binutils-gdb/gdb/w65-tdep.c
1999-04-16 01:35:26 +00:00

296 lines
5.9 KiB
C

/* Target-machine dependent code for WDC-65816, for GDB.
Copyright (C) 1995 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"
/* Return the saved PC from this frame. */
CORE_ADDR
w65_frame_saved_pc (frame)
struct frame_info *frame;
{
return (read_memory_integer (frame->frame + 2, 4) & 0xffffff);
}
CORE_ADDR
w65_addr_bits_remove (addr)
CORE_ADDR addr;
{
return ((addr) & 0xffffff);
}
read_memory_pointer (x)
CORE_ADDR x;
{
return read_memory_integer (ADDR_BITS_REMOVE (x), 4);
}
init_frame_pc ()
{
abort ();
}
void
w65_push_dummy_frame ()
{
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.
We cache the result of doing this in the frame_cache_obstack, since
it is fairly expensive. */
void
frame_find_saved_regs (fip, fsrp)
struct frame_info *fip;
struct frame_saved_regs *fsrp;
{
int locals;
CORE_ADDR pc;
CORE_ADDR adr;
int i;
memset (fsrp, 0, sizeof *fsrp);
}
int
saved_pc_after_call ()
{
int sp = read_register (SP_REGNUM);
int val = read_memory_integer (sp + 1, 4);
return ADDR_BITS_REMOVE (val);
}
extract_return_value (type, regbuf, valbuf)
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 (type, valbuf)
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 (addr, sp)
CORE_ADDR addr;
CORE_ADDR sp;
{
write_register (2, addr);
}
void
w65_pop_frame ()
{
}
init_extra_frame_info ()
{
}
pop_frame ()
{
}
w65_frame_chain (thisframe)
struct frame_info *thisframe;
{
return 0xffff & read_memory_integer ((thisframe)->frame, 2);
}
static int
gb (x)
{
return read_memory_integer (x, 1) & 0xff;
}
extern CORE_ADDR
w65_skip_prologue (pc)
CORE_ADDR pc;
{
CORE_ADDR too_far = pc + 20;
/* looking for bits of the prologue, we can expect to
see this in a frameful function:
stack adjust:
3B tsc
1A inc a
18 clc
69E2FF adc #0xffe2
3A dec a
1B tcs
1A inc a
link:
A500 lda <r15
48 pha
3B tsc
1a inc a
8500 sta <r15
*/
#define TSC 0x3b
#define TCS 0x1b
#define INCA 0x1a
#define PHA 0x48
#define LDADIR 0xa5
#define STADIR 0x85
/* Skip a stack adjust - any area between a tsc and tcs */
if (gb (pc) == TSC)
{
while (pc < too_far && gb (pc) != TCS)
{
pc++;
}
pc++;
/* Skip a stupid inc a */
if (gb (pc) == INCA)
pc++;
}
/* Stack adjust can also be done with n pha's */
while (gb (pc) == PHA)
pc++;
/* Skip a link - that's a ld/ph/tsc/inc/sta */
if (gb (pc) == LDADIR
&& gb (pc + 5) == STADIR
&& gb (pc + 1) == gb (pc + 6)
&& gb (pc + 2) == PHA
&& gb (pc + 3) == TSC
&& gb (pc + 4) == INCA)
{
pc += 7;
}
return pc;
}
register_raw_size (n)
{
return sim_reg_size (n);
}
void
print_register_hook (regno)
{
if (regno == P_REGNUM)
{
/* CCR register */
int C, Z, N, V, I, D, X, M;
unsigned char b[1];
unsigned char l;
read_relative_register_raw_bytes (regno, b);
l = b[0];
printf_unfiltered ("\t");
C = (l & 0x1) != 0;
Z = (l & 0x2) != 0;
I = (l & 0x4) != 0;
D = (l & 0x8) != 0;
X = (l & 0x10) != 0;
M = (l & 0x20) != 0;
V = (l & 0x40) != 0;
N = (l & 0x80) != 0;
printf_unfiltered ("N-%d ", N);
printf_unfiltered ("V-%d ", V);
printf_unfiltered ("M-%d ", M);
printf_unfiltered ("X-%d ", X);
printf_unfiltered ("D-%d ", D);
printf_unfiltered ("I-%d ", I);
printf_unfiltered ("Z-%d ", Z);
printf_unfiltered ("C-%d ", C);
if ((C | Z) == 0)
printf_unfiltered ("u> ");
if ((C | Z) == 1)
printf_unfiltered ("u<= ");
if ((C == 0))
printf_unfiltered ("u>= ");
if (C == 1)
printf_unfiltered ("u< ");
if (Z == 0)
printf_unfiltered ("!= ");
if (Z == 1)
printf_unfiltered ("== ");
if ((N ^ V) == 0)
printf_unfiltered (">= ");
if ((N ^ V) == 1)
printf_unfiltered ("< ");
if ((Z | (N ^ V)) == 0)
printf_unfiltered ("> ");
if ((Z | (N ^ V)) == 1)
printf_unfiltered ("<= ");
}
}
void
_initialize_w65_tdep ()
{
tm_print_insn = print_insn_w65;
}