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 (frame)
47 struct frame_info *frame;
49 return read_memory_pointer (frame->frame + (BIG ? 4 : 2));
52 #define IS_PUSHL(x) (BIG ? ((x & 0xfff0) == 0x91e0):((x & 0xfff0) == 0x91F0))
53 #define IS_PUSHW(x) (BIG ? ((x & 0xfff0) == 0x93e0):((x & 0xfff0)==0x93f0))
54 #define IS_MOVE_FP(x) (BIG ? x == 0xa1ea : x == 0xa1fa)
55 #define IS_MOV_SP_FP(x) (BIG ? x == 0x94ea : x == 0x0d76)
56 #define IS_SUB2_SP(x) (x==0x1b87)
57 #define IS_MOVK_R5(x) (x==0x7905)
58 #define IS_SUB_SP(x) ((x & 0xffff) == 0x020f)
59 #define IS_PUSH_FP(x) (BIG ? (x == 0x93ea) : (x == 0x93fa))
61 /* work out how much local space is on the stack and
62 return the pc pointing to the first push */
65 skip_adjust (pc, size)
71 if (IS_PUSH_FP (read_memory_short (pc))
72 && IS_MOV_SP_FP (read_memory_short (pc + 2)))
74 /* This is a function with an explict frame pointer */
76 *size += 2; /* remember the frame pointer */
79 /* remember any stack adjustment */
80 if (IS_SUB_SP (read_memory_short (pc)))
82 *size += read_memory_short (pc + 2);
88 static CORE_ADDR examine_frame PARAMS ((CORE_ADDR, CORE_ADDR * regs, CORE_ADDR));
90 examine_frame (pc, regs, sp)
95 int w = read_memory_short (pc);
99 for (regno = 0; regno < NUM_REGS; regno++)
102 while (IS_PUSHW (w) || IS_PUSHL (w))
104 /* work out which register is being pushed to where */
107 regs[w & 0xf] = offset;
108 regs[(w & 0xf) + 1] = offset + 2;
113 regs[w & 0xf] = offset;
117 w = read_memory_short (pc);
125 else if (IS_SUB_SP (w))
127 /* Subtracting a value from the sp, so were in a function
128 which needs stack space for locals, but has no fp. We fake up
129 the values as if we had an fp */
130 regs[FP_REGNUM] = sp;
134 /* This one didn't have an fp, we'll fake it up */
135 regs[SP_REGNUM] = sp;
137 /* stack pointer contains address of next frame */
138 /* regs[fp_regnum()] = fp; */
139 regs[SP_REGNUM] = sp;
144 z8k_skip_prologue (start_pc)
147 CORE_ADDR dummy[NUM_REGS];
149 return examine_frame (start_pc, dummy, 0);
153 z8k_addr_bits_remove (addr)
156 return (addr & PTR_MASK);
160 read_memory_pointer (CORE_ADDR x)
162 return read_memory_integer (ADDR_BITS_REMOVE (x), BIG ? 4 : 2);
166 z8k_frame_chain (thisframe)
167 struct frame_info *thisframe;
169 if (thisframe->prev == 0)
171 /* This is the top of the stack, let's get the sp for real */
173 if (!inside_entry_file (thisframe->pc))
175 return read_memory_pointer (thisframe->frame);
186 /* Put here the code to store, into a struct frame_saved_regs,
187 the addresses of the saved registers of frame described by FRAME_INFO.
188 This includes special registers such as pc and fp saved in special
189 ways in the stack frame. sp is even more special:
190 the address we return for it IS the sp for the next frame. */
193 z8k_frame_init_saved_regs (frame_info)
194 struct frame_info *frame_info;
199 frame_saved_regs_zalloc (frame_info);
200 pc = get_pc_function_start (frame_info->pc);
202 /* wander down the instruction stream */
203 examine_frame (pc, frame_info->saved_regs, frame_info->frame);
208 z8k_push_dummy_frame ()
214 gdb_print_insn_z8k (memaddr, info)
216 disassemble_info *info;
219 return print_insn_z8001 (memaddr, info);
221 return print_insn_z8002 (memaddr, info);
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)
238 read_memory (addr, buf, 2);
239 *pword1 = extract_signed_integer (buf, 2);
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 = FRAME_FP (fip) - 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;
301 z8k_saved_pc_after_call (struct frame_info *frame)
303 return ADDR_BITS_REMOVE
304 (read_memory_integer (read_register (SP_REGNUM), PTR_SIZE));
309 extract_return_value (type, regbuf, valbuf)
315 int len = TYPE_LENGTH (type);
317 for (b = 0; b < len; b += 2)
323 memcpy (valbuf + b, regbuf + b, todo);
328 write_return_value (type, valbuf)
335 for (len = 0; len < TYPE_LENGTH (type); len += 2)
336 write_register_bytes (REGISTER_BYTE (len / 2 + 2), valbuf + len, 2);
340 store_struct_return (addr, sp)
344 write_register (2, addr);
349 z8k_print_register_hook (regno)
352 if ((regno & 1) == 0 && regno < 16)
356 read_relative_register_raw_bytes (regno, (char *) (l + 0));
357 read_relative_register_raw_bytes (regno + 1, (char *) (l + 1));
358 printf_unfiltered ("\t");
359 printf_unfiltered ("%04x%04x", l[0], l[1]);
362 if ((regno & 3) == 0 && regno < 16)
366 read_relative_register_raw_bytes (regno, (char *) (l + 0));
367 read_relative_register_raw_bytes (regno + 1, (char *) (l + 1));
368 read_relative_register_raw_bytes (regno + 2, (char *) (l + 2));
369 read_relative_register_raw_bytes (regno + 3, (char *) (l + 3));
371 printf_unfiltered ("\t");
372 printf_unfiltered ("%04x%04x%04x%04x", l[0], l[1], l[2], l[3]);
379 read_relative_register_raw_bytes (regno, (char *) (&rval));
381 printf_unfiltered ("\n");
382 for (i = 0; i < 10; i += 2)
384 printf_unfiltered ("(sp+%d=%04x)", i,
385 (unsigned int)read_memory_short (rval + i));
396 struct cmd_list_element *setmemorylist;
399 z8k_set_pointer_size (newsize)
402 static int oldsize = 0;
404 if (oldsize != newsize)
406 printf_unfiltered ("pointer size set to %d bits\n", newsize);
416 /* FIXME: This code should be using the GDBARCH framework to
417 handle changed type sizes. If this problem is ever fixed
418 (the direct reference to _initialize_gdbtypes() below
419 eliminated) then Makefile.in should be updated so that
420 z8k-tdep.c is again compiled with -Werror. */
421 _initialize_gdbtypes ();
426 segmented_command (args, from_tty)
430 z8k_set_pointer_size (32);
434 unsegmented_command (args, from_tty)
438 z8k_set_pointer_size (16);
442 set_memory (args, from_tty)
446 printf_unfiltered ("\"set memory\" must be followed by the name of a memory subcommand.\n");
447 help_list (setmemorylist, "set memory ", -1, gdb_stdout);
451 _initialize_z8ktdep ()
453 tm_print_insn = gdb_print_insn_z8k;
455 add_prefix_cmd ("memory", no_class, set_memory,
456 "set the memory model", &setmemorylist, "set memory ", 0,
458 add_cmd ("segmented", class_support, segmented_command,
459 "Set segmented memory model.", &setmemorylist);
460 add_cmd ("unsegmented", class_support, unsegmented_command,
461 "Set unsegmented memory model.", &setmemorylist);