1 /* Target-machine dependent code for Motorola MCore for GDB, the GNU debugger
2 Copyright 1999, 2000, 2001 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, Boston, MA 02111-1307, USA. */
29 #include "arch-utils.h"
30 #include "gdb_string.h"
32 /* Functions declared and used only in this file */
34 static CORE_ADDR mcore_analyze_prologue (struct frame_info *fi, CORE_ADDR pc, int skip_prologue);
36 static struct frame_info *analyze_dummy_frame (CORE_ADDR pc, CORE_ADDR frame);
38 static int get_insn (CORE_ADDR pc);
40 /* Functions exported from this file */
42 int mcore_use_struct_convention (int gcc_p, struct type *type);
44 void _initialize_mcore (void);
46 void mcore_init_extra_frame_info (int fromleaf, struct frame_info *fi);
48 CORE_ADDR mcore_frame_saved_pc (struct frame_info *fi);
50 CORE_ADDR mcore_find_callers_reg (struct frame_info *fi, int regnum);
52 CORE_ADDR mcore_frame_args_address (struct frame_info *fi);
54 CORE_ADDR mcore_frame_locals_address (struct frame_info *fi);
56 CORE_ADDR mcore_push_return_address (CORE_ADDR pc, CORE_ADDR sp);
58 CORE_ADDR mcore_push_arguments (int nargs, struct value ** args, CORE_ADDR sp,
59 int struct_return, CORE_ADDR struct_addr);
61 void mcore_pop_frame ();
63 CORE_ADDR mcore_skip_prologue (CORE_ADDR pc);
65 CORE_ADDR mcore_frame_chain (struct frame_info *fi);
67 const unsigned char *mcore_breakpoint_from_pc (CORE_ADDR * bp_addr, int *bp_size);
69 int mcore_use_struct_convention (int gcc_p, struct type *type);
71 void mcore_store_return_value (struct type *type, char *valbuf);
73 CORE_ADDR mcore_extract_struct_value_address (char *regbuf);
75 void mcore_extract_return_value (struct type *type, char *regbuf, char *valbuf);
82 /* All registers are 4 bytes long. */
83 #define MCORE_REG_SIZE 4
84 #define MCORE_NUM_REGS 65
86 /* Some useful register numbers. */
88 #define FIRST_ARGREG 2
90 #define RETVAL_REGNUM 2
93 /* Additional info that we use for managing frames */
94 struct frame_extra_info
96 /* A generic status word */
99 /* Size of this frame */
102 /* The register that is acting as a frame pointer, if
103 it is being used. This is undefined if status
104 does not contain the flag MY_FRAME_IN_FP. */
108 /* frame_extra_info status flags */
110 /* The base of the current frame is actually in the stack pointer.
111 This happens when there is no frame pointer (MCore ABI does not
112 require a frame pointer) or when we're stopped in the prologue or
113 epilogue itself. In these cases, mcore_analyze_prologue will need
114 to update fi->frame before returning or analyzing the register
115 save instructions. */
116 #define MY_FRAME_IN_SP 0x1
118 /* The base of the current frame is in a frame pointer register.
119 This register is noted in frame_extra_info->fp_regnum.
121 Note that the existence of an FP might also indicate that the
122 function has called alloca. */
123 #define MY_FRAME_IN_FP 0x2
125 /* This flag is set to indicate that this frame is the top-most
126 frame. This tells frame chain not to bother trying to unwind
127 beyond this frame. */
128 #define NO_MORE_FRAMES 0x4
130 /* Instruction macros used for analyzing the prologue */
131 #define IS_SUBI0(x) (((x) & 0xfe0f) == 0x2400) /* subi r0,oimm5 */
132 #define IS_STM(x) (((x) & 0xfff0) == 0x0070) /* stm rf-r15,r0 */
133 #define IS_STWx0(x) (((x) & 0xf00f) == 0x9000) /* stw rz,(r0,disp) */
134 #define IS_STWxy(x) (((x) & 0xf000) == 0x9000) /* stw rx,(ry,disp) */
135 #define IS_MOVx0(x) (((x) & 0xfff0) == 0x1200) /* mov rn,r0 */
136 #define IS_LRW1(x) (((x) & 0xff00) == 0x7100) /* lrw r1,literal */
137 #define IS_MOVI1(x) (((x) & 0xf80f) == 0x6001) /* movi r1,imm7 */
138 #define IS_BGENI1(x) (((x) & 0xfe0f) == 0x3201) /* bgeni r1,imm5 */
139 #define IS_BMASKI1(x) (((x) & 0xfe0f) == 0x2C01) /* bmaski r1,imm5 */
140 #define IS_ADDI1(x) (((x) & 0xfe0f) == 0x2001) /* addi r1,oimm5 */
141 #define IS_SUBI1(x) (((x) & 0xfe0f) == 0x2401) /* subi r1,oimm5 */
142 #define IS_RSUBI1(x) (((x) & 0xfe0f) == 0x2801) /* rsubi r1,imm5 */
143 #define IS_NOT1(x) (((x) & 0xffff) == 0x01f1) /* not r1 */
144 #define IS_ROTLI1(x) (((x) & 0xfe0f) == 0x3801) /* rotli r1,imm5 */
145 #define IS_BSETI1(x) (((x) & 0xfe0f) == 0x3401) /* bseti r1,imm5 */
146 #define IS_BCLRI1(x) (((x) & 0xfe0f) == 0x3001) /* bclri r1,imm5 */
147 #define IS_IXH1(x) (((x) & 0xffff) == 0x1d11) /* ixh r1,r1 */
148 #define IS_IXW1(x) (((x) & 0xffff) == 0x1511) /* ixw r1,r1 */
149 #define IS_SUB01(x) (((x) & 0xffff) == 0x0510) /* subu r0,r1 */
150 #define IS_RTS(x) (((x) & 0xffff) == 0x00cf) /* jmp r15 */
152 #define IS_R1_ADJUSTER(x) \
153 (IS_ADDI1(x) || IS_SUBI1(x) || IS_ROTLI1(x) || IS_BSETI1(x) \
154 || IS_BCLRI1(x) || IS_RSUBI1(x) || IS_NOT1(x) \
155 || IS_IXH1(x) || IS_IXW1(x))
160 mcore_dump_insn (char *commnt, CORE_ADDR pc, int insn)
164 printf_filtered ("MCORE: %s %08x %08x ",
165 commnt, (unsigned int) pc, (unsigned int) insn);
166 TARGET_PRINT_INSN (pc, &tm_print_insn_info);
167 printf_filtered ("\n");
170 #define mcore_insn_debug(args) { if (mcore_debug) printf_filtered args; }
171 #else /* !MCORE_DEBUG */
172 #define mcore_dump_insn(a,b,c) {}
173 #define mcore_insn_debug(args) {}
178 mcore_register_virtual_type (int regnum)
180 if (regnum < 0 || regnum >= MCORE_NUM_REGS)
181 internal_error (__FILE__, __LINE__,
182 "mcore_register_virtual_type: illegal register number %d",
185 return builtin_type_int;
189 mcore_register_byte (int regnum)
191 if (regnum < 0 || regnum >= MCORE_NUM_REGS)
192 internal_error (__FILE__, __LINE__,
193 "mcore_register_byte: illegal register number %d",
196 return (regnum * MCORE_REG_SIZE);
200 mcore_register_size (int regnum)
203 if (regnum < 0 || regnum >= MCORE_NUM_REGS)
204 internal_error (__FILE__, __LINE__,
205 "mcore_register_size: illegal register number %d",
208 return MCORE_REG_SIZE;
211 /* The registers of the Motorola MCore processors */
214 mcore_register_name (int regnum)
217 static char *register_names[] = {
218 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
219 "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
220 "ar0", "ar1", "ar2", "ar3", "ar4", "ar5", "ar6", "ar7",
221 "ar8", "ar9", "ar10", "ar11", "ar12", "ar13", "ar14", "ar15",
222 "psr", "vbr", "epsr", "fpsr", "epc", "fpc", "ss0", "ss1",
223 "ss2", "ss3", "ss4", "gcr", "gsr", "cr13", "cr14", "cr15",
224 "cr16", "cr17", "cr18", "cr19", "cr20", "cr21", "cr22", "cr23",
225 "cr24", "cr25", "cr26", "cr27", "cr28", "cr29", "cr30", "cr31",
230 regnum >= sizeof (register_names) / sizeof (register_names[0]))
231 internal_error (__FILE__, __LINE__,
232 "mcore_register_name: illegal register number %d",
235 return register_names[regnum];
238 /* Given the address at which to insert a breakpoint (BP_ADDR),
239 what will that breakpoint be?
241 For MCore, we have a breakpoint instruction. Since all MCore
242 instructions are 16 bits, this is all we need, regardless of
243 address. bpkt = 0x0000 */
245 const unsigned char *
246 mcore_breakpoint_from_pc (CORE_ADDR * bp_addr, int *bp_size)
248 static char breakpoint[] =
255 mcore_saved_pc_after_call (struct frame_info *frame)
257 return read_register (PR_REGNUM);
260 /* This is currently handled by init_extra_frame_info. */
262 mcore_frame_init_saved_regs (struct frame_info *frame)
267 /* This is currently handled by mcore_push_arguments */
269 mcore_store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
275 mcore_reg_struct_has_addr (int gcc_p, struct type *type)
281 /* Helper function for several routines below. This funtion simply
282 sets up a fake, aka dummy, frame (not a _call_ dummy frame) that
283 we can analyze with mcore_analyze_prologue. */
285 static struct frame_info *
286 analyze_dummy_frame (CORE_ADDR pc, CORE_ADDR frame)
288 static struct frame_info *dummy = NULL;
292 dummy = (struct frame_info *) xmalloc (sizeof (struct frame_info));
293 dummy->saved_regs = (CORE_ADDR *) xmalloc (SIZEOF_FRAME_SAVED_REGS);
295 (struct frame_extra_info *) xmalloc (sizeof (struct frame_extra_info));
300 deprecated_update_frame_pc_hack (dummy, pc);
301 dummy->frame = frame;
302 dummy->extra_info->status = 0;
303 dummy->extra_info->framesize = 0;
304 memset (dummy->saved_regs, '\000', SIZEOF_FRAME_SAVED_REGS);
305 mcore_analyze_prologue (dummy, 0, 0);
309 /* Function prologues on the Motorola MCore processors consist of:
311 - adjustments to the stack pointer (r1 used as scratch register)
312 - store word/multiples that use r0 as the base address
313 - making a copy of r0 into another register (a "frame" pointer)
315 Note that the MCore really doesn't have a real frame pointer.
316 Instead, the compiler may copy the SP into a register (usually
317 r8) to act as an arg pointer. For our target-dependent purposes,
318 the frame info's "frame" member will be the beginning of the
319 frame. The SP could, in fact, point below this.
321 The prologue ends when an instruction fails to meet either of
322 the first two criteria or when an FP is made. We make a special
323 exception for gcc. When compiling unoptimized code, gcc will
324 setup stack slots. We need to make sure that we skip the filling
325 of these stack slots as much as possible. This is only done
326 when SKIP_PROLOGUE is set, so that it does not mess up
329 /* Analyze the prologue of frame FI to determine where registers are saved,
330 the end of the prologue, etc. Return the address of the first line
331 of "real" code (i.e., the end of the prologue). */
334 mcore_analyze_prologue (struct frame_info *fi, CORE_ADDR pc, int skip_prologue)
336 CORE_ADDR func_addr, func_end, addr, stop;
337 CORE_ADDR stack_size;
340 int fp_regnum = 0; /* dummy, valid when (flags & MY_FRAME_IN_FP) */
343 int register_offsets[NUM_REGS];
346 /* If provided, use the PC in the frame to look up the
347 start of this function. */
348 pc = (fi == NULL ? pc : get_frame_pc (fi));
350 /* Find the start of this function. */
351 status = find_pc_partial_function (pc, &name, &func_addr, &func_end);
353 /* If the start of this function could not be found or if the debbuger
354 is stopped at the first instruction of the prologue, do nothing. */
358 /* If the debugger is entry function, give up. */
359 if (func_addr == entry_point_address ())
362 fi->extra_info->status |= NO_MORE_FRAMES;
366 /* At the start of a function, our frame is in the stack pointer. */
367 flags = MY_FRAME_IN_SP;
369 /* Start decoding the prologue. We start by checking two special cases:
371 1. We're about to return
372 2. We're at the first insn of the prologue.
374 If we're about to return, our frame has already been deallocated.
375 If we are stopped at the first instruction of a prologue,
376 then our frame has not yet been set up. */
378 /* Get the first insn from memory (all MCore instructions are 16 bits) */
379 mcore_insn_debug (("MCORE: starting prologue decoding\n"));
380 insn = get_insn (pc);
381 mcore_dump_insn ("got 1: ", pc, insn);
383 /* Check for return. */
384 if (fi != NULL && IS_RTS (insn))
386 mcore_insn_debug (("MCORE: got jmp r15"));
387 if (fi->next == NULL)
388 fi->frame = read_sp ();
389 return get_frame_pc (fi);
392 /* Check for first insn of prologue */
393 if (fi != NULL && get_frame_pc (fi) == func_addr)
395 if (fi->next == NULL)
396 fi->frame = read_sp ();
397 return get_frame_pc (fi);
400 /* Figure out where to stop scanning */
401 stop = (fi ? get_frame_pc (fi) : func_end);
403 /* Don't walk off the end of the function */
404 stop = (stop > func_end ? func_end : stop);
406 /* REGISTER_OFFSETS will contain offsets, from the top of the frame
407 (NOT the frame pointer), for the various saved registers or -1
408 if the register is not saved. */
409 for (rn = 0; rn < NUM_REGS; rn++)
410 register_offsets[rn] = -1;
412 /* Analyze the prologue. Things we determine from analyzing the
414 * the size of the frame
415 * where saved registers are located (and which are saved)
417 mcore_insn_debug (("MCORE: Scanning prologue: func_addr=0x%x, stop=0x%x\n",
418 (unsigned int) func_addr, (unsigned int) stop));
421 for (addr = func_addr; addr < stop; addr += 2)
424 insn = get_insn (addr);
425 mcore_dump_insn ("got 2: ", addr, insn);
429 int offset = 1 + ((insn >> 4) & 0x1f);
430 mcore_insn_debug (("MCORE: got subi r0,%d; continuing\n", offset));
434 else if (IS_STM (insn))
436 /* Spill register(s) */
440 /* BIG WARNING! The MCore ABI does not restrict functions
441 to taking only one stack allocation. Therefore, when
442 we save a register, we record the offset of where it was
443 saved relative to the current framesize. This will
444 then give an offset from the SP upon entry to our
445 function. Remember, framesize is NOT constant until
446 we're done scanning the prologue. */
447 start_register = (insn & 0xf);
448 mcore_insn_debug (("MCORE: got stm r%d-r15,(r0)\n", start_register));
450 for (rn = start_register, offset = 0; rn <= 15; rn++, offset += 4)
452 register_offsets[rn] = framesize - offset;
453 mcore_insn_debug (("MCORE: r%d saved at 0x%x (offset %d)\n", rn,
454 register_offsets[rn], offset));
456 mcore_insn_debug (("MCORE: continuing\n"));
459 else if (IS_STWx0 (insn))
461 /* Spill register: see note for IS_STM above. */
464 rn = (insn >> 8) & 0xf;
465 imm = (insn >> 4) & 0xf;
466 register_offsets[rn] = framesize - (imm << 2);
467 mcore_insn_debug (("MCORE: r%d saved at offset 0x%x\n", rn, register_offsets[rn]));
468 mcore_insn_debug (("MCORE: continuing\n"));
471 else if (IS_MOVx0 (insn))
473 /* We have a frame pointer, so this prologue is over. Note
474 the register which is acting as the frame pointer. */
475 flags |= MY_FRAME_IN_FP;
476 flags &= ~MY_FRAME_IN_SP;
477 fp_regnum = insn & 0xf;
478 mcore_insn_debug (("MCORE: Found a frame pointer: r%d\n", fp_regnum));
480 /* If we found an FP, we're at the end of the prologue. */
481 mcore_insn_debug (("MCORE: end of prologue\n"));
485 /* If we're decoding prologue, stop here. */
489 else if (IS_STWxy (insn) && (flags & MY_FRAME_IN_FP) && ((insn & 0xf) == fp_regnum))
491 /* Special case. Skip over stack slot allocs, too. */
492 mcore_insn_debug (("MCORE: push arg onto stack.\n"));
495 else if (IS_LRW1 (insn) || IS_MOVI1 (insn)
496 || IS_BGENI1 (insn) || IS_BMASKI1 (insn))
502 mcore_insn_debug (("MCORE: looking at large frame\n"));
506 read_memory_integer ((addr + 2 + ((insn & 0xff) << 2)) & 0xfffffffc, 4);
508 else if (IS_MOVI1 (insn))
509 adjust = (insn >> 4) & 0x7f;
510 else if (IS_BGENI1 (insn))
511 adjust = 1 << ((insn >> 4) & 0x1f);
512 else /* IS_BMASKI (insn) */
513 adjust = (1 << (adjust >> 4) & 0x1f) - 1;
515 mcore_insn_debug (("MCORE: base framesize=0x%x\n", adjust));
517 /* May have zero or more insns which modify r1 */
518 mcore_insn_debug (("MCORE: looking for r1 adjusters...\n"));
520 insn2 = get_insn (addr + offset);
521 while (IS_R1_ADJUSTER (insn2))
525 imm = (insn2 >> 4) & 0x1f;
526 mcore_dump_insn ("got 3: ", addr + offset, insn);
527 if (IS_ADDI1 (insn2))
530 mcore_insn_debug (("MCORE: addi r1,%d\n", imm + 1));
532 else if (IS_SUBI1 (insn2))
535 mcore_insn_debug (("MCORE: subi r1,%d\n", imm + 1));
537 else if (IS_RSUBI1 (insn2))
539 adjust = imm - adjust;
540 mcore_insn_debug (("MCORE: rsubi r1,%d\n", imm + 1));
542 else if (IS_NOT1 (insn2))
545 mcore_insn_debug (("MCORE: not r1\n"));
547 else if (IS_ROTLI1 (insn2))
550 mcore_insn_debug (("MCORE: rotli r1,%d\n", imm + 1));
552 else if (IS_BSETI1 (insn2))
554 adjust |= (1 << imm);
555 mcore_insn_debug (("MCORE: bseti r1,%d\n", imm));
557 else if (IS_BCLRI1 (insn2))
559 adjust &= ~(1 << imm);
560 mcore_insn_debug (("MCORE: bclri r1,%d\n", imm));
562 else if (IS_IXH1 (insn2))
565 mcore_insn_debug (("MCORE: ix.h r1,r1\n"));
567 else if (IS_IXW1 (insn2))
570 mcore_insn_debug (("MCORE: ix.w r1,r1\n"));
574 insn2 = get_insn (addr + offset);
577 mcore_insn_debug (("MCORE: done looking for r1 adjusters\n"));
579 /* If the next insn adjusts the stack pointer, we keep everything;
580 if not, we scrap it and we've found the end of the prologue. */
581 if (IS_SUB01 (insn2))
585 mcore_insn_debug (("MCORE: found stack adjustment of 0x%x bytes.\n", adjust));
586 mcore_insn_debug (("MCORE: skipping to new address 0x%x\n", addr));
587 mcore_insn_debug (("MCORE: continuing\n"));
591 /* None of these instructions are prologue, so don't touch
593 mcore_insn_debug (("MCORE: no subu r1,r0, NOT altering framesize.\n"));
597 /* This is not a prologue insn, so stop here. */
598 mcore_insn_debug (("MCORE: insn is not a prologue insn -- ending scan\n"));
602 mcore_insn_debug (("MCORE: done analyzing prologue\n"));
603 mcore_insn_debug (("MCORE: prologue end = 0x%x\n", addr));
605 /* Save everything we have learned about this frame into FI. */
608 fi->extra_info->framesize = framesize;
609 fi->extra_info->fp_regnum = fp_regnum;
610 fi->extra_info->status = flags;
612 /* Fix the frame pointer. When gcc uses r8 as a frame pointer,
613 it is really an arg ptr. We adjust fi->frame to be a "real"
615 if (fi->next == NULL)
617 if (fi->extra_info->status & MY_FRAME_IN_SP)
618 fi->frame = read_sp () + framesize;
620 fi->frame = read_register (fp_regnum) + framesize;
623 /* Note where saved registers are stored. The offsets in REGISTER_OFFSETS
624 are computed relative to the top of the frame. */
625 for (rn = 0; rn < NUM_REGS; rn++)
627 if (register_offsets[rn] >= 0)
629 fi->saved_regs[rn] = fi->frame - register_offsets[rn];
630 mcore_insn_debug (("Saved register %s stored at 0x%08x, value=0x%08x\n",
631 mcore_register_names[rn], fi->saved_regs[rn],
632 read_memory_integer (fi->saved_regs[rn], 4)));
637 /* Return addr of first non-prologue insn. */
641 /* Given a GDB frame, determine the address of the calling function's
642 frame. This will be used to create a new GDB frame struct, and
643 then INIT_EXTRA_FRAME_INFO and DEPRECATED_INIT_FRAME_PC will be
644 called for the new frame. */
647 mcore_frame_chain (struct frame_info * fi)
649 struct frame_info *dummy;
650 CORE_ADDR callers_addr;
652 /* Analyze the prologue of this function. */
653 if (fi->extra_info->status == 0)
654 mcore_analyze_prologue (fi, 0, 0);
656 /* If mcore_analyze_prologue set NO_MORE_FRAMES, quit now. */
657 if (fi->extra_info->status & NO_MORE_FRAMES)
660 /* Now that we've analyzed our prologue, we can start to ask
661 for information about our caller. The easiest way to do
662 this is to analyze our caller's prologue.
664 If our caller has a frame pointer, then we need to find
665 the value of that register upon entry to our frame.
666 This value is either in fi->saved_regs[rn] if it's saved,
667 or it's still in a register.
669 If our caller does not have a frame pointer, then his frame base
670 is <our base> + -<caller's frame size>. */
671 dummy = analyze_dummy_frame (FRAME_SAVED_PC (fi), fi->frame);
673 if (dummy->extra_info->status & MY_FRAME_IN_FP)
675 int fp = dummy->extra_info->fp_regnum;
677 /* Our caller has a frame pointer. */
678 if (fi->saved_regs[fp] != 0)
680 /* The "FP" was saved on the stack. Don't forget to adjust
681 the "FP" with the framesize to get a real FP. */
682 callers_addr = read_memory_integer (fi->saved_regs[fp], REGISTER_SIZE)
683 + dummy->extra_info->framesize;
687 /* It's still in the register. Don't forget to adjust
688 the "FP" with the framesize to get a real FP. */
689 callers_addr = read_register (fp) + dummy->extra_info->framesize;
694 /* Our caller does not have a frame pointer. */
695 callers_addr = fi->frame + dummy->extra_info->framesize;
701 /* Skip the prologue of the function at PC. */
704 mcore_skip_prologue (CORE_ADDR pc)
706 CORE_ADDR func_addr, func_end;
707 struct symtab_and_line sal;
709 /* If we have line debugging information, then the end of the
710 prologue should be the first assembly instruction of the first
712 if (find_pc_partial_function (pc, NULL, &func_addr, &func_end))
714 sal = find_pc_line (func_addr, 0);
715 if (sal.end && sal.end < func_end)
719 return mcore_analyze_prologue (NULL, pc, 1);
722 /* Return the address at which function arguments are offset. */
724 mcore_frame_args_address (struct frame_info * fi)
726 return fi->frame - fi->extra_info->framesize;
730 mcore_frame_locals_address (struct frame_info * fi)
732 return fi->frame - fi->extra_info->framesize;
735 /* Return the frame pointer in use at address PC. */
738 mcore_virtual_frame_pointer (CORE_ADDR pc, int *reg, LONGEST *offset)
740 struct frame_info *dummy = analyze_dummy_frame (pc, 0);
741 if (dummy->extra_info->status & MY_FRAME_IN_SP)
748 *reg = dummy->extra_info->fp_regnum;
753 /* Find the value of register REGNUM in frame FI. */
756 mcore_find_callers_reg (struct frame_info *fi, int regnum)
758 for (; fi != NULL; fi = fi->next)
760 if (DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (fi), fi->frame, fi->frame))
761 return deprecated_read_register_dummy (get_frame_pc (fi), fi->frame, regnum);
762 else if (fi->saved_regs[regnum] != 0)
763 return read_memory_integer (fi->saved_regs[regnum],
767 return read_register (regnum);
770 /* Find the saved pc in frame FI. */
773 mcore_frame_saved_pc (struct frame_info * fi)
776 if (DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (fi), fi->frame, fi->frame))
777 return deprecated_read_register_dummy (get_frame_pc (fi), fi->frame, PC_REGNUM);
779 return mcore_find_callers_reg (fi, PR_REGNUM);
782 /* INFERIOR FUNCTION CALLS */
784 /* This routine gets called when either the user uses the "return"
785 command, or the call dummy breakpoint gets hit. */
788 mcore_pop_frame (void)
791 struct frame_info *fi = get_current_frame ();
793 if (DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (fi), fi->frame, fi->frame))
794 generic_pop_dummy_frame ();
797 /* Write out the PC we saved. */
798 write_register (PC_REGNUM, FRAME_SAVED_PC (fi));
800 /* Restore any saved registers. */
801 for (rn = 0; rn < NUM_REGS; rn++)
803 if (fi->saved_regs[rn] != 0)
807 value = read_memory_unsigned_integer (fi->saved_regs[rn],
809 write_register (rn, value);
813 /* Actually cut back the stack. */
814 write_register (SP_REGNUM, get_frame_base (fi));
817 /* Finally, throw away any cached frame information. */
818 flush_cached_frames ();
821 /* Setup arguments and PR for a call to the target. First six arguments
822 go in FIRST_ARGREG -> LAST_ARGREG, subsequent args go on to the stack.
824 * Types with lengths greater than REGISTER_SIZE may not be split
825 between registers and the stack, and they must start in an even-numbered
826 register. Subsequent args will go onto the stack.
828 * Structs may be split between registers and stack, left-aligned.
830 * If the function returns a struct which will not fit into registers (it's
831 more than eight bytes), we must allocate for that, too. Gdb will tell
832 us where this buffer is (STRUCT_ADDR), and we simply place it into
833 FIRST_ARGREG, since the MCORE treats struct returns (of less than eight
834 bytes) as hidden first arguments. */
837 mcore_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
838 int struct_return, CORE_ADDR struct_addr)
850 stack_args = (struct stack_arg *) alloca (nargs * sizeof (struct stack_arg));
852 argreg = FIRST_ARGREG;
854 /* Align the stack. This is mostly a nop, but not always. It will be needed
855 if we call a function which has argument overflow. */
858 /* If this function returns a struct which does not fit in the
859 return registers, we must pass a buffer to the function
860 which it can use to save the return value. */
862 write_register (argreg++, struct_addr);
864 /* FIXME: what about unions? */
865 for (argnum = 0; argnum < nargs; argnum++)
867 char *val = (char *) VALUE_CONTENTS (args[argnum]);
868 int len = TYPE_LENGTH (VALUE_TYPE (args[argnum]));
869 struct type *type = VALUE_TYPE (args[argnum]);
872 mcore_insn_debug (("MCORE PUSH: argreg=%d; len=%d; %s\n",
873 argreg, len, TYPE_CODE (type) == TYPE_CODE_STRUCT ? "struct" : "not struct"));
874 /* Arguments larger than a register must start in an even
875 numbered register. */
878 if (TYPE_CODE (type) != TYPE_CODE_STRUCT && len > REGISTER_SIZE && argreg % 2)
880 mcore_insn_debug (("MCORE PUSH: %d > REGISTER_SIZE: and %s is not even\n",
881 len, mcore_register_names[argreg]));
885 if ((argreg <= LAST_ARGREG && len <= (LAST_ARGREG - argreg + 1) * REGISTER_SIZE)
886 || (TYPE_CODE (type) == TYPE_CODE_STRUCT))
888 /* Something that will fit entirely into registers (or a struct
889 which may be split between registers and stack). */
890 mcore_insn_debug (("MCORE PUSH: arg %d going into regs\n", argnum));
892 if (TYPE_CODE (type) == TYPE_CODE_STRUCT && olen < REGISTER_SIZE)
894 /* Small structs must be right aligned within the register,
895 the most significant bits are undefined. */
896 write_register (argreg, extract_unsigned_integer (val, len));
901 while (len > 0 && argreg <= LAST_ARGREG)
903 write_register (argreg, extract_unsigned_integer (val, REGISTER_SIZE));
905 val += REGISTER_SIZE;
906 len -= REGISTER_SIZE;
909 /* Any remainder for the stack is noted below... */
911 else if (TYPE_CODE (VALUE_TYPE (args[argnum])) != TYPE_CODE_STRUCT
912 && len > REGISTER_SIZE)
914 /* All subsequent args go onto the stack. */
915 mcore_insn_debug (("MCORE PUSH: does not fit into regs, going onto stack\n"));
916 argnum = LAST_ARGREG + 1;
921 /* Note that this must be saved onto the stack */
922 mcore_insn_debug (("MCORE PUSH: adding arg %d to stack\n", argnum));
923 stack_args[nstack_args].val = val;
924 stack_args[nstack_args].len = len;
930 /* We're done with registers and stack allocation. Now do the actual
932 while (nstack_args--)
934 sp -= stack_args[nstack_args].len;
935 write_memory (sp, stack_args[nstack_args].val, stack_args[nstack_args].len);
938 /* Return adjusted stack pointer. */
942 /* Store the return address for the call dummy. For MCore, we've
943 opted to use generic call dummies, so we simply store the
944 CALL_DUMMY_ADDRESS into the PR register (r15). */
947 mcore_push_return_address (CORE_ADDR pc, CORE_ADDR sp)
949 write_register (PR_REGNUM, CALL_DUMMY_ADDRESS ());
953 /* Setting/getting return values from functions.
955 The Motorola MCore processors use r2/r3 to return anything
956 not larger than 32 bits. Everything else goes into a caller-
957 supplied buffer, which is passed in via a hidden first
960 For gdb, this leaves us two routes, based on what
961 USE_STRUCT_CONVENTION (mcore_use_struct_convention) returns.
962 If this macro returns 1, gdb will call STORE_STRUCT_RETURN and
963 EXTRACT_STRUCT_VALUE_ADDRESS.
965 If USE_STRUCT_CONVENTION retruns 0, then gdb uses STORE_RETURN_VALUE
966 and EXTRACT_RETURN_VALUE to store/fetch the functions return value. */
968 /* Should we use EXTRACT_STRUCT_VALUE_ADDRESS instead of
969 EXTRACT_RETURN_VALUE? GCC_P is true if compiled with gcc
970 and TYPE is the type (which is known to be struct, union or array). */
973 mcore_use_struct_convention (int gcc_p, struct type *type)
975 return (TYPE_LENGTH (type) > 8);
978 /* Where is the return value saved? For MCore, a pointer to
979 this buffer was passed as a hidden first argument, so
980 just return that address. */
983 mcore_extract_struct_value_address (char *regbuf)
985 return extract_address (regbuf + REGISTER_BYTE (FIRST_ARGREG), REGISTER_SIZE);
988 /* Given a function which returns a value of type TYPE, extract the
989 the function's return value and place the result into VALBUF.
990 REGBUF is the register contents of the target. */
993 mcore_extract_return_value (struct type *type, char *regbuf, char *valbuf)
995 /* Copy the return value (starting) in RETVAL_REGNUM to VALBUF. */
996 /* Only getting the first byte! if len = 1, we need the last byte of
997 the register, not the first. */
998 memcpy (valbuf, regbuf + REGISTER_BYTE (RETVAL_REGNUM) +
999 (TYPE_LENGTH (type) < 4 ? 4 - TYPE_LENGTH (type) : 0), TYPE_LENGTH (type));
1002 /* Store the return value in VALBUF (of type TYPE) where the caller
1005 Values less than 32 bits are stored in r2, right justified and
1006 sign or zero extended.
1008 Values between 32 and 64 bits are stored in r2 (most
1009 significant word) and r3 (least significant word, left justified).
1010 Note that this includes structures of less than eight bytes, too. */
1013 mcore_store_return_value (struct type *type, char *valbuf)
1020 value_size = TYPE_LENGTH (type);
1022 /* Return value fits into registers. */
1023 return_size = (value_size + REGISTER_SIZE - 1) & ~(REGISTER_SIZE - 1);
1024 offset = REGISTER_BYTE (RETVAL_REGNUM) + (return_size - value_size);
1025 zeros = alloca (return_size);
1026 memset (zeros, 0, return_size);
1028 deprecated_write_register_bytes (REGISTER_BYTE (RETVAL_REGNUM), zeros,
1030 deprecated_write_register_bytes (offset, valbuf, value_size);
1033 /* Initialize our target-dependent "stuff" for this newly created frame.
1035 This includes allocating space for saved registers and analyzing
1036 the prologue of this frame. */
1039 mcore_init_extra_frame_info (int fromleaf, struct frame_info *fi)
1042 deprecated_update_frame_pc_hack (fi, FRAME_SAVED_PC (fi->next));
1044 frame_saved_regs_zalloc (fi);
1046 fi->extra_info = (struct frame_extra_info *)
1047 frame_obstack_alloc (sizeof (struct frame_extra_info));
1048 fi->extra_info->status = 0;
1049 fi->extra_info->framesize = 0;
1051 if (DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (fi), fi->frame, fi->frame))
1053 /* We need to setup fi->frame here because run_stack_dummy gets it wrong
1054 by assuming it's always FP. */
1055 fi->frame = deprecated_read_register_dummy (get_frame_pc (fi), fi->frame, SP_REGNUM);
1058 mcore_analyze_prologue (fi, 0, 0);
1061 /* Get an insturction from memory. */
1064 get_insn (CORE_ADDR pc)
1067 int status = read_memory_nobpt (pc, buf, 2);
1071 return extract_unsigned_integer (buf, 2);
1074 static struct gdbarch *
1075 mcore_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
1077 static LONGEST call_dummy_words[7] = { };
1078 struct gdbarch_tdep *tdep = NULL;
1079 struct gdbarch *gdbarch;
1081 /* find a candidate among the list of pre-declared architectures. */
1082 arches = gdbarch_list_lookup_by_info (arches, &info);
1084 return (arches->gdbarch);
1086 gdbarch = gdbarch_alloc (&info, 0);
1088 /* NOTE: cagney/2002-12-06: This can be deleted when this arch is
1089 ready to unwind the PC first (see frame.c:get_prev_frame()). */
1090 set_gdbarch_deprecated_init_frame_pc (gdbarch, init_frame_pc_default);
1094 /* All registers are 32 bits */
1095 set_gdbarch_register_size (gdbarch, MCORE_REG_SIZE);
1096 set_gdbarch_max_register_raw_size (gdbarch, MCORE_REG_SIZE);
1097 set_gdbarch_max_register_virtual_size (gdbarch, MCORE_REG_SIZE);
1098 set_gdbarch_register_name (gdbarch, mcore_register_name);
1099 set_gdbarch_register_virtual_type (gdbarch, mcore_register_virtual_type);
1100 set_gdbarch_register_virtual_size (gdbarch, mcore_register_size);
1101 set_gdbarch_register_raw_size (gdbarch, mcore_register_size);
1102 set_gdbarch_register_byte (gdbarch, mcore_register_byte);
1103 set_gdbarch_register_bytes (gdbarch, MCORE_REG_SIZE * MCORE_NUM_REGS);
1104 set_gdbarch_num_regs (gdbarch, MCORE_NUM_REGS);
1105 set_gdbarch_pc_regnum (gdbarch, 64);
1106 set_gdbarch_sp_regnum (gdbarch, 0);
1107 set_gdbarch_fp_regnum (gdbarch, 0);
1111 set_gdbarch_call_dummy_p (gdbarch, 1);
1112 set_gdbarch_call_dummy_words (gdbarch, call_dummy_words);
1113 set_gdbarch_sizeof_call_dummy_words (gdbarch, 0);
1114 set_gdbarch_call_dummy_start_offset (gdbarch, 0);
1115 set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 1);
1116 set_gdbarch_call_dummy_breakpoint_offset (gdbarch, 0);
1117 set_gdbarch_fix_call_dummy (gdbarch, generic_fix_call_dummy);
1118 set_gdbarch_call_dummy_address (gdbarch, entry_point_address);
1119 set_gdbarch_save_dummy_frame_tos (gdbarch, generic_save_dummy_frame_tos);
1120 set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0);
1121 set_gdbarch_saved_pc_after_call (gdbarch, mcore_saved_pc_after_call);
1122 set_gdbarch_function_start_offset (gdbarch, 0);
1123 set_gdbarch_decr_pc_after_break (gdbarch, 0);
1124 set_gdbarch_breakpoint_from_pc (gdbarch, mcore_breakpoint_from_pc);
1125 set_gdbarch_push_return_address (gdbarch, mcore_push_return_address);
1126 set_gdbarch_push_dummy_frame (gdbarch, generic_push_dummy_frame);
1127 set_gdbarch_push_arguments (gdbarch, mcore_push_arguments);
1128 set_gdbarch_call_dummy_length (gdbarch, 0);
1132 set_gdbarch_init_extra_frame_info (gdbarch, mcore_init_extra_frame_info);
1133 set_gdbarch_frame_chain (gdbarch, mcore_frame_chain);
1134 set_gdbarch_frame_chain_valid (gdbarch, generic_func_frame_chain_valid);
1135 set_gdbarch_frame_init_saved_regs (gdbarch, mcore_frame_init_saved_regs);
1136 set_gdbarch_frame_saved_pc (gdbarch, mcore_frame_saved_pc);
1137 set_gdbarch_deprecated_store_return_value (gdbarch, mcore_store_return_value);
1138 set_gdbarch_deprecated_extract_return_value (gdbarch,
1139 mcore_extract_return_value);
1140 set_gdbarch_store_struct_return (gdbarch, mcore_store_struct_return);
1141 set_gdbarch_deprecated_extract_struct_value_address (gdbarch,
1142 mcore_extract_struct_value_address);
1143 set_gdbarch_skip_prologue (gdbarch, mcore_skip_prologue);
1144 set_gdbarch_frame_args_skip (gdbarch, 0);
1145 set_gdbarch_frame_args_address (gdbarch, mcore_frame_args_address);
1146 set_gdbarch_frame_locals_address (gdbarch, mcore_frame_locals_address);
1147 set_gdbarch_frame_num_args (gdbarch, frame_num_args_unknown);
1148 set_gdbarch_pop_frame (gdbarch, mcore_pop_frame);
1149 set_gdbarch_virtual_frame_pointer (gdbarch, mcore_virtual_frame_pointer);
1153 /* Stack grows down. */
1154 set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
1155 set_gdbarch_use_struct_convention (gdbarch, mcore_use_struct_convention);
1156 set_gdbarch_believe_pcc_promotion (gdbarch, 1);
1157 /* MCore will never pass a sturcture by reference. It will always be split
1158 between registers and stack. */
1159 set_gdbarch_reg_struct_has_addr (gdbarch, mcore_reg_struct_has_addr);
1165 mcore_dump_tdep (struct gdbarch *current_gdbarch, struct ui_file *file)
1171 _initialize_mcore_tdep (void)
1173 extern int print_insn_mcore (bfd_vma, disassemble_info *);
1174 gdbarch_register (bfd_arch_mcore, mcore_gdbarch_init, mcore_dump_tdep);
1175 tm_print_insn = print_insn_mcore;
1178 add_show_from_set (add_set_cmd ("mcoredebug", no_class,
1179 var_boolean, (char *) &mcore_debug,
1180 "Set mcore debugging.\n", &setlist),