1 /* Target-machine dependent code for Hitachi H8/300, for GDB.
2 Copyright (C) 1988, 1990, 1991 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
29 #define UNSIGNED_SHORT(X) ((X) & 0xffff)
31 /* an easy to debug H8 stack frame looks like:
35 0x7905 nnnn mov.w #n,r5 or 0x1b87 subs #2,sp
40 #define IS_PUSH(x) ((x & 0xff00)==0x6d00)
41 #define IS_PUSH_FP(x) (x == 0x6df6)
42 #define IS_MOVE_FP(x) (x == 0x0d76)
43 #define IS_MOV_SP_FP(x) (x == 0x0d76)
44 #define IS_SUB2_SP(x) (x==0x1b87)
45 #define IS_MOVK_R5(x) (x==0x7905)
46 #define IS_SUB_R5SP(x) (x==0x1957)
47 CORE_ADDR
examine_prologue ();
49 void frame_find_saved_regs ();
51 h8300_skip_prologue (start_pc
)
57 w
= read_memory_short (start_pc
);
58 /* Skip past all push insns */
59 while (IS_PUSH_FP (w
))
62 w
= read_memory_short (start_pc
);
65 /* Skip past a move to FP */
69 w
= read_memory_short (start_pc
);
72 /* Skip the stack adjust */
77 w
= read_memory_short (start_pc
);
82 w
= read_memory_short (start_pc
);
84 while (IS_SUB2_SP (w
))
87 w
= read_memory_short (start_pc
);
95 print_insn (memaddr
, stream
)
99 /* Nothing is bigger than 8 bytes */
102 read_memory (memaddr
, data
, sizeof (data
));
103 return print_insn_h8300 (memaddr
, data
, stream
);
106 /* Given a GDB frame, determine the address of the calling function's frame.
107 This will be used to create a new GDB frame struct, and then
108 INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame.
110 For us, the frame address is its stack pointer value, so we look up
111 the function prologue to determine the caller's sp value, and return it. */
114 FRAME_CHAIN (thisframe
)
118 frame_find_saved_regs (thisframe
, (struct frame_saved_regs
*) 0);
119 return thisframe
->fsr
->regs
[SP_REGNUM
];
122 /* Put here the code to store, into a struct frame_saved_regs,
123 the addresses of the saved registers of frame described by FRAME_INFO.
124 This includes special registers such as pc and fp saved in special
125 ways in the stack frame. sp is even more special:
126 the address we return for it IS the sp for the next frame.
128 We cache the result of doing this in the frame_cache_obstack, since
129 it is fairly expensive. */
132 frame_find_saved_regs (fi
, fsr
)
133 struct frame_info
*fi
;
134 struct frame_saved_regs
*fsr
;
136 register CORE_ADDR next_addr
;
137 register CORE_ADDR
*saved_regs
;
139 register struct frame_saved_regs
*cache_fsr
;
140 extern struct obstack frame_cache_obstack
;
142 struct symtab_and_line sal
;
147 cache_fsr
= (struct frame_saved_regs
*)
148 obstack_alloc (&frame_cache_obstack
,
149 sizeof (struct frame_saved_regs
));
150 bzero (cache_fsr
, sizeof (struct frame_saved_regs
));
154 /* Find the start and end of the function prologue. If the PC
155 is in the function prologue, we only consider the part that
156 has executed already. */
158 ip
= get_pc_function_start (fi
->pc
);
159 sal
= find_pc_line (ip
, 0);
160 limit
= (sal
.end
&& sal
.end
< fi
->pc
) ? sal
.end
: fi
->pc
;
162 /* This will fill in fields in *fi as well as in cache_fsr. */
163 examine_prologue (ip
, limit
, fi
->frame
, cache_fsr
, fi
);
170 /* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or
171 is not the address of a valid instruction, the address of the next
172 instruction beyond ADDR otherwise. *PWORD1 receives the first word
173 of the instruction.*/
176 NEXT_PROLOGUE_INSN (addr
, lim
, pword1
)
183 read_memory (addr
, pword1
, sizeof (*pword1
));
184 SWAP_TARGET_AND_HOST (pword1
, sizeof (short));
191 /* Examine the prologue of a function. `ip' points to the first instruction.
192 `limit' is the limit of the prologue (e.g. the addr of the first
193 linenumber, or perhaps the program counter if we're stepping through).
194 `frame_sp' is the stack pointer value in use in this frame.
195 `fsr' is a pointer to a frame_saved_regs structure into which we put
196 info about the registers saved by this frame.
197 `fi' is a struct frame_info pointer; we fill in various fields in it
198 to reflect the offsets of the arg pointer and the locals pointer. */
201 examine_prologue (ip
, limit
, after_prolog_fp
, fsr
, fi
)
202 register CORE_ADDR ip
;
203 register CORE_ADDR limit
;
204 FRAME_ADDR after_prolog_fp
;
205 struct frame_saved_regs
*fsr
;
206 struct frame_info
*fi
;
208 register CORE_ADDR next_ip
;
214 register struct pic_prologue_code
*pcode
;
217 unsigned int reg_save_depth
= 2; /* Number of things pushed onto
218 stack, starts at 2, 'cause the
219 PC is already there */
221 unsigned int auto_depth
= 0; /* Number of bytes of autos */
223 char in_frame
[NUM_REGS
]; /* One for each reg */
225 memset (in_frame
, 1, NUM_REGS
);
226 for (r
= 0; r
< NUM_REGS
; r
++)
230 if (after_prolog_fp
== 0)
232 after_prolog_fp
= read_register (SP_REGNUM
);
234 if (ip
== 0 || ip
& ~0xffff)
237 next_ip
= NEXT_PROLOGUE_INSN (ip
, limit
, &insn_word
);
239 /* Skip over any fp push instructions */
240 fsr
->regs
[6] = after_prolog_fp
;
241 while (next_ip
&& IS_PUSH_FP (insn_word
))
245 in_frame
[insn_word
& 0x7] = reg_save_depth
;
246 next_ip
= NEXT_PROLOGUE_INSN (ip
, limit
, &insn_word
);
250 /* Is this a move into the fp */
251 if (next_ip
&& IS_MOV_SP_FP (insn_word
))
254 next_ip
= NEXT_PROLOGUE_INSN (ip
, limit
, &insn_word
);
258 /* Skip over any stack adjustment, happens either with a number of
259 sub#2,sp or a mov #x,r5 sub r5,sp */
261 if (next_ip
&& IS_SUB2_SP (insn_word
))
263 while (next_ip
&& IS_SUB2_SP (insn_word
))
267 next_ip
= NEXT_PROLOGUE_INSN (ip
, limit
, &insn_word
);
272 if (next_ip
&& IS_MOVK_R5 (insn_word
))
275 next_ip
= NEXT_PROLOGUE_INSN (ip
, limit
, &insn_word
);
276 auto_depth
+= insn_word
;
278 next_ip
= NEXT_PROLOGUE_INSN (next_ip
, limit
, &insn_word
);
279 auto_depth
+= insn_word
;
283 /* Work out which regs are stored where */
284 while (next_ip
&& IS_PUSH (insn_word
))
287 next_ip
= NEXT_PROLOGUE_INSN (ip
, limit
, &insn_word
);
288 fsr
->regs
[r
] = after_prolog_fp
+ auto_depth
;
292 /* The args are always reffed based from the stack pointer */
293 fi
->args_pointer
= after_prolog_fp
;
294 /* Locals are always reffed based from the fp */
295 fi
->locals_pointer
= after_prolog_fp
;
296 /* The PC is at a known place */
297 fi
->from_pc
= read_memory_short (after_prolog_fp
+ 2);
299 /* Rememeber any others too */
300 in_frame
[PC_REGNUM
] = 0;
303 /* We keep the old FP in the SP spot */
304 fsr
->regs
[SP_REGNUM
] = (read_memory_short (fsr
->regs
[6]));
306 fsr
->regs
[SP_REGNUM
] = after_prolog_fp
+ auto_depth
;
312 init_extra_frame_info (fromleaf
, fi
)
314 struct frame_info
*fi
;
316 fi
->fsr
= 0; /* Not yet allocated */
317 fi
->args_pointer
= 0; /* Unknown */
318 fi
->locals_pointer
= 0; /* Unknown */
323 /* Return the saved PC from this frame.
325 If the frame has a memory copy of SRP_REGNUM, use that. If not,
326 just use the register SRP_REGNUM itself. */
329 frame_saved_pc (frame
)
333 return frame
->from_pc
;
337 frame_locals_address (fi
)
338 struct frame_info
*fi
;
340 if (!fi
->locals_pointer
)
342 struct frame_saved_regs ignore
;
344 get_frame_saved_regs (fi
, &ignore
);
347 return fi
->locals_pointer
;
350 /* Return the address of the argument block for the frame
351 described by FI. Returns 0 if the address is unknown. */
354 frame_args_address (fi
)
355 struct frame_info
*fi
;
357 if (!fi
->args_pointer
)
359 struct frame_saved_regs ignore
;
361 get_frame_saved_regs (fi
, &ignore
);
365 return fi
->args_pointer
;
372 struct frame_saved_regs fsr
;
373 struct frame_info
*fi
;
375 FRAME frame
= get_current_frame ();
377 fi
= get_frame_info (frame
);
378 get_frame_saved_regs (fi
, &fsr
);
380 for (regnum
= 0; regnum
< NUM_REGS
; regnum
++)
382 if (fsr
.regs
[regnum
])
384 write_register (regnum
, read_memory_short (fsr
.regs
[regnum
]));
387 flush_cached_frames ();
388 set_current_frame (create_new_frame (read_register (FP_REGNUM
),
396 print_register_hook (regno
)
406 read_relative_register_raw_bytes (regno
, b
);
409 printf ("I-%d - ", (l
& 0x80) != 0);
410 printf ("H-%d - ", (l
& 0x20) != 0);
435 if ((Z
| (N
^ V
)) == 0)
437 if ((Z
| (N
^ V
)) == 1)