nios2-linux-tdep.c revision 1.1
1/* Target-dependent code for GNU/Linux on Nios II. 2 Copyright (C) 2012-2014 Free Software Foundation, Inc. 3 Contributed by Mentor Graphics, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20#include "defs.h" 21#include "frame.h" 22#include "gdb_assert.h" 23#include <string.h> 24#include "osabi.h" 25#include "solib-svr4.h" 26#include "trad-frame.h" 27#include "tramp-frame.h" 28#include "symtab.h" 29#include "regset.h" 30#include "regcache.h" 31#include "linux-tdep.h" 32#include "glibc-tdep.h" 33#include "nios2-tdep.h" 34 35#include "features/nios2-linux.c" 36 37/* Core file and register set support. */ 38 39/* Map from the normal register enumeration order to the order that 40 registers appear in core files, which corresponds to the order 41 of the register slots in the kernel's struct pt_regs. */ 42 43static const int reg_offsets[NIOS2_NUM_REGS] = 44{ 45 -1, 8, 9, 10, 11, 12, 13, 14, /* r0 - r7 */ 46 0, 1, 2, 3, 4, 5, 6, 7, /* r8 - r15 */ 47 23, 24, 25, 26, 27, 28, 29, 30, /* r16 - r23 */ 48 -1, -1, 19, 18, 17, 21, -1, 16, /* et bt gp sp fp ea sstatus ra */ 49 21, /* pc */ 50 -1, 20, -1, -1, -1, -1, -1, -1, /* status estatus ... */ 51 -1, -1, -1, -1, -1, -1, -1, -1 52}; 53 54/* Implement the supply_regset hook for core files. */ 55 56static void 57nios2_supply_gregset (const struct regset *regset, 58 struct regcache *regcache, 59 int regnum, const void *gregs_buf, size_t len) 60{ 61 const gdb_byte *gregs = gregs_buf; 62 int regno; 63 static const gdb_byte zero_buf[4] = {0, 0, 0, 0}; 64 65 for (regno = NIOS2_Z_REGNUM; regno <= NIOS2_MPUACC_REGNUM; regno++) 66 if (regnum == -1 || regnum == regno) 67 { 68 if (reg_offsets[regno] != -1) 69 regcache_raw_supply (regcache, regno, 70 gregs + 4 * reg_offsets[regno]); 71 else 72 regcache_raw_supply (regcache, regno, zero_buf); 73 } 74} 75 76static struct regset nios2_core_regset = 77{ 78 NULL, 79 nios2_supply_gregset, 80 NULL, 81 NULL 82}; 83 84/* Implement the regset_from_core_section gdbarch method. */ 85 86static const struct regset * 87nios2_regset_from_core_section (struct gdbarch *gdbarch, 88 const char *sect_name, size_t sect_size) 89{ 90 if (strcmp (sect_name, ".reg") == 0) 91 return &nios2_core_regset; 92 93 return NULL; 94} 95 96/* Initialize a trad-frame cache corresponding to the tramp-frame. 97 FUNC is the address of the instruction TRAMP[0] in memory. */ 98 99static void 100nios2_linux_rt_sigreturn_init (const struct tramp_frame *self, 101 struct frame_info *next_frame, 102 struct trad_frame_cache *this_cache, 103 CORE_ADDR func) 104{ 105 CORE_ADDR base = func + 41 * 4; 106 int i; 107 108 for (i = 0; i < 23; i++) 109 trad_frame_set_reg_addr (this_cache, i + 1, base + i * 4); 110 trad_frame_set_reg_addr (this_cache, NIOS2_RA_REGNUM, base + 23 * 4); 111 trad_frame_set_reg_addr (this_cache, NIOS2_FP_REGNUM, base + 24 * 4); 112 trad_frame_set_reg_addr (this_cache, NIOS2_GP_REGNUM, base + 25 * 4); 113 trad_frame_set_reg_addr (this_cache, NIOS2_PC_REGNUM, base + 27 * 4); 114 trad_frame_set_reg_addr (this_cache, NIOS2_SP_REGNUM, base + 28 * 4); 115 116 /* Save a frame ID. */ 117 trad_frame_set_id (this_cache, frame_id_build (base, func)); 118} 119 120static struct tramp_frame nios2_linux_rt_sigreturn_tramp_frame = 121{ 122 SIGTRAMP_FRAME, 123 4, 124 { 125 { 0x00800004 | (139 << 6), -1 }, /* movi r2,__NR_rt_sigreturn */ 126 { 0x003b683a, -1 }, /* trap */ 127 { TRAMP_SENTINEL_INSN } 128 }, 129 nios2_linux_rt_sigreturn_init 130}; 131 132/* When FRAME is at a syscall instruction, return the PC of the next 133 instruction to be executed. */ 134 135static CORE_ADDR 136nios2_linux_syscall_next_pc (struct frame_info *frame) 137{ 138 CORE_ADDR pc = get_frame_pc (frame); 139 ULONGEST syscall_nr = get_frame_register_unsigned (frame, NIOS2_R2_REGNUM); 140 141 /* If we are about to make a sigreturn syscall, use the unwinder to 142 decode the signal frame. */ 143 if (syscall_nr == 139 /* rt_sigreturn */) 144 return frame_unwind_caller_pc (frame); 145 146 return pc + NIOS2_OPCODE_SIZE; 147} 148 149/* Hook function for gdbarch_register_osabi. */ 150 151static void 152nios2_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) 153{ 154 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 155 156 linux_init_abi (info, gdbarch); 157 158 /* Shared library handling. */ 159 set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); 160 set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver); 161 162 set_solib_svr4_fetch_link_map_offsets (gdbarch, 163 svr4_ilp32_fetch_link_map_offsets); 164 /* Enable TLS support. */ 165 set_gdbarch_fetch_tls_load_module_address (gdbarch, 166 svr4_fetch_objfile_link_map); 167 /* Core file support. */ 168 set_gdbarch_regset_from_core_section (gdbarch, 169 nios2_regset_from_core_section); 170 /* Linux signal frame unwinders. */ 171 tramp_frame_prepend_unwinder (gdbarch, 172 &nios2_linux_rt_sigreturn_tramp_frame); 173 174 tdep->syscall_next_pc = nios2_linux_syscall_next_pc; 175 176 /* Index of target address word in glibc jmp_buf. */ 177 tdep->jb_pc = 10; 178} 179 180/* Provide a prototype to silence -Wmissing-prototypes. */ 181 182extern initialize_file_ftype _initialize_nios2_linux_tdep; 183 184void 185_initialize_nios2_linux_tdep (void) 186{ 187 gdbarch_register_osabi (bfd_arch_nios2, 0, GDB_OSABI_LINUX, 188 nios2_linux_init_abi); 189 190 initialize_tdesc_nios2_linux (); 191} 192