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 PARAMS ((char *filename));
72 void h8300_frame_find_saved_regs ();
75 h8300_skip_prologue (start_pc)
81 /* Skip past all push and stm insns. */
84 w = read_memory_unsigned_integer (start_pc, 2);
85 /* First look for push insns. */
86 if (w == 0x0100 || w == 0x0110 || w == 0x0120 || w == 0x0130)
88 w = read_memory_unsigned_integer (start_pc + 2, 2);
94 start_pc += 2 + adjust;
95 w = read_memory_unsigned_integer (start_pc, 2);
102 /* Skip past a move to FP, either word or long sized */
103 w = read_memory_unsigned_integer (start_pc, 2);
106 w = read_memory_unsigned_integer (start_pc + 2, 2);
112 start_pc += 2 + adjust;
113 w = read_memory_unsigned_integer (start_pc, 2);
116 /* Check for loading either a word constant into r5;
117 long versions are handled by the SUBL_SP below. */
121 w = read_memory_unsigned_integer (start_pc, 2);
124 /* Now check for subtracting r5 from sp, word sized only. */
127 start_pc += 2 + adjust;
128 w = read_memory_unsigned_integer (start_pc, 2);
131 /* Check for subs #2 and subs #4. */
132 while (IS_SUB2_SP (w) || IS_SUB4_SP (w))
134 start_pc += 2 + adjust;
135 w = read_memory_unsigned_integer (start_pc, 2);
138 /* Check for a 32bit subtract. */
140 start_pc += 6 + adjust;
146 gdb_print_insn_h8300 (memaddr, info)
148 disassemble_info *info;
151 return print_insn_h8300s (memaddr, info);
153 return print_insn_h8300h (memaddr, info);
155 return print_insn_h8300 (memaddr, info);
158 /* Given a GDB frame, determine the address of the calling function's frame.
159 This will be used to create a new GDB frame struct, and then
160 INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame.
162 For us, the frame address is its stack pointer value, so we look up
163 the function prologue to determine the caller's sp value, and return it. */
166 h8300_frame_chain (thisframe)
167 struct frame_info *thisframe;
169 if (PC_IN_CALL_DUMMY (thisframe->pc, thisframe->frame, thisframe->frame))
170 { /* initialize the from_pc now */
171 thisframe->from_pc = generic_read_register_dummy (thisframe->pc,
174 return thisframe->frame;
176 h8300_frame_find_saved_regs (thisframe, (struct frame_saved_regs *) 0);
177 return thisframe->fsr->regs[SP_REGNUM];
180 /* Put here the code to store, into a struct frame_saved_regs,
181 the addresses of the saved registers of frame described by FRAME_INFO.
182 This includes special registers such as pc and fp saved in special
183 ways in the stack frame. sp is even more special:
184 the address we return for it IS the sp for the next frame.
186 We cache the result of doing this in the frame_obstack, since it is
190 h8300_frame_find_saved_regs (fi, fsr)
191 struct frame_info *fi;
192 struct frame_saved_regs *fsr;
194 register struct frame_saved_regs *cache_fsr;
196 struct symtab_and_line sal;
201 cache_fsr = (struct frame_saved_regs *)
202 frame_obstack_alloc (sizeof (struct frame_saved_regs));
203 memset (cache_fsr, '\0', sizeof (struct frame_saved_regs));
207 if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
208 { /* no more to do. */
213 /* Find the start and end of the function prologue. If the PC
214 is in the function prologue, we only consider the part that
215 has executed already. */
217 ip = get_pc_function_start (fi->pc);
218 sal = find_pc_line (ip, 0);
219 limit = (sal.end && sal.end < fi->pc) ? sal.end : fi->pc;
221 /* This will fill in fields in *fi as well as in cache_fsr. */
222 examine_prologue (ip, limit, fi->frame, cache_fsr, fi);
229 /* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or
230 is not the address of a valid instruction, the address of the next
231 instruction beyond ADDR otherwise. *PWORD1 receives the first word
232 of the instruction. */
235 NEXT_PROLOGUE_INSN (addr, lim, pword1)
243 read_memory (addr, buf, 2);
244 *pword1 = extract_signed_integer (buf, 2);
251 /* Examine the prologue of a function. `ip' points to the first instruction.
252 `limit' is the limit of the prologue (e.g. the addr of the first
253 linenumber, or perhaps the program counter if we're stepping through).
254 `frame_sp' is the stack pointer value in use in this frame.
255 `fsr' is a pointer to a frame_saved_regs structure into which we put
256 info about the registers saved by this frame.
257 `fi' is a struct frame_info pointer; we fill in various fields in it
258 to reflect the offsets of the arg pointer and the locals pointer. */
261 examine_prologue (ip, limit, after_prolog_fp, fsr, fi)
262 register CORE_ADDR ip;
263 register CORE_ADDR limit;
264 CORE_ADDR after_prolog_fp;
265 struct frame_saved_regs *fsr;
266 struct frame_info *fi;
268 register CORE_ADDR next_ip;
272 /* Number of things pushed onto stack, starts at 2/4, 'cause the
273 PC is already there */
274 unsigned int reg_save_depth = h8300hmode ? 4 : 2;
276 unsigned int auto_depth = 0; /* Number of bytes of autos */
278 char in_frame[11]; /* One for each reg */
282 memset (in_frame, 1, 11);
283 for (r = 0; r < 8; r++)
287 if (after_prolog_fp == 0)
289 after_prolog_fp = read_register (SP_REGNUM);
292 /* If the PC isn't valid, quit now. */
293 if (ip == 0 || ip & (h8300hmode ? ~0xffffff : ~0xffff))
296 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
298 if (insn_word == 0x0100)
300 insn_word = read_memory_unsigned_integer (ip + 2, 2);
304 /* Skip over any fp push instructions */
305 fsr->regs[6] = after_prolog_fp;
306 while (next_ip && IS_PUSH_FP (insn_word))
308 ip = next_ip + adjust;
310 in_frame[insn_word & 0x7] = reg_save_depth;
311 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
312 reg_save_depth += 2 + adjust;
315 /* Is this a move into the fp */
316 if (next_ip && IS_MOV_SP_FP (insn_word))
319 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
323 /* Skip over any stack adjustment, happens either with a number of
324 sub#2,sp or a mov #x,r5 sub r5,sp */
326 if (next_ip && (IS_SUB2_SP (insn_word) || IS_SUB4_SP (insn_word)))
328 while (next_ip && (IS_SUB2_SP (insn_word) || IS_SUB4_SP (insn_word)))
330 auto_depth += IS_SUB2_SP (insn_word) ? 2 : 4;
332 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
337 if (next_ip && IS_MOVK_R5 (insn_word))
340 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
341 auto_depth += insn_word;
343 next_ip = NEXT_PROLOGUE_INSN (next_ip, limit, &insn_word);
344 auto_depth += insn_word;
346 if (next_ip && IS_SUBL_SP (insn_word))
349 auto_depth += read_memory_unsigned_integer (ip, 4);
352 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
356 /* Now examine the push insns to determine where everything lives
364 if (insn_word == 0x0100)
367 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
371 if (IS_PUSH (insn_word))
374 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
375 fsr->regs[r] = after_prolog_fp + auto_depth;
376 auto_depth += 2 + adjust;
380 /* Now check for push multiple insns. */
381 if (insn_word == 0x0110 || insn_word == 0x0120 || insn_word == 0x0130)
383 int count = ((insn_word >> 4) & 0xf) + 1;
387 next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
388 start = insn_word & 0x7;
390 for (i = start; i <= start + count; i++)
392 fsr->regs[i] = after_prolog_fp + auto_depth;
399 /* The args are always reffed based from the stack pointer */
400 fi->args_pointer = after_prolog_fp;
401 /* Locals are always reffed based from the fp */
402 fi->locals_pointer = after_prolog_fp;
403 /* The PC is at a known place */
404 fi->from_pc = read_memory_unsigned_integer (after_prolog_fp + BINWORD, BINWORD);
406 /* Rememeber any others too */
407 in_frame[PC_REGNUM] = 0;
410 /* We keep the old FP in the SP spot */
411 fsr->regs[SP_REGNUM] = read_memory_unsigned_integer (fsr->regs[6], BINWORD);
413 fsr->regs[SP_REGNUM] = after_prolog_fp + auto_depth;
419 h8300_init_extra_frame_info (fromleaf, fi)
421 struct frame_info *fi;
423 fi->fsr = 0; /* Not yet allocated */
424 fi->args_pointer = 0; /* Unknown */
425 fi->locals_pointer = 0; /* Unknown */
427 if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
428 { /* anything special to do? */
433 /* Return the saved PC from this frame.
435 If the frame has a memory copy of SRP_REGNUM, use that. If not,
436 just use the register SRP_REGNUM itself. */
439 h8300_frame_saved_pc (frame)
440 struct frame_info *frame;
442 if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
443 return generic_read_register_dummy (frame->pc, frame->frame, PC_REGNUM);
445 return frame->from_pc;
449 frame_locals_address (fi)
450 struct frame_info *fi;
452 if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
453 return (CORE_ADDR) 0; /* Not sure what else to do... */
454 if (!fi->locals_pointer)
456 struct frame_saved_regs ignore;
458 get_frame_saved_regs (fi, &ignore);
461 return fi->locals_pointer;
464 /* Return the address of the argument block for the frame
465 described by FI. Returns 0 if the address is unknown. */
468 frame_args_address (fi)
469 struct frame_info *fi;
471 if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
472 return (CORE_ADDR) 0; /* Not sure what else to do... */
473 if (!fi->args_pointer)
475 struct frame_saved_regs ignore;
477 get_frame_saved_regs (fi, &ignore);
481 return fi->args_pointer;
484 /* Function: push_arguments
485 Setup the function arguments for calling a function in the inferior.
487 On the Hitachi H8/300 architecture, there are three registers (R0 to R2)
488 which are dedicated for passing function arguments. Up to the first
489 three arguments (depending on size) may go into these registers.
490 The rest go on the stack.
492 Arguments that are smaller than WORDSIZE bytes will still take up a
493 whole register or a whole WORDSIZE word on the stack, and will be
494 right-justified in the register or the stack word. This includes
495 chars and small aggregate types. Note that WORDSIZE depends on the
498 Arguments that are larger than WORDSIZE bytes will be split between
499 two or more registers as available, but will NOT be split between a
500 register and the stack.
502 An exceptional case exists for struct arguments (and possibly other
503 aggregates such as arrays) -- if the size is larger than WORDSIZE
504 bytes but not a multiple of WORDSIZE bytes. In this case the
505 argument is never split between the registers and the stack, but
506 instead is copied in its entirety onto the stack, AND also copied
507 into as many registers as there is room for. In other words, space
508 in registers permitting, two copies of the same argument are passed
509 in. As far as I can tell, only the one on the stack is used,
510 although that may be a function of the level of compiler
511 optimization. I suspect this is a compiler bug. Arguments of
512 these odd sizes are left-justified within the word (as opposed to
513 arguments smaller than WORDSIZE bytes, which are right-justified).
515 If the function is to return an aggregate type such as a struct,
516 the caller must allocate space into which the callee will copy the
517 return value. In this case, a pointer to the return value location
518 is passed into the callee in register R0, which displaces one of
519 the other arguments passed in via registers R0 to R2. */
522 h8300_push_arguments (nargs, args, sp, struct_return, struct_addr)
526 unsigned char struct_return;
527 CORE_ADDR struct_addr;
529 int stack_align, stack_alloc, stack_offset;
539 if (h8300hmode || h8300smode)
550 /* first force sp to a n-byte alignment */
551 sp = sp & ~stack_align;
553 /* Now make sure there's space on the stack */
554 for (argnum = 0, stack_alloc = 0;
555 argnum < nargs; argnum++)
556 stack_alloc += ((TYPE_LENGTH (VALUE_TYPE (args[argnum])) + stack_align)
558 sp -= stack_alloc; /* make room on stack for args */
559 /* we may over-allocate a little here, but that won't hurt anything */
561 argreg = ARG0_REGNUM;
562 if (struct_return) /* "struct return" pointer takes up one argreg */
564 write_register (argreg++, struct_addr);
567 /* Now load as many as possible of the first arguments into
568 registers, and push the rest onto the stack. There are 3N bytes
569 in three registers available. Loop thru args from first to last. */
571 for (argnum = 0, stack_offset = 0; argnum < nargs; argnum++)
573 type = VALUE_TYPE (args[argnum]);
574 len = TYPE_LENGTH (type);
575 memset (valbuf, 0, sizeof (valbuf));
578 /* the purpose of this is to right-justify the value within the word */
579 memcpy (valbuf + (wordsize - len),
580 (char *) VALUE_CONTENTS (args[argnum]), len);
584 val = (char *) VALUE_CONTENTS (args[argnum]);
586 if (len > (ARGLAST_REGNUM + 1 - argreg) * REGISTER_RAW_SIZE (ARG0_REGNUM) ||
587 (len > wordsize && (len & stack_align) != 0))
588 { /* passed on the stack */
589 write_memory (sp + stack_offset, val,
590 len < wordsize ? wordsize : len);
591 stack_offset += (len + stack_align) & ~stack_align;
593 /* NOTE WELL!!!!! This is not an "else if" clause!!!
594 That's because some *&^%$ things get passed on the stack
595 AND in the registers! */
596 if (len <= (ARGLAST_REGNUM + 1 - argreg) * REGISTER_RAW_SIZE (ARG0_REGNUM))
598 { /* there's room in registers */
599 regval = extract_address (val, wordsize);
600 write_register (argreg, regval);
609 /* Function: push_return_address
610 Setup the return address for a dummy frame, as called by
611 call_function_by_hand. Only necessary when you are using an
612 empty CALL_DUMMY, ie. the target will not actually be executing
613 a JSR/BSR instruction. */
616 h8300_push_return_address (pc, sp)
620 unsigned char buf[4];
623 if (h8300hmode || h8300smode)
629 store_unsigned_integer (buf, wordsize, CALL_DUMMY_ADDRESS ());
630 write_memory (sp, buf, wordsize);
634 /* Function: pop_frame
635 Restore the machine to the state it had before the current frame
636 was created. Usually used either by the "RETURN" command, or by
637 call_function_by_hand after the dummy_frame is finished. */
643 struct frame_saved_regs fsr;
644 struct frame_info *frame = get_current_frame ();
646 if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
648 generic_pop_dummy_frame ();
652 get_frame_saved_regs (frame, &fsr);
654 for (regnum = 0; regnum < 8; regnum++)
656 /* Don't forget SP_REGNUM is a frame_saved_regs struct is the
657 actual value we want, not the address of the value we want. */
658 if (fsr.regs[regnum] && regnum != SP_REGNUM)
659 write_register (regnum,
660 read_memory_integer (fsr.regs[regnum], BINWORD));
661 else if (fsr.regs[regnum] && regnum == SP_REGNUM)
662 write_register (regnum, frame->frame + 2 * BINWORD);
665 /* Don't forget the update the PC too! */
666 write_pc (frame->from_pc);
668 flush_cached_frames ();
671 /* Function: extract_return_value
672 Figure out where in REGBUF the called function has left its return value.
673 Copy that into VALBUF. Be sure to account for CPU type. */
676 h8300_extract_return_value (type, regbuf, valbuf)
683 if (h8300smode || h8300hmode)
688 len = TYPE_LENGTH (type);
693 case 2: /* (short), (int) */
694 memcpy (valbuf, regbuf + REGISTER_BYTE (0) + (wordsize - len), len);
696 case 4: /* (long), (float) */
697 if (h8300smode || h8300hmode)
699 memcpy (valbuf, regbuf + REGISTER_BYTE (0), 4);
703 memcpy (valbuf, regbuf + REGISTER_BYTE (0), 2);
704 memcpy (valbuf + 2, regbuf + REGISTER_BYTE (1), 2);
707 case 8: /* (double) (doesn't seem to happen, which is good,
708 because this almost certainly isn't right. */
709 error ("I don't know how a double is returned.");
714 /* Function: store_return_value
715 Place the appropriate value in the appropriate registers.
716 Primarily used by the RETURN command. */
719 h8300_store_return_value (type, valbuf)
723 int wordsize, len, regval;
725 if (h8300hmode || h8300smode)
730 len = TYPE_LENGTH (type);
734 case 2: /* short, int */
735 regval = extract_address (valbuf, len);
736 write_register (0, regval);
738 case 4: /* long, float */
739 regval = extract_address (valbuf, len);
740 if (h8300smode || h8300hmode)
742 write_register (0, regval);
746 write_register (0, regval >> 16);
747 write_register (1, regval & 0xffff);
750 case 8: /* presumeably double, but doesn't seem to happen */
751 error ("I don't know how to return a double.");
756 struct cmd_list_element *setmemorylist;
759 set_register_names ()
762 h8300_register_names = h8300h_register_names;
764 h8300_register_names = original_register_names;
768 h8300_command (args, from_tty)
770 extern int h8300hmode;
773 set_register_names ();
777 h8300h_command (args, from_tty)
779 extern int h8300hmode;
782 set_register_names ();
786 h8300s_command (args, from_tty)
788 extern int h8300smode;
789 extern int h8300hmode;
792 set_register_names ();
797 set_machine (args, from_tty)
801 printf_unfiltered ("\"set machine\" must be followed by h8300, h8300h");
802 printf_unfiltered ("or h8300s");
803 help_list (setmemorylist, "set memory ", -1, gdb_stdout);
806 /* set_machine_hook is called as the exec file is being opened, but
807 before the symbol file is opened. This allows us to set the
808 h8300hmode flag based on the machine type specified in the exec
809 file. This in turn will cause subsequently defined pointer types
810 to be 16 or 32 bits as appropriate for the machine. */
813 set_machine_hook (filename)
816 if (bfd_get_mach (exec_bfd) == bfd_mach_h8300s)
821 else if (bfd_get_mach (exec_bfd) == bfd_mach_h8300h)
831 set_register_names ();
835 _initialize_h8300m ()
837 add_prefix_cmd ("machine", no_class, set_machine,
838 "set the machine type",
839 &setmemorylist, "set machine ", 0,
842 add_cmd ("h8300", class_support, h8300_command,
843 "Set machine to be H8/300.", &setmemorylist);
845 add_cmd ("h8300h", class_support, h8300h_command,
846 "Set machine to be H8/300H.", &setmemorylist);
848 add_cmd ("h8300s", class_support, h8300s_command,
849 "Set machine to be H8/300S.", &setmemorylist);
851 /* Add a hook to set the machine type when we're loading a file. */
853 specify_exec_file_hook (set_machine_hook);
859 print_register_hook (regno)
867 read_relative_register_raw_bytes (regno, b);
868 l = b[REGISTER_VIRTUAL_SIZE (8) - 1];
869 printf_unfiltered ("\t");
870 printf_unfiltered ("I-%d - ", (l & 0x80) != 0);
871 printf_unfiltered ("H-%d - ", (l & 0x20) != 0);
876 printf_unfiltered ("N-%d ", N);
877 printf_unfiltered ("Z-%d ", Z);
878 printf_unfiltered ("V-%d ", V);
879 printf_unfiltered ("C-%d ", C);
881 printf_unfiltered ("u> ");
883 printf_unfiltered ("u<= ");
885 printf_unfiltered ("u>= ");
887 printf_unfiltered ("u< ");
889 printf_unfiltered ("!= ");
891 printf_unfiltered ("== ");
893 printf_unfiltered (">= ");
895 printf_unfiltered ("< ");
896 if ((Z | (N ^ V)) == 0)
897 printf_unfiltered ("> ");
898 if ((Z | (N ^ V)) == 1)
899 printf_unfiltered ("<= ");
904 _initialize_h8300_tdep ()
906 tm_print_insn = gdb_print_insn_h8300;