1 /* Target dependent code for GDB on TI C6x systems.
3 Copyright (C) 2010-2016 Free Software Foundation, Inc.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "frame-unwind.h"
25 #include "frame-base.h"
26 #include "trad-frame.h"
27 #include "dwarf2-frame.h"
38 #include "arch-utils.h"
39 #include "floatformat.h"
40 #include "glibc-tdep.h"
43 #include "tramp-frame.h"
44 #include "linux-tdep.h"
48 #include "tic6x-tdep.h"
50 #include "target-descriptions.h"
53 #include "features/tic6x-c64xp.c"
54 #include "features/tic6x-c64x.c"
55 #include "features/tic6x-c62x.c"
57 #define TIC6X_OPCODE_SIZE 4
58 #define TIC6X_FETCH_PACKET_SIZE 32
60 #define INST_S_BIT(INST) ((INST >> 1) & 1)
61 #define INST_X_BIT(INST) ((INST >> 12) & 1)
63 const gdb_byte tic6x_bkpt_illegal_opcode_be[] = { 0x56, 0x45, 0x43, 0x14 };
64 const gdb_byte tic6x_bkpt_illegal_opcode_le[] = { 0x14, 0x43, 0x45, 0x56 };
66 struct tic6x_unwind_cache
68 /* The frame's base, optionally used by the high-level debug info. */
71 /* The previous frame's inner most stack address. Used as this
72 frame ID's stack_addr. */
75 /* The address of the first instruction in this function */
78 /* Which register holds the return address for the frame. */
81 /* The offset of register saved on stack. If register is not saved, the
82 corresponding element is -1. */
83 CORE_ADDR reg_saved[TIC6X_NUM_CORE_REGS];
87 /* Name of TI C6x core registers. */
88 static const char *const tic6x_register_names[] =
90 "A0", "A1", "A2", "A3", /* 0 1 2 3 */
91 "A4", "A5", "A6", "A7", /* 4 5 6 7 */
92 "A8", "A9", "A10", "A11", /* 8 9 10 11 */
93 "A12", "A13", "A14", "A15", /* 12 13 14 15 */
94 "B0", "B1", "B2", "B3", /* 16 17 18 19 */
95 "B4", "B5", "B6", "B7", /* 20 21 22 23 */
96 "B8", "B9", "B10", "B11", /* 24 25 26 27 */
97 "B12", "B13", "B14", "B15", /* 28 29 30 31 */
98 "CSR", "PC", /* 32 33 */
101 /* This array maps the arguments to the register number which passes argument
102 in function call according to C6000 ELF ABI. */
103 static const int arg_regs[] = { 4, 20, 6, 22, 8, 24, 10, 26, 12, 28 };
105 /* This is the implementation of gdbarch method register_name. */
108 tic6x_register_name (struct gdbarch *gdbarch, int regno)
113 if (tdesc_has_registers (gdbarch_target_desc (gdbarch)))
114 return tdesc_register_name (gdbarch, regno);
115 else if (regno >= ARRAY_SIZE (tic6x_register_names))
118 return tic6x_register_names[regno];
121 /* This is the implementation of gdbarch method register_type. */
124 tic6x_register_type (struct gdbarch *gdbarch, int regno)
127 if (regno == TIC6X_PC_REGNUM)
128 return builtin_type (gdbarch)->builtin_func_ptr;
130 return builtin_type (gdbarch)->builtin_uint32;
134 tic6x_setup_default (struct tic6x_unwind_cache *cache)
138 for (i = 0; i < TIC6X_NUM_CORE_REGS; i++)
139 cache->reg_saved[i] = -1;
142 static unsigned long tic6x_fetch_instruction (struct gdbarch *, CORE_ADDR);
143 static int tic6x_register_number (int reg, int side, int crosspath);
145 /* Do a full analysis of the prologue at START_PC and update CACHE accordingly.
146 Bail out early if CURRENT_PC is reached. Returns the address of the first
147 instruction after the prologue. */
150 tic6x_analyze_prologue (struct gdbarch *gdbarch, const CORE_ADDR start_pc,
151 const CORE_ADDR current_pc,
152 struct tic6x_unwind_cache *cache,
153 struct frame_info *this_frame)
156 unsigned int src_reg, base_reg, dst_reg;
158 CORE_ADDR pc = start_pc;
159 CORE_ADDR return_pc = start_pc;
160 int frame_base_offset_to_sp = 0;
161 /* Counter of non-stw instructions after first insn ` sub sp, xxx, sp'. */
162 int non_stw_insn_counter = 0;
164 if (start_pc >= current_pc)
165 return_pc = current_pc;
169 /* The landmarks in prologue is one or two SUB instructions to SP.
170 Instructions on setting up dsbt are in the last part of prologue, if
171 needed. In maxim, prologue can be divided to three parts by two
172 `sub sp, xx, sp' insns. */
174 /* Step 1: Look for the 1st and 2nd insn `sub sp, xx, sp', in which, the
175 2nd one is optional. */
176 while (pc < current_pc)
178 unsigned long inst = tic6x_fetch_instruction (gdbarch, pc);
180 if ((inst & 0x1ffc) == 0x1dc0 || (inst & 0x1ffc) == 0x1bc0
181 || (inst & 0x0ffc) == 0x9c0)
183 /* SUBAW/SUBAH/SUB, and src1 is ucst 5. */
184 unsigned int src2 = tic6x_register_number ((inst >> 18) & 0x1f,
185 INST_S_BIT (inst), 0);
186 unsigned int dst = tic6x_register_number ((inst >> 23) & 0x1f,
187 INST_S_BIT (inst), 0);
189 if (src2 == TIC6X_SP_REGNUM && dst == TIC6X_SP_REGNUM)
191 /* Extract const from insn SUBAW/SUBAH/SUB, and translate it to
192 offset. The constant offset is decoded in bit 13-17 in all
193 these three kinds of instructions. */
194 unsigned int ucst5 = (inst >> 13) & 0x1f;
196 if ((inst & 0x1ffc) == 0x1dc0) /* SUBAW */
197 frame_base_offset_to_sp += ucst5 << 2;
198 else if ((inst & 0x1ffc) == 0x1bc0) /* SUBAH */
199 frame_base_offset_to_sp += ucst5 << 1;
200 else if ((inst & 0x0ffc) == 0x9c0) /* SUB */
201 frame_base_offset_to_sp += ucst5;
203 gdb_assert_not_reached ("unexpected instruction");
208 else if ((inst & 0x174) == 0x74) /* stw SRC, *+b15(uconst) */
210 /* The y bit determines which file base is read from. */
211 base_reg = tic6x_register_number ((inst >> 18) & 0x1f,
214 if (base_reg == TIC6X_SP_REGNUM)
216 src_reg = tic6x_register_number ((inst >> 23) & 0x1f,
217 INST_S_BIT (inst), 0);
219 cache->reg_saved[src_reg] = ((inst >> 13) & 0x1f) << 2;
223 non_stw_insn_counter = 0;
227 non_stw_insn_counter++;
228 /* Following instruction sequence may be emitted in prologue:
230 <+0>: subah .D2 b15,28,b15
231 <+4>: or .L2X 0,a4,b0
232 <+8>: || stw .D2T2 b14,*+b15(56)
233 <+12>:[!b0] b .S1 0xe50e4c1c <sleep+220>
234 <+16>:|| stw .D2T1 a10,*+b15(48)
235 <+20>:stw .D2T2 b3,*+b15(52)
236 <+24>:stw .D2T1 a4,*+b15(40)
238 we should look forward for next instruction instead of breaking loop
239 here. So far, we allow almost two sequential non-stw instructions
241 if (non_stw_insn_counter >= 2)
248 /* Step 2: Skip insn on setting up dsbt if it is. Usually, it looks like,
249 ldw .D2T2 *+b14(0),b14 */
250 inst = tic6x_fetch_instruction (gdbarch, pc);
251 /* The s bit determines which file dst will be loaded into, same effect as
253 dst_reg = tic6x_register_number ((inst >> 23) & 0x1f, (inst >> 1) & 1, 0);
254 /* The y bit (bit 7), instead of s bit, determines which file base be
256 base_reg = tic6x_register_number ((inst >> 18) & 0x1f, (inst >> 7) & 1, 0);
258 if ((inst & 0x164) == 0x64 /* ldw */
259 && dst_reg == TIC6X_DP_REGNUM /* dst is B14 */
260 && base_reg == TIC6X_DP_REGNUM) /* baseR is B14 */
267 cache->base = get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM);
269 if (cache->reg_saved[TIC6X_FP_REGNUM] != -1)
271 /* If the FP now holds an offset from the CFA then this is a frame
272 which uses the frame pointer. */
274 cache->cfa = get_frame_register_unsigned (this_frame,
279 /* FP doesn't hold an offset from the CFA. If SP still holds an
280 offset from the CFA then we might be in a function which omits
281 the frame pointer. */
283 cache->cfa = cache->base + frame_base_offset_to_sp;
287 /* Adjust all the saved registers such that they contain addresses
288 instead of offsets. */
289 for (i = 0; i < TIC6X_NUM_CORE_REGS; i++)
290 if (cache->reg_saved[i] != -1)
291 cache->reg_saved[i] = cache->base + cache->reg_saved[i];
296 /* This is the implementation of gdbarch method skip_prologue. */
299 tic6x_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc)
302 struct tic6x_unwind_cache cache;
304 /* See if we can determine the end of the prologue via the symbol table.
305 If so, then return either PC, or the PC after the prologue, whichever is
307 if (find_pc_partial_function (start_pc, NULL, &func_addr, NULL))
309 CORE_ADDR post_prologue_pc
310 = skip_prologue_using_sal (gdbarch, func_addr);
311 if (post_prologue_pc != 0)
312 return std::max (start_pc, post_prologue_pc);
315 /* Can't determine prologue from the symbol table, need to examine
317 return tic6x_analyze_prologue (gdbarch, start_pc, (CORE_ADDR) -1, &cache,
321 /* Implement the breakpoint_kind_from_pc gdbarch method. */
324 tic6x_breakpoint_kind_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr)
329 /* Implement the sw_breakpoint_from_kind gdbarch method. */
331 static const gdb_byte *
332 tic6x_sw_breakpoint_from_kind (struct gdbarch *gdbarch, int kind, int *size)
334 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
338 if (tdep == NULL || tdep->breakpoint == NULL)
340 if (BFD_ENDIAN_BIG == gdbarch_byte_order_for_code (gdbarch))
341 return tic6x_bkpt_illegal_opcode_be;
343 return tic6x_bkpt_illegal_opcode_le;
346 return tdep->breakpoint;
349 /* This is the implementation of gdbarch method print_insn. */
352 tic6x_print_insn (bfd_vma memaddr, disassemble_info *info)
354 return print_insn_tic6x (memaddr, info);
358 tic6x_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
359 struct dwarf2_frame_state_reg *reg,
360 struct frame_info *this_frame)
362 /* Mark the PC as the destination for the return address. */
363 if (regnum == gdbarch_pc_regnum (gdbarch))
364 reg->how = DWARF2_FRAME_REG_RA;
366 /* Mark the stack pointer as the call frame address. */
367 else if (regnum == gdbarch_sp_regnum (gdbarch))
368 reg->how = DWARF2_FRAME_REG_CFA;
370 /* The above was taken from the default init_reg in dwarf2-frame.c
371 while the below is c6x specific. */
373 /* Callee save registers. The ABI designates A10-A15 and B10-B15 as
375 else if ((regnum >= 10 && regnum <= 15) || (regnum >= 26 && regnum <= 31))
376 reg->how = DWARF2_FRAME_REG_SAME_VALUE;
378 /* All other registers are caller-save. */
379 reg->how = DWARF2_FRAME_REG_UNDEFINED;
382 /* This is the implementation of gdbarch method unwind_pc. */
385 tic6x_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
389 frame_unwind_register (next_frame, TIC6X_PC_REGNUM, buf);
390 return extract_typed_address (buf, builtin_type (gdbarch)->builtin_func_ptr);
393 /* This is the implementation of gdbarch method unwind_sp. */
396 tic6x_unwind_sp (struct gdbarch *gdbarch, struct frame_info *this_frame)
398 return frame_unwind_register_unsigned (this_frame, TIC6X_SP_REGNUM);
402 /* Frame base handling. */
404 static struct tic6x_unwind_cache*
405 tic6x_frame_unwind_cache (struct frame_info *this_frame,
406 void **this_prologue_cache)
408 struct gdbarch *gdbarch = get_frame_arch (this_frame);
409 CORE_ADDR current_pc;
410 struct tic6x_unwind_cache *cache;
412 if (*this_prologue_cache)
413 return (struct tic6x_unwind_cache *) *this_prologue_cache;
415 cache = FRAME_OBSTACK_ZALLOC (struct tic6x_unwind_cache);
416 (*this_prologue_cache) = cache;
418 cache->return_regnum = TIC6X_RA_REGNUM;
420 tic6x_setup_default (cache);
422 cache->pc = get_frame_func (this_frame);
423 current_pc = get_frame_pc (this_frame);
425 /* Prologue analysis does the rest... */
427 tic6x_analyze_prologue (gdbarch, cache->pc, current_pc, cache, this_frame);
433 tic6x_frame_this_id (struct frame_info *this_frame, void **this_cache,
434 struct frame_id *this_id)
436 struct tic6x_unwind_cache *cache =
437 tic6x_frame_unwind_cache (this_frame, this_cache);
439 /* This marks the outermost frame. */
440 if (cache->base == 0)
443 (*this_id) = frame_id_build (cache->cfa, cache->pc);
446 static struct value *
447 tic6x_frame_prev_register (struct frame_info *this_frame, void **this_cache,
450 struct tic6x_unwind_cache *cache =
451 tic6x_frame_unwind_cache (this_frame, this_cache);
453 gdb_assert (regnum >= 0);
455 /* The PC of the previous frame is stored in the RA register of
456 the current frame. Frob regnum so that we pull the value from
457 the correct place. */
458 if (regnum == TIC6X_PC_REGNUM)
459 regnum = cache->return_regnum;
461 if (regnum == TIC6X_SP_REGNUM && cache->cfa)
462 return frame_unwind_got_constant (this_frame, regnum, cache->cfa);
464 /* If we've worked out where a register is stored then load it from
466 if (regnum < TIC6X_NUM_CORE_REGS && cache->reg_saved[regnum] != -1)
467 return frame_unwind_got_memory (this_frame, regnum,
468 cache->reg_saved[regnum]);
470 return frame_unwind_got_register (this_frame, regnum, regnum);
474 tic6x_frame_base_address (struct frame_info *this_frame, void **this_cache)
476 struct tic6x_unwind_cache *info
477 = tic6x_frame_unwind_cache (this_frame, this_cache);
481 static const struct frame_unwind tic6x_frame_unwind =
484 default_frame_unwind_stop_reason,
486 tic6x_frame_prev_register,
488 default_frame_sniffer
491 static const struct frame_base tic6x_frame_base =
494 tic6x_frame_base_address,
495 tic6x_frame_base_address,
496 tic6x_frame_base_address
500 static struct tic6x_unwind_cache *
501 tic6x_make_stub_cache (struct frame_info *this_frame)
503 struct tic6x_unwind_cache *cache;
505 cache = FRAME_OBSTACK_ZALLOC (struct tic6x_unwind_cache);
507 cache->return_regnum = TIC6X_RA_REGNUM;
509 tic6x_setup_default (cache);
511 cache->cfa = get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM);
517 tic6x_stub_this_id (struct frame_info *this_frame, void **this_cache,
518 struct frame_id *this_id)
520 struct tic6x_unwind_cache *cache;
522 if (*this_cache == NULL)
523 *this_cache = tic6x_make_stub_cache (this_frame);
524 cache = (struct tic6x_unwind_cache *) *this_cache;
526 *this_id = frame_id_build (cache->cfa, get_frame_pc (this_frame));
530 tic6x_stub_unwind_sniffer (const struct frame_unwind *self,
531 struct frame_info *this_frame,
532 void **this_prologue_cache)
534 CORE_ADDR addr_in_block;
536 addr_in_block = get_frame_address_in_block (this_frame);
537 if (in_plt_section (addr_in_block))
543 static const struct frame_unwind tic6x_stub_unwind =
546 default_frame_unwind_stop_reason,
548 tic6x_frame_prev_register,
550 tic6x_stub_unwind_sniffer
553 /* Return the instruction on address PC. */
556 tic6x_fetch_instruction (struct gdbarch *gdbarch, CORE_ADDR pc)
558 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
559 return read_memory_unsigned_integer (pc, TIC6X_OPCODE_SIZE, byte_order);
562 /* Compute the condition of INST if it is a conditional instruction. Always
563 return 1 if INST is not a conditional instruction. */
566 tic6x_condition_true (struct frame_info *frame, unsigned long inst)
570 static const int register_numbers[8] = { -1, 16, 17, 18, 1, 2, 0, -1 };
572 register_number = register_numbers[(inst >> 29) & 7];
573 if (register_number == -1)
576 register_value = get_frame_register_signed (frame, register_number);
577 if ((inst & 0x10000000) != 0)
578 return register_value == 0;
579 return register_value != 0;
582 /* Get the register number by decoding raw bits REG, SIDE, and CROSSPATH in
586 tic6x_register_number (int reg, int side, int crosspath)
588 int r = (reg & 15) | ((crosspath ^ side) << 4);
589 if ((reg & 16) != 0) /* A16 - A31, B16 - B31 */
595 tic6x_extract_signed_field (int value, int low_bit, int bits)
597 int mask = (1 << bits) - 1;
598 int r = (value >> low_bit) & mask;
599 if ((r & (1 << (bits - 1))) != 0)
604 /* Determine where to set a single step breakpoint. */
607 tic6x_get_next_pc (struct frame_info *frame, CORE_ADDR pc)
609 struct gdbarch *gdbarch = get_frame_arch (frame);
616 inst = tic6x_fetch_instruction (gdbarch, pc);
620 if (inst == TIC6X_INST_SWE)
622 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
624 if (tdep->syscall_next_pc != NULL)
625 return tdep->syscall_next_pc (frame);
628 if (tic6x_condition_true (frame, inst))
630 if ((inst & 0x0000007c) == 0x00000010)
632 /* B with displacement */
633 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
634 pc += tic6x_extract_signed_field (inst, 7, 21) << 2;
637 if ((inst & 0x0f83effc) == 0x00000360)
639 /* B with register */
641 register_number = tic6x_register_number ((inst >> 18) & 0x1f,
644 pc = get_frame_register_unsigned (frame, register_number);
647 if ((inst & 0x00001ffc) == 0x00001020)
650 register_number = tic6x_register_number ((inst >> 23) & 0x1f,
651 INST_S_BIT (inst), 0);
652 if (get_frame_register_signed (frame, register_number) >= 0)
654 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
655 pc += tic6x_extract_signed_field (inst, 7, 10) << 2;
659 if ((inst & 0x00001ffc) == 0x00000120)
661 /* BNOP with displacement */
662 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
663 pc += tic6x_extract_signed_field (inst, 16, 12) << 2;
666 if ((inst & 0x0f830ffe) == 0x00800362)
668 /* BNOP with register */
669 register_number = tic6x_register_number ((inst >> 18) & 0x1f,
670 1, INST_X_BIT (inst));
671 pc = get_frame_register_unsigned (frame, register_number);
674 if ((inst & 0x00001ffc) == 0x00000020)
677 register_number = tic6x_register_number ((inst >> 23) & 0x1f,
678 INST_S_BIT (inst), 0);
679 if (get_frame_register_signed (frame, register_number) >= 0)
681 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
682 pc += tic6x_extract_signed_field (inst, 13, 10) << 2;
686 if ((inst & 0xf000007c) == 0x10000010)
689 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
690 pc += tic6x_extract_signed_field (inst, 7, 21) << 2;
694 pc += TIC6X_OPCODE_SIZE;
700 /* This is the implementation of gdbarch method software_single_step. */
703 tic6x_software_single_step (struct frame_info *frame)
705 struct gdbarch *gdbarch = get_frame_arch (frame);
706 struct address_space *aspace = get_frame_address_space (frame);
707 CORE_ADDR next_pc = tic6x_get_next_pc (frame, get_frame_pc (frame));
709 insert_single_step_breakpoint (gdbarch, aspace, next_pc);
714 /* This is the implementation of gdbarch method frame_align. */
717 tic6x_frame_align (struct gdbarch *gdbarch, CORE_ADDR addr)
719 return align_down (addr, 8);
722 /* Given a return value in REGCACHE with a type VALTYPE, extract and copy its
723 value into VALBUF. */
726 tic6x_extract_return_value (struct type *valtype, struct regcache *regcache,
727 enum bfd_endian byte_order, gdb_byte *valbuf)
729 int len = TYPE_LENGTH (valtype);
731 /* pointer types are returned in register A4,
732 up to 32-bit types in A4
733 up to 64-bit types in A5:A4 */
737 - one-byte structure or union occupies the LSB of single even register.
738 - for two-byte structure or union, the first byte occupies byte 1 of
739 register and the second byte occupies byte 0.
740 so, we read the contents in VAL from the LSBs of register. */
741 if (len < 3 && byte_order == BFD_ENDIAN_BIG)
742 regcache_cooked_read_part (regcache, TIC6X_A4_REGNUM, 4 - len, len,
745 regcache_cooked_read (regcache, TIC6X_A4_REGNUM, valbuf);
749 /* For a 5-8 byte structure or union in big-endian, the first byte
750 occupies byte 3 (the MSB) of the upper (odd) register and the
751 remaining bytes fill the decreasingly significant bytes. 5-7
752 byte structures or unions have padding in the LSBs of the
753 lower (even) register. */
754 if (byte_order == BFD_ENDIAN_BIG)
756 regcache_cooked_read (regcache, TIC6X_A4_REGNUM, valbuf + 4);
757 regcache_cooked_read (regcache, TIC6X_A5_REGNUM, valbuf);
761 regcache_cooked_read (regcache, TIC6X_A4_REGNUM, valbuf);
762 regcache_cooked_read (regcache, TIC6X_A5_REGNUM, valbuf + 4);
767 /* Write into appropriate registers a function return value
768 of type TYPE, given in virtual format. */
771 tic6x_store_return_value (struct type *valtype, struct regcache *regcache,
772 enum bfd_endian byte_order, const gdb_byte *valbuf)
774 int len = TYPE_LENGTH (valtype);
776 /* return values of up to 8 bytes are returned in A5:A4 */
780 if (len < 3 && byte_order == BFD_ENDIAN_BIG)
781 regcache_cooked_write_part (regcache, TIC6X_A4_REGNUM, 4 - len, len,
784 regcache_cooked_write (regcache, TIC6X_A4_REGNUM, valbuf);
788 if (byte_order == BFD_ENDIAN_BIG)
790 regcache_cooked_write (regcache, TIC6X_A4_REGNUM, valbuf + 4);
791 regcache_cooked_write (regcache, TIC6X_A5_REGNUM, valbuf);
795 regcache_cooked_write (regcache, TIC6X_A4_REGNUM, valbuf);
796 regcache_cooked_write (regcache, TIC6X_A5_REGNUM, valbuf + 4);
801 /* This is the implementation of gdbarch method return_value. */
803 static enum return_value_convention
804 tic6x_return_value (struct gdbarch *gdbarch, struct value *function,
805 struct type *type, struct regcache *regcache,
806 gdb_byte *readbuf, const gdb_byte *writebuf)
808 /* In C++, when function returns an object, even its size is small
809 enough, it stii has to be passed via reference, pointed by register
811 if (current_language->la_language == language_cplus)
815 type = check_typedef (type);
816 if (language_pass_by_reference (type))
817 return RETURN_VALUE_STRUCT_CONVENTION;
821 if (TYPE_LENGTH (type) > 8)
822 return RETURN_VALUE_STRUCT_CONVENTION;
825 tic6x_extract_return_value (type, regcache,
826 gdbarch_byte_order (gdbarch), readbuf);
828 tic6x_store_return_value (type, regcache,
829 gdbarch_byte_order (gdbarch), writebuf);
831 return RETURN_VALUE_REGISTER_CONVENTION;
834 /* This is the implementation of gdbarch method dummy_id. */
836 static struct frame_id
837 tic6x_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
839 return frame_id_build
840 (get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM),
841 get_frame_pc (this_frame));
844 /* Get the alignment requirement of TYPE. */
847 tic6x_arg_type_alignment (struct type *type)
849 int len = TYPE_LENGTH (check_typedef (type));
850 enum type_code typecode = TYPE_CODE (check_typedef (type));
852 if (typecode == TYPE_CODE_STRUCT || typecode == TYPE_CODE_UNION)
854 /* The stack alignment of a structure (and union) passed by value is the
855 smallest power of two greater than or equal to its size.
856 This cannot exceed 8 bytes, which is the largest allowable size for
857 a structure passed by value. */
866 gdb_assert_not_reached ("unexpected length of data");
874 if (typecode == TYPE_CODE_COMPLEX)
881 if (typecode == TYPE_CODE_COMPLEX)
887 internal_error (__FILE__, __LINE__, _("unexpected length %d of type"),
892 /* This is the implementation of gdbarch method push_dummy_call. */
895 tic6x_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
896 struct regcache *regcache, CORE_ADDR bp_addr,
897 int nargs, struct value **args, CORE_ADDR sp,
898 int struct_return, CORE_ADDR struct_addr)
902 int stack_offset = 4;
903 int references_offset = 4;
904 CORE_ADDR func_addr = find_function_addr (function, NULL);
905 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
906 struct type *func_type = value_type (function);
907 /* The first arg passed on stack. Mostly the first 10 args are passed by
909 int first_arg_on_stack = 10;
911 /* Set the return address register to point to the entry point of
912 the program, where a breakpoint lies in wait. */
913 regcache_cooked_write_unsigned (regcache, TIC6X_RA_REGNUM, bp_addr);
915 /* The caller must pass an argument in A3 containing a destination address
916 for the returned value. The callee returns the object by copying it to
917 the address in A3. */
919 regcache_cooked_write_unsigned (regcache, 3, struct_addr);
921 /* Determine the type of this function. */
922 func_type = check_typedef (func_type);
923 if (TYPE_CODE (func_type) == TYPE_CODE_PTR)
924 func_type = check_typedef (TYPE_TARGET_TYPE (func_type));
926 gdb_assert (TYPE_CODE (func_type) == TYPE_CODE_FUNC
927 || TYPE_CODE (func_type) == TYPE_CODE_METHOD);
929 /* For a variadic C function, the last explicitly declared argument and all
930 remaining arguments are passed on the stack. */
931 if (TYPE_VARARGS (func_type))
932 first_arg_on_stack = TYPE_NFIELDS (func_type) - 1;
934 /* Now make space on the stack for the args. */
935 for (argnum = 0; argnum < nargs; argnum++)
937 int len = align_up (TYPE_LENGTH (value_type (args[argnum])), 4);
938 if (argnum >= 10 - argreg)
939 references_offset += len;
943 /* SP should be 8-byte aligned, see C6000 ABI section 4.4.1
945 sp = align_down (sp, 8);
948 /* Now load as many as possible of the first arguments into
949 registers, and push the rest onto the stack. Loop through args
950 from first to last. */
951 for (argnum = 0; argnum < nargs; argnum++)
954 struct value *arg = args[argnum];
955 struct type *arg_type = check_typedef (value_type (arg));
956 int len = TYPE_LENGTH (arg_type);
957 enum type_code typecode = TYPE_CODE (arg_type);
959 val = value_contents (arg);
961 /* Copy the argument to general registers or the stack in
962 register-sized pieces. */
963 if (argreg < first_arg_on_stack)
967 if (typecode == TYPE_CODE_STRUCT || typecode == TYPE_CODE_UNION)
970 - one-byte structure or union occupies the LSB of single
972 - for two-byte structure or union, the first byte
973 occupies byte 1 of register and the second byte occupies
975 so, we write the contents in VAL to the lsp of
977 if (len < 3 && byte_order == BFD_ENDIAN_BIG)
978 regcache_cooked_write_part (regcache, arg_regs[argreg],
981 regcache_cooked_write (regcache, arg_regs[argreg], val);
985 /* The argument is being passed by value in a single
987 CORE_ADDR regval = extract_unsigned_integer (val, len,
990 regcache_cooked_write_unsigned (regcache, arg_regs[argreg],
998 if (typecode == TYPE_CODE_STRUCT
999 || typecode == TYPE_CODE_UNION)
1001 /* For a 5-8 byte structure or union in big-endian, the
1002 first byte occupies byte 3 (the MSB) of the upper (odd)
1003 register and the remaining bytes fill the decreasingly
1004 significant bytes. 5-7 byte structures or unions have
1005 padding in the LSBs of the lower (even) register. */
1006 if (byte_order == BFD_ENDIAN_BIG)
1008 regcache_cooked_write (regcache,
1009 arg_regs[argreg] + 1, val);
1010 regcache_cooked_write_part (regcache,
1011 arg_regs[argreg], 0,
1016 regcache_cooked_write (regcache, arg_regs[argreg],
1018 regcache_cooked_write_part (regcache,
1019 arg_regs[argreg] + 1, 0,
1025 /* The argument is being passed by value in a pair of
1027 ULONGEST regval = extract_unsigned_integer (val, len,
1030 regcache_cooked_write_unsigned (regcache,
1033 regcache_cooked_write_unsigned (regcache,
1034 arg_regs[argreg] + 1,
1040 /* The argument is being passed by reference in a single
1044 /* It is not necessary to adjust REFERENCES_OFFSET to
1045 8-byte aligned in some cases, in which 4-byte alignment
1046 is sufficient. For simplicity, we adjust
1047 REFERENCES_OFFSET to 8-byte aligned. */
1048 references_offset = align_up (references_offset, 8);
1050 addr = sp + references_offset;
1051 write_memory (addr, val, len);
1052 references_offset += align_up (len, 4);
1053 regcache_cooked_write_unsigned (regcache, arg_regs[argreg],
1061 /* The argument is being passed on the stack. */
1064 /* There are six different cases of alignment, and these rules can
1065 be found in tic6x_arg_type_alignment:
1067 1) 4-byte aligned if size is less than or equal to 4 byte, such
1068 as short, int, struct, union etc.
1069 2) 8-byte aligned if size is less than or equal to 8-byte, such
1070 as double, long long,
1071 3) 4-byte aligned if it is of type _Complex float, even its size
1073 4) 8-byte aligned if it is of type _Complex double or _Complex
1074 long double, even its size is 16-byte. Because, the address of
1075 variable is passed as reference.
1076 5) struct and union larger than 8-byte are passed by reference, so
1077 it is 4-byte aligned.
1078 6) struct and union of size between 4 byte and 8 byte varies.
1079 alignment of struct variable is the alignment of its first field,
1080 while alignment of union variable is the max of all its fields'
1084 ; /* Default is 4-byte aligned. Nothing to be done. */
1086 stack_offset = align_up (stack_offset,
1087 tic6x_arg_type_alignment (arg_type));
1090 /* _Complex double or _Complex long double */
1091 if (typecode == TYPE_CODE_COMPLEX)
1093 /* The argument is being passed by reference on stack. */
1095 references_offset = align_up (references_offset, 8);
1097 addr = sp + references_offset;
1098 /* Store variable on stack. */
1099 write_memory (addr, val, len);
1101 references_offset += align_up (len, 4);
1103 /* Pass the address of variable on stack as reference. */
1104 store_unsigned_integer ((gdb_byte *) val, 4, byte_order,
1110 internal_error (__FILE__, __LINE__,
1111 _("unexpected type %d of arg %d"),
1115 internal_error (__FILE__, __LINE__,
1116 _("unexpected length %d of arg %d"), len, argnum);
1118 addr = sp + stack_offset;
1119 write_memory (addr, val, len);
1120 stack_offset += align_up (len, 4);
1124 regcache_cooked_write_signed (regcache, TIC6X_SP_REGNUM, sp);
1126 /* Return adjusted stack pointer. */
1130 /* This is the implementation of gdbarch method stack_frame_destroyed_p. */
1133 tic6x_stack_frame_destroyed_p (struct gdbarch *gdbarch, CORE_ADDR pc)
1135 unsigned long inst = tic6x_fetch_instruction (gdbarch, pc);
1136 /* Normally, the epilogue is composed by instruction `b .S2 b3'. */
1137 if ((inst & 0x0f83effc) == 0x360)
1139 unsigned int src2 = tic6x_register_number ((inst >> 18) & 0x1f,
1142 if (src2 == TIC6X_RA_REGNUM)
1149 /* This is the implementation of gdbarch method get_longjmp_target. */
1152 tic6x_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
1154 struct gdbarch *gdbarch = get_frame_arch (frame);
1155 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
1159 /* JMP_BUF is passed by reference in A4. */
1160 jb_addr = get_frame_register_unsigned (frame, 4);
1162 /* JMP_BUF contains 13 elements of type int, and return address is stored
1163 in the last slot. */
1164 if (target_read_memory (jb_addr + 12 * 4, buf, 4))
1167 *pc = extract_unsigned_integer (buf, 4, byte_order);
1172 /* This is the implementation of gdbarch method
1173 return_in_first_hidden_param_p. */
1176 tic6x_return_in_first_hidden_param_p (struct gdbarch *gdbarch,
1182 static struct gdbarch *
1183 tic6x_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
1185 struct gdbarch *gdbarch;
1186 struct gdbarch_tdep *tdep;
1187 struct tdesc_arch_data *tdesc_data = NULL;
1188 const struct target_desc *tdesc = info.target_desc;
1191 /* Check any target description for validity. */
1192 if (tdesc_has_registers (tdesc))
1194 const struct tdesc_feature *feature;
1197 feature = tdesc_find_feature (tdesc, "org.gnu.gdb.tic6x.core");
1199 if (feature == NULL)
1202 tdesc_data = tdesc_data_alloc ();
1205 for (i = 0; i < 32; i++) /* A0 - A15, B0 - B15 */
1206 valid_p &= tdesc_numbered_register (feature, tdesc_data, i,
1207 tic6x_register_names[i]);
1210 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++,
1211 tic6x_register_names[TIC6X_CSR_REGNUM]);
1212 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++,
1213 tic6x_register_names[TIC6X_PC_REGNUM]);
1217 tdesc_data_cleanup (tdesc_data);
1221 feature = tdesc_find_feature (tdesc, "org.gnu.gdb.tic6x.gp");
1225 static const char *const gp[] =
1227 "A16", "A17", "A18", "A19", "A20", "A21", "A22", "A23",
1228 "A24", "A25", "A26", "A27", "A28", "A29", "A30", "A31",
1229 "B16", "B17", "B18", "B19", "B20", "B21", "B22", "B23",
1230 "B24", "B25", "B26", "B27", "B28", "B29", "B30", "B31",
1235 for (j = 0; j < 32; j++) /* A16 - A31, B16 - B31 */
1236 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++,
1241 tdesc_data_cleanup (tdesc_data);
1246 feature = tdesc_find_feature (tdesc, "org.gnu.gdb.tic6x.c6xp");
1249 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++, "TSR");
1250 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++, "ILC");
1251 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++, "RILC");
1255 tdesc_data_cleanup (tdesc_data);
1262 /* Find a candidate among extant architectures. */
1263 for (arches = gdbarch_list_lookup_by_info (arches, &info);
1265 arches = gdbarch_list_lookup_by_info (arches->next, &info))
1267 tdep = gdbarch_tdep (arches->gdbarch);
1269 if (has_gp != tdep->has_gp)
1272 if (tdep && tdep->breakpoint)
1273 return arches->gdbarch;
1276 tdep = XCNEW (struct gdbarch_tdep);
1278 tdep->has_gp = has_gp;
1279 gdbarch = gdbarch_alloc (&info, tdep);
1281 /* Data type sizes. */
1282 set_gdbarch_ptr_bit (gdbarch, 32);
1283 set_gdbarch_addr_bit (gdbarch, 32);
1284 set_gdbarch_short_bit (gdbarch, 16);
1285 set_gdbarch_int_bit (gdbarch, 32);
1286 set_gdbarch_long_bit (gdbarch, 32);
1287 set_gdbarch_long_long_bit (gdbarch, 64);
1288 set_gdbarch_float_bit (gdbarch, 32);
1289 set_gdbarch_double_bit (gdbarch, 64);
1291 set_gdbarch_float_format (gdbarch, floatformats_ieee_single);
1292 set_gdbarch_double_format (gdbarch, floatformats_ieee_double);
1294 /* The register set. */
1295 set_gdbarch_num_regs (gdbarch, TIC6X_NUM_REGS);
1296 set_gdbarch_sp_regnum (gdbarch, TIC6X_SP_REGNUM);
1297 set_gdbarch_pc_regnum (gdbarch, TIC6X_PC_REGNUM);
1299 set_gdbarch_register_name (gdbarch, tic6x_register_name);
1300 set_gdbarch_register_type (gdbarch, tic6x_register_type);
1302 set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
1304 set_gdbarch_skip_prologue (gdbarch, tic6x_skip_prologue);
1305 SET_GDBARCH_BREAKPOINT_MANIPULATION (tic6x);
1307 set_gdbarch_unwind_pc (gdbarch, tic6x_unwind_pc);
1308 set_gdbarch_unwind_sp (gdbarch, tic6x_unwind_sp);
1311 dwarf2_append_unwinders (gdbarch);
1313 frame_unwind_append_unwinder (gdbarch, &tic6x_stub_unwind);
1314 frame_unwind_append_unwinder (gdbarch, &tic6x_frame_unwind);
1315 frame_base_set_default (gdbarch, &tic6x_frame_base);
1317 dwarf2_frame_set_init_reg (gdbarch, tic6x_dwarf2_frame_init_reg);
1319 /* Single stepping. */
1320 set_gdbarch_software_single_step (gdbarch, tic6x_software_single_step);
1322 set_gdbarch_print_insn (gdbarch, tic6x_print_insn);
1324 /* Call dummy code. */
1325 set_gdbarch_frame_align (gdbarch, tic6x_frame_align);
1327 set_gdbarch_return_value (gdbarch, tic6x_return_value);
1329 set_gdbarch_dummy_id (gdbarch, tic6x_dummy_id);
1331 /* Enable inferior call support. */
1332 set_gdbarch_push_dummy_call (gdbarch, tic6x_push_dummy_call);
1334 set_gdbarch_get_longjmp_target (gdbarch, tic6x_get_longjmp_target);
1336 set_gdbarch_stack_frame_destroyed_p (gdbarch, tic6x_stack_frame_destroyed_p);
1338 set_gdbarch_return_in_first_hidden_param_p (gdbarch,
1339 tic6x_return_in_first_hidden_param_p);
1341 /* Hook in ABI-specific overrides, if they have been registered. */
1342 gdbarch_init_osabi (info, gdbarch);
1345 tdesc_use_registers (gdbarch, tdesc, tdesc_data);
1350 /* -Wmissing-prototypes */
1351 extern initialize_file_ftype _initialize_tic6x_tdep;
1354 _initialize_tic6x_tdep (void)
1356 register_gdbarch_init (bfd_arch_tic6x, tic6x_gdbarch_init);
1358 initialize_tdesc_tic6x_c64xp ();
1359 initialize_tdesc_tic6x_c64x ();
1360 initialize_tdesc_tic6x_c62x ();