1 /* Target-machine dependent code for Zilog Z8000, for GDB.
2 Copyright (C) 1992,1993 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
21 Contributed by Steve Chamberlain
32 /* Return the saved PC from this frame.
34 If the frame has a memory copy of SRP_REGNUM, use that. If not,
35 just use the register SRP_REGNUM itself. */
38 frame_saved_pc (frame
)
41 return (read_memory_pointer (frame
->frame
+ (BIG
? 4 : 2)));
44 #define IS_PUSHL(x) (BIG ? ((x & 0xfff0) == 0x91e0):((x & 0xfff0) == 0x91F0))
45 #define IS_PUSHW(x) (BIG ? ((x & 0xfff0) == 0x93e0):((x & 0xfff0)==0x93f0))
46 #define IS_MOVE_FP(x) (BIG ? x == 0xa1ea : x == 0xa1fa)
47 #define IS_MOV_SP_FP(x) (BIG ? x == 0x94ea : x == 0x0d76)
48 #define IS_SUB2_SP(x) (x==0x1b87)
49 #define IS_MOVK_R5(x) (x==0x7905)
50 #define IS_SUB_SP(x) ((x & 0xffff) == 0x020f)
51 #define IS_PUSH_FP(x) (BIG ? (x == 0x93ea) : (x == 0x93fa))
53 /* work out how much local space is on the stack and
54 return the pc pointing to the first push */
57 skip_adjust (pc
, size
)
63 if (IS_PUSH_FP (read_memory_short (pc
))
64 && IS_MOV_SP_FP (read_memory_short (pc
+ 2)))
66 /* This is a function with an explict frame pointer */
68 *size
+= 2; /* remember the frame pointer */
71 /* remember any stack adjustment */
72 if (IS_SUB_SP (read_memory_short (pc
)))
74 *size
+= read_memory_short (pc
+ 2);
81 examine_frame (pc
, regs
, sp
)
83 struct frame_saved_regs
*regs
;
86 int w
= read_memory_short (pc
);
90 for (regno
= 0; regno
< NUM_REGS
; regno
++)
91 regs
->regs
[regno
] = 0;
93 while (IS_PUSHW (w
) || IS_PUSHL (w
))
95 /* work out which register is being pushed to where */
98 regs
->regs
[w
& 0xf] = offset
;
99 regs
->regs
[(w
& 0xf) + 1] = offset
+ 2;
104 regs
->regs
[w
& 0xf] = offset
;
108 w
= read_memory_short (pc
);
116 else if (IS_SUB_SP (w
))
118 /* Subtracting a value from the sp, so were in a function
119 which needs stack space for locals, but has no fp. We fake up
120 the values as if we had an fp */
121 regs
->regs
[FP_REGNUM
] = sp
;
125 /* This one didn't have an fp, we'll fake it up */
126 regs
->regs
[SP_REGNUM
] = sp
;
128 /* stack pointer contains address of next frame */
129 /* regs->regs[fp_regnum()] = fp;*/
130 regs
->regs
[SP_REGNUM
] = sp
;
135 z8k_skip_prologue (start_pc
)
138 struct frame_saved_regs dummy
;
140 return examine_frame (start_pc
, &dummy
, 0);
150 read_memory_pointer (x
)
154 return read_memory_integer (ADDR_BITS_REMOVE (x
), BIG
? 4 : 2);
158 frame_chain (thisframe
)
161 if (thisframe
->prev
== 0)
163 /* This is the top of the stack, let's get the sp for real */
165 if (!inside_entry_file ((thisframe
)->pc
))
167 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 get_frame_saved_regs (frame_info
, frame_saved_regs
)
185 struct frame_info
*frame_info
;
186 struct frame_saved_regs
*frame_saved_regs
;
192 bzero (frame_saved_regs
, sizeof (*frame_saved_regs
));
193 pc
= get_pc_function_start (frame_info
->pc
);
195 /* wander down the instruction stream */
196 examine_frame (pc
, frame_saved_regs
, frame_info
->frame
);
201 z8k_push_dummy_frame ()
207 print_insn (memaddr
, stream
)
213 read_memory (memaddr
, temp
, 20);
216 return print_insn_z8001 (memaddr
, temp
, stream
);
220 return print_insn_z8002 (memaddr
, temp
, stream
);
224 /* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or
225 is not the address of a valid instruction, the address of the next
226 instruction beyond ADDR otherwise. *PWORD1 receives the first word
227 of the instruction.*/
230 NEXT_PROLOGUE_INSN (addr
, lim
, pword1
)
237 read_memory (addr
, pword1
, sizeof (*pword1
));
238 SWAP_TARGET_AND_HOST (pword1
, sizeof (short));
247 /* Put here the code to store, into a struct frame_saved_regs,
248 the addresses of the saved registers of frame described by FRAME_INFO.
249 This includes special registers such as pc and fp saved in special
250 ways in the stack frame. sp is even more special:
251 the address we return for it IS the sp for the next frame.
253 We cache the result of doing this in the frame_cache_obstack, since
254 it is fairly expensive. */
257 frame_find_saved_regs (fip
, fsrp
)
258 struct frame_info
*fip
;
259 struct frame_saved_regs
*fsrp
;
266 memset (fsrp
, 0, sizeof *fsrp
);
268 pc
= skip_adjust (get_pc_function_start (fip
->pc
), &locals
);
271 adr
= fip
->frame
- locals
;
272 for (i
= 0; i
< 8; i
++)
274 int word
= read_memory_short (pc
);
279 fsrp
->regs
[word
& 0xf] = adr
;
280 fsrp
->regs
[(word
& 0xf) + 1] = adr
- 2;
283 else if (IS_PUSHW (word
))
285 fsrp
->regs
[word
& 0xf] = adr
;
294 fsrp
->regs
[PC_REGNUM
] = fip
->frame
+ 4;
295 fsrp
->regs
[FP_REGNUM
] = fip
->frame
;
306 saved_pc_after_call ()
308 return addr_bits_remove
309 (read_memory_integer (read_register (SP_REGNUM
), PTR_SIZE
));
313 extract_return_value(type
, regbuf
, valbuf
)
319 int len
= TYPE_LENGTH(type
);
321 for (b
= 0; b
< len
; b
+= 2) {
325 memcpy(valbuf
+ b
, regbuf
+ b
, todo
);
330 write_return_value(type
, valbuf
)
336 for (len
= 0; len
< TYPE_LENGTH(type
); len
+= 2)
338 write_register_bytes(REGISTER_BYTE(len
/2 + 2), valbuf
+ len
, 2);
343 store_struct_return(addr
, sp
)
347 write_register(2, addr
);
352 print_register_hook (regno
)
355 if ((regno
& 1) == 0 && regno
< 16)
359 read_relative_register_raw_bytes (regno
, (char *) (l
+ 0));
360 read_relative_register_raw_bytes (regno
+ 1, (char *) (l
+ 1));
362 printf ("%04x%04x", l
[0], l
[1]);
365 if ((regno
& 3) == 0 && regno
< 16)
369 read_relative_register_raw_bytes (regno
, (char *) (l
+ 0));
370 read_relative_register_raw_bytes (regno
+ 1, (char *) (l
+ 1));
371 read_relative_register_raw_bytes (regno
+ 2, (char *) (l
+ 2));
372 read_relative_register_raw_bytes (regno
+ 3, (char *) (l
+ 3));
375 printf ("%04x%04x%04x%04x", l
[0], l
[1], l
[2], l
[3]);
382 read_relative_register_raw_bytes (regno
, (char *) (&rval
));
385 for (i
= 0; i
< 10; i
+= 2)
387 printf ("(sp+%d=%04x)", i
, read_memory_short (rval
+ i
));
394 register_convert_to_virtual (regnum
, from
, to
)
405 register_convert_to_raw (regnum
, to
, from
)
420 struct cmd_list_element
*setmemorylist
;
423 z8k_set_pointer_size (newsize
)
426 static int oldsize
= 0;
428 if (oldsize
!= newsize
)
430 printf ("pointer size set to %d bits\n", newsize
);
440 _initialize_gdbtypes ();
445 segmented_command (args
, from_tty
)
449 z8k_set_pointer_size (32);
453 unsegmented_command (args
, from_tty
)
457 z8k_set_pointer_size (16);
462 set_memory (args
, from_tty
)
466 printf ("\"set memory\" must be followed by the name of a memory subcommand.\n");
467 help_list (setmemorylist
, "set memory ", -1, stdout
);
470 _initialize_z8ktdep ()
472 add_prefix_cmd ("memory", no_class
, set_memory
,
473 "set the memory model", &setmemorylist
, "set memory ", 0,
475 add_cmd ("segmented", class_support
, segmented_command
,
476 "Set segmented memory model.", &setmemorylist
);
477 add_cmd ("unsegmented", class_support
, unsegmented_command
,
478 "Set unsegmented memory model.", &setmemorylist
);