1 /* Target-machine dependent code for Zilog Z8000, for GDB.
2 Copyright (C) 1992, 1993, 1994 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 Contributed by Steve Chamberlain
35 #include "value.h" /* For read_register() */
38 static int read_memory_pointer (CORE_ADDR x
);
40 /* Return the saved PC from this frame.
42 If the frame has a memory copy of SRP_REGNUM, use that. If not,
43 just use the register SRP_REGNUM itself. */
46 z8k_frame_saved_pc (struct frame_info
*frame
)
48 return read_memory_pointer (frame
->frame
+ (BIG
? 4 : 2));
51 #define IS_PUSHL(x) (BIG ? ((x & 0xfff0) == 0x91e0):((x & 0xfff0) == 0x91F0))
52 #define IS_PUSHW(x) (BIG ? ((x & 0xfff0) == 0x93e0):((x & 0xfff0)==0x93f0))
53 #define IS_MOVE_FP(x) (BIG ? x == 0xa1ea : x == 0xa1fa)
54 #define IS_MOV_SP_FP(x) (BIG ? x == 0x94ea : x == 0x0d76)
55 #define IS_SUB2_SP(x) (x==0x1b87)
56 #define IS_MOVK_R5(x) (x==0x7905)
57 #define IS_SUB_SP(x) ((x & 0xffff) == 0x020f)
58 #define IS_PUSH_FP(x) (BIG ? (x == 0x93ea) : (x == 0x93fa))
60 /* work out how much local space is on the stack and
61 return the pc pointing to the first push */
64 skip_adjust (CORE_ADDR pc
, int *size
)
68 if (IS_PUSH_FP (read_memory_short (pc
))
69 && IS_MOV_SP_FP (read_memory_short (pc
+ 2)))
71 /* This is a function with an explict frame pointer */
73 *size
+= 2; /* remember the frame pointer */
76 /* remember any stack adjustment */
77 if (IS_SUB_SP (read_memory_short (pc
)))
79 *size
+= read_memory_short (pc
+ 2);
85 static CORE_ADDR
examine_frame (CORE_ADDR
, CORE_ADDR
* regs
, CORE_ADDR
);
87 examine_frame (CORE_ADDR pc
, CORE_ADDR
*regs
, CORE_ADDR sp
)
89 int w
= read_memory_short (pc
);
93 for (regno
= 0; regno
< NUM_REGS
; regno
++)
96 while (IS_PUSHW (w
) || IS_PUSHL (w
))
98 /* work out which register is being pushed to where */
101 regs
[w
& 0xf] = offset
;
102 regs
[(w
& 0xf) + 1] = offset
+ 2;
107 regs
[w
& 0xf] = offset
;
111 w
= read_memory_short (pc
);
119 else if (IS_SUB_SP (w
))
121 /* Subtracting a value from the sp, so were in a function
122 which needs stack space for locals, but has no fp. We fake up
123 the values as if we had an fp */
124 regs
[FP_REGNUM
] = sp
;
128 /* This one didn't have an fp, we'll fake it up */
129 regs
[SP_REGNUM
] = sp
;
131 /* stack pointer contains address of next frame */
132 /* regs[fp_regnum()] = fp; */
133 regs
[SP_REGNUM
] = sp
;
138 z8k_skip_prologue (CORE_ADDR start_pc
)
140 CORE_ADDR dummy
[NUM_REGS
];
142 return examine_frame (start_pc
, dummy
, 0);
146 z8k_addr_bits_remove (CORE_ADDR addr
)
148 return (addr
& PTR_MASK
);
152 read_memory_pointer (CORE_ADDR x
)
154 return read_memory_integer (ADDR_BITS_REMOVE (x
), BIG
? 4 : 2);
158 z8k_frame_chain (struct frame_info
*thisframe
)
160 if (thisframe
->prev
== 0)
162 /* This is the top of the stack, let's get the sp for real */
164 if (!inside_entry_file (thisframe
->pc
))
166 return read_memory_pointer (thisframe
->frame
);
177 /* Put here the code to store, into a struct frame_saved_regs,
178 the addresses of the saved registers of frame described by FRAME_INFO.
179 This includes special registers such as pc and fp saved in special
180 ways in the stack frame. sp is even more special:
181 the address we return for it IS the sp for the next frame. */
184 z8k_frame_init_saved_regs (struct frame_info
*frame_info
)
189 frame_saved_regs_zalloc (frame_info
);
190 pc
= get_pc_function_start (frame_info
->pc
);
192 /* wander down the instruction stream */
193 examine_frame (pc
, frame_info
->saved_regs
, frame_info
->frame
);
198 z8k_push_dummy_frame (void)
204 gdb_print_insn_z8k (bfd_vma memaddr
, disassemble_info
*info
)
207 return print_insn_z8001 (memaddr
, info
);
209 return print_insn_z8002 (memaddr
, info
);
212 /* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or
213 is not the address of a valid instruction, the address of the next
214 instruction beyond ADDR otherwise. *PWORD1 receives the first word
215 of the instruction. */
218 NEXT_PROLOGUE_INSN (CORE_ADDR addr
, CORE_ADDR lim
, short *pword1
)
223 read_memory (addr
, buf
, 2);
224 *pword1
= extract_signed_integer (buf
, 2);
232 /* Put here the code to store, into a struct frame_saved_regs,
233 the addresses of the saved registers of frame described by FRAME_INFO.
234 This includes special registers such as pc and fp saved in special
235 ways in the stack frame. sp is even more special:
236 the address we return for it IS the sp for the next frame.
238 We cache the result of doing this in the frame_cache_obstack, since
239 it is fairly expensive. */
242 frame_find_saved_regs (struct frame_info
*fip
, struct frame_saved_regs
*fsrp
)
249 memset (fsrp
, 0, sizeof *fsrp
);
251 pc
= skip_adjust (get_pc_function_start (fip
->pc
), &locals
);
254 adr
= FRAME_FP (fip
) - locals
;
255 for (i
= 0; i
< 8; i
++)
257 int word
= read_memory_short (pc
);
262 fsrp
->regs
[word
& 0xf] = adr
;
263 fsrp
->regs
[(word
& 0xf) + 1] = adr
- 2;
266 else if (IS_PUSHW (word
))
268 fsrp
->regs
[word
& 0xf] = adr
;
277 fsrp
->regs
[PC_REGNUM
] = fip
->frame
+ 4;
278 fsrp
->regs
[FP_REGNUM
] = fip
->frame
;
284 z8k_saved_pc_after_call (struct frame_info
*frame
)
286 return ADDR_BITS_REMOVE
287 (read_memory_integer (read_register (SP_REGNUM
), PTR_SIZE
));
292 extract_return_value (struct type
*type
, char *regbuf
, char *valbuf
)
295 int len
= TYPE_LENGTH (type
);
297 for (b
= 0; b
< len
; b
+= 2)
303 memcpy (valbuf
+ b
, regbuf
+ b
, todo
);
308 write_return_value (struct type
*type
, char *valbuf
)
313 for (len
= 0; len
< TYPE_LENGTH (type
); len
+= 2)
314 write_register_bytes (REGISTER_BYTE (len
/ 2 + 2), valbuf
+ len
, 2);
318 store_struct_return (CORE_ADDR addr
, CORE_ADDR sp
)
320 write_register (2, addr
);
325 z8k_print_register_hook (int regno
)
327 if ((regno
& 1) == 0 && regno
< 16)
331 read_relative_register_raw_bytes (regno
, (char *) (l
+ 0));
332 read_relative_register_raw_bytes (regno
+ 1, (char *) (l
+ 1));
333 printf_unfiltered ("\t");
334 printf_unfiltered ("%04x%04x", l
[0], l
[1]);
337 if ((regno
& 3) == 0 && regno
< 16)
341 read_relative_register_raw_bytes (regno
, (char *) (l
+ 0));
342 read_relative_register_raw_bytes (regno
+ 1, (char *) (l
+ 1));
343 read_relative_register_raw_bytes (regno
+ 2, (char *) (l
+ 2));
344 read_relative_register_raw_bytes (regno
+ 3, (char *) (l
+ 3));
346 printf_unfiltered ("\t");
347 printf_unfiltered ("%04x%04x%04x%04x", l
[0], l
[1], l
[2], l
[3]);
354 read_relative_register_raw_bytes (regno
, (char *) (&rval
));
356 printf_unfiltered ("\n");
357 for (i
= 0; i
< 10; i
+= 2)
359 printf_unfiltered ("(sp+%d=%04x)", i
,
360 (unsigned int)read_memory_short (rval
+ i
));
371 struct cmd_list_element
*setmemorylist
;
374 z8k_set_pointer_size (int newsize
)
376 static int oldsize
= 0;
378 if (oldsize
!= newsize
)
380 printf_unfiltered ("pointer size set to %d bits\n", newsize
);
390 /* FIXME: This code should be using the GDBARCH framework to
391 handle changed type sizes. If this problem is ever fixed
392 (the direct reference to _initialize_gdbtypes() below
393 eliminated) then Makefile.in should be updated so that
394 z8k-tdep.c is again compiled with -Werror. */
395 _initialize_gdbtypes ();
400 segmented_command (char *args
, int from_tty
)
402 z8k_set_pointer_size (32);
406 unsegmented_command (char *args
, int from_tty
)
408 z8k_set_pointer_size (16);
412 set_memory (char *args
, int from_tty
)
414 printf_unfiltered ("\"set memory\" must be followed by the name of a memory subcommand.\n");
415 help_list (setmemorylist
, "set memory ", -1, gdb_stdout
);
419 _initialize_z8ktdep (void)
421 tm_print_insn
= gdb_print_insn_z8k
;
423 add_prefix_cmd ("memory", no_class
, set_memory
,
424 "set the memory model", &setmemorylist
, "set memory ", 0,
426 add_cmd ("segmented", class_support
, segmented_command
,
427 "Set segmented memory model.", &setmemorylist
);
428 add_cmd ("unsegmented", class_support
, unsegmented_command
,
429 "Set unsegmented memory model.", &setmemorylist
);
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