1 /* Target dependent code for GDB on TI C6x systems.
3 Copyright (C) 2010-2019 Free Software Foundation, Inc.
4 Contributed by Andrew Jenner <andrew@codesourcery.com>
5 Contributed by Yao Qi <yao@codesourcery.com>
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 "glibc-tdep.h"
42 #include "tramp-frame.h"
43 #include "linux-tdep.h"
47 #include "tic6x-tdep.h"
49 #include "target-descriptions.h"
52 #define TIC6X_OPCODE_SIZE 4
53 #define TIC6X_FETCH_PACKET_SIZE 32
55 #define INST_S_BIT(INST) ((INST >> 1) & 1)
56 #define INST_X_BIT(INST) ((INST >> 12) & 1)
58 const gdb_byte tic6x_bkpt_illegal_opcode_be[] = { 0x56, 0x45, 0x43, 0x14 };
59 const gdb_byte tic6x_bkpt_illegal_opcode_le[] = { 0x14, 0x43, 0x45, 0x56 };
61 struct tic6x_unwind_cache
63 /* The frame's base, optionally used by the high-level debug info. */
66 /* The previous frame's inner most stack address. Used as this
67 frame ID's stack_addr. */
70 /* The address of the first instruction in this function */
73 /* Which register holds the return address for the frame. */
76 /* The offset of register saved on stack. If register is not saved, the
77 corresponding element is -1. */
78 CORE_ADDR reg_saved[TIC6X_NUM_CORE_REGS];
82 /* Name of TI C6x core registers. */
83 static const char *const tic6x_register_names[] =
85 "A0", "A1", "A2", "A3", /* 0 1 2 3 */
86 "A4", "A5", "A6", "A7", /* 4 5 6 7 */
87 "A8", "A9", "A10", "A11", /* 8 9 10 11 */
88 "A12", "A13", "A14", "A15", /* 12 13 14 15 */
89 "B0", "B1", "B2", "B3", /* 16 17 18 19 */
90 "B4", "B5", "B6", "B7", /* 20 21 22 23 */
91 "B8", "B9", "B10", "B11", /* 24 25 26 27 */
92 "B12", "B13", "B14", "B15", /* 28 29 30 31 */
93 "CSR", "PC", /* 32 33 */
96 /* This array maps the arguments to the register number which passes argument
97 in function call according to C6000 ELF ABI. */
98 static const int arg_regs[] = { 4, 20, 6, 22, 8, 24, 10, 26, 12, 28 };
100 /* This is the implementation of gdbarch method register_name. */
103 tic6x_register_name (struct gdbarch *gdbarch, int regno)
108 if (tdesc_has_registers (gdbarch_target_desc (gdbarch)))
109 return tdesc_register_name (gdbarch, regno);
110 else if (regno >= ARRAY_SIZE (tic6x_register_names))
113 return tic6x_register_names[regno];
116 /* This is the implementation of gdbarch method register_type. */
119 tic6x_register_type (struct gdbarch *gdbarch, int regno)
122 if (regno == TIC6X_PC_REGNUM)
123 return builtin_type (gdbarch)->builtin_func_ptr;
125 return builtin_type (gdbarch)->builtin_uint32;
129 tic6x_setup_default (struct tic6x_unwind_cache *cache)
133 for (i = 0; i < TIC6X_NUM_CORE_REGS; i++)
134 cache->reg_saved[i] = -1;
137 static unsigned long tic6x_fetch_instruction (struct gdbarch *, CORE_ADDR);
138 static int tic6x_register_number (int reg, int side, int crosspath);
140 /* Do a full analysis of the prologue at START_PC and update CACHE accordingly.
141 Bail out early if CURRENT_PC is reached. Returns the address of the first
142 instruction after the prologue. */
145 tic6x_analyze_prologue (struct gdbarch *gdbarch, const CORE_ADDR start_pc,
146 const CORE_ADDR current_pc,
147 struct tic6x_unwind_cache *cache,
148 struct frame_info *this_frame)
150 unsigned int src_reg, base_reg, dst_reg;
152 CORE_ADDR pc = start_pc;
153 CORE_ADDR return_pc = start_pc;
154 int frame_base_offset_to_sp = 0;
155 /* Counter of non-stw instructions after first insn ` sub sp, xxx, sp'. */
156 int non_stw_insn_counter = 0;
158 if (start_pc >= current_pc)
159 return_pc = current_pc;
163 /* The landmarks in prologue is one or two SUB instructions to SP.
164 Instructions on setting up dsbt are in the last part of prologue, if
165 needed. In maxim, prologue can be divided to three parts by two
166 `sub sp, xx, sp' insns. */
168 /* Step 1: Look for the 1st and 2nd insn `sub sp, xx, sp', in which, the
169 2nd one is optional. */
170 while (pc < current_pc)
172 unsigned long inst = tic6x_fetch_instruction (gdbarch, pc);
174 if ((inst & 0x1ffc) == 0x1dc0 || (inst & 0x1ffc) == 0x1bc0
175 || (inst & 0x0ffc) == 0x9c0)
177 /* SUBAW/SUBAH/SUB, and src1 is ucst 5. */
178 unsigned int src2 = tic6x_register_number ((inst >> 18) & 0x1f,
179 INST_S_BIT (inst), 0);
180 unsigned int dst = tic6x_register_number ((inst >> 23) & 0x1f,
181 INST_S_BIT (inst), 0);
183 if (src2 == TIC6X_SP_REGNUM && dst == TIC6X_SP_REGNUM)
185 /* Extract const from insn SUBAW/SUBAH/SUB, and translate it to
186 offset. The constant offset is decoded in bit 13-17 in all
187 these three kinds of instructions. */
188 unsigned int ucst5 = (inst >> 13) & 0x1f;
190 if ((inst & 0x1ffc) == 0x1dc0) /* SUBAW */
191 frame_base_offset_to_sp += ucst5 << 2;
192 else if ((inst & 0x1ffc) == 0x1bc0) /* SUBAH */
193 frame_base_offset_to_sp += ucst5 << 1;
194 else if ((inst & 0x0ffc) == 0x9c0) /* SUB */
195 frame_base_offset_to_sp += ucst5;
197 gdb_assert_not_reached ("unexpected instruction");
202 else if ((inst & 0x174) == 0x74) /* stw SRC, *+b15(uconst) */
204 /* The y bit determines which file base is read from. */
205 base_reg = tic6x_register_number ((inst >> 18) & 0x1f,
208 if (base_reg == TIC6X_SP_REGNUM)
210 src_reg = tic6x_register_number ((inst >> 23) & 0x1f,
211 INST_S_BIT (inst), 0);
213 cache->reg_saved[src_reg] = ((inst >> 13) & 0x1f) << 2;
217 non_stw_insn_counter = 0;
221 non_stw_insn_counter++;
222 /* Following instruction sequence may be emitted in prologue:
224 <+0>: subah .D2 b15,28,b15
225 <+4>: or .L2X 0,a4,b0
226 <+8>: || stw .D2T2 b14,*+b15(56)
227 <+12>:[!b0] b .S1 0xe50e4c1c <sleep+220>
228 <+16>:|| stw .D2T1 a10,*+b15(48)
229 <+20>:stw .D2T2 b3,*+b15(52)
230 <+24>:stw .D2T1 a4,*+b15(40)
232 we should look forward for next instruction instead of breaking loop
233 here. So far, we allow almost two sequential non-stw instructions
235 if (non_stw_insn_counter >= 2)
242 /* Step 2: Skip insn on setting up dsbt if it is. Usually, it looks like,
243 ldw .D2T2 *+b14(0),b14 */
244 unsigned long inst = tic6x_fetch_instruction (gdbarch, pc);
245 /* The s bit determines which file dst will be loaded into, same effect as
247 dst_reg = tic6x_register_number ((inst >> 23) & 0x1f, (inst >> 1) & 1, 0);
248 /* The y bit (bit 7), instead of s bit, determines which file base be
250 base_reg = tic6x_register_number ((inst >> 18) & 0x1f, (inst >> 7) & 1, 0);
252 if ((inst & 0x164) == 0x64 /* ldw */
253 && dst_reg == TIC6X_DP_REGNUM /* dst is B14 */
254 && base_reg == TIC6X_DP_REGNUM) /* baseR is B14 */
261 cache->base = get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM);
263 if (cache->reg_saved[TIC6X_FP_REGNUM] != -1)
265 /* If the FP now holds an offset from the CFA then this is a frame
266 which uses the frame pointer. */
268 cache->cfa = get_frame_register_unsigned (this_frame,
273 /* FP doesn't hold an offset from the CFA. If SP still holds an
274 offset from the CFA then we might be in a function which omits
275 the frame pointer. */
277 cache->cfa = cache->base + frame_base_offset_to_sp;
281 /* Adjust all the saved registers such that they contain addresses
282 instead of offsets. */
283 for (i = 0; i < TIC6X_NUM_CORE_REGS; i++)
284 if (cache->reg_saved[i] != -1)
285 cache->reg_saved[i] = cache->base + cache->reg_saved[i];
290 /* This is the implementation of gdbarch method skip_prologue. */
293 tic6x_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc)
296 struct tic6x_unwind_cache cache;
298 /* See if we can determine the end of the prologue via the symbol table.
299 If so, then return either PC, or the PC after the prologue, whichever is
301 if (find_pc_partial_function (start_pc, NULL, &func_addr, NULL))
303 CORE_ADDR post_prologue_pc
304 = skip_prologue_using_sal (gdbarch, func_addr);
305 if (post_prologue_pc != 0)
306 return std::max (start_pc, post_prologue_pc);
309 /* Can't determine prologue from the symbol table, need to examine
311 return tic6x_analyze_prologue (gdbarch, start_pc, (CORE_ADDR) -1, &cache,
315 /* Implement the breakpoint_kind_from_pc gdbarch method. */
318 tic6x_breakpoint_kind_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr)
323 /* Implement the sw_breakpoint_from_kind gdbarch method. */
325 static const gdb_byte *
326 tic6x_sw_breakpoint_from_kind (struct gdbarch *gdbarch, int kind, int *size)
328 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
332 if (tdep == NULL || tdep->breakpoint == NULL)
334 if (BFD_ENDIAN_BIG == gdbarch_byte_order_for_code (gdbarch))
335 return tic6x_bkpt_illegal_opcode_be;
337 return tic6x_bkpt_illegal_opcode_le;
340 return tdep->breakpoint;
344 tic6x_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
345 struct dwarf2_frame_state_reg *reg,
346 struct frame_info *this_frame)
348 /* Mark the PC as the destination for the return address. */
349 if (regnum == gdbarch_pc_regnum (gdbarch))
350 reg->how = DWARF2_FRAME_REG_RA;
352 /* Mark the stack pointer as the call frame address. */
353 else if (regnum == gdbarch_sp_regnum (gdbarch))
354 reg->how = DWARF2_FRAME_REG_CFA;
356 /* The above was taken from the default init_reg in dwarf2-frame.c
357 while the below is c6x specific. */
359 /* Callee save registers. The ABI designates A10-A15 and B10-B15 as
361 else if ((regnum >= 10 && regnum <= 15) || (regnum >= 26 && regnum <= 31))
362 reg->how = DWARF2_FRAME_REG_SAME_VALUE;
364 /* All other registers are caller-save. */
365 reg->how = DWARF2_FRAME_REG_UNDEFINED;
368 /* This is the implementation of gdbarch method unwind_pc. */
371 tic6x_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
375 frame_unwind_register (next_frame, TIC6X_PC_REGNUM, buf);
376 return extract_typed_address (buf, builtin_type (gdbarch)->builtin_func_ptr);
379 /* This is the implementation of gdbarch method unwind_sp. */
382 tic6x_unwind_sp (struct gdbarch *gdbarch, struct frame_info *this_frame)
384 return frame_unwind_register_unsigned (this_frame, TIC6X_SP_REGNUM);
388 /* Frame base handling. */
390 static struct tic6x_unwind_cache*
391 tic6x_frame_unwind_cache (struct frame_info *this_frame,
392 void **this_prologue_cache)
394 struct gdbarch *gdbarch = get_frame_arch (this_frame);
395 CORE_ADDR current_pc;
396 struct tic6x_unwind_cache *cache;
398 if (*this_prologue_cache)
399 return (struct tic6x_unwind_cache *) *this_prologue_cache;
401 cache = FRAME_OBSTACK_ZALLOC (struct tic6x_unwind_cache);
402 (*this_prologue_cache) = cache;
404 cache->return_regnum = TIC6X_RA_REGNUM;
406 tic6x_setup_default (cache);
408 cache->pc = get_frame_func (this_frame);
409 current_pc = get_frame_pc (this_frame);
411 /* Prologue analysis does the rest... */
413 tic6x_analyze_prologue (gdbarch, cache->pc, current_pc, cache, this_frame);
419 tic6x_frame_this_id (struct frame_info *this_frame, void **this_cache,
420 struct frame_id *this_id)
422 struct tic6x_unwind_cache *cache =
423 tic6x_frame_unwind_cache (this_frame, this_cache);
425 /* This marks the outermost frame. */
426 if (cache->base == 0)
429 (*this_id) = frame_id_build (cache->cfa, cache->pc);
432 static struct value *
433 tic6x_frame_prev_register (struct frame_info *this_frame, void **this_cache,
436 struct tic6x_unwind_cache *cache =
437 tic6x_frame_unwind_cache (this_frame, this_cache);
439 gdb_assert (regnum >= 0);
441 /* The PC of the previous frame is stored in the RA register of
442 the current frame. Frob regnum so that we pull the value from
443 the correct place. */
444 if (regnum == TIC6X_PC_REGNUM)
445 regnum = cache->return_regnum;
447 if (regnum == TIC6X_SP_REGNUM && cache->cfa)
448 return frame_unwind_got_constant (this_frame, regnum, cache->cfa);
450 /* If we've worked out where a register is stored then load it from
452 if (regnum < TIC6X_NUM_CORE_REGS && cache->reg_saved[regnum] != -1)
453 return frame_unwind_got_memory (this_frame, regnum,
454 cache->reg_saved[regnum]);
456 return frame_unwind_got_register (this_frame, regnum, regnum);
460 tic6x_frame_base_address (struct frame_info *this_frame, void **this_cache)
462 struct tic6x_unwind_cache *info
463 = tic6x_frame_unwind_cache (this_frame, this_cache);
467 static const struct frame_unwind tic6x_frame_unwind =
470 default_frame_unwind_stop_reason,
472 tic6x_frame_prev_register,
474 default_frame_sniffer
477 static const struct frame_base tic6x_frame_base =
480 tic6x_frame_base_address,
481 tic6x_frame_base_address,
482 tic6x_frame_base_address
486 static struct tic6x_unwind_cache *
487 tic6x_make_stub_cache (struct frame_info *this_frame)
489 struct tic6x_unwind_cache *cache;
491 cache = FRAME_OBSTACK_ZALLOC (struct tic6x_unwind_cache);
493 cache->return_regnum = TIC6X_RA_REGNUM;
495 tic6x_setup_default (cache);
497 cache->cfa = get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM);
503 tic6x_stub_this_id (struct frame_info *this_frame, void **this_cache,
504 struct frame_id *this_id)
506 struct tic6x_unwind_cache *cache;
508 if (*this_cache == NULL)
509 *this_cache = tic6x_make_stub_cache (this_frame);
510 cache = (struct tic6x_unwind_cache *) *this_cache;
512 *this_id = frame_id_build (cache->cfa, get_frame_pc (this_frame));
516 tic6x_stub_unwind_sniffer (const struct frame_unwind *self,
517 struct frame_info *this_frame,
518 void **this_prologue_cache)
520 CORE_ADDR addr_in_block;
522 addr_in_block = get_frame_address_in_block (this_frame);
523 if (in_plt_section (addr_in_block))
529 static const struct frame_unwind tic6x_stub_unwind =
532 default_frame_unwind_stop_reason,
534 tic6x_frame_prev_register,
536 tic6x_stub_unwind_sniffer
539 /* Return the instruction on address PC. */
542 tic6x_fetch_instruction (struct gdbarch *gdbarch, CORE_ADDR pc)
544 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
545 return read_memory_unsigned_integer (pc, TIC6X_OPCODE_SIZE, byte_order);
548 /* Compute the condition of INST if it is a conditional instruction. Always
549 return 1 if INST is not a conditional instruction. */
552 tic6x_condition_true (struct regcache *regcache, unsigned long inst)
556 static const int register_numbers[8] = { -1, 16, 17, 18, 1, 2, 0, -1 };
558 register_number = register_numbers[(inst >> 29) & 7];
559 if (register_number == -1)
562 register_value = regcache_raw_get_signed (regcache, register_number);
563 if ((inst & 0x10000000) != 0)
564 return register_value == 0;
565 return register_value != 0;
568 /* Get the register number by decoding raw bits REG, SIDE, and CROSSPATH in
572 tic6x_register_number (int reg, int side, int crosspath)
574 int r = (reg & 15) | ((crosspath ^ side) << 4);
575 if ((reg & 16) != 0) /* A16 - A31, B16 - B31 */
581 tic6x_extract_signed_field (int value, int low_bit, int bits)
583 int mask = (1 << bits) - 1;
584 int r = (value >> low_bit) & mask;
585 if ((r & (1 << (bits - 1))) != 0)
590 /* Determine where to set a single step breakpoint. */
593 tic6x_get_next_pc (struct regcache *regcache, CORE_ADDR pc)
595 struct gdbarch *gdbarch = regcache->arch ();
602 inst = tic6x_fetch_instruction (gdbarch, pc);
606 if (inst == TIC6X_INST_SWE)
608 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
610 if (tdep->syscall_next_pc != NULL)
611 return tdep->syscall_next_pc (get_current_frame ());
614 if (tic6x_condition_true (regcache, inst))
616 if ((inst & 0x0000007c) == 0x00000010)
618 /* B with displacement */
619 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
620 pc += tic6x_extract_signed_field (inst, 7, 21) << 2;
623 if ((inst & 0x0f83effc) == 0x00000360)
625 /* B with register */
627 register_number = tic6x_register_number ((inst >> 18) & 0x1f,
630 pc = regcache_raw_get_unsigned (regcache, register_number);
633 if ((inst & 0x00001ffc) == 0x00001020)
636 register_number = tic6x_register_number ((inst >> 23) & 0x1f,
637 INST_S_BIT (inst), 0);
638 if (regcache_raw_get_signed (regcache, register_number) >= 0)
640 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
641 pc += tic6x_extract_signed_field (inst, 7, 10) << 2;
645 if ((inst & 0x00001ffc) == 0x00000120)
647 /* BNOP with displacement */
648 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
649 pc += tic6x_extract_signed_field (inst, 16, 12) << 2;
652 if ((inst & 0x0f830ffe) == 0x00800362)
654 /* BNOP with register */
655 register_number = tic6x_register_number ((inst >> 18) & 0x1f,
656 1, INST_X_BIT (inst));
657 pc = regcache_raw_get_unsigned (regcache, register_number);
660 if ((inst & 0x00001ffc) == 0x00000020)
663 register_number = tic6x_register_number ((inst >> 23) & 0x1f,
664 INST_S_BIT (inst), 0);
665 if (regcache_raw_get_signed (regcache, register_number) >= 0)
667 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
668 pc += tic6x_extract_signed_field (inst, 13, 10) << 2;
672 if ((inst & 0xf000007c) == 0x10000010)
675 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
676 pc += tic6x_extract_signed_field (inst, 7, 21) << 2;
680 pc += TIC6X_OPCODE_SIZE;
686 /* This is the implementation of gdbarch method software_single_step. */
688 static std::vector<CORE_ADDR>
689 tic6x_software_single_step (struct regcache *regcache)
691 CORE_ADDR next_pc = tic6x_get_next_pc (regcache, regcache_read_pc (regcache));
696 /* This is the implementation of gdbarch method frame_align. */
699 tic6x_frame_align (struct gdbarch *gdbarch, CORE_ADDR addr)
701 return align_down (addr, 8);
704 /* Given a return value in REGCACHE with a type VALTYPE, extract and copy its
705 value into VALBUF. */
708 tic6x_extract_return_value (struct type *valtype, struct regcache *regcache,
709 enum bfd_endian byte_order, gdb_byte *valbuf)
711 int len = TYPE_LENGTH (valtype);
713 /* pointer types are returned in register A4,
714 up to 32-bit types in A4
715 up to 64-bit types in A5:A4 */
719 - one-byte structure or union occupies the LSB of single even register.
720 - for two-byte structure or union, the first byte occupies byte 1 of
721 register and the second byte occupies byte 0.
722 so, we read the contents in VAL from the LSBs of register. */
723 if (len < 3 && byte_order == BFD_ENDIAN_BIG)
724 regcache->cooked_read_part (TIC6X_A4_REGNUM, 4 - len, len, valbuf);
726 regcache->cooked_read (TIC6X_A4_REGNUM, valbuf);
730 /* For a 5-8 byte structure or union in big-endian, the first byte
731 occupies byte 3 (the MSB) of the upper (odd) register and the
732 remaining bytes fill the decreasingly significant bytes. 5-7
733 byte structures or unions have padding in the LSBs of the
734 lower (even) register. */
735 if (byte_order == BFD_ENDIAN_BIG)
737 regcache->cooked_read (TIC6X_A4_REGNUM, valbuf + 4);
738 regcache->cooked_read (TIC6X_A5_REGNUM, valbuf);
742 regcache->cooked_read (TIC6X_A4_REGNUM, valbuf);
743 regcache->cooked_read (TIC6X_A5_REGNUM, valbuf + 4);
748 /* Write into appropriate registers a function return value
749 of type TYPE, given in virtual format. */
752 tic6x_store_return_value (struct type *valtype, struct regcache *regcache,
753 enum bfd_endian byte_order, const gdb_byte *valbuf)
755 int len = TYPE_LENGTH (valtype);
757 /* return values of up to 8 bytes are returned in A5:A4 */
761 if (len < 3 && byte_order == BFD_ENDIAN_BIG)
762 regcache->cooked_write_part (TIC6X_A4_REGNUM, 4 - len, len, valbuf);
764 regcache->cooked_write (TIC6X_A4_REGNUM, valbuf);
768 if (byte_order == BFD_ENDIAN_BIG)
770 regcache->cooked_write (TIC6X_A4_REGNUM, valbuf + 4);
771 regcache->cooked_write (TIC6X_A5_REGNUM, valbuf);
775 regcache->cooked_write (TIC6X_A4_REGNUM, valbuf);
776 regcache->cooked_write (TIC6X_A5_REGNUM, valbuf + 4);
781 /* This is the implementation of gdbarch method return_value. */
783 static enum return_value_convention
784 tic6x_return_value (struct gdbarch *gdbarch, struct value *function,
785 struct type *type, struct regcache *regcache,
786 gdb_byte *readbuf, const gdb_byte *writebuf)
788 /* In C++, when function returns an object, even its size is small
789 enough, it stii has to be passed via reference, pointed by register
791 if (current_language->la_language == language_cplus)
795 type = check_typedef (type);
796 if (language_pass_by_reference (type))
797 return RETURN_VALUE_STRUCT_CONVENTION;
801 if (TYPE_LENGTH (type) > 8)
802 return RETURN_VALUE_STRUCT_CONVENTION;
805 tic6x_extract_return_value (type, regcache,
806 gdbarch_byte_order (gdbarch), readbuf);
808 tic6x_store_return_value (type, regcache,
809 gdbarch_byte_order (gdbarch), writebuf);
811 return RETURN_VALUE_REGISTER_CONVENTION;
814 /* This is the implementation of gdbarch method dummy_id. */
816 static struct frame_id
817 tic6x_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
819 return frame_id_build
820 (get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM),
821 get_frame_pc (this_frame));
824 /* Get the alignment requirement of TYPE. */
827 tic6x_arg_type_alignment (struct type *type)
829 int len = TYPE_LENGTH (check_typedef (type));
830 enum type_code typecode = TYPE_CODE (check_typedef (type));
832 if (typecode == TYPE_CODE_STRUCT || typecode == TYPE_CODE_UNION)
834 /* The stack alignment of a structure (and union) passed by value is the
835 smallest power of two greater than or equal to its size.
836 This cannot exceed 8 bytes, which is the largest allowable size for
837 a structure passed by value. */
846 gdb_assert_not_reached ("unexpected length of data");
854 if (typecode == TYPE_CODE_COMPLEX)
861 if (typecode == TYPE_CODE_COMPLEX)
867 internal_error (__FILE__, __LINE__, _("unexpected length %d of type"),
872 /* This is the implementation of gdbarch method push_dummy_call. */
875 tic6x_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
876 struct regcache *regcache, CORE_ADDR bp_addr,
877 int nargs, struct value **args, CORE_ADDR sp,
878 function_call_return_method return_method,
879 CORE_ADDR struct_addr)
883 int stack_offset = 4;
884 int references_offset = 4;
885 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
886 struct type *func_type = value_type (function);
887 /* The first arg passed on stack. Mostly the first 10 args are passed by
889 int first_arg_on_stack = 10;
891 /* Set the return address register to point to the entry point of
892 the program, where a breakpoint lies in wait. */
893 regcache_cooked_write_unsigned (regcache, TIC6X_RA_REGNUM, bp_addr);
895 /* The caller must pass an argument in A3 containing a destination address
896 for the returned value. The callee returns the object by copying it to
897 the address in A3. */
898 if (return_method == return_method_struct)
899 regcache_cooked_write_unsigned (regcache, 3, struct_addr);
901 /* Determine the type of this function. */
902 func_type = check_typedef (func_type);
903 if (TYPE_CODE (func_type) == TYPE_CODE_PTR)
904 func_type = check_typedef (TYPE_TARGET_TYPE (func_type));
906 gdb_assert (TYPE_CODE (func_type) == TYPE_CODE_FUNC
907 || TYPE_CODE (func_type) == TYPE_CODE_METHOD);
909 /* For a variadic C function, the last explicitly declared argument and all
910 remaining arguments are passed on the stack. */
911 if (TYPE_VARARGS (func_type))
912 first_arg_on_stack = TYPE_NFIELDS (func_type) - 1;
914 /* Now make space on the stack for the args. */
915 for (argnum = 0; argnum < nargs; argnum++)
917 int len = align_up (TYPE_LENGTH (value_type (args[argnum])), 4);
918 if (argnum >= 10 - argreg)
919 references_offset += len;
923 /* SP should be 8-byte aligned, see C6000 ABI section 4.4.1
925 sp = align_down (sp, 8);
928 /* Now load as many as possible of the first arguments into
929 registers, and push the rest onto the stack. Loop through args
930 from first to last. */
931 for (argnum = 0; argnum < nargs; argnum++)
934 struct value *arg = args[argnum];
935 struct type *arg_type = check_typedef (value_type (arg));
936 int len = TYPE_LENGTH (arg_type);
937 enum type_code typecode = TYPE_CODE (arg_type);
939 val = value_contents (arg);
941 /* Copy the argument to general registers or the stack in
942 register-sized pieces. */
943 if (argreg < first_arg_on_stack)
947 if (typecode == TYPE_CODE_STRUCT || typecode == TYPE_CODE_UNION)
950 - one-byte structure or union occupies the LSB of single
952 - for two-byte structure or union, the first byte
953 occupies byte 1 of register and the second byte occupies
955 so, we write the contents in VAL to the lsp of
957 if (len < 3 && byte_order == BFD_ENDIAN_BIG)
958 regcache->cooked_write_part (arg_regs[argreg], 4 - len, len,
961 regcache->cooked_write (arg_regs[argreg], val);
965 /* The argument is being passed by value in a single
967 CORE_ADDR regval = extract_unsigned_integer (val, len,
970 regcache_cooked_write_unsigned (regcache, arg_regs[argreg],
978 if (typecode == TYPE_CODE_STRUCT
979 || typecode == TYPE_CODE_UNION)
981 /* For a 5-8 byte structure or union in big-endian, the
982 first byte occupies byte 3 (the MSB) of the upper (odd)
983 register and the remaining bytes fill the decreasingly
984 significant bytes. 5-7 byte structures or unions have
985 padding in the LSBs of the lower (even) register. */
986 if (byte_order == BFD_ENDIAN_BIG)
988 regcache->cooked_write (arg_regs[argreg] + 1, val);
989 regcache->cooked_write_part (arg_regs[argreg], 0,
994 regcache->cooked_write (arg_regs[argreg], val);
995 regcache->cooked_write_part (arg_regs[argreg] + 1, 0,
1001 /* The argument is being passed by value in a pair of
1003 ULONGEST regval = extract_unsigned_integer (val, len,
1006 regcache_cooked_write_unsigned (regcache,
1009 regcache_cooked_write_unsigned (regcache,
1010 arg_regs[argreg] + 1,
1016 /* The argument is being passed by reference in a single
1020 /* It is not necessary to adjust REFERENCES_OFFSET to
1021 8-byte aligned in some cases, in which 4-byte alignment
1022 is sufficient. For simplicity, we adjust
1023 REFERENCES_OFFSET to 8-byte aligned. */
1024 references_offset = align_up (references_offset, 8);
1026 addr = sp + references_offset;
1027 write_memory (addr, val, len);
1028 references_offset += align_up (len, 4);
1029 regcache_cooked_write_unsigned (regcache, arg_regs[argreg],
1037 /* The argument is being passed on the stack. */
1040 /* There are six different cases of alignment, and these rules can
1041 be found in tic6x_arg_type_alignment:
1043 1) 4-byte aligned if size is less than or equal to 4 byte, such
1044 as short, int, struct, union etc.
1045 2) 8-byte aligned if size is less than or equal to 8-byte, such
1046 as double, long long,
1047 3) 4-byte aligned if it is of type _Complex float, even its size
1049 4) 8-byte aligned if it is of type _Complex double or _Complex
1050 long double, even its size is 16-byte. Because, the address of
1051 variable is passed as reference.
1052 5) struct and union larger than 8-byte are passed by reference, so
1053 it is 4-byte aligned.
1054 6) struct and union of size between 4 byte and 8 byte varies.
1055 alignment of struct variable is the alignment of its first field,
1056 while alignment of union variable is the max of all its fields'
1060 ; /* Default is 4-byte aligned. Nothing to be done. */
1062 stack_offset = align_up (stack_offset,
1063 tic6x_arg_type_alignment (arg_type));
1066 /* _Complex double or _Complex long double */
1067 if (typecode == TYPE_CODE_COMPLEX)
1069 /* The argument is being passed by reference on stack. */
1070 references_offset = align_up (references_offset, 8);
1072 addr = sp + references_offset;
1073 /* Store variable on stack. */
1074 write_memory (addr, val, len);
1076 references_offset += align_up (len, 4);
1078 /* Pass the address of variable on stack as reference. */
1079 store_unsigned_integer ((gdb_byte *) val, 4, byte_order,
1085 internal_error (__FILE__, __LINE__,
1086 _("unexpected type %d of arg %d"),
1090 internal_error (__FILE__, __LINE__,
1091 _("unexpected length %d of arg %d"), len, argnum);
1093 addr = sp + stack_offset;
1094 write_memory (addr, val, len);
1095 stack_offset += align_up (len, 4);
1099 regcache_cooked_write_signed (regcache, TIC6X_SP_REGNUM, sp);
1101 /* Return adjusted stack pointer. */
1105 /* This is the implementation of gdbarch method stack_frame_destroyed_p. */
1108 tic6x_stack_frame_destroyed_p (struct gdbarch *gdbarch, CORE_ADDR pc)
1110 unsigned long inst = tic6x_fetch_instruction (gdbarch, pc);
1111 /* Normally, the epilogue is composed by instruction `b .S2 b3'. */
1112 if ((inst & 0x0f83effc) == 0x360)
1114 unsigned int src2 = tic6x_register_number ((inst >> 18) & 0x1f,
1117 if (src2 == TIC6X_RA_REGNUM)
1124 /* This is the implementation of gdbarch method get_longjmp_target. */
1127 tic6x_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
1129 struct gdbarch *gdbarch = get_frame_arch (frame);
1130 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
1134 /* JMP_BUF is passed by reference in A4. */
1135 jb_addr = get_frame_register_unsigned (frame, 4);
1137 /* JMP_BUF contains 13 elements of type int, and return address is stored
1138 in the last slot. */
1139 if (target_read_memory (jb_addr + 12 * 4, buf, 4))
1142 *pc = extract_unsigned_integer (buf, 4, byte_order);
1147 /* This is the implementation of gdbarch method
1148 return_in_first_hidden_param_p. */
1151 tic6x_return_in_first_hidden_param_p (struct gdbarch *gdbarch,
1157 static struct gdbarch *
1158 tic6x_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
1160 struct gdbarch *gdbarch;
1161 struct gdbarch_tdep *tdep;
1162 struct tdesc_arch_data *tdesc_data = NULL;
1163 const struct target_desc *tdesc = info.target_desc;
1166 /* Check any target description for validity. */
1167 if (tdesc_has_registers (tdesc))
1169 const struct tdesc_feature *feature;
1172 feature = tdesc_find_feature (tdesc, "org.gnu.gdb.tic6x.core");
1174 if (feature == NULL)
1177 tdesc_data = tdesc_data_alloc ();
1180 for (i = 0; i < 32; i++) /* A0 - A15, B0 - B15 */
1181 valid_p &= tdesc_numbered_register (feature, tdesc_data, i,
1182 tic6x_register_names[i]);
1185 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++,
1186 tic6x_register_names[TIC6X_CSR_REGNUM]);
1187 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++,
1188 tic6x_register_names[TIC6X_PC_REGNUM]);
1192 tdesc_data_cleanup (tdesc_data);
1196 feature = tdesc_find_feature (tdesc, "org.gnu.gdb.tic6x.gp");
1200 static const char *const gp[] =
1202 "A16", "A17", "A18", "A19", "A20", "A21", "A22", "A23",
1203 "A24", "A25", "A26", "A27", "A28", "A29", "A30", "A31",
1204 "B16", "B17", "B18", "B19", "B20", "B21", "B22", "B23",
1205 "B24", "B25", "B26", "B27", "B28", "B29", "B30", "B31",
1210 for (j = 0; j < 32; j++) /* A16 - A31, B16 - B31 */
1211 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++,
1216 tdesc_data_cleanup (tdesc_data);
1221 feature = tdesc_find_feature (tdesc, "org.gnu.gdb.tic6x.c6xp");
1224 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++, "TSR");
1225 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++, "ILC");
1226 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++, "RILC");
1230 tdesc_data_cleanup (tdesc_data);
1237 /* Find a candidate among extant architectures. */
1238 for (arches = gdbarch_list_lookup_by_info (arches, &info);
1240 arches = gdbarch_list_lookup_by_info (arches->next, &info))
1242 tdep = gdbarch_tdep (arches->gdbarch);
1244 if (has_gp != tdep->has_gp)
1247 if (tdep && tdep->breakpoint)
1248 return arches->gdbarch;
1251 tdep = XCNEW (struct gdbarch_tdep);
1253 tdep->has_gp = has_gp;
1254 gdbarch = gdbarch_alloc (&info, tdep);
1256 /* Data type sizes. */
1257 set_gdbarch_ptr_bit (gdbarch, 32);
1258 set_gdbarch_addr_bit (gdbarch, 32);
1259 set_gdbarch_short_bit (gdbarch, 16);
1260 set_gdbarch_int_bit (gdbarch, 32);
1261 set_gdbarch_long_bit (gdbarch, 32);
1262 set_gdbarch_long_long_bit (gdbarch, 64);
1263 set_gdbarch_float_bit (gdbarch, 32);
1264 set_gdbarch_double_bit (gdbarch, 64);
1266 set_gdbarch_float_format (gdbarch, floatformats_ieee_single);
1267 set_gdbarch_double_format (gdbarch, floatformats_ieee_double);
1269 /* The register set. */
1270 set_gdbarch_num_regs (gdbarch, TIC6X_NUM_REGS);
1271 set_gdbarch_sp_regnum (gdbarch, TIC6X_SP_REGNUM);
1272 set_gdbarch_pc_regnum (gdbarch, TIC6X_PC_REGNUM);
1274 set_gdbarch_register_name (gdbarch, tic6x_register_name);
1275 set_gdbarch_register_type (gdbarch, tic6x_register_type);
1277 set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
1279 set_gdbarch_skip_prologue (gdbarch, tic6x_skip_prologue);
1280 set_gdbarch_breakpoint_kind_from_pc (gdbarch,
1281 tic6x_breakpoint_kind_from_pc);
1282 set_gdbarch_sw_breakpoint_from_kind (gdbarch,
1283 tic6x_sw_breakpoint_from_kind);
1285 set_gdbarch_unwind_pc (gdbarch, tic6x_unwind_pc);
1286 set_gdbarch_unwind_sp (gdbarch, tic6x_unwind_sp);
1289 dwarf2_append_unwinders (gdbarch);
1291 frame_unwind_append_unwinder (gdbarch, &tic6x_stub_unwind);
1292 frame_unwind_append_unwinder (gdbarch, &tic6x_frame_unwind);
1293 frame_base_set_default (gdbarch, &tic6x_frame_base);
1295 dwarf2_frame_set_init_reg (gdbarch, tic6x_dwarf2_frame_init_reg);
1297 /* Single stepping. */
1298 set_gdbarch_software_single_step (gdbarch, tic6x_software_single_step);
1300 /* Call dummy code. */
1301 set_gdbarch_frame_align (gdbarch, tic6x_frame_align);
1303 set_gdbarch_return_value (gdbarch, tic6x_return_value);
1305 set_gdbarch_dummy_id (gdbarch, tic6x_dummy_id);
1307 /* Enable inferior call support. */
1308 set_gdbarch_push_dummy_call (gdbarch, tic6x_push_dummy_call);
1310 set_gdbarch_get_longjmp_target (gdbarch, tic6x_get_longjmp_target);
1312 set_gdbarch_stack_frame_destroyed_p (gdbarch, tic6x_stack_frame_destroyed_p);
1314 set_gdbarch_return_in_first_hidden_param_p (gdbarch,
1315 tic6x_return_in_first_hidden_param_p);
1317 /* Hook in ABI-specific overrides, if they have been registered. */
1318 gdbarch_init_osabi (info, gdbarch);
1321 tdesc_use_registers (gdbarch, tdesc, tdesc_data);
1327 _initialize_tic6x_tdep (void)
1329 register_gdbarch_init (bfd_arch_tic6x, tic6x_gdbarch_init);