313 lines
8.5 KiB
C
313 lines
8.5 KiB
C
/* Motorola m68k target-dependent support for GNU/Linux.
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Copyright 1996, 1998, 2000, 2001, 2002, 2003 Free Software Foundation,
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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., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "gdbcore.h"
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#include "doublest.h"
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#include "floatformat.h"
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#include "frame.h"
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#include "target.h"
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#include "gdb_string.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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/* 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 PC points into the signal trampoline. For the
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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 (CORE_ADDR pc, char *name)
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{
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CORE_ADDR sp;
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char buf[12];
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unsigned long insn0, insn1, insn2;
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if (read_memory_nobpt (pc - 4, buf, sizeof (buf)))
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return 0;
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insn1 = extract_unsigned_integer (buf + 4, 4);
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insn2 = extract_unsigned_integer (buf + 8, 4);
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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);
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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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5 * 4 + 2, /* %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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/* 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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static struct m68k_sigtramp_info
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m68k_linux_get_sigtramp_info (struct frame_info *next_frame)
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{
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CORE_ADDR sp;
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char buf[4];
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struct m68k_sigtramp_info info;
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frame_unwind_register (next_frame, M68K_SP_REGNUM, buf);
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sp = extract_unsigned_integer (buf, 4);
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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);
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if (m68k_linux_pc_in_sigtramp (frame_pc_unwind (next_frame), 0) == 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 = m68k_linux_sigcontext_reg_offset;
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return info;
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}
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/* Extract from an array REGBUF containing the (raw) register state, a
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function return value of TYPE, and copy that, in virtual format,
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into VALBUF. */
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static void
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m68k_linux_extract_return_value (struct type *type, struct regcache *regcache,
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void *valbuf)
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{
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int len = TYPE_LENGTH (type);
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char buf[M68K_MAX_REGISTER_SIZE];
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if (TYPE_CODE (type) == TYPE_CODE_STRUCT
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&& TYPE_NFIELDS (type) == 1)
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{
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m68k_linux_extract_return_value (TYPE_FIELD_TYPE (type, 0), regcache,
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valbuf);
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return;
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}
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if (TYPE_CODE (type) == TYPE_CODE_FLT)
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{
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regcache_raw_read (regcache, M68K_FP0_REGNUM, buf);
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convert_typed_floating (buf, builtin_type_m68881_ext, valbuf, type);
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}
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else if (TYPE_CODE (type) == TYPE_CODE_PTR)
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regcache_raw_read (regcache, M68K_A0_REGNUM, valbuf);
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else
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{
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if (len <= 4)
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{
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regcache_raw_read (regcache, M68K_D0_REGNUM, buf);
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memcpy (valbuf, buf + (4 - len), len);
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}
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else if (len <= 8)
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{
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regcache_raw_read (regcache, M68K_D0_REGNUM, buf);
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memcpy (valbuf, buf + (8 - len), len - 4);
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regcache_raw_read (regcache, M68K_D1_REGNUM,
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(char *) valbuf + (len - 4));
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}
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else
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internal_error (__FILE__, __LINE__,
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"Cannot extract return value of %d bytes long.", len);
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}
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}
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/* Write into the appropriate registers a function return value stored
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in VALBUF of type TYPE, given in virtual format. */
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static void
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m68k_linux_store_return_value (struct type *type, struct regcache *regcache,
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const void *valbuf)
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{
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int len = TYPE_LENGTH (type);
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if (TYPE_CODE (type) == TYPE_CODE_STRUCT
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&& TYPE_NFIELDS (type) == 1)
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{
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m68k_linux_store_return_value (TYPE_FIELD_TYPE (type, 0), regcache,
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valbuf);
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return;
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}
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if (TYPE_CODE (type) == TYPE_CODE_FLT)
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{
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char buf[M68K_MAX_REGISTER_SIZE];
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convert_typed_floating (valbuf, type, buf, builtin_type_m68881_ext);
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regcache_raw_write (regcache, M68K_FP0_REGNUM, buf);
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}
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else if (TYPE_CODE (type) == TYPE_CODE_PTR)
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regcache_raw_write (regcache, M68K_A0_REGNUM, valbuf);
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else
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{
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if (len <= 4)
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regcache_raw_write_part (regcache, M68K_D0_REGNUM,
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4 - len, len, valbuf);
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else if (len <= 8)
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{
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regcache_raw_write_part (regcache, M68K_D1_REGNUM, 8 - len,
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len - 4, valbuf);
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regcache_raw_write (regcache, M68K_D0_REGNUM,
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(char *) valbuf + (len - 4));
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}
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else
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internal_error (__FILE__, __LINE__,
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"Cannot store return value of %d bytes long.", len);
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}
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}
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/* Extract from an array REGBUF containing the (raw) register state
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the address in which a function should return its structure value,
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as a CORE_ADDR. */
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static CORE_ADDR
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m68k_linux_extract_struct_value_address (struct regcache *regcache)
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{
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char buf[4];
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regcache_cooked_read (regcache, M68K_A0_REGNUM, buf);
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return extract_unsigned_integer (buf, 4);
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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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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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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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tdep->get_sigtramp_info = m68k_linux_get_sigtramp_info;
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tdep->struct_return = reg_struct_return;
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set_gdbarch_extract_return_value (gdbarch, m68k_linux_extract_return_value);
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set_gdbarch_store_return_value (gdbarch, m68k_linux_store_return_value);
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set_gdbarch_extract_struct_value_address (gdbarch,
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m68k_linux_extract_struct_value_address);
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set_gdbarch_pc_in_sigtramp (gdbarch, m68k_linux_pc_in_sigtramp);
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/* Shared library handling. */
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set_gdbarch_in_solib_call_trampoline (gdbarch, in_plt_section);
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set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
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}
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void
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_initialize_m68k_linux_tdep (void)
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{
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gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_LINUX,
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m68k_linux_init_abi);
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}
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