[deliverable/binutils-gdb.git] / gdb / tic6x-linux-tdep.c

/* GNU/Linux on  TI C6x target support.
   Copyright (C) 2011-2019 Free Software Foundation, Inc.
   Contributed by Yao Qi <yao@codesourcery.com>

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "solib.h"
#include "osabi.h"
#include "linux-tdep.h"
#include "tic6x-tdep.h"
#include "trad-frame.h"
#include "tramp-frame.h"
#include "elf-bfd.h"
#include "elf/tic6x.h"
#include "gdbarch.h"

/* The offset from rt_sigframe pointer to SP register.  */
#define TIC6X_SP_RT_SIGFRAME 8
/* Size of struct siginfo info.  */
#define TIC6X_SIGINFO_SIZE 128
/* Size of type stack_t, which contains three fields of type void*, int, and
   size_t respectively.  */
#define TIC6X_STACK_T_SIZE (3 * 4)

static const gdb_byte tic6x_bkpt_bnop_be[] = { 0x00, 0x00, 0xa1, 0x22 };
static const gdb_byte tic6x_bkpt_bnop_le[] = { 0x22, 0xa1, 0x00, 0x00 };

/* Return the offset of register REGNUM in struct sigcontext.  Return 0 if no
   such register in sigcontext.  */

static unsigned int
tic6x_register_sigcontext_offset (unsigned int regnum, struct gdbarch *gdbarch)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  if (regnum == TIC6X_A4_REGNUM || regnum == TIC6X_A4_REGNUM + 2
      || regnum == TIC6X_A4_REGNUM + 4)
    return 4 * (regnum - TIC6X_A4_REGNUM + 2);	/* A4, A6, A8 */
  else if (regnum == TIC6X_A5_REGNUM || regnum == TIC6X_A5_REGNUM + 2
	   || regnum == TIC6X_A5_REGNUM + 4)
    return 4 * (regnum - TIC6X_A5_REGNUM + 12);	/* A5, A7, A9 */
  else if (regnum == TIC6X_B4_REGNUM || regnum == TIC6X_B4_REGNUM + 2
	   || regnum == TIC6X_B4_REGNUM + 4)
    return 4 * (regnum - TIC6X_B4_REGNUM + 3);	/* B4, B6, B8 */
  else if (regnum == TIC6X_B5_REGNUM || regnum == TIC6X_B5_REGNUM + 2
	   || regnum == TIC6X_B5_REGNUM + 4)
    return 4 * (regnum - TIC6X_B5_REGNUM + 19);	/* B5, B7, B9 */
  else if (regnum < TIC6X_A4_REGNUM)
    return 4 * (regnum - 0 + 8);	/* A0 - A3 */
  else if (regnum >= TIC6X_B0_REGNUM && regnum < TIC6X_B4_REGNUM)
    return 4 * (regnum - TIC6X_B0_REGNUM + 15);	/* B0 - B3 */
  else if (regnum >= 34 && regnum < 34 + 32)
    return 4 * (regnum - 34 + 23);	/* A16 - A31, B16 - B31 */
  else if (regnum == TIC6X_PC_REGNUM)
    return 4 * (tdep->has_gp ? 55 : 23);
  else if (regnum == TIC6X_SP_REGNUM)
    return 4;

  return 0;
}

/* Support unwinding frame in signal trampoline.  We don't check sigreturn,
   since it is not used in kernel.  */

static void
tic6x_linux_rt_sigreturn_init (const struct tramp_frame *self,
			       struct frame_info *this_frame,
			       struct trad_frame_cache *this_cache,
			       CORE_ADDR func)
{
  struct gdbarch *gdbarch = get_frame_arch (this_frame);
  CORE_ADDR sp = get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM);
  /* The base of struct sigcontext is computed by examining the definition of
     struct rt_sigframe in linux kernel source arch/c6x/kernel/signal.c.  */
  CORE_ADDR base = (sp + TIC6X_SP_RT_SIGFRAME
		    /* Pointer type *pinfo and *puc in struct rt_sigframe.  */
		    + 4 + 4
		    + TIC6X_SIGINFO_SIZE
		    + 4 + 4 /* uc_flags and *uc_link in struct ucontext.  */
		    + TIC6X_STACK_T_SIZE);
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  unsigned int reg_offset;
  unsigned int i;

  for (i = 0; i < 10; i++)	/* A0 - A9 */
    {
      reg_offset = tic6x_register_sigcontext_offset (i, gdbarch);
      gdb_assert (reg_offset != 0);

      trad_frame_set_reg_addr (this_cache, i, base + reg_offset);
    }

  for (i = TIC6X_B0_REGNUM; i < TIC6X_B0_REGNUM + 10; i++)	/* B0 - B9 */
    {
      reg_offset = tic6x_register_sigcontext_offset (i, gdbarch);
      gdb_assert (reg_offset != 0);

      trad_frame_set_reg_addr (this_cache, i, base + reg_offset);
    }

  if (tdep->has_gp)
    for (i = 34; i < 34 + 32; i++)	/* A16 - A31, B16 - B31 */
      {
	reg_offset = tic6x_register_sigcontext_offset (i, gdbarch);
	gdb_assert (reg_offset != 0);

	trad_frame_set_reg_addr (this_cache, i, base + reg_offset);
      }

  trad_frame_set_reg_addr (this_cache, TIC6X_PC_REGNUM,
			   base + tic6x_register_sigcontext_offset (TIC6X_PC_REGNUM,
								    gdbarch));
  trad_frame_set_reg_addr (this_cache, TIC6X_SP_REGNUM,
			   base + tic6x_register_sigcontext_offset (TIC6X_SP_REGNUM,
								    gdbarch));

  /* Save a frame ID.  */
  trad_frame_set_id (this_cache, frame_id_build (sp, func));
}

static struct tramp_frame tic6x_linux_rt_sigreturn_tramp_frame =
{
  SIGTRAMP_FRAME,
  4,
  {
    {0x000045aa, 0x0fffffff},	/* mvk .S2 139,b0 */
    {0x10000000, ULONGEST_MAX},		/* swe */
    {TRAMP_SENTINEL_INSN}
  },
  tic6x_linux_rt_sigreturn_init
};

/* When FRAME is at a syscall instruction, return the PC of the next
   instruction to be executed.  */

static CORE_ADDR
tic6x_linux_syscall_next_pc (struct frame_info *frame)
{
  ULONGEST syscall_number = get_frame_register_unsigned (frame,
							 TIC6X_B0_REGNUM);
  CORE_ADDR pc = get_frame_pc (frame);

  if (syscall_number == 139 /* rt_sigreturn */)
    return frame_unwind_caller_pc (frame);

  return pc + 4;
}


extern struct target_so_ops dsbt_so_ops;
static void
tic6x_uclinux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  linux_init_abi (info, gdbarch);

  /* Shared library handling.  */
  set_solib_ops (gdbarch, &dsbt_so_ops);

  tdep->syscall_next_pc = tic6x_linux_syscall_next_pc;

#ifdef HAVE_ELF
  /* In tic6x Linux kernel, breakpoint instructions varies on different archs.
     On C64x+ and C67x+, breakpoint instruction is 0x56454314, which is an
     illegal opcode.  On other arch, breakpoint instruction is 0x0000a122
     (BNOP .S2 0,5).  */
  if (info.abfd)
    switch (bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC, Tag_ISA))
      {
      case C6XABI_Tag_ISA_C64XP:
      case C6XABI_Tag_ISA_C67XP:
	if (info.byte_order == BFD_ENDIAN_BIG)
	  tdep->breakpoint = tic6x_bkpt_illegal_opcode_be;
	else
	  tdep->breakpoint = tic6x_bkpt_illegal_opcode_le;
	break;
      default:
	{
	  if (info.byte_order == BFD_ENDIAN_BIG)
	    tdep->breakpoint = tic6x_bkpt_bnop_be;
	  else
	    tdep->breakpoint = tic6x_bkpt_bnop_le;
	}
      }
#endif

  /* Signal trampoline support.  */
  tramp_frame_prepend_unwinder (gdbarch,
				&tic6x_linux_rt_sigreturn_tramp_frame);
}

void
_initialize_tic6x_linux_tdep (void)
{
  gdbarch_register_osabi (bfd_arch_tic6x, 0, GDB_OSABI_LINUX,
			  tic6x_uclinux_init_abi);
}
Commit	Line	Data
8cd64e00	1	/* GNU/Linux on TI C6x target support.
42a4f53d	2	Copyright (C) 2011-2019 Free Software Foundation, Inc.
8cd64e00 YQ	3	Contributed by Yao Qi <yao@codesourcery.com>
	4
	5	This file is part of GDB.
	6
	7	This program is free software; you can redistribute it and/or modify
	8	it under the terms of the GNU General Public License as published by
	9	the Free Software Foundation; either version 3 of the License, or
	10	(at your option) any later version.
	11
	12	This program is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
	16
	17	You should have received a copy of the GNU General Public License
	18	along with this program. If not, see <http://www.gnu.org/licenses/>. */
	19
	20	#include "defs.h"
	21	#include "solib.h"
	22	#include "osabi.h"
	23	#include "linux-tdep.h"
	24	#include "tic6x-tdep.h"
	25	#include "trad-frame.h"
	26	#include "tramp-frame.h"
8cd64e00 YQ	27	#include "elf-bfd.h"
8cd64e00 YQ	28	#include "elf/tic6x.h"
0d12e84c	29	#include "gdbarch.h"
8cd64e00	30
8cd64e00 YQ	31	/* The offset from rt_sigframe pointer to SP register. */
	32	#define TIC6X_SP_RT_SIGFRAME 8
	33	/* Size of struct siginfo info. */
	34	#define TIC6X_SIGINFO_SIZE 128
	35	/* Size of type stack_t, which contains three fields of type void*, int, and
	36	size_t respectively. */
	37	#define TIC6X_STACK_T_SIZE (3 * 4)
	38
8cd64e00 YQ	39	static const gdb_byte tic6x_bkpt_bnop_be[] = { 0x00, 0x00, 0xa1, 0x22 };
	40	static const gdb_byte tic6x_bkpt_bnop_le[] = { 0x22, 0xa1, 0x00, 0x00 };
	41
	42	/* Return the offset of register REGNUM in struct sigcontext. Return 0 if no
	43	such register in sigcontext. */
	44
	45	static unsigned int
	46	tic6x_register_sigcontext_offset (unsigned int regnum, struct gdbarch *gdbarch)
	47	{
	48	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	49
	50	if (regnum == TIC6X_A4_REGNUM \|\| regnum == TIC6X_A4_REGNUM + 2
	51	\|\| regnum == TIC6X_A4_REGNUM + 4)
	52	return 4 * (regnum - TIC6X_A4_REGNUM + 2); /* A4, A6, A8 */
	53	else if (regnum == TIC6X_A5_REGNUM \|\| regnum == TIC6X_A5_REGNUM + 2
	54	\|\| regnum == TIC6X_A5_REGNUM + 4)
	55	return 4 * (regnum - TIC6X_A5_REGNUM + 12); /* A5, A7, A9 */
	56	else if (regnum == TIC6X_B4_REGNUM \|\| regnum == TIC6X_B4_REGNUM + 2
	57	\|\| regnum == TIC6X_B4_REGNUM + 4)
	58	return 4 * (regnum - TIC6X_B4_REGNUM + 3); /* B4, B6, B8 */
	59	else if (regnum == TIC6X_B5_REGNUM \|\| regnum == TIC6X_B5_REGNUM + 2
	60	\|\| regnum == TIC6X_B5_REGNUM + 4)
	61	return 4 * (regnum - TIC6X_B5_REGNUM + 19); /* B5, B7, B9 */
7cd12a76	62	else if (regnum < TIC6X_A4_REGNUM)
8cd64e00 YQ	63	return 4 * (regnum - 0 + 8); /* A0 - A3 */
	64	else if (regnum >= TIC6X_B0_REGNUM && regnum < TIC6X_B4_REGNUM)
	65	return 4 * (regnum - TIC6X_B0_REGNUM + 15); /* B0 - B3 */
	66	else if (regnum >= 34 && regnum < 34 + 32)
	67	return 4 * (regnum - 34 + 23); /* A16 - A31, B16 - B31 */
	68	else if (regnum == TIC6X_PC_REGNUM)
	69	return 4 * (tdep->has_gp ? 55 : 23);
	70	else if (regnum == TIC6X_SP_REGNUM)
	71	return 4;
	72
	73	return 0;
	74	}
	75
	76	/* Support unwinding frame in signal trampoline. We don't check sigreturn,
	77	since it is not used in kernel. */
	78
	79	static void
	80	tic6x_linux_rt_sigreturn_init (const struct tramp_frame *self,
	81	struct frame_info *this_frame,
	82	struct trad_frame_cache *this_cache,
	83	CORE_ADDR func)
	84	{
	85	struct gdbarch *gdbarch = get_frame_arch (this_frame);
	86	CORE_ADDR sp = get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM);
	87	/* The base of struct sigcontext is computed by examining the definition of
	88	struct rt_sigframe in linux kernel source arch/c6x/kernel/signal.c. */
	89	CORE_ADDR base = (sp + TIC6X_SP_RT_SIGFRAME
	90	/* Pointer type pinfo and puc in struct rt_sigframe. */
	91	+ 4 + 4
	92	+ TIC6X_SIGINFO_SIZE
	93	+ 4 + 4 /* uc_flags and uc_link in struct ucontext. /
	94	+ TIC6X_STACK_T_SIZE);
	95	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	96	unsigned int reg_offset;
	97	unsigned int i;
	98
	99	for (i = 0; i < 10; i++) /* A0 - A9 */
	100	{
	101	reg_offset = tic6x_register_sigcontext_offset (i, gdbarch);
	102	gdb_assert (reg_offset != 0);
	103
	104	trad_frame_set_reg_addr (this_cache, i, base + reg_offset);
	105	}
	106
	107	for (i = TIC6X_B0_REGNUM; i < TIC6X_B0_REGNUM + 10; i++) /* B0 - B9 */
	108	{
	109	reg_offset = tic6x_register_sigcontext_offset (i, gdbarch);
	110	gdb_assert (reg_offset != 0);
	111
	112	trad_frame_set_reg_addr (this_cache, i, base + reg_offset);
	113	}
	114
	115	if (tdep->has_gp)
	116	for (i = 34; i < 34 + 32; i++) /* A16 - A31, B16 - B31 */
	117	{
	118	reg_offset = tic6x_register_sigcontext_offset (i, gdbarch);
	119	gdb_assert (reg_offset != 0);
	120
	121	trad_frame_set_reg_addr (this_cache, i, base + reg_offset);
	122	}
	123
	124	trad_frame_set_reg_addr (this_cache, TIC6X_PC_REGNUM,
	125	base + tic6x_register_sigcontext_offset (TIC6X_PC_REGNUM,
	126	gdbarch));
127	trad_frame_set_reg_addr (this_cache, TIC6X_SP_REGNUM,
128	base + tic6x_register_sigcontext_offset (TIC6X_SP_REGNUM,
129	gdbarch));
130
131	/* Save a frame ID. */
132	trad_frame_set_id (this_cache, frame_id_build (sp, func));
133	}
134
135	static struct tramp_frame tic6x_linux_rt_sigreturn_tramp_frame =
136	{
137	SIGTRAMP_FRAME,
138	4,
139	{
140	{0x000045aa, 0x0fffffff}, /* mvk .S2 139,b0 */
7bc02706	141	{0x10000000, ULONGEST_MAX}, /* swe */
8cd64e00 YQ	142	{TRAMP_SENTINEL_INSN}
	143	},
	144	tic6x_linux_rt_sigreturn_init
	145	};
	146
	147	/* When FRAME is at a syscall instruction, return the PC of the next
	148	instruction to be executed. */
	149
	150	static CORE_ADDR
	151	tic6x_linux_syscall_next_pc (struct frame_info *frame)
	152	{
	153	ULONGEST syscall_number = get_frame_register_unsigned (frame,
	154	TIC6X_B0_REGNUM);
	155	CORE_ADDR pc = get_frame_pc (frame);
	156
	157	if (syscall_number == 139 /* rt_sigreturn */)
	158	return frame_unwind_caller_pc (frame);
	159
	160	return pc + 4;
	161	}
	162
	163
	164	extern struct target_so_ops dsbt_so_ops;
	165	static void
	166	tic6x_uclinux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	167	{
	168	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	169
	170	linux_init_abi (info, gdbarch);
	171
	172	/* Shared library handling. */
	173	set_solib_ops (gdbarch, &dsbt_so_ops);
	174
	175	tdep->syscall_next_pc = tic6x_linux_syscall_next_pc;
	176
	177	#ifdef HAVE_ELF
	178	/* In tic6x Linux kernel, breakpoint instructions varies on different archs.
	179	On C64x+ and C67x+, breakpoint instruction is 0x56454314, which is an
	180	illegal opcode. On other arch, breakpoint instruction is 0x0000a122
	181	(BNOP .S2 0,5). */
	182	if (info.abfd)
	183	switch (bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC, Tag_ISA))
	184	{
	185	case C6XABI_Tag_ISA_C64XP:
	186	case C6XABI_Tag_ISA_C67XP:
	187	if (info.byte_order == BFD_ENDIAN_BIG)
	188	tdep->breakpoint = tic6x_bkpt_illegal_opcode_be;
	189	else
	190	tdep->breakpoint = tic6x_bkpt_illegal_opcode_le;
	191	break;
	192	default:
	193	{
	194	if (info.byte_order == BFD_ENDIAN_BIG)
	195	tdep->breakpoint = tic6x_bkpt_bnop_be;
	196	else
	197	tdep->breakpoint = tic6x_bkpt_bnop_le;
	198	}
	199	}
	200	#endif
	201
	202	/* Signal trampoline support. */
	203	tramp_frame_prepend_unwinder (gdbarch,
	204	&tic6x_linux_rt_sigreturn_tramp_frame);
	205	}
206
8cd64e00 YQ	207	void
	208	_initialize_tic6x_linux_tdep (void)
	209	{
	210	gdbarch_register_osabi (bfd_arch_tic6x, 0, GDB_OSABI_LINUX,
	211	tic6x_uclinux_init_abi);
8cd64e00	212	}