255 lines
7.2 KiB
C
255 lines
7.2 KiB
C
/* Target-dependent code for OpenBSD/sparc.
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Copyright (C) 2004-2017 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 "floatformat.h"
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#include "frame.h"
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#include "frame-unwind.h"
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#include "gdbcore.h"
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#include "osabi.h"
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#include "regcache.h"
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#include "symtab.h"
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#include "trad-frame.h"
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#include "obsd-tdep.h"
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#include "sparc-tdep.h"
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#include "solib-svr4.h"
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#include "bsd-uthread.h"
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/* Signal trampolines. */
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/* The OpenBSD kernel maps the signal trampoline at some random
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location in user space, which means that the traditional BSD way of
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detecting it won't work.
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The signal trampoline will be mapped at an address that is page
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aligned. We recognize the signal trampoline by looking for the
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sigreturn system call. */
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static const int sparc32obsd_page_size = 4096;
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static int
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sparc32obsd_pc_in_sigtramp (CORE_ADDR pc, const char *name)
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{
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CORE_ADDR start_pc = (pc & ~(sparc32obsd_page_size - 1));
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unsigned long insn;
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if (name)
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return 0;
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/* Check for "restore %g0, SYS_sigreturn, %g1". */
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insn = sparc_fetch_instruction (start_pc + 0xec);
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if (insn != 0x83e82067)
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return 0;
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/* Check for "t ST_SYSCALL". */
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insn = sparc_fetch_instruction (start_pc + 0xf4);
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if (insn != 0x91d02000)
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return 0;
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return 1;
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}
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static struct sparc_frame_cache *
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sparc32obsd_sigtramp_frame_cache (struct frame_info *this_frame,
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void **this_cache)
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{
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struct sparc_frame_cache *cache;
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CORE_ADDR addr;
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if (*this_cache)
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return (struct sparc_frame_cache *) *this_cache;
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cache = sparc_frame_cache (this_frame, this_cache);
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gdb_assert (cache == *this_cache);
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/* If we couldn't find the frame's function, we're probably dealing
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with an on-stack signal trampoline. */
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if (cache->pc == 0)
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{
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cache->pc = get_frame_pc (this_frame);
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cache->pc &= ~(sparc32obsd_page_size - 1);
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/* Since we couldn't find the frame's function, the cache was
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initialized under the assumption that we're frameless. */
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sparc_record_save_insn (cache);
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addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM);
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cache->base = addr;
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}
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cache->saved_regs = sparc32nbsd_sigcontext_saved_regs (this_frame);
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return cache;
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}
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static void
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sparc32obsd_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 sparc_frame_cache *cache =
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sparc32obsd_sigtramp_frame_cache (this_frame, this_cache);
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(*this_id) = frame_id_build (cache->base, cache->pc);
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}
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static struct value *
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sparc32obsd_sigtramp_frame_prev_register (struct frame_info *this_frame,
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void **this_cache, int regnum)
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{
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struct sparc_frame_cache *cache =
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sparc32obsd_sigtramp_frame_cache (this_frame, this_cache);
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return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum);
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}
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static int
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sparc32obsd_sigtramp_frame_sniffer (const struct frame_unwind *self,
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struct frame_info *this_frame,
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void **this_cache)
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{
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CORE_ADDR pc = get_frame_pc (this_frame);
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const char *name;
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find_pc_partial_function (pc, &name, NULL, NULL);
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if (sparc32obsd_pc_in_sigtramp (pc, name))
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return 1;
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return 0;
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}
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static const struct frame_unwind sparc32obsd_sigtramp_frame_unwind =
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{
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SIGTRAMP_FRAME,
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default_frame_unwind_stop_reason,
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sparc32obsd_sigtramp_frame_this_id,
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sparc32obsd_sigtramp_frame_prev_register,
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NULL,
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sparc32obsd_sigtramp_frame_sniffer
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};
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/* Offset wthin the thread structure where we can find %fp and %i7. */
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#define SPARC32OBSD_UTHREAD_FP_OFFSET 128
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#define SPARC32OBSD_UTHREAD_PC_OFFSET 132
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static void
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sparc32obsd_supply_uthread (struct regcache *regcache,
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int regnum, CORE_ADDR addr)
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{
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struct gdbarch *gdbarch = get_regcache_arch (regcache);
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enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
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CORE_ADDR fp, fp_addr = addr + SPARC32OBSD_UTHREAD_FP_OFFSET;
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gdb_byte buf[4];
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gdb_assert (regnum >= -1);
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fp = read_memory_unsigned_integer (fp_addr, 4, byte_order);
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if (regnum == SPARC_SP_REGNUM || regnum == -1)
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{
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store_unsigned_integer (buf, 4, byte_order, fp);
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regcache_raw_supply (regcache, SPARC_SP_REGNUM, buf);
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if (regnum == SPARC_SP_REGNUM)
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return;
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}
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if (regnum == SPARC32_PC_REGNUM || regnum == SPARC32_NPC_REGNUM
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|| regnum == -1)
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{
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CORE_ADDR i7, i7_addr = addr + SPARC32OBSD_UTHREAD_PC_OFFSET;
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i7 = read_memory_unsigned_integer (i7_addr, 4, byte_order);
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if (regnum == SPARC32_PC_REGNUM || regnum == -1)
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{
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store_unsigned_integer (buf, 4, byte_order, i7 + 8);
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regcache_raw_supply (regcache, SPARC32_PC_REGNUM, buf);
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}
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if (regnum == SPARC32_NPC_REGNUM || regnum == -1)
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{
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store_unsigned_integer (buf, 4, byte_order, i7 + 12);
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regcache_raw_supply (regcache, SPARC32_NPC_REGNUM, buf);
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}
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if (regnum == SPARC32_PC_REGNUM || regnum == SPARC32_NPC_REGNUM)
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return;
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}
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sparc_supply_rwindow (regcache, fp, regnum);
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}
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static void
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sparc32obsd_collect_uthread(const struct regcache *regcache,
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int regnum, CORE_ADDR addr)
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{
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struct gdbarch *gdbarch = get_regcache_arch (regcache);
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enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
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CORE_ADDR sp;
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gdb_byte buf[4];
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gdb_assert (regnum >= -1);
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if (regnum == SPARC_SP_REGNUM || regnum == -1)
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{
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CORE_ADDR fp_addr = addr + SPARC32OBSD_UTHREAD_FP_OFFSET;
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regcache_raw_collect (regcache, SPARC_SP_REGNUM, buf);
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write_memory (fp_addr,buf, 4);
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}
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if (regnum == SPARC32_PC_REGNUM || regnum == -1)
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{
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CORE_ADDR i7, i7_addr = addr + SPARC32OBSD_UTHREAD_PC_OFFSET;
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regcache_raw_collect (regcache, SPARC32_PC_REGNUM, buf);
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i7 = extract_unsigned_integer (buf, 4, byte_order) - 8;
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write_memory_unsigned_integer (i7_addr, 4, byte_order, i7);
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if (regnum == SPARC32_PC_REGNUM)
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return;
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}
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regcache_raw_collect (regcache, SPARC_SP_REGNUM, buf);
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sp = extract_unsigned_integer (buf, 4, byte_order);
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sparc_collect_rwindow (regcache, sp, regnum);
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}
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static void
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sparc32obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
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{
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/* OpenBSD/sparc is very similar to NetBSD/sparc ELF. */
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sparc32nbsd_init_abi (info, gdbarch);
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set_gdbarch_skip_solib_resolver (gdbarch, obsd_skip_solib_resolver);
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frame_unwind_append_unwinder (gdbarch, &sparc32obsd_sigtramp_frame_unwind);
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/* OpenBSD provides a user-level threads implementation. */
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bsd_uthread_set_supply_uthread (gdbarch, sparc32obsd_supply_uthread);
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bsd_uthread_set_collect_uthread (gdbarch, sparc32obsd_collect_uthread);
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}
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void
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_initialize_sparc32obsd_tdep (void)
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{
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gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_OPENBSD,
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sparc32obsd_init_abi);
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}
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