289 lines
7.5 KiB
C
289 lines
7.5 KiB
C
/* Target-dependent code for NetBSD/i386.
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Copyright (C) 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002,
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2003, 2004
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Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor,
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Boston, MA 02110-1301, USA. */
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#include "defs.h"
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#include "arch-utils.h"
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#include "frame.h"
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#include "gdbcore.h"
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#include "regcache.h"
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#include "regset.h"
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#include "osabi.h"
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#include "symtab.h"
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#include "gdb_assert.h"
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#include "gdb_string.h"
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#include "i386-tdep.h"
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#include "i387-tdep.h"
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#include "nbsd-tdep.h"
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#include "solib-svr4.h"
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/* From <machine/reg.h>. */
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static int i386nbsd_r_reg_offset[] =
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{
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0 * 4, /* %eax */
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1 * 4, /* %ecx */
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2 * 4, /* %edx */
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3 * 4, /* %ebx */
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4 * 4, /* %esp */
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5 * 4, /* %ebp */
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6 * 4, /* %esi */
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7 * 4, /* %edi */
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8 * 4, /* %eip */
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9 * 4, /* %eflags */
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10 * 4, /* %cs */
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11 * 4, /* %ss */
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12 * 4, /* %ds */
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13 * 4, /* %es */
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14 * 4, /* %fs */
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15 * 4 /* %gs */
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};
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static void
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i386nbsd_aout_supply_regset (const struct regset *regset,
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struct regcache *regcache, int regnum,
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const void *regs, size_t len)
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{
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const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch);
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gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE);
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i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset);
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i387_supply_fsave (regcache, regnum, (char *) regs + tdep->sizeof_gregset);
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}
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static const struct regset *
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i386nbsd_aout_regset_from_core_section (struct gdbarch *gdbarch,
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const char *sect_name,
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size_t sect_size)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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/* NetBSD a.out core dumps don't use seperate register sets for the
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general-purpose and floating-point registers. */
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if (strcmp (sect_name, ".reg") == 0
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&& sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE)
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{
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if (tdep->gregset == NULL)
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tdep->gregset =
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regset_alloc (gdbarch, i386nbsd_aout_supply_regset, NULL);
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return tdep->gregset;
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}
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return NULL;
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}
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/* Under NetBSD/i386, signal handler invocations can be identified by the
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designated code sequence that is used to return from a signal handler.
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In particular, the return address of a signal handler points to the
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following code sequence:
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leal 0x10(%esp), %eax
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pushl %eax
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pushl %eax
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movl $0x127, %eax # __sigreturn14
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int $0x80
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Each instruction has a unique encoding, so we simply attempt to match
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the instruction the PC is pointing to with any of the above instructions.
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If there is a hit, we know the offset to the start of the designated
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sequence and can then check whether we really are executing in the
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signal trampoline. If not, -1 is returned, otherwise the offset from the
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start of the return sequence is returned. */
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#define RETCODE_INSN1 0x8d
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#define RETCODE_INSN2 0x50
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#define RETCODE_INSN3 0x50
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#define RETCODE_INSN4 0xb8
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#define RETCODE_INSN5 0xcd
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#define RETCODE_INSN2_OFF 4
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#define RETCODE_INSN3_OFF 5
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#define RETCODE_INSN4_OFF 6
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#define RETCODE_INSN5_OFF 11
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static const unsigned char sigtramp_retcode[] =
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{
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RETCODE_INSN1, 0x44, 0x24, 0x10,
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RETCODE_INSN2,
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RETCODE_INSN3,
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RETCODE_INSN4, 0x27, 0x01, 0x00, 0x00,
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RETCODE_INSN5, 0x80,
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};
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static LONGEST
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i386nbsd_sigtramp_offset (struct frame_info *next_frame)
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{
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CORE_ADDR pc = frame_pc_unwind (next_frame);
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unsigned char ret[sizeof(sigtramp_retcode)], insn;
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LONGEST off;
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int i;
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if (!safe_frame_unwind_memory (next_frame, pc, &insn, 1))
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return -1;
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switch (insn)
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{
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case RETCODE_INSN1:
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off = 0;
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break;
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case RETCODE_INSN2:
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/* INSN2 and INSN3 are the same. Read at the location of PC+1
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to determine if we're actually looking at INSN2 or INSN3. */
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if (!safe_frame_unwind_memory (next_frame, pc + 1, &insn, 1))
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return -1;
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if (insn == RETCODE_INSN3)
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off = RETCODE_INSN2_OFF;
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else
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off = RETCODE_INSN3_OFF;
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break;
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case RETCODE_INSN4:
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off = RETCODE_INSN4_OFF;
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break;
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case RETCODE_INSN5:
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off = RETCODE_INSN5_OFF;
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break;
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default:
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return -1;
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}
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pc -= off;
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if (!safe_frame_unwind_memory (next_frame, pc, ret, sizeof (ret)))
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return -1;
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if (memcmp (ret, sigtramp_retcode, sizeof (ret)) == 0)
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return off;
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return -1;
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}
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/* Return whether the frame preceding NEXT_FRAME corresponds to a
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NetBSD sigtramp routine. */
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static int
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i386nbsd_sigtramp_p (struct frame_info *next_frame)
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{
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CORE_ADDR pc = frame_pc_unwind (next_frame);
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char *name;
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find_pc_partial_function (pc, &name, NULL, NULL);
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return (nbsd_pc_in_sigtramp (pc, name)
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|| i386nbsd_sigtramp_offset (next_frame) >= 0);
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}
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/* From <machine/signal.h>. */
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int i386nbsd_sc_reg_offset[] =
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{
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10 * 4, /* %eax */
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9 * 4, /* %ecx */
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8 * 4, /* %edx */
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7 * 4, /* %ebx */
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14 * 4, /* %esp */
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6 * 4, /* %ebp */
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5 * 4, /* %esi */
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4 * 4, /* %edi */
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11 * 4, /* %eip */
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13 * 4, /* %eflags */
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12 * 4, /* %cs */
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15 * 4, /* %ss */
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3 * 4, /* %ds */
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2 * 4, /* %es */
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1 * 4, /* %fs */
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0 * 4 /* %gs */
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};
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static void
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i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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/* Obviously NetBSD is BSD-based. */
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i386bsd_init_abi (info, gdbarch);
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/* NetBSD has a different `struct reg'. */
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tdep->gregset_reg_offset = i386nbsd_r_reg_offset;
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tdep->gregset_num_regs = ARRAY_SIZE (i386nbsd_r_reg_offset);
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tdep->sizeof_gregset = 16 * 4;
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/* NetBSD has different signal trampoline conventions. */
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tdep->sigtramp_start = 0;
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tdep->sigtramp_end = 0;
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tdep->sigtramp_p = i386nbsd_sigtramp_p;
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/* NetBSD uses -freg-struct-return by default. */
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tdep->struct_return = reg_struct_return;
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/* NetBSD has a `struct sigcontext' that's different from the
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original 4.3 BSD. */
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tdep->sc_reg_offset = i386nbsd_sc_reg_offset;
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tdep->sc_num_regs = ARRAY_SIZE (i386nbsd_sc_reg_offset);
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}
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/* NetBSD a.out. */
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static void
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i386nbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
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{
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i386nbsd_init_abi (info, gdbarch);
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/* NetBSD a.out has a single register set. */
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set_gdbarch_regset_from_core_section
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(gdbarch, i386nbsd_aout_regset_from_core_section);
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}
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/* NetBSD ELF. */
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static void
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i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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/* It's still NetBSD. */
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i386nbsd_init_abi (info, gdbarch);
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/* But ELF-based. */
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i386_elf_init_abi (info, gdbarch);
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/* NetBSD ELF uses SVR4-style shared libraries. */
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set_solib_svr4_fetch_link_map_offsets
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(gdbarch, svr4_ilp32_fetch_link_map_offsets);
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/* NetBSD ELF uses -fpcc-struct-return by default. */
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tdep->struct_return = pcc_struct_return;
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}
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void
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_initialize_i386nbsd_tdep (void)
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{
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gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_AOUT,
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i386nbsdaout_init_abi);
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gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_ELF,
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i386nbsdelf_init_abi);
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}
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