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., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 Contributed by Steve Chamberlain
34 #include "gdb_string.h"
37 extern int h8300hmode, h8300smode;
42 #define UNSIGNED_SHORT(X) ((X) & 0xffff)
44 #define IS_PUSH(x) ((x & 0xfff0)==0x6df0)
45 #define IS_PUSH_FP(x) (x == 0x6df6)
46 #define IS_MOVE_FP(x) (x == 0x0d76 || x == 0x0ff6)
47 #define IS_MOV_SP_FP(x) (x == 0x0d76 || x == 0x0ff6)
48 #define IS_SUB2_SP(x) (x==0x1b87)
49 #define IS_SUB4_SP(x) (x==0x1b97)
50 #define IS_SUBL_SP(x) (x==0x7a37)
51 #define IS_MOVK_R5(x) (x==0x7905)
52 #define IS_SUB_R5SP(x) (x==0x1957)
55 /* The register names change depending on whether the h8300h processor
58 static char *original_register_names[] = REGISTER_NAMES;
60 static char *h8300h_register_names[] =
61 {"er0", "er1", "er2", "er3", "er4", "er5", "er6",
62 "sp", "ccr", "pc", "cycles", "tick", "inst"};
64 char **h8300_register_names = original_register_names;
67 /* Local function declarations. */
69 static CORE_ADDR examine_prologue ();
70 static void set_machine_hook (char *filename);
72 void h8300_frame_find_saved_regs ();
75 h8300_skip_prologue (CORE_ADDR start_pc)
80 /* Skip past all push and stm insns. */
83 w = read_memory_unsigned_integer (start_pc, 2);
84 /* First look for push insns. */
85 if (w == 0x0100 || w == 0x0110 || w == 0x0120 || w == 0x0130)
87 w = read_memory_unsigned_integer (start_pc + 2, 2);
93 start_pc += 2 + adjust;
94 w = read_memory_unsigned_integer (start_pc, 2);
101 /* Skip past a move to FP, either word or long sized */
102 w = read_memory_unsigned_integer (start_pc, 2);
105 w = read_memory_unsigned_integer (start_pc + 2, 2);
111 start_pc += 2 + adjust;
112 w = read_memory_unsigned_integer (start_pc, 2);
115 /* Check for loading either a word constant into r5;
116 long versions are handled by the SUBL_SP below. */
120 w = read_memory_unsigned_integer (start_pc, 2);
123 /* Now check for subtracting r5 from sp, word sized only. */
126 start_pc += 2 + adjust;
127 w = read_memory_unsigned_integer (start_pc, 2);
130 /* Check for subs #2 and subs #4. */
131 while (IS_SUB2_SP (w) || IS_SUB4_SP (w))
133 start_pc += 2 + adjust;
134 w = read_memory_unsigned_integer (start_pc, 2);
137 /* Check for a 32bit subtract. */
139 start_pc += 6 + adjust;
145 gdb_print_insn_h8300 (bfd_vma memaddr, disassemble_info *info)
148 return print_insn_h8300s (memaddr, info);
150 return print_insn_h8300h (memaddr, info);
152 return print_insn_h8300 (memaddr, info);
155 /* Given a GDB frame, determine the address of the calling function's frame.
156 This will be used to create a new GDB frame struct, and then
157 INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame.
159 For us, the frame address is its stack pointer value, so we look up
160 the function prologue to determine the caller's sp value, and return it. */
163 h8300_frame_chain (struct frame_info *thisframe)
165 if (PC_IN_CALL_DUMMY (thisframe->pc, thisframe->frame, thisframe->frame))
166 { /* initialize the from_pc now */
167 thisframe->from_pc = generic_read_register_dummy (thisframe->pc,
170 return thisframe->frame;
172 h8300_frame_find_saved_regs (thisframe, (struct frame_saved_regs *) 0);
173 return thisframe->fsr->regs[SP_REGNUM];
176 /* Put here the code to store, into a struct frame_saved_regs,
177 the addresses of the saved registers of frame described by FRAME_INFO.
178 This includes special registers such as pc and fp saved in special
179 ways in the stack frame. sp is even more special:
180 the address we return for it IS the sp for the next frame.
182 We cache the result of doing this in the frame_obstack, since it is
186 h8300_frame_find_saved_regs (struct frame_info *fi,
187 struct frame_saved_regs *fsr)
189 register struct frame_saved_regs *cache_fsr;
191 struct symtab_and_line sal;
196 cache_fsr = (struct frame_saved_regs *)
197 frame_obstack_alloc (sizeof (struct frame_saved_regs));
198 memset (cache_fsr, '\0', sizeof (struct frame_saved_regs));
202 if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
203 { /* no more to do. */
208 /* Find the start and end of the function prologue. If the PC
209 is in the function prologue, we only consider the part that
210 has executed already. */
212 ip = get_pc_function_start (fi->pc);
213 sal = find_pc_line (ip, 0);
214 limit = (sal.end && sal.end < fi->pc) ? sal.end : fi->pc;
216 /* This will fill in fields in *fi as well as in cache_fsr. */
217 examine_prologue (ip, limit, fi->frame, cache_fsr, fi);
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 (CORE_ADDR addr, CORE_ADDR lim, INSN_WORD *pword1)
235 read_memory (addr, buf, 2);
236 *pword1 = extract_signed_integer (buf, 2);
243 /* Examine the prologue of a function. `ip' points to the first instruction.
244 `limit' is the limit of the prologue (e.g. the addr of the first
245 linenumber, or perhaps the program counter if we're stepping through).
246 `frame_sp' is the stack pointer value in use in this frame.
247 `fsr' is a pointer to a frame_saved_regs structure into which we put
248 info about the registers saved by this frame.
249 `fi' is a struct frame_info pointer; we fill in various fields in it
250 to reflect the offsets of the arg pointer and the locals pointer. */
253 examine_prologue (register CORE_ADDR ip, register CORE_ADDR limit,
254 CORE_ADDR after_prolog_fp, struct frame_saved_regs *fsr,
255 struct frame_info *fi)
257 register CORE_ADDR next_ip;
261 /* Number of things pushed onto stack, starts at 2/4, 'cause the
262 PC is already there */
263 unsigned int reg_save_depth = h8300hmode ? 4 : 2;
265 unsigned int auto_depth = 0; /* Number of bytes of autos */
267 char in_frame[11]; /* One for each reg */
271 memset (in_frame, 1, 11);
272 for (r = 0; r < 8; r++)
276 if (after_prolog_fp == 0)
278 after_prolog_fp = read_register (SP_REGNUM);
281 /* If the PC isn't valid, quit now. */
282 if (ip == 0 || ip & (h8300hmode ? ~0xffffff : ~0xffff))
285 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
287 if (insn_word == 0x0100)
289 insn_word = read_memory_unsigned_integer (ip + 2, 2);
293 /* Skip over any fp push instructions */
294 fsr->regs[6] = after_prolog_fp;
295 while (next_ip && IS_PUSH_FP (insn_word))
297 ip = next_ip + adjust;
299 in_frame[insn_word & 0x7] = reg_save_depth;
300 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
301 reg_save_depth += 2 + adjust;
304 /* Is this a move into the fp */
305 if (next_ip && IS_MOV_SP_FP (insn_word))
308 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
312 /* Skip over any stack adjustment, happens either with a number of
313 sub#2,sp or a mov #x,r5 sub r5,sp */
315 if (next_ip && (IS_SUB2_SP (insn_word) || IS_SUB4_SP (insn_word)))
317 while (next_ip && (IS_SUB2_SP (insn_word) || IS_SUB4_SP (insn_word)))
319 auto_depth += IS_SUB2_SP (insn_word) ? 2 : 4;
321 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
326 if (next_ip && IS_MOVK_R5 (insn_word))
329 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
330 auto_depth += insn_word;
332 next_ip = NEXT_PROLOGUE_INSN (next_ip, limit, &insn_word);
333 auto_depth += insn_word;
335 if (next_ip && IS_SUBL_SP (insn_word))
338 auto_depth += read_memory_unsigned_integer (ip, 4);
341 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
345 /* Now examine the push insns to determine where everything lives
353 if (insn_word == 0x0100)
356 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
360 if (IS_PUSH (insn_word))
363 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
364 fsr->regs[r] = after_prolog_fp + auto_depth;
365 auto_depth += 2 + adjust;
369 /* Now check for push multiple insns. */
370 if (insn_word == 0x0110 || insn_word == 0x0120 || insn_word == 0x0130)
372 int count = ((insn_word >> 4) & 0xf) + 1;
376 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
377 start = insn_word & 0x7;
379 for (i = start; i <= start + count; i++)
381 fsr->regs[i] = after_prolog_fp + auto_depth;
388 /* The args are always reffed based from the stack pointer */
389 fi->args_pointer = after_prolog_fp;
390 /* Locals are always reffed based from the fp */
391 fi->locals_pointer = after_prolog_fp;
392 /* The PC is at a known place */
393 fi->from_pc = read_memory_unsigned_integer (after_prolog_fp + BINWORD, BINWORD);
395 /* Rememeber any others too */
396 in_frame[PC_REGNUM] = 0;
399 /* We keep the old FP in the SP spot */
400 fsr->regs[SP_REGNUM] = read_memory_unsigned_integer (fsr->regs[6], BINWORD);
402 fsr->regs[SP_REGNUM] = after_prolog_fp + auto_depth;
408 h8300_init_extra_frame_info (int fromleaf, struct frame_info *fi)
410 fi->fsr = 0; /* Not yet allocated */
411 fi->args_pointer = 0; /* Unknown */
412 fi->locals_pointer = 0; /* Unknown */
414 if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
415 { /* anything special to do? */
420 /* Return the saved PC from this frame.
422 If the frame has a memory copy of SRP_REGNUM, use that. If not,
423 just use the register SRP_REGNUM itself. */
426 h8300_frame_saved_pc (struct frame_info *frame)
428 if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
429 return generic_read_register_dummy (frame->pc, frame->frame, PC_REGNUM);
431 return frame->from_pc;
435 frame_locals_address (struct frame_info *fi)
437 if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
438 return (CORE_ADDR) 0; /* Not sure what else to do... */
439 if (!fi->locals_pointer)
441 struct frame_saved_regs ignore;
443 get_frame_saved_regs (fi, &ignore);
446 return fi->locals_pointer;
449 /* Return the address of the argument block for the frame
450 described by FI. Returns 0 if the address is unknown. */
453 frame_args_address (struct frame_info *fi)
455 if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
456 return (CORE_ADDR) 0; /* Not sure what else to do... */
457 if (!fi->args_pointer)
459 struct frame_saved_regs ignore;
461 get_frame_saved_regs (fi, &ignore);
465 return fi->args_pointer;
468 /* Function: push_arguments
469 Setup the function arguments for calling a function in the inferior.
471 On the Hitachi H8/300 architecture, there are three registers (R0 to R2)
472 which are dedicated for passing function arguments. Up to the first
473 three arguments (depending on size) may go into these registers.
474 The rest go on the stack.
476 Arguments that are smaller than WORDSIZE bytes will still take up a
477 whole register or a whole WORDSIZE word on the stack, and will be
478 right-justified in the register or the stack word. This includes
479 chars and small aggregate types. Note that WORDSIZE depends on the
482 Arguments that are larger than WORDSIZE bytes will be split between
483 two or more registers as available, but will NOT be split between a
484 register and the stack.
486 An exceptional case exists for struct arguments (and possibly other
487 aggregates such as arrays) -- if the size is larger than WORDSIZE
488 bytes but not a multiple of WORDSIZE bytes. In this case the
489 argument is never split between the registers and the stack, but
490 instead is copied in its entirety onto the stack, AND also copied
491 into as many registers as there is room for. In other words, space
492 in registers permitting, two copies of the same argument are passed
493 in. As far as I can tell, only the one on the stack is used,
494 although that may be a function of the level of compiler
495 optimization. I suspect this is a compiler bug. Arguments of
496 these odd sizes are left-justified within the word (as opposed to
497 arguments smaller than WORDSIZE bytes, which are right-justified).
499 If the function is to return an aggregate type such as a struct,
500 the caller must allocate space into which the callee will copy the
501 return value. In this case, a pointer to the return value location
502 is passed into the callee in register R0, which displaces one of
503 the other arguments passed in via registers R0 to R2. */
506 h8300_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
507 unsigned char struct_return, CORE_ADDR struct_addr)
509 int stack_align, stack_alloc, stack_offset;
519 if (h8300hmode || h8300smode)
530 /* first force sp to a n-byte alignment */
531 sp = sp & ~stack_align;
533 /* Now make sure there's space on the stack */
534 for (argnum = 0, stack_alloc = 0;
535 argnum < nargs; argnum++)
536 stack_alloc += ((TYPE_LENGTH (VALUE_TYPE (args[argnum])) + stack_align)
538 sp -= stack_alloc; /* make room on stack for args */
539 /* we may over-allocate a little here, but that won't hurt anything */
541 argreg = ARG0_REGNUM;
542 if (struct_return) /* "struct return" pointer takes up one argreg */
544 write_register (argreg++, struct_addr);
547 /* Now load as many as possible of the first arguments into
548 registers, and push the rest onto the stack. There are 3N bytes
549 in three registers available. Loop thru args from first to last. */
551 for (argnum = 0, stack_offset = 0; argnum < nargs; argnum++)
553 type = VALUE_TYPE (args[argnum]);
554 len = TYPE_LENGTH (type);
555 memset (valbuf, 0, sizeof (valbuf));
558 /* the purpose of this is to right-justify the value within the word */
559 memcpy (valbuf + (wordsize - len),
560 (char *) VALUE_CONTENTS (args[argnum]), len);
564 val = (char *) VALUE_CONTENTS (args[argnum]);
566 if (len > (ARGLAST_REGNUM + 1 - argreg) * REGISTER_RAW_SIZE (ARG0_REGNUM) ||
567 (len > wordsize && (len & stack_align) != 0))
568 { /* passed on the stack */
569 write_memory (sp + stack_offset, val,
570 len < wordsize ? wordsize : len);
571 stack_offset += (len + stack_align) & ~stack_align;
573 /* NOTE WELL!!!!! This is not an "else if" clause!!!
574 That's because some *&^%$ things get passed on the stack
575 AND in the registers! */
576 if (len <= (ARGLAST_REGNUM + 1 - argreg) * REGISTER_RAW_SIZE (ARG0_REGNUM))
578 { /* there's room in registers */
579 regval = extract_address (val, wordsize);
580 write_register (argreg, regval);
589 /* Function: push_return_address
590 Setup the return address for a dummy frame, as called by
591 call_function_by_hand. Only necessary when you are using an
592 empty CALL_DUMMY, ie. the target will not actually be executing
593 a JSR/BSR instruction. */
596 h8300_push_return_address (CORE_ADDR pc, CORE_ADDR sp)
598 unsigned char buf[4];
601 if (h8300hmode || h8300smode)
607 store_unsigned_integer (buf, wordsize, CALL_DUMMY_ADDRESS ());
608 write_memory (sp, buf, wordsize);
612 /* Function: pop_frame
613 Restore the machine to the state it had before the current frame
614 was created. Usually used either by the "RETURN" command, or by
615 call_function_by_hand after the dummy_frame is finished. */
618 h8300_pop_frame (void)
621 struct frame_saved_regs fsr;
622 struct frame_info *frame = get_current_frame ();
624 if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
626 generic_pop_dummy_frame ();
630 get_frame_saved_regs (frame, &fsr);
632 for (regnum = 0; regnum < 8; regnum++)
634 /* Don't forget SP_REGNUM is a frame_saved_regs struct is the
635 actual value we want, not the address of the value we want. */
636 if (fsr.regs[regnum] && regnum != SP_REGNUM)
637 write_register (regnum,
638 read_memory_integer (fsr.regs[regnum], BINWORD));
639 else if (fsr.regs[regnum] && regnum == SP_REGNUM)
640 write_register (regnum, frame->frame + 2 * BINWORD);
643 /* Don't forget the update the PC too! */
644 write_pc (frame->from_pc);
646 flush_cached_frames ();
649 /* Function: extract_return_value
650 Figure out where in REGBUF the called function has left its return value.
651 Copy that into VALBUF. Be sure to account for CPU type. */
654 h8300_extract_return_value (struct type *type, char *regbuf, char *valbuf)
658 if (h8300smode || h8300hmode)
663 len = TYPE_LENGTH (type);
668 case 2: /* (short), (int) */
669 memcpy (valbuf, regbuf + REGISTER_BYTE (0) + (wordsize - len), len);
671 case 4: /* (long), (float) */
672 if (h8300smode || h8300hmode)
674 memcpy (valbuf, regbuf + REGISTER_BYTE (0), 4);
678 memcpy (valbuf, regbuf + REGISTER_BYTE (0), 2);
679 memcpy (valbuf + 2, regbuf + REGISTER_BYTE (1), 2);
682 case 8: /* (double) (doesn't seem to happen, which is good,
683 because this almost certainly isn't right. */
684 error ("I don't know how a double is returned.");
689 /* Function: store_return_value
690 Place the appropriate value in the appropriate registers.
691 Primarily used by the RETURN command. */
694 h8300_store_return_value (struct type *type, char *valbuf)
696 int wordsize, len, regval;
698 if (h8300hmode || h8300smode)
703 len = TYPE_LENGTH (type);
707 case 2: /* short, int */
708 regval = extract_address (valbuf, len);
709 write_register (0, regval);
711 case 4: /* long, float */
712 regval = extract_address (valbuf, len);
713 if (h8300smode || h8300hmode)
715 write_register (0, regval);
719 write_register (0, regval >> 16);
720 write_register (1, regval & 0xffff);
723 case 8: /* presumeably double, but doesn't seem to happen */
724 error ("I don't know how to return a double.");
729 struct cmd_list_element *setmemorylist;
732 set_register_names (void)
735 h8300_register_names = h8300h_register_names;
737 h8300_register_names = original_register_names;
741 h8300_command (int args, int from_tty)
743 extern int h8300hmode;
746 set_register_names ();
750 h8300h_command (int args, int from_tty)
752 extern int h8300hmode;
755 set_register_names ();
759 h8300s_command (int args, int from_tty)
761 extern int h8300smode;
762 extern int h8300hmode;
765 set_register_names ();
770 set_machine (char *args, int from_tty)
772 printf_unfiltered ("\"set machine\" must be followed by h8300, h8300h");
773 printf_unfiltered ("or h8300s");
774 help_list (setmemorylist, "set memory ", -1, gdb_stdout);
777 /* set_machine_hook is called as the exec file is being opened, but
778 before the symbol file is opened. This allows us to set the
779 h8300hmode flag based on the machine type specified in the exec
780 file. This in turn will cause subsequently defined pointer types
781 to be 16 or 32 bits as appropriate for the machine. */
784 set_machine_hook (char *filename)
786 if (bfd_get_mach (exec_bfd) == bfd_mach_h8300s)
791 else if (bfd_get_mach (exec_bfd) == bfd_mach_h8300h)
801 set_register_names ();
805 _initialize_h8300m (void)
807 add_prefix_cmd ("machine", no_class, set_machine,
808 "set the machine type",
809 &setmemorylist, "set machine ", 0,
812 add_cmd ("h8300", class_support, h8300_command,
813 "Set machine to be H8/300.", &setmemorylist);
815 add_cmd ("h8300h", class_support, h8300h_command,
816 "Set machine to be H8/300H.", &setmemorylist);
818 add_cmd ("h8300s", class_support, h8300s_command,
819 "Set machine to be H8/300S.", &setmemorylist);
821 /* Add a hook to set the machine type when we're loading a file. */
823 specify_exec_file_hook (set_machine_hook);
829 print_register_hook (int regno)
837 read_relative_register_raw_bytes (regno, b);
838 l = b[REGISTER_VIRTUAL_SIZE (8) - 1];
839 printf_unfiltered ("\t");
840 printf_unfiltered ("I-%d - ", (l & 0x80) != 0);
841 printf_unfiltered ("H-%d - ", (l & 0x20) != 0);
846 printf_unfiltered ("N-%d ", N);
847 printf_unfiltered ("Z-%d ", Z);
848 printf_unfiltered ("V-%d ", V);
849 printf_unfiltered ("C-%d ", C);
851 printf_unfiltered ("u> ");
853 printf_unfiltered ("u<= ");
855 printf_unfiltered ("u>= ");
857 printf_unfiltered ("u< ");
859 printf_unfiltered ("!= ");
861 printf_unfiltered ("== ");
863 printf_unfiltered (">= ");
865 printf_unfiltered ("< ");
866 if ((Z | (N ^ V)) == 0)
867 printf_unfiltered ("> ");
868 if ((Z | (N ^ V)) == 1)
869 printf_unfiltered ("<= ");
874 _initialize_h8300_tdep (void)
876 tm_print_insn = gdb_print_insn_h8300;