| 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 | |
| 43 | static 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 | |
| 56 | static void |
| 57 | nios2_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 | |
| 76 | static 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 | |
| 86 | static const struct regset * |
| 87 | nios2_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 | |
| 99 | static void |
| 100 | nios2_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 | |
| 120 | static 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 | |
| 135 | static CORE_ADDR |
| 136 | nios2_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 | |
| 151 | static void |
| 152 | nios2_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 | |
| 182 | extern initialize_file_ftype _initialize_nios2_linux_tdep; |
| 183 | |
| 184 | void |
| 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 | } |