gdbcore.h"

 #include "value.h" /* For read_register() */


 static int read_memory_pointer (CORE_ADDR x);

 /* Return the saved PC from this frame.

    If the frame has a memory copy of SRP_REGNUM, use that.  If not,
    just use the register SRP_REGNUM itself.  */

 CORE_ADDR
 z8k_frame_saved_pc (struct frame_info *frame)
 {
   return read_memory_pointer (frame->frame + (BIG ? 4 : 2));
 }

 #define IS_PUSHL(x) (BIG ? ((x & 0xfff0) == 0x91e0):((x & 0xfff0) == 0x91F0))
 #define IS_PUSHW(x) (BIG ? ((x & 0xfff0) == 0x93e0):((x & 0xfff0)==0x93f0))
 #define IS_MOVE_FP(x) (BIG ? x == 0xa1ea : x == 0xa1fa)
 #define IS_MOV_SP_FP(x) (BIG ? x == 0x94ea : x == 0x0d76)
 #define IS_SUB2_SP(x) (x==0x1b87)
 #define IS_MOVK_R5(x) (x==0x7905)
 #define IS_SUB_SP(x) ((x & 0xffff) == 0x020f)
 #define IS_PUSH_FP(x) (BIG ? (x == 0x93ea) : (x == 0x93fa))

 /* work out how much local space is on the stack and
    return the pc pointing to the first push */

 static CORE_ADDR
 skip_adjust (CORE_ADDR pc, int *size)
 {
   *size = 0;

   if (IS_PUSH_FP (read_memory_short (pc))
       && IS_MOV_SP_FP (read_memory_short (pc + 2)))
     {
       /* This is a function with an explict frame pointer */
       pc += 4;
       *size += 2;		/* remember the frame pointer */
     }

   /* remember any stack adjustment */
   if (IS_SUB_SP (read_memory_short (pc)))
     {
       *size += read_memory_short (pc + 2);
       pc += 4;
     }
   return pc;
 }

 static CORE_ADDR examine_frame (CORE_ADDR, CORE_ADDR * regs, CORE_ADDR);
 static CORE_ADDR
 examine_frame (CORE_ADDR pc, CORE_ADDR *regs, CORE_ADDR sp)
 {
   int w = read_memory_short (pc);
   int offset = 0;
   int regno;

   for (regno = 0; regno < NUM_REGS; regno++)
     regs[regno] = 0;

   while (IS_PUSHW (w) || IS_PUSHL (w))
     {
       /* work out which register is being pushed to where */
       if (IS_PUSHL (w))
 	{
 	  regs[w & 0xf] = offset;
 	  regs[(w & 0xf) + 1] = offset + 2;
 	  offset += 4;
 	}
       else
 	{
 	  regs[w & 0xf] = offset;
 	  offset += 2;
 	}
       pc += 2;
       w = read_memory_short (pc);
     }

   if (IS_MOVE_FP (w))
     {
       /* We know the fp */

     }
   else if (IS_SUB_SP (w))
     {
       /* Subtracting a value from the sp, so were in a function
          which needs stack space for locals, but has no fp.  We fake up
          the values as if we had an fp */
       regs[FP_REGNUM] = sp;
     }
   else
     {
       /* This one didn't have an fp, we'll fake it up */
       regs[SP_REGNUM] = sp;
     }
   /* stack pointer contains address of next frame */
   /*  regs[fp_regnum()] = fp; */
   regs[SP_REGNUM] = sp;
   return pc;
 }

 CORE_ADDR
 z8k_skip_prologue (CORE_ADDR start_pc)
 {
   CORE_ADDR dummy[NUM_REGS];

   return examine_frame (start_pc, dummy, 0);
 }

 CORE_ADDR
 z8k_addr_bits_remove (CORE_ADDR addr)
 {
   return (addr & PTR_MASK);
 }

 static int
 read_memory_pointer (CORE_ADDR x)
 {
   return read_memory_integer (ADDR_BITS_REMOVE (x), BIG ? 4 : 2);
 }

 CORE_ADDR
 z8k_frame_chain (struct frame_info *thisframe)
 {
   if (thisframe->prev == 0)
     {
       /* This is the top of the stack, let's get the sp for real */
     }
   if (!inside_entry_file (thisframe->pc))
     {
       return read_memory_pointer (thisframe->frame);
     }
   return 0;
 }

 void
 init_frame_pc (void)
 {
   abort ();
 }

 /* Put here the code to store, into a struct frame_saved_regs,
    the addresses of the saved registers of frame described by FRAME_INFO.
    This includes special registers such as pc and fp saved in special
    ways in the stack frame.  sp is even more special:
    the address we return for it IS the sp for the next frame.  */

 void
 z8k_frame_init_saved_regs (struct frame_info *frame_info)
 {
   CORE_ADDR pc;
   int w;

   frame_saved_regs_zalloc (frame_info);
   pc = get_pc_function_start (frame_info->pc);

   /* wander down the instruction stream */
   examine_frame (pc, frame_info->saved_regs, frame_info->frame);

 }

 void
 z8k_push_dummy_frame (void)
 {
   abort ();
 }

 int
 gdb_print_insn_z8k (bfd_vma memaddr, disassemble_info *info)
 {
   if (BIG)
     return print_insn_z8001 (memaddr, info);
   else
     return print_insn_z8002 (memaddr, info);
 }

 /* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or
    is not the address of a valid instruction, the address of the next
    instruction beyond ADDR otherwise.  *PWORD1 receives the first word
    of the instruction. */

 CORE_ADDR
 NEXT_PROLOGUE_INSN (CORE_ADDR addr, CORE_ADDR lim, short *pword1)
 {
   char buf[2];
   if (addr < lim + 8)
     {
       read_memory (addr, buf, 2);
       *pword1 = extract_signed_integer (buf, 2);

       return addr + 2;
     }
   return 0;
 }

 #if 0
 /* Put here the code to store, into a struct frame_saved_regs,
    the addresses of the saved registers of frame described by FRAME_INFO.
    This includes special registers such as pc and fp saved in special
    ways in the stack frame.  sp is even more special:
    the address we return for it IS the sp for the next frame.

    We cache the result of doing this in the frame_cache_obstack, since
    it is fairly expensive.  */

 void
 frame_find_saved_regs (struct frame_info *fip, struct frame_saved_regs *fsrp)
 {
   int locals;
   CORE_ADDR pc;
   CORE_ADDR adr;
   int i;

   memset (fsrp, 0, sizeof *fsrp);

   pc = skip_adjust (get_pc_function_start (fip->pc), &locals);

   {
     adr = FRAME_FP (fip) - locals;
     for (i = 0; i < 8; i++)
       {
 	int word = read_memory_short (pc);

 	pc += 2;
 	if (IS_PUSHL (word))
 	  {
 	    fsrp->regs[word & 0xf] = adr;
 	    fsrp->regs[(word & 0xf) + 1] = adr - 2;
 	    adr -= 4;
 	  }
 	else if (IS_PUSHW (word))
 	  {
 	    fsrp->regs[word & 0xf] = adr;
 	    adr -= 2;
 	  }
 	else
 	  break;
       }

   }

   fsrp->regs[PC_REGNUM] = fip->frame + 4;
   fsrp->regs[FP_REGNUM] = fip->frame;

 }
 #endif

 int
 z8k_saved_pc_after_call (struct frame_info *frame)
 {
   return ADDR_BITS_REMOVE
     (read_memory_integer (read_register (SP_REGNUM), PTR_SIZE));
 }


 void
 extract_return_value (struct type *type, char *regbuf, char *valbuf)
 {
   int b;
   int len = TYPE_LENGTH (type);

   for (b = 0; b < len; b += 2)
     {
       int todo = len - b;

       if (todo > 2)
 	todo = 2;
       memcpy (valbuf + b, regbuf + b, todo);
     }
 }

 void
 write_return_value (struct type *type, char *valbuf)
 {
   int reg;
   int len;

   for (len = 0; len < TYPE_LENGTH (type); len += 2)
     write_register_bytes (REGISTER_BYTE (len / 2 + 2), valbuf + len, 2);
 }

 void
 store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
 {
   write_register (2, addr);
 }


 void
 z8k_print_register_hook (int regno)
 {
   if ((regno & 1) == 0 && regno < 16)
     {
       unsigned short l[2];

       read_relative_register_raw_bytes (regno, (char *) (l + 0));
       read_relative_register_raw_bytes (regno + 1, (char *) (l + 1));
       printf_unfiltered ("\t");
       printf_unfiltered ("%04x%04x", l[0], l[1]);
     }

   if ((regno & 3) == 0 && regno < 16)
     {
       unsigned short l[4];

       read_relative_register_raw_bytes (regno, (char *) (l + 0));
       read_relative_register_raw_bytes (regno + 1, (char *) (l + 1));
       read_relative_register_raw_bytes (regno + 2, (char *) (l + 2));
       read_relative_register_raw_bytes (regno + 3, (char *) (l + 3));

       printf_unfiltered ("\t");
       printf_unfiltered ("%04x%04x%04x%04x", l[0], l[1], l[2], l[3]);
     }
   if (regno == 15)
     {
       unsigned short rval;
       int i;

       read_relative_register_raw_bytes (regno, (char *) (&rval));

       printf_unfiltered ("\n");
       for (i = 0; i < 10; i += 2)
 	{
 	  printf_unfiltered ("(sp+%d=%04x)", i,
 			     (unsigned int)read_memory_short (rval + i));
 	}
     }

 }

 void
 z8k_pop_frame (void)
 {
 }

 struct cmd_list_element *setmemorylist;

 void
 z8k_set_pointer_size (int newsize)
 {
   static int oldsize = 0;

   if (oldsize != newsize)
     {
       printf_unfiltered ("pointer size set to %d bits\n", newsize);
       oldsize = newsize;
       if (newsize == 32)
 	{
 	  BIG = 1;
 	}
       else
 	{
 	  BIG = 0;
 	}
       /* FIXME: This code should be using the GDBARCH framework to
          handle changed type sizes.  If this problem is ever fixed
          (the direct reference to _initialize_gdbtypes() below
          eliminated) then Makefile.in should be updated so that
          z8k-tdep.c is again compiled with -Werror. */
       _initialize_gdbtypes ();
     }
 }

 static void
 segmented_command (char *args, int from_tty)
 {
   z8k_set_pointer_size (32);
 }

 static void
 unsegmented_command (char *args, int from_tty)
 {
   z8k_set_pointer_size (16);
 }

 static void
 set_memory (char *args, int from_tty)
 {
   printf_unfiltered ("\"set memory\" must be followed by the name of a memory subcommand.\n");
   help_list (setmemorylist, "set memory ", -1, gdb_stdout);
 }

 void
 _initialize_z8ktdep (void)
 {
   tm_print_insn = gdb_print_insn_z8k;

   add_prefix_cmd ("memory", no_class, set_memory,
 		  "set the memory model", &setmemorylist, "set memory ", 0,
 		  &setlist);
   add_cmd ("segmented", class_support, segmented_command,
 	   "Set segmented memory model.", &setmemorylist);
   add_cmd ("unsegmented", class_support, unsegmented_command,
 	   "Set unsegmented memory model.", &setmemorylist);

 }
	/* Target-machine dependent code for Zilog Z8000, for GDB.
	Copyright (C) 1992, 1993, 1994 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. */

	/*
	Contributed by Steve Chamberlain
	sac@cygnus.com
	*/

	#include "defs.h"
	#include "frame.h"
	#include "obstack.h"
	#include "symtab.h"
	#include "gdbcmd.h"
	#include "gdbtypes.h"
	#include "dis-asm.h"
	#include "gdbcore.h"

	#include "value.h" /* For read_register() */


	static int read_memory_pointer (CORE_ADDR x);

	/* Return the saved PC from this frame.

	If the frame has a memory copy of SRP_REGNUM, use that. If not,
	just use the register SRP_REGNUM itself. */

	CORE_ADDR
	z8k_frame_saved_pc (struct frame_info *frame)
	{
	return read_memory_pointer (frame->frame + (BIG ? 4 : 2));
	}

	#define IS_PUSHL(x) (BIG ? ((x & 0xfff0) == 0x91e0):((x & 0xfff0) == 0x91F0))
	#define IS_PUSHW(x) (BIG ? ((x & 0xfff0) == 0x93e0):((x & 0xfff0)==0x93f0))
	#define IS_MOVE_FP(x) (BIG ? x == 0xa1ea : x == 0xa1fa)
	#define IS_MOV_SP_FP(x) (BIG ? x == 0x94ea : x == 0x0d76)
	#define IS_SUB2_SP(x) (x==0x1b87)
	#define IS_MOVK_R5(x) (x==0x7905)
	#define IS_SUB_SP(x) ((x & 0xffff) == 0x020f)
	#define IS_PUSH_FP(x) (BIG ? (x == 0x93ea) : (x == 0x93fa))

	/* work out how much local space is on the stack and
	return the pc pointing to the first push */

	static CORE_ADDR
	skip_adjust (CORE_ADDR pc, int *size)
	{
	*size = 0;

	if (IS_PUSH_FP (read_memory_short (pc))
	&& IS_MOV_SP_FP (read_memory_short (pc + 2)))
	{
	/* This is a function with an explict frame pointer */
	pc += 4;
	size += 2; / remember the frame pointer */
	}

	/* remember any stack adjustment */
	if (IS_SUB_SP (read_memory_short (pc)))
	{
	*size += read_memory_short (pc + 2);
	pc += 4;
	}
	return pc;
	}

	static CORE_ADDR examine_frame (CORE_ADDR, CORE_ADDR * regs, CORE_ADDR);
	static CORE_ADDR
	examine_frame (CORE_ADDR pc, CORE_ADDR *regs, CORE_ADDR sp)
	{
	int w = read_memory_short (pc);
	int offset = 0;
	int regno;

	for (regno = 0; regno < NUM_REGS; regno++)
	regs[regno] = 0;

	while (IS_PUSHW (w) \|\| IS_PUSHL (w))
	{
	/* work out which register is being pushed to where */
	if (IS_PUSHL (w))
	{
	regs[w & 0xf] = offset;
	regs[(w & 0xf) + 1] = offset + 2;
	offset += 4;
	}
	else
	{
	regs[w & 0xf] = offset;
	offset += 2;
	}
	pc += 2;
	w = read_memory_short (pc);
	}

	if (IS_MOVE_FP (w))
	{
	/* We know the fp */

	}
	else if (IS_SUB_SP (w))
	{
	/* Subtracting a value from the sp, so were in a function
	which needs stack space for locals, but has no fp. We fake up
	the values as if we had an fp */
	regs[FP_REGNUM] = sp;
	}
	else
	{
	/* This one didn't have an fp, we'll fake it up */
	regs[SP_REGNUM] = sp;
	}
	/* stack pointer contains address of next frame */
	/* regs[fp_regnum()] = fp; */
	regs[SP_REGNUM] = sp;
	return pc;
	}

	CORE_ADDR
	z8k_skip_prologue (CORE_ADDR start_pc)
	{
	CORE_ADDR dummy[NUM_REGS];

	return examine_frame (start_pc, dummy, 0);
	}

	CORE_ADDR
	z8k_addr_bits_remove (CORE_ADDR addr)
	{
	return (addr & PTR_MASK);
	}

	static int
	read_memory_pointer (CORE_ADDR x)
	{
	return read_memory_integer (ADDR_BITS_REMOVE (x), BIG ? 4 : 2);
	}

	CORE_ADDR
	z8k_frame_chain (struct frame_info *thisframe)
	{
	if (thisframe->prev == 0)
	{
	/* This is the top of the stack, let's get the sp for real */
	}
	if (!inside_entry_file (thisframe->pc))
	{
	return read_memory_pointer (thisframe->frame);
	}
	return 0;
	}

	void
	init_frame_pc (void)
	{
	abort ();
	}

	/* Put here the code to store, into a struct frame_saved_regs,
	the addresses of the saved registers of frame described by FRAME_INFO.
	This includes special registers such as pc and fp saved in special
	ways in the stack frame. sp is even more special:
	the address we return for it IS the sp for the next frame. */

	void
	z8k_frame_init_saved_regs (struct frame_info *frame_info)
	{
	CORE_ADDR pc;
	int w;

	frame_saved_regs_zalloc (frame_info);
	pc = get_pc_function_start (frame_info->pc);

	/* wander down the instruction stream */
	examine_frame (pc, frame_info->saved_regs, frame_info->frame);

	}

	void
	z8k_push_dummy_frame (void)
	{
	abort ();
	}

	int
	gdb_print_insn_z8k (bfd_vma memaddr, disassemble_info *info)
	{
	if (BIG)
	return print_insn_z8001 (memaddr, info);
	else
	return print_insn_z8002 (memaddr, info);
	}

	/* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or
	is not the address of a valid instruction, the address of the next
	instruction beyond ADDR otherwise. *PWORD1 receives the first word
	of the instruction. */

	CORE_ADDR
	NEXT_PROLOGUE_INSN (CORE_ADDR addr, CORE_ADDR lim, short *pword1)
	{
	char buf[2];
	if (addr < lim + 8)
	{
	read_memory (addr, buf, 2);
	*pword1 = extract_signed_integer (buf, 2);

	return addr + 2;
	}
	return 0;
	}

	#if 0
	/* Put here the code to store, into a struct frame_saved_regs,
	the addresses of the saved registers of frame described by FRAME_INFO.
	This includes special registers such as pc and fp saved in special
	ways in the stack frame. sp is even more special:
	the address we return for it IS the sp for the next frame.

	We cache the result of doing this in the frame_cache_obstack, since
	it is fairly expensive. */

	void
	frame_find_saved_regs (struct frame_info fip, struct frame_saved_regs fsrp)
	{
	int locals;
	CORE_ADDR pc;
	CORE_ADDR adr;
	int i;

	memset (fsrp, 0, sizeof *fsrp);

	pc = skip_adjust (get_pc_function_start (fip->pc), &locals);

	{
	adr = FRAME_FP (fip) - locals;
	for (i = 0; i < 8; i++)
	{
	int word = read_memory_short (pc);

	pc += 2;
	if (IS_PUSHL (word))
	{
	fsrp->regs[word & 0xf] = adr;
	fsrp->regs[(word & 0xf) + 1] = adr - 2;
	adr -= 4;
	}
	else if (IS_PUSHW (word))
	{
	fsrp->regs[word & 0xf] = adr;
	adr -= 2;
	}
	else
	break;
	}

	}

	fsrp->regs[PC_REGNUM] = fip->frame + 4;
	fsrp->regs[FP_REGNUM] = fip->frame;

	}
	#endif

	int
	z8k_saved_pc_after_call (struct frame_info *frame)
	{
	return ADDR_BITS_REMOVE
	(read_memory_integer (read_register (SP_REGNUM), PTR_SIZE));
	}


	void
	extract_return_value (struct type type, char regbuf, char *valbuf)
	{
	int b;
	int len = TYPE_LENGTH (type);

	for (b = 0; b < len; b += 2)
	{
	int todo = len - b;

	if (todo > 2)
	todo = 2;
	memcpy (valbuf + b, regbuf + b, todo);
	}
	}

	void
	write_return_value (struct type type, char valbuf)
	{
	int reg;
	int len;

	for (len = 0; len < TYPE_LENGTH (type); len += 2)
	write_register_bytes (REGISTER_BYTE (len / 2 + 2), valbuf + len, 2);
	}

	void
	store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
	{
	write_register (2, addr);
	}


	void
	z8k_print_register_hook (int regno)
	{
	if ((regno & 1) == 0 && regno < 16)
	{
	unsigned short l[2];

	read_relative_register_raw_bytes (regno, (char *) (l + 0));
	read_relative_register_raw_bytes (regno + 1, (char *) (l + 1));
	printf_unfiltered ("\t");
	printf_unfiltered ("%04x%04x", l[0], l[1]);
	}

	if ((regno & 3) == 0 && regno < 16)
	{
	unsigned short l[4];

	read_relative_register_raw_bytes (regno, (char *) (l + 0));
	read_relative_register_raw_bytes (regno + 1, (char *) (l + 1));
	read_relative_register_raw_bytes (regno + 2, (char *) (l + 2));
	read_relative_register_raw_bytes (regno + 3, (char *) (l + 3));

	printf_unfiltered ("\t");
	printf_unfiltered ("%04x%04x%04x%04x", l[0], l[1], l[2], l[3]);
	}
	if (regno == 15)
	{
	unsigned short rval;
	int i;

	read_relative_register_raw_bytes (regno, (char *) (&rval));

	printf_unfiltered ("\n");
	for (i = 0; i < 10; i += 2)
	{
	printf_unfiltered ("(sp+%d=%04x)", i,
	(unsigned int)read_memory_short (rval + i));
	}
	}

	}

	void
	z8k_pop_frame (void)
	{
	}

	struct cmd_list_element *setmemorylist;

	void
	z8k_set_pointer_size (int newsize)
	{
	static int oldsize = 0;

	if (oldsize != newsize)
	{
	printf_unfiltered ("pointer size set to %d bits\n", newsize);
	oldsize = newsize;
	if (newsize == 32)
	{
	BIG = 1;
	}
	else
	{
	BIG = 0;
	}
	/* FIXME: This code should be using the GDBARCH framework to
	handle changed type sizes. If this problem is ever fixed
	(the direct reference to _initialize_gdbtypes() below
	eliminated) then Makefile.in should be updated so that
	z8k-tdep.c is again compiled with -Werror. */
	_initialize_gdbtypes ();
	}
	}

	static void
	segmented_command (char *args, int from_tty)
	{
	z8k_set_pointer_size (32);
	}

	static void
	unsegmented_command (char *args, int from_tty)
	{
	z8k_set_pointer_size (16);
	}

	static void
	set_memory (char *args, int from_tty)
	{
	printf_unfiltered ("\"set memory\" must be followed by the name of a memory subcommand.\n");
	help_list (setmemorylist, "set memory ", -1, gdb_stdout);
	}

	void
	_initialize_z8ktdep (void)
	{
	tm_print_insn = gdb_print_insn_z8k;

	add_prefix_cmd ("memory", no_class, set_memory,
	"set the memory model", &setmemorylist, "set memory ", 0,
	&setlist);
	add_cmd ("segmented", class_support, segmented_command,
	"Set segmented memory model.", &setmemorylist);
	add_cmd ("unsegmented", class_support, unsegmented_command,
	"Set unsegmented memory model.", &setmemorylist);

	}