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/* Motorola m68k target-dependent support for GNU/Linux.
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Copyright (C) 1996-2022 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 3 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, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "gdbcore.h"
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#include "frame.h"
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#include "target.h"
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#include "gdbtypes.h"
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#include "osabi.h"
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#include "regcache.h"
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#include "objfiles.h"
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#include "symtab.h"
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#include "m68k-tdep.h"
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#include "trad-frame.h"
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#include "frame-unwind.h"
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#include "glibc-tdep.h"
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#include "solib-svr4.h"
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#include "auxv.h"
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#include "observable.h"
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#include "elf/common.h"
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#include "linux-tdep.h"
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#include "regset.h"
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/* Offsets (in target ints) into jmp_buf. */
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#define M68K_LINUX_JB_ELEMENT_SIZE 4
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#define M68K_LINUX_JB_PC 7
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/* Check whether insn1 and insn2 are parts of a signal trampoline. */
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#define IS_SIGTRAMP(insn1, insn2) \
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(/* addaw #20,sp; moveq #119,d0; trap #0 */ \
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(insn1 == 0xdefc0014 && insn2 == 0x70774e40) \
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/* moveq #119,d0; trap #0 */ \
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|| insn1 == 0x70774e40)
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#define IS_RT_SIGTRAMP(insn1, insn2) \
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(/* movel #173,d0; trap #0 */ \
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(insn1 == 0x203c0000 && insn2 == 0x00ad4e40) \
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/* moveq #82,d0; notb d0; trap #0 */ \
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|| (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40))
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/* Return non-zero if THIS_FRAME corresponds to a signal trampoline. For
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the sake of m68k_linux_get_sigtramp_info we also distinguish between
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non-RT and RT signal trampolines. */
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static int
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m68k_linux_pc_in_sigtramp (struct frame_info *this_frame)
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{
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struct gdbarch *gdbarch = get_frame_arch (this_frame);
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enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
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gdb_byte buf[12];
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unsigned long insn0, insn1, insn2;
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CORE_ADDR pc = get_frame_pc (this_frame);
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if (!safe_frame_unwind_memory (this_frame, pc - 4, {buf, sizeof (buf)}))
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return 0;
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insn1 = extract_unsigned_integer (buf + 4, 4, byte_order);
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insn2 = extract_unsigned_integer (buf + 8, 4, byte_order);
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if (IS_SIGTRAMP (insn1, insn2))
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return 1;
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if (IS_RT_SIGTRAMP (insn1, insn2))
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return 2;
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insn0 = extract_unsigned_integer (buf, 4, byte_order);
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if (IS_SIGTRAMP (insn0, insn1))
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return 1;
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if (IS_RT_SIGTRAMP (insn0, insn1))
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return 2;
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insn0 = ((insn0 << 16) & 0xffffffff) | (insn1 >> 16);
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insn1 = ((insn1 << 16) & 0xffffffff) | (insn2 >> 16);
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if (IS_SIGTRAMP (insn0, insn1))
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return 1;
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if (IS_RT_SIGTRAMP (insn0, insn1))
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return 2;
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return 0;
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}
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/* From <asm/sigcontext.h>. */
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static int m68k_linux_sigcontext_reg_offset[M68K_NUM_REGS] =
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{
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2 * 4, /* %d0 */
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3 * 4, /* %d1 */
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-1, /* %d2 */
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-1, /* %d3 */
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-1, /* %d4 */
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-1, /* %d5 */
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-1, /* %d6 */
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-1, /* %d7 */
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4 * 4, /* %a0 */
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5 * 4, /* %a1 */
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-1, /* %a2 */
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-1, /* %a3 */
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-1, /* %a4 */
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-1, /* %a5 */
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-1, /* %fp */
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1 * 4, /* %sp */
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6 * 4, /* %sr */
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6 * 4 + 2, /* %pc */
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8 * 4, /* %fp0 */
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11 * 4, /* %fp1 */
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-1, /* %fp2 */
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-1, /* %fp3 */
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-1, /* %fp4 */
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-1, /* %fp5 */
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-1, /* %fp6 */
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-1, /* %fp7 */
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14 * 4, /* %fpcr */
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15 * 4, /* %fpsr */
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16 * 4 /* %fpiaddr */
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};
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static int m68k_uclinux_sigcontext_reg_offset[M68K_NUM_REGS] =
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{
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2 * 4, /* %d0 */
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3 * 4, /* %d1 */
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-1, /* %d2 */
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-1, /* %d3 */
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-1, /* %d4 */
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-1, /* %d5 */
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-1, /* %d6 */
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-1, /* %d7 */
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4 * 4, /* %a0 */
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5 * 4, /* %a1 */
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-1, /* %a2 */
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-1, /* %a3 */
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-1, /* %a4 */
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6 * 4, /* %a5 */
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-1, /* %fp */
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1 * 4, /* %sp */
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7 * 4, /* %sr */
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7 * 4 + 2, /* %pc */
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-1, /* %fp0 */
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-1, /* %fp1 */
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-1, /* %fp2 */
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-1, /* %fp3 */
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-1, /* %fp4 */
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-1, /* %fp5 */
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-1, /* %fp6 */
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-1, /* %fp7 */
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-1, /* %fpcr */
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-1, /* %fpsr */
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-1 /* %fpiaddr */
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};
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/* From <asm/ucontext.h>. */
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static int m68k_linux_ucontext_reg_offset[M68K_NUM_REGS] =
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{
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6 * 4, /* %d0 */
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7 * 4, /* %d1 */
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8 * 4, /* %d2 */
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9 * 4, /* %d3 */
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10 * 4, /* %d4 */
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11 * 4, /* %d5 */
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12 * 4, /* %d6 */
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13 * 4, /* %d7 */
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14 * 4, /* %a0 */
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15 * 4, /* %a1 */
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16 * 4, /* %a2 */
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17 * 4, /* %a3 */
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18 * 4, /* %a4 */
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19 * 4, /* %a5 */
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20 * 4, /* %fp */
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21 * 4, /* %sp */
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23 * 4, /* %sr */
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22 * 4, /* %pc */
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27 * 4, /* %fp0 */
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30 * 4, /* %fp1 */
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33 * 4, /* %fp2 */
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36 * 4, /* %fp3 */
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39 * 4, /* %fp4 */
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42 * 4, /* %fp5 */
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45 * 4, /* %fp6 */
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48 * 4, /* %fp7 */
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24 * 4, /* %fpcr */
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25 * 4, /* %fpsr */
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26 * 4 /* %fpiaddr */
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};
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/* Get info about saved registers in sigtramp. */
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struct m68k_linux_sigtramp_info
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{
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/* Address of sigcontext. */
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CORE_ADDR sigcontext_addr;
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/* Offset of registers in `struct sigcontext'. */
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int *sc_reg_offset;
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};
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/* Nonzero if running on uClinux. */
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static int target_is_uclinux;
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static void
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m68k_linux_inferior_created (inferior *inf)
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{
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/* Record that we will need to re-evaluate whether we are running on a
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uClinux or normal GNU/Linux target (see m68k_linux_get_sigtramp_info). */
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target_is_uclinux = -1;
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}
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static struct m68k_linux_sigtramp_info
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m68k_linux_get_sigtramp_info (struct frame_info *this_frame)
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{
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struct gdbarch *gdbarch = get_frame_arch (this_frame);
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enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
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CORE_ADDR sp;
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struct m68k_linux_sigtramp_info info;
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/* Determine whether we are running on a uClinux or normal GNU/Linux
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target so we can use the correct sigcontext layouts. */
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if (target_is_uclinux == -1)
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target_is_uclinux = linux_is_uclinux ();
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sp = get_frame_register_unsigned (this_frame, M68K_SP_REGNUM);
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/* Get sigcontext address, it is the third parameter on the stack. */
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info.sigcontext_addr = read_memory_unsigned_integer (sp + 8, 4, byte_order);
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if (m68k_linux_pc_in_sigtramp (this_frame) == 2)
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info.sc_reg_offset = m68k_linux_ucontext_reg_offset;
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else
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info.sc_reg_offset = (target_is_uclinux
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? m68k_uclinux_sigcontext_reg_offset
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: m68k_linux_sigcontext_reg_offset);
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return info;
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}
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/* Signal trampolines. */
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static struct trad_frame_cache *
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m68k_linux_sigtramp_frame_cache (struct frame_info *this_frame,
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void **this_cache)
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{
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struct frame_id this_id;
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struct trad_frame_cache *cache;
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struct gdbarch *gdbarch = get_frame_arch (this_frame);
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enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
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struct m68k_linux_sigtramp_info info;
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gdb_byte buf[4];
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int i;
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if (*this_cache)
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return (struct trad_frame_cache *) *this_cache;
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cache = trad_frame_cache_zalloc (this_frame);
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/* FIXME: cagney/2004-05-01: This is is long standing broken code.
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The frame ID's code address should be the start-address of the
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signal trampoline and not the current PC within that
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trampoline. */
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get_frame_register (this_frame, M68K_SP_REGNUM, buf);
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/* See the end of m68k_push_dummy_call. */
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this_id = frame_id_build (extract_unsigned_integer (buf, 4, byte_order)
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- 4 + 8, get_frame_pc (this_frame));
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trad_frame_set_id (cache, this_id);
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info = m68k_linux_get_sigtramp_info (this_frame);
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for (i = 0; i < M68K_NUM_REGS; i++)
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if (info.sc_reg_offset[i] != -1)
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trad_frame_set_reg_addr (cache, i,
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info.sigcontext_addr + info.sc_reg_offset[i]);
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*this_cache = cache;
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return cache;
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}
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static void
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m68k_linux_sigtramp_frame_this_id (struct frame_info *this_frame,
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void **this_cache,
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struct frame_id *this_id)
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{
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struct trad_frame_cache *cache =
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m68k_linux_sigtramp_frame_cache (this_frame, this_cache);
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trad_frame_get_id (cache, this_id);
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}
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static struct value *
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m68k_linux_sigtramp_frame_prev_register (struct frame_info *this_frame,
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void **this_cache,
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int regnum)
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{
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/* Make sure we've initialized the cache. */
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struct trad_frame_cache *cache =
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m68k_linux_sigtramp_frame_cache (this_frame, this_cache);
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return trad_frame_get_register (cache, this_frame, regnum);
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}
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static int
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m68k_linux_sigtramp_frame_sniffer (const struct frame_unwind *self,
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struct frame_info *this_frame,
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void **this_prologue_cache)
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{
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return m68k_linux_pc_in_sigtramp (this_frame);
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}
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static const struct frame_unwind m68k_linux_sigtramp_frame_unwind =
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{
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"m68k linux sigtramp",
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SIGTRAMP_FRAME,
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default_frame_unwind_stop_reason,
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m68k_linux_sigtramp_frame_this_id,
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m68k_linux_sigtramp_frame_prev_register,
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NULL,
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m68k_linux_sigtramp_frame_sniffer
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};
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/* Register maps for supply/collect regset functions. */
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static const struct regcache_map_entry m68k_linux_gregmap[] =
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{
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{ 7, M68K_D1_REGNUM, 4 }, /* d1 ... d7 */
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{ 7, M68K_A0_REGNUM, 4 }, /* a0 ... a6 */
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{ 1, M68K_D0_REGNUM, 4 },
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{ 1, M68K_SP_REGNUM, 4 },
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{ 1, REGCACHE_MAP_SKIP, 4 }, /* orig_d0 (skip) */
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{ 1, M68K_PS_REGNUM, 4 },
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{ 1, M68K_PC_REGNUM, 4 },
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/* Ignore 16-bit fields 'fmtvec' and '__fill'. */
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{ 0 }
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};
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#define M68K_LINUX_GREGS_SIZE (20 * 4)
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static const struct regcache_map_entry m68k_linux_fpregmap[] =
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{
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{ 8, M68K_FP0_REGNUM, 12 }, /* fp0 ... fp7 */
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{ 1, M68K_FPC_REGNUM, 4 },
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{ 1, M68K_FPS_REGNUM, 4 },
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{ 1, M68K_FPI_REGNUM, 4 },
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{ 0 }
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};
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#define M68K_LINUX_FPREGS_SIZE (27 * 4)
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/* Register sets. */
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static const struct regset m68k_linux_gregset =
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{
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m68k_linux_gregmap,
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regcache_supply_regset, regcache_collect_regset
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};
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static const struct regset m68k_linux_fpregset =
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{
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m68k_linux_fpregmap,
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regcache_supply_regset, regcache_collect_regset
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};
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/* Iterate over core file register note sections. */
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static void
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m68k_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
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iterate_over_regset_sections_cb *cb,
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void *cb_data,
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const struct regcache *regcache)
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{
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cb (".reg", M68K_LINUX_GREGS_SIZE, M68K_LINUX_GREGS_SIZE, &m68k_linux_gregset,
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NULL, cb_data);
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cb (".reg2", M68K_LINUX_FPREGS_SIZE, M68K_LINUX_FPREGS_SIZE,
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&m68k_linux_fpregset, NULL, cb_data);
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}
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static void
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m68k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
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{
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m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
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linux_init_abi (info, gdbarch, 0);
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tdep->jb_pc = M68K_LINUX_JB_PC;
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tdep->jb_elt_size = M68K_LINUX_JB_ELEMENT_SIZE;
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/* GNU/Linux uses a calling convention that's similar to SVR4. It
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returns integer values in %d0/%d1, pointer values in %a0 and
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floating values in %fp0, just like SVR4, but uses %a1 to pass the
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address to store a structure value. It also returns small
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structures in registers instead of memory. */
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m68k_svr4_init_abi (info, gdbarch);
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tdep->struct_value_regnum = M68K_A1_REGNUM;
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tdep->struct_return = reg_struct_return;
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set_gdbarch_decr_pc_after_break (gdbarch, 2);
|
|
|
|
|
|
frame_unwind_append_unwinder (gdbarch, &m68k_linux_sigtramp_frame_unwind);
|
|
|
|
|
|
/* Shared library handling. */
|
|
|
|
|
|
/* GNU/Linux uses SVR4-style shared libraries. */
|
|
|
set_solib_svr4_fetch_link_map_offsets (gdbarch,
|
|
|
linux_ilp32_fetch_link_map_offsets);
|
|
|
|
|
|
/* GNU/Linux uses the dynamic linker included in the GNU C Library. */
|
|
|
set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
|
|
|
|
|
|
set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
|
|
|
|
|
|
/* Core file support. */
|
|
|
set_gdbarch_iterate_over_regset_sections
|
|
|
(gdbarch, m68k_linux_iterate_over_regset_sections);
|
|
|
|
|
|
/* Enable TLS support. */
|
|
|
set_gdbarch_fetch_tls_load_module_address (gdbarch,
|
|
|
svr4_fetch_objfile_link_map);
|
|
|
}
|
|
|
|
|
|
void _initialize_m68k_linux_tdep ();
|
|
|
void
|
|
|
_initialize_m68k_linux_tdep ()
|
|
|
{
|
|
|
gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_LINUX,
|
|
|
m68k_linux_init_abi);
|
|
|
gdb::observers::inferior_created.attach (m68k_linux_inferior_created,
|
|
|
"m68k-linux-tdep");
|
|
|
}
|