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- /* Target-dependent code for NetBSD/alpha.
- Copyright (C) 2002-2022 Free Software Foundation, Inc.
- Contributed by Wasabi Systems, Inc.
- This file is part of GDB.
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
- #include "defs.h"
- #include "frame.h"
- #include "gdbcore.h"
- #include "osabi.h"
- #include "regcache.h"
- #include "regset.h"
- #include "value.h"
- #include "alpha-tdep.h"
- #include "alpha-bsd-tdep.h"
- #include "netbsd-tdep.h"
- #include "solib-svr4.h"
- #include "target.h"
- /* Core file support. */
- /* Sizeof `struct reg' in <machine/reg.h>. */
- #define ALPHANBSD_SIZEOF_GREGS (32 * 8)
- /* Sizeof `struct fpreg' in <machine/reg.h. */
- #define ALPHANBSD_SIZEOF_FPREGS ((32 * 8) + 8)
- /* Supply register REGNUM from the buffer specified by FPREGS and LEN
- in the floating-point register set REGSET to register cache
- REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
- static void
- alphanbsd_supply_fpregset (const struct regset *regset,
- struct regcache *regcache,
- int regnum, const void *fpregs, size_t len)
- {
- const gdb_byte *regs = (const gdb_byte *) fpregs;
- int i;
- gdb_assert (len >= ALPHANBSD_SIZEOF_FPREGS);
- for (i = ALPHA_FP0_REGNUM; i < ALPHA_FP0_REGNUM + 31; i++)
- {
- if (regnum == i || regnum == -1)
- regcache->raw_supply (i, regs + (i - ALPHA_FP0_REGNUM) * 8);
- }
- if (regnum == ALPHA_FPCR_REGNUM || regnum == -1)
- regcache->raw_supply (ALPHA_FPCR_REGNUM, regs + 32 * 8);
- }
- /* Supply register REGNUM from the buffer specified by GREGS and LEN
- in the general-purpose register set REGSET to register cache
- REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
- static void
- alphanbsd_aout_supply_gregset (const struct regset *regset,
- struct regcache *regcache,
- int regnum, const void *gregs, size_t len)
- {
- const gdb_byte *regs = (const gdb_byte *) gregs;
- int i;
- /* Table to map a GDB register number to a trapframe register index. */
- static const int regmap[] =
- {
- 0, 1, 2, 3,
- 4, 5, 6, 7,
- 8, 9, 10, 11,
- 12, 13, 14, 15,
- 30, 31, 32, 16,
- 17, 18, 19, 20,
- 21, 22, 23, 24,
- 25, 29, 26
- };
- gdb_assert (len >= ALPHANBSD_SIZEOF_GREGS);
- for (i = 0; i < ARRAY_SIZE(regmap); i++)
- {
- if (regnum == i || regnum == -1)
- regcache->raw_supply (i, regs + regmap[i] * 8);
- }
- if (regnum == ALPHA_PC_REGNUM || regnum == -1)
- regcache->raw_supply (ALPHA_PC_REGNUM, regs + 31 * 8);
- if (len >= ALPHANBSD_SIZEOF_GREGS + ALPHANBSD_SIZEOF_FPREGS)
- {
- regs += ALPHANBSD_SIZEOF_GREGS;
- len -= ALPHANBSD_SIZEOF_GREGS;
- alphanbsd_supply_fpregset (regset, regcache, regnum, regs, len);
- }
- }
- /* Supply register REGNUM from the buffer specified by GREGS and LEN
- in the general-purpose register set REGSET to register cache
- REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
- static void
- alphanbsd_supply_gregset (const struct regset *regset,
- struct regcache *regcache,
- int regnum, const void *gregs, size_t len)
- {
- const gdb_byte *regs = (const gdb_byte *) gregs;
- int i;
- if (len >= ALPHANBSD_SIZEOF_GREGS + ALPHANBSD_SIZEOF_FPREGS)
- {
- alphanbsd_aout_supply_gregset (regset, regcache, regnum, gregs, len);
- return;
- }
- for (i = 0; i < ALPHA_ZERO_REGNUM; i++)
- {
- if (regnum == i || regnum == -1)
- regcache->raw_supply (i, regs + i * 8);
- }
- if (regnum == ALPHA_PC_REGNUM || regnum == -1)
- regcache->raw_supply (ALPHA_PC_REGNUM, regs + 31 * 8);
- }
- /* NetBSD/alpha register sets. */
- static const struct regset alphanbsd_gregset =
- {
- NULL,
- alphanbsd_supply_gregset,
- NULL,
- REGSET_VARIABLE_SIZE
- };
- static const struct regset alphanbsd_fpregset =
- {
- NULL,
- alphanbsd_supply_fpregset
- };
- /* Iterate over supported core file register note sections. */
- void
- alphanbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
- iterate_over_regset_sections_cb *cb,
- void *cb_data,
- const struct regcache *regcache)
- {
- cb (".reg", ALPHANBSD_SIZEOF_GREGS, ALPHANBSD_SIZEOF_GREGS,
- &alphanbsd_gregset, NULL, cb_data);
- cb (".reg2", ALPHANBSD_SIZEOF_FPREGS, ALPHANBSD_SIZEOF_FPREGS,
- &alphanbsd_fpregset, NULL, cb_data);
- }
- /* Signal trampolines. */
- /* Under NetBSD/alpha, signal handler invocations can be identified by the
- designated code sequence that is used to return from a signal handler.
- In particular, the return address of a signal handler points to the
- following code sequence:
- ldq a0, 0(sp)
- lda sp, 16(sp)
- lda v0, 295(zero) # __sigreturn14
- call_pal callsys
- Each instruction has a unique encoding, so we simply attempt to match
- the instruction the PC is pointing to with any of the above instructions.
- If there is a hit, we know the offset to the start of the designated
- sequence and can then check whether we really are executing in the
- signal trampoline. If not, -1 is returned, otherwise the offset from the
- start of the return sequence is returned. */
- static const gdb_byte sigtramp_retcode[] =
- {
- 0x00, 0x00, 0x1e, 0xa6, /* ldq a0, 0(sp) */
- 0x10, 0x00, 0xde, 0x23, /* lda sp, 16(sp) */
- 0x27, 0x01, 0x1f, 0x20, /* lda v0, 295(zero) */
- 0x83, 0x00, 0x00, 0x00, /* call_pal callsys */
- };
- #define RETCODE_NWORDS 4
- #define RETCODE_SIZE (RETCODE_NWORDS * 4)
- static LONGEST
- alphanbsd_sigtramp_offset (struct gdbarch *gdbarch, CORE_ADDR pc)
- {
- gdb_byte ret[RETCODE_SIZE], w[4];
- LONGEST off;
- int i;
- if (target_read_memory (pc, w, 4) != 0)
- return -1;
- for (i = 0; i < RETCODE_NWORDS; i++)
- {
- if (memcmp (w, sigtramp_retcode + (i * 4), 4) == 0)
- break;
- }
- if (i == RETCODE_NWORDS)
- return (-1);
- off = i * 4;
- pc -= off;
- if (target_read_memory (pc, ret, sizeof (ret)) != 0)
- return -1;
- if (memcmp (ret, sigtramp_retcode, RETCODE_SIZE) == 0)
- return off;
- return -1;
- }
- static int
- alphanbsd_pc_in_sigtramp (struct gdbarch *gdbarch,
- CORE_ADDR pc, const char *func_name)
- {
- return (nbsd_pc_in_sigtramp (pc, func_name)
- || alphanbsd_sigtramp_offset (gdbarch, pc) >= 0);
- }
- static CORE_ADDR
- alphanbsd_sigcontext_addr (struct frame_info *frame)
- {
- /* FIXME: This is not correct for all versions of NetBSD/alpha.
- We will probably need to disassemble the trampoline to figure
- out which trampoline frame type we have. */
- if (!get_next_frame (frame))
- return 0;
- return get_frame_base (get_next_frame (frame));
- }
- static void
- alphanbsd_init_abi (struct gdbarch_info info,
- struct gdbarch *gdbarch)
- {
- alpha_gdbarch_tdep *tdep = (alpha_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- /* Hook into the DWARF CFI frame unwinder. */
- alpha_dwarf2_init_abi (info, gdbarch);
- /* Hook into the MDEBUG frame unwinder. */
- alpha_mdebug_init_abi (info, gdbarch);
- nbsd_init_abi (info, gdbarch);
- /* NetBSD/alpha does not provide single step support via ptrace(2); we
- must use software single-stepping. */
- set_gdbarch_software_single_step (gdbarch, alpha_software_single_step);
- /* NetBSD/alpha has SVR4-style shared libraries. */
- set_solib_svr4_fetch_link_map_offsets
- (gdbarch, svr4_lp64_fetch_link_map_offsets);
- tdep->dynamic_sigtramp_offset = alphanbsd_sigtramp_offset;
- tdep->pc_in_sigtramp = alphanbsd_pc_in_sigtramp;
- tdep->sigcontext_addr = alphanbsd_sigcontext_addr;
- tdep->jb_pc = 2;
- tdep->jb_elt_size = 8;
- set_gdbarch_iterate_over_regset_sections
- (gdbarch, alphanbsd_iterate_over_regset_sections);
- }
- void _initialize_alphanbsd_tdep ();
- void
- _initialize_alphanbsd_tdep ()
- {
- /* Even though NetBSD/alpha used ELF since day one, it used the
- traditional a.out-style core dump format before NetBSD 1.6, but
- we don't support those. */
- gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_NETBSD,
- alphanbsd_init_abi);
- }
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