413 lines
11 KiB
C
413 lines
11 KiB
C
/* Target-dependent code for NetBSD/mips.
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Copyright (C) 2002, 2003, 2004, 2006, 2007 Free Software Foundation, Inc.
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Contributed by Wasabi Systems, 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 "gdbcore.h"
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#include "regcache.h"
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#include "regset.h"
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#include "target.h"
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#include "value.h"
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#include "osabi.h"
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#include "gdb_assert.h"
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#include "gdb_string.h"
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#include "nbsd-tdep.h"
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#include "mipsnbsd-tdep.h"
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#include "mips-tdep.h"
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#include "solib-svr4.h"
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/* Shorthand for some register numbers used below. */
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#define MIPS_PC_REGNUM MIPS_EMBED_PC_REGNUM
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#define MIPS_FP0_REGNUM MIPS_EMBED_FP0_REGNUM
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#define MIPS_FSR_REGNUM MIPS_EMBED_FP0_REGNUM + 32
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/* Core file support. */
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/* Number of registers in `struct reg' from <machine/reg.h>. */
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#define MIPSNBSD_NUM_GREGS 38
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/* Number of registers in `struct fpreg' from <machine/reg.h>. */
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#define MIPSNBSD_NUM_FPREGS 33
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/* Supply register REGNUM from the buffer specified by FPREGS and LEN
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in the floating-point register set REGSET to register cache
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REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
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static void
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mipsnbsd_supply_fpregset (const struct regset *regset,
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struct regcache *regcache,
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int regnum, const void *fpregs, size_t len)
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{
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size_t regsize = mips_isa_regsize (get_regcache_arch (regcache));
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const char *regs = fpregs;
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int i;
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gdb_assert (len >= MIPSNBSD_NUM_FPREGS * regsize);
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for (i = MIPS_FP0_REGNUM; i <= MIPS_FSR_REGNUM; i++)
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{
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if (regnum == i || regnum == -1)
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regcache_raw_supply (regcache, i,
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regs + (i - MIPS_FP0_REGNUM) * regsize);
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}
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}
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/* Supply register REGNUM from the buffer specified by GREGS and LEN
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in the general-purpose register set REGSET to register cache
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REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
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static void
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mipsnbsd_supply_gregset (const struct regset *regset,
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struct regcache *regcache, int regnum,
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const void *gregs, size_t len)
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{
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size_t regsize = mips_isa_regsize (get_regcache_arch (regcache));
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const char *regs = gregs;
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int i;
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gdb_assert (len >= MIPSNBSD_NUM_GREGS * regsize);
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for (i = 0; i <= MIPS_PC_REGNUM; i++)
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{
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if (regnum == i || regnum == -1)
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regcache_raw_supply (regcache, i, regs + i * regsize);
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}
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if (len >= (MIPSNBSD_NUM_GREGS + MIPSNBSD_NUM_FPREGS) * regsize)
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{
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regs += MIPSNBSD_NUM_GREGS * regsize;
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len -= MIPSNBSD_NUM_GREGS * regsize;
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mipsnbsd_supply_fpregset (regset, regcache, regnum, regs, len);
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}
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}
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/* NetBSD/mips register sets. */
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static struct regset mipsnbsd_gregset =
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{
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NULL,
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mipsnbsd_supply_gregset
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};
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static struct regset mipsnbsd_fpregset =
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{
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NULL,
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mipsnbsd_supply_fpregset
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};
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/* Return the appropriate register set for the core section identified
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by SECT_NAME and SECT_SIZE. */
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static const struct regset *
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mipsnbsd_regset_from_core_section (struct gdbarch *gdbarch,
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const char *sect_name, size_t sect_size)
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{
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size_t regsize = mips_isa_regsize (gdbarch);
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if (strcmp (sect_name, ".reg") == 0
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&& sect_size >= MIPSNBSD_NUM_GREGS * regsize)
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return &mipsnbsd_gregset;
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if (strcmp (sect_name, ".reg2") == 0
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&& sect_size >= MIPSNBSD_NUM_FPREGS * regsize)
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return &mipsnbsd_fpregset;
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return NULL;
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}
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/* Conveniently, GDB uses the same register numbering as the
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ptrace register structure used by NetBSD/mips. */
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void
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mipsnbsd_supply_reg (struct regcache *regcache, const char *regs, int regno)
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{
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int i;
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for (i = 0; i <= PC_REGNUM; i++)
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{
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if (regno == i || regno == -1)
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{
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if (CANNOT_FETCH_REGISTER (i))
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regcache_raw_supply (regcache, i, NULL);
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else
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regcache_raw_supply (regcache, i,
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regs + (i * mips_isa_regsize (current_gdbarch)));
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}
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}
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}
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void
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mipsnbsd_fill_reg (const struct regcache *regcache, char *regs, int regno)
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{
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int i;
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for (i = 0; i <= PC_REGNUM; i++)
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if ((regno == i || regno == -1) && ! CANNOT_STORE_REGISTER (i))
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regcache_raw_collect (regcache, i,
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regs + (i * mips_isa_regsize (current_gdbarch)));
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}
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void
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mipsnbsd_supply_fpreg (struct regcache *regcache, const char *fpregs, int regno)
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{
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int i;
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for (i = FP0_REGNUM;
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i <= mips_regnum (current_gdbarch)->fp_implementation_revision;
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i++)
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{
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if (regno == i || regno == -1)
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{
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if (CANNOT_FETCH_REGISTER (i))
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regcache_raw_supply (regcache, i, NULL);
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else
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regcache_raw_supply (regcache, i,
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fpregs + ((i - FP0_REGNUM) * mips_isa_regsize (current_gdbarch)));
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}
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}
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}
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void
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mipsnbsd_fill_fpreg (const struct regcache *regcache, char *fpregs, int regno)
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{
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int i;
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for (i = FP0_REGNUM; i <= mips_regnum (current_gdbarch)->fp_control_status;
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i++)
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if ((regno == i || regno == -1) && ! CANNOT_STORE_REGISTER (i))
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regcache_raw_collect (regcache, i,
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fpregs + ((i - FP0_REGNUM) * mips_isa_regsize (current_gdbarch)));
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}
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/* Under NetBSD/mips, 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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addu a0, sp, 16
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li v0, 295 # __sigreturn14
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syscall
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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_NWORDS 3
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#define RETCODE_SIZE (RETCODE_NWORDS * 4)
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static const unsigned char sigtramp_retcode_mipsel[RETCODE_SIZE] =
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{
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0x10, 0x00, 0xa4, 0x27, /* addu a0, sp, 16 */
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0x27, 0x01, 0x02, 0x24, /* li v0, 295 */
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0x0c, 0x00, 0x00, 0x00, /* syscall */
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};
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static const unsigned char sigtramp_retcode_mipseb[RETCODE_SIZE] =
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{
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0x27, 0xa4, 0x00, 0x10, /* addu a0, sp, 16 */
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0x24, 0x02, 0x01, 0x27, /* li v0, 295 */
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0x00, 0x00, 0x00, 0x0c, /* syscall */
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};
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static LONGEST
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mipsnbsd_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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const char *retcode = TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
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? sigtramp_retcode_mipseb : sigtramp_retcode_mipsel;
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unsigned char ret[RETCODE_SIZE], w[4];
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LONGEST off;
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int i;
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if (!safe_frame_unwind_memory (next_frame, pc, w, sizeof (w)))
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return -1;
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for (i = 0; i < RETCODE_NWORDS; i++)
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{
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if (memcmp (w, retcode + (i * 4), 4) == 0)
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break;
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}
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if (i == RETCODE_NWORDS)
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return -1;
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off = i * 4;
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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, retcode, RETCODE_SIZE) == 0)
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return off;
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return -1;
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}
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/* Figure out where the longjmp will land. We expect that we have
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just entered longjmp and haven't yet setup the stack frame, so the
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args are still in the argument regs. MIPS_A0_REGNUM points at the
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jmp_buf structure from which we extract the PC that we will land
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at. The PC is copied into *pc. This routine returns true on
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success. */
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#define NBSD_MIPS_JB_PC (2 * 4)
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#define NBSD_MIPS_JB_ELEMENT_SIZE mips_isa_regsize (current_gdbarch)
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#define NBSD_MIPS_JB_OFFSET (NBSD_MIPS_JB_PC * \
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NBSD_MIPS_JB_ELEMENT_SIZE)
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static int
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mipsnbsd_get_longjmp_target (CORE_ADDR *pc)
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{
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CORE_ADDR jb_addr;
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char *buf;
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buf = alloca (NBSD_MIPS_JB_ELEMENT_SIZE);
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jb_addr = read_register (MIPS_A0_REGNUM);
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if (target_read_memory (jb_addr + NBSD_MIPS_JB_OFFSET, buf,
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NBSD_MIPS_JB_ELEMENT_SIZE))
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return 0;
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*pc = extract_unsigned_integer (buf, NBSD_MIPS_JB_ELEMENT_SIZE);
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return 1;
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}
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static int
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mipsnbsd_cannot_fetch_register (int regno)
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{
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return (regno == MIPS_ZERO_REGNUM
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|| regno == mips_regnum (current_gdbarch)->fp_implementation_revision);
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}
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static int
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mipsnbsd_cannot_store_register (int regno)
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{
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return (regno == MIPS_ZERO_REGNUM
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|| regno == mips_regnum (current_gdbarch)->fp_implementation_revision);
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}
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/* Shared library support. */
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/* NetBSD/mips uses a slightly different `struct link_map' than the
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other NetBSD platforms. */
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static struct link_map_offsets *
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mipsnbsd_ilp32_fetch_link_map_offsets (void)
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{
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static struct link_map_offsets lmo;
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static struct link_map_offsets *lmp = NULL;
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if (lmp == NULL)
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{
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lmp = &lmo;
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lmo.r_version_offset = 0;
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lmo.r_version_size = 4;
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lmo.r_map_offset = 4;
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lmo.r_ldsomap_offset = -1;
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/* Everything we need is in the first 24 bytes. */
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lmo.link_map_size = 24;
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lmo.l_addr_offset = 4;
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lmo.l_name_offset = 8;
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lmo.l_ld_offset = 12;
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lmo.l_next_offset = 16;
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lmo.l_prev_offset = 20;
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}
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return lmp;
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}
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static struct link_map_offsets *
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mipsnbsd_lp64_fetch_link_map_offsets (void)
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{
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static struct link_map_offsets lmo;
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static struct link_map_offsets *lmp = NULL;
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if (lmp == NULL)
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{
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lmp = &lmo;
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lmo.r_version_offset = 0;
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lmo.r_version_size = 4;
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lmo.r_map_offset = 8;
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lmo.r_ldsomap_offset = -1;
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/* Everything we need is in the first 40 bytes. */
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lmo.link_map_size = 48;
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lmo.l_addr_offset = 0;
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lmo.l_name_offset = 16;
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lmo.l_ld_offset = 24;
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lmo.l_next_offset = 32;
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lmo.l_prev_offset = 40;
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}
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return lmp;
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}
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static void
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mipsnbsd_init_abi (struct gdbarch_info info,
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struct gdbarch *gdbarch)
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{
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set_gdbarch_regset_from_core_section
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(gdbarch, mipsnbsd_regset_from_core_section);
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set_gdbarch_get_longjmp_target (gdbarch, mipsnbsd_get_longjmp_target);
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set_gdbarch_cannot_fetch_register (gdbarch, mipsnbsd_cannot_fetch_register);
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set_gdbarch_cannot_store_register (gdbarch, mipsnbsd_cannot_store_register);
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set_gdbarch_software_single_step (gdbarch, mips_software_single_step);
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/* NetBSD/mips has SVR4-style shared libraries. */
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set_solib_svr4_fetch_link_map_offsets
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(gdbarch, (gdbarch_ptr_bit (gdbarch) == 32 ?
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mipsnbsd_ilp32_fetch_link_map_offsets :
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mipsnbsd_lp64_fetch_link_map_offsets));
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}
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static enum gdb_osabi
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mipsnbsd_core_osabi_sniffer (bfd *abfd)
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{
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if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
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return GDB_OSABI_NETBSD_ELF;
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return GDB_OSABI_UNKNOWN;
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}
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void
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_initialize_mipsnbsd_tdep (void)
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{
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gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_NETBSD_ELF,
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mipsnbsd_init_abi);
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}
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