1 /* Target-dependent code for FreeBSD/arm. 2 3 Copyright (C) 2017-2019 Free Software Foundation, 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 22 #include "elf/common.h" 23 #include "arm-tdep.h" 24 #include "arm-fbsd-tdep.h" 25 #include "auxv.h" 26 #include "fbsd-tdep.h" 27 #include "gdbcore.h" 28 #include "osabi.h" 29 #include "solib-svr4.h" 30 #include "trad-frame.h" 31 #include "tramp-frame.h" 32 33 /* Register maps. */ 34 35 static const struct regcache_map_entry arm_fbsd_gregmap[] = 36 { 37 { 13, ARM_A1_REGNUM, 4 }, /* r0 ... r12 */ 38 { 1, ARM_SP_REGNUM, 4 }, 39 { 1, ARM_LR_REGNUM, 4 }, 40 { 1, ARM_PC_REGNUM, 4 }, 41 { 1, ARM_PS_REGNUM, 4 }, 42 { 0 } 43 }; 44 45 static const struct regcache_map_entry arm_fbsd_vfpregmap[] = 46 { 47 { 32, ARM_D0_REGNUM, 8 }, /* d0 ... d31 */ 48 { 1, ARM_FPSCR_REGNUM, 4 }, 49 { 0 } 50 }; 51 52 /* In a signal frame, sp points to a 'struct sigframe' which is 53 defined as: 54 55 struct sigframe { 56 siginfo_t sf_si; 57 ucontext_t sf_uc; 58 mcontext_vfp_t sf_vfp; 59 }; 60 61 ucontext_t is defined as: 62 63 struct __ucontext { 64 sigset_t uc_sigmask; 65 mcontext_t uc_mcontext; 66 ... 67 }; 68 69 mcontext_t is defined as: 70 71 struct { 72 unsigned int __gregs[17]; 73 size_t mc_vfp_size; 74 void *mc_vfp_ptr; 75 ... 76 }; 77 78 mcontext_vfp_t is defined as: 79 80 struct { 81 uint64_t mcv_reg[32]; 82 uint32_t mcv_fpscr; 83 }; 84 85 If the VFP state is valid, then mc_vfp_ptr will point to sf_vfp in 86 the sigframe, otherwise it is NULL. There is no non-VFP floating 87 point register state saved in the signal frame. */ 88 89 #define ARM_SIGFRAME_UCONTEXT_OFFSET 64 90 #define ARM_UCONTEXT_MCONTEXT_OFFSET 16 91 #define ARM_MCONTEXT_VFP_PTR_OFFSET 72 92 93 /* Implement the "init" method of struct tramp_frame. */ 94 95 static void 96 arm_fbsd_sigframe_init (const struct tramp_frame *self, 97 struct frame_info *this_frame, 98 struct trad_frame_cache *this_cache, 99 CORE_ADDR func) 100 { 101 struct gdbarch *gdbarch = get_frame_arch (this_frame); 102 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); 103 CORE_ADDR sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM); 104 CORE_ADDR mcontext_addr = (sp 105 + ARM_SIGFRAME_UCONTEXT_OFFSET 106 + ARM_UCONTEXT_MCONTEXT_OFFSET); 107 ULONGEST mcontext_vfp_addr; 108 109 trad_frame_set_reg_regmap (this_cache, arm_fbsd_gregmap, mcontext_addr, 110 regcache_map_entry_size (arm_fbsd_gregmap)); 111 112 if (safe_read_memory_unsigned_integer (mcontext_addr 113 + ARM_MCONTEXT_VFP_PTR_OFFSET, 4, 114 byte_order, 115 &mcontext_vfp_addr) 116 && mcontext_vfp_addr != 0) 117 trad_frame_set_reg_regmap (this_cache, arm_fbsd_vfpregmap, mcontext_vfp_addr, 118 regcache_map_entry_size (arm_fbsd_vfpregmap)); 119 120 trad_frame_set_id (this_cache, frame_id_build (sp, func)); 121 } 122 123 static const struct tramp_frame arm_fbsd_sigframe = 124 { 125 SIGTRAMP_FRAME, 126 4, 127 { 128 {0xe1a0000d, ULONGEST_MAX}, /* mov r0, sp */ 129 {0xe2800040, ULONGEST_MAX}, /* add r0, r0, #SIGF_UC */ 130 {0xe59f700c, ULONGEST_MAX}, /* ldr r7, [pc, #12] */ 131 {0xef0001a1, ULONGEST_MAX}, /* swi SYS_sigreturn */ 132 {TRAMP_SENTINEL_INSN, ULONGEST_MAX} 133 }, 134 arm_fbsd_sigframe_init 135 }; 136 137 /* Register set definitions. */ 138 139 const struct regset arm_fbsd_gregset = 140 { 141 arm_fbsd_gregmap, 142 regcache_supply_regset, regcache_collect_regset 143 }; 144 145 const struct regset arm_fbsd_vfpregset = 146 { 147 arm_fbsd_vfpregmap, 148 regcache_supply_regset, regcache_collect_regset 149 }; 150 151 /* Implement the "regset_from_core_section" gdbarch method. */ 152 153 static void 154 arm_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch, 155 iterate_over_regset_sections_cb *cb, 156 void *cb_data, 157 const struct regcache *regcache) 158 { 159 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 160 161 cb (".reg", ARM_FBSD_SIZEOF_GREGSET, ARM_FBSD_SIZEOF_GREGSET, 162 &arm_fbsd_gregset, NULL, cb_data); 163 164 /* While FreeBSD/arm cores do contain a NT_FPREGSET / ".reg2" 165 register set, it is not populated with register values by the 166 kernel but just contains all zeroes. */ 167 if (tdep->vfp_register_count > 0) 168 cb (".reg-arm-vfp", ARM_FBSD_SIZEOF_VFPREGSET, ARM_FBSD_SIZEOF_VFPREGSET, 169 &arm_fbsd_vfpregset, "VFP floating-point", cb_data); 170 } 171 172 /* Lookup a target description from a target's AT_HWCAP auxiliary 173 vector. */ 174 175 const struct target_desc * 176 arm_fbsd_read_description_auxv (struct target_ops *target) 177 { 178 CORE_ADDR arm_hwcap = 0; 179 180 if (target_auxv_search (target, AT_FREEBSD_HWCAP, &arm_hwcap) != 1) 181 return NULL; 182 183 if (arm_hwcap & HWCAP_VFP) 184 { 185 if (arm_hwcap & HWCAP_NEON) 186 return tdesc_arm_with_neon; 187 else if ((arm_hwcap & (HWCAP_VFPv3 | HWCAP_VFPD32)) 188 == (HWCAP_VFPv3 | HWCAP_VFPD32)) 189 return tdesc_arm_with_vfpv3; 190 else 191 return tdesc_arm_with_vfpv2; 192 } 193 194 return NULL; 195 } 196 197 /* Implement the "core_read_description" gdbarch method. */ 198 199 static const struct target_desc * 200 arm_fbsd_core_read_description (struct gdbarch *gdbarch, 201 struct target_ops *target, 202 bfd *abfd) 203 { 204 return arm_fbsd_read_description_auxv (target); 205 } 206 207 /* Implement the 'init_osabi' method of struct gdb_osabi_handler. */ 208 209 static void 210 arm_fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) 211 { 212 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 213 214 /* Generic FreeBSD support. */ 215 fbsd_init_abi (info, gdbarch); 216 217 if (tdep->fp_model == ARM_FLOAT_AUTO) 218 tdep->fp_model = ARM_FLOAT_SOFT_VFP; 219 220 tramp_frame_prepend_unwinder (gdbarch, &arm_fbsd_sigframe); 221 222 set_solib_svr4_fetch_link_map_offsets 223 (gdbarch, svr4_ilp32_fetch_link_map_offsets); 224 225 tdep->jb_pc = 24; 226 tdep->jb_elt_size = 4; 227 228 set_gdbarch_iterate_over_regset_sections 229 (gdbarch, arm_fbsd_iterate_over_regset_sections); 230 set_gdbarch_core_read_description (gdbarch, arm_fbsd_core_read_description); 231 232 /* Single stepping. */ 233 set_gdbarch_software_single_step (gdbarch, arm_software_single_step); 234 } 235 236 void 237 _initialize_arm_fbsd_tdep (void) 238 { 239 gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_FREEBSD, 240 arm_fbsd_init_abi); 241 } 242