1 /* Target-dependent code for FreeBSD/arm. 2 3 Copyright (C) 2017-2020 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 "target-descriptions.h" 24 #include "aarch32-tdep.h" 25 #include "arm-tdep.h" 26 #include "arm-fbsd-tdep.h" 27 #include "auxv.h" 28 #include "fbsd-tdep.h" 29 #include "gdbcore.h" 30 #include "osabi.h" 31 #include "solib-svr4.h" 32 #include "trad-frame.h" 33 #include "tramp-frame.h" 34 35 /* Register maps. */ 36 37 static const struct regcache_map_entry arm_fbsd_gregmap[] = 38 { 39 { 13, ARM_A1_REGNUM, 4 }, /* r0 ... r12 */ 40 { 1, ARM_SP_REGNUM, 4 }, 41 { 1, ARM_LR_REGNUM, 4 }, 42 { 1, ARM_PC_REGNUM, 4 }, 43 { 1, ARM_PS_REGNUM, 4 }, 44 { 0 } 45 }; 46 47 static const struct regcache_map_entry arm_fbsd_vfpregmap[] = 48 { 49 { 32, ARM_D0_REGNUM, 8 }, /* d0 ... d31 */ 50 { 1, ARM_FPSCR_REGNUM, 4 }, 51 { 0 } 52 }; 53 54 /* In a signal frame, sp points to a 'struct sigframe' which is 55 defined as: 56 57 struct sigframe { 58 siginfo_t sf_si; 59 ucontext_t sf_uc; 60 mcontext_vfp_t sf_vfp; 61 }; 62 63 ucontext_t is defined as: 64 65 struct __ucontext { 66 sigset_t uc_sigmask; 67 mcontext_t uc_mcontext; 68 ... 69 }; 70 71 mcontext_t is defined as: 72 73 struct { 74 unsigned int __gregs[17]; 75 size_t mc_vfp_size; 76 void *mc_vfp_ptr; 77 ... 78 }; 79 80 mcontext_vfp_t is defined as: 81 82 struct { 83 uint64_t mcv_reg[32]; 84 uint32_t mcv_fpscr; 85 }; 86 87 If the VFP state is valid, then mc_vfp_ptr will point to sf_vfp in 88 the sigframe, otherwise it is NULL. There is no non-VFP floating 89 point register state saved in the signal frame. */ 90 91 #define ARM_SIGFRAME_UCONTEXT_OFFSET 64 92 #define ARM_UCONTEXT_MCONTEXT_OFFSET 16 93 #define ARM_MCONTEXT_VFP_PTR_OFFSET 72 94 95 /* Implement the "init" method of struct tramp_frame. */ 96 97 static void 98 arm_fbsd_sigframe_init (const struct tramp_frame *self, 99 struct frame_info *this_frame, 100 struct trad_frame_cache *this_cache, 101 CORE_ADDR func) 102 { 103 struct gdbarch *gdbarch = get_frame_arch (this_frame); 104 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); 105 CORE_ADDR sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM); 106 CORE_ADDR mcontext_addr = (sp 107 + ARM_SIGFRAME_UCONTEXT_OFFSET 108 + ARM_UCONTEXT_MCONTEXT_OFFSET); 109 ULONGEST mcontext_vfp_addr; 110 111 trad_frame_set_reg_regmap (this_cache, arm_fbsd_gregmap, mcontext_addr, 112 regcache_map_entry_size (arm_fbsd_gregmap)); 113 114 if (safe_read_memory_unsigned_integer (mcontext_addr 115 + ARM_MCONTEXT_VFP_PTR_OFFSET, 4, 116 byte_order, 117 &mcontext_vfp_addr) 118 && mcontext_vfp_addr != 0) 119 trad_frame_set_reg_regmap (this_cache, arm_fbsd_vfpregmap, mcontext_vfp_addr, 120 regcache_map_entry_size (arm_fbsd_vfpregmap)); 121 122 trad_frame_set_id (this_cache, frame_id_build (sp, func)); 123 } 124 125 static const struct tramp_frame arm_fbsd_sigframe = 126 { 127 SIGTRAMP_FRAME, 128 4, 129 { 130 {0xe1a0000d, ULONGEST_MAX}, /* mov r0, sp */ 131 {0xe2800040, ULONGEST_MAX}, /* add r0, r0, #SIGF_UC */ 132 {0xe59f700c, ULONGEST_MAX}, /* ldr r7, [pc, #12] */ 133 {0xef0001a1, ULONGEST_MAX}, /* swi SYS_sigreturn */ 134 {TRAMP_SENTINEL_INSN, ULONGEST_MAX} 135 }, 136 arm_fbsd_sigframe_init 137 }; 138 139 /* Register set definitions. */ 140 141 const struct regset arm_fbsd_gregset = 142 { 143 arm_fbsd_gregmap, 144 regcache_supply_regset, regcache_collect_regset 145 }; 146 147 const struct regset arm_fbsd_vfpregset = 148 { 149 arm_fbsd_vfpregmap, 150 regcache_supply_regset, regcache_collect_regset 151 }; 152 153 /* Implement the "iterate_over_regset_sections" gdbarch method. */ 154 155 static void 156 arm_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch, 157 iterate_over_regset_sections_cb *cb, 158 void *cb_data, 159 const struct regcache *regcache) 160 { 161 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 162 163 cb (".reg", ARM_FBSD_SIZEOF_GREGSET, ARM_FBSD_SIZEOF_GREGSET, 164 &arm_fbsd_gregset, NULL, cb_data); 165 166 /* While FreeBSD/arm cores do contain a NT_FPREGSET / ".reg2" 167 register set, it is not populated with register values by the 168 kernel but just contains all zeroes. */ 169 if (tdep->vfp_register_count > 0) 170 cb (".reg-arm-vfp", ARM_FBSD_SIZEOF_VFPREGSET, ARM_FBSD_SIZEOF_VFPREGSET, 171 &arm_fbsd_vfpregset, "VFP floating-point", cb_data); 172 } 173 174 /* Lookup a target description from a target's AT_HWCAP auxiliary 175 vector. */ 176 177 const struct target_desc * 178 arm_fbsd_read_description_auxv (struct target_ops *target) 179 { 180 CORE_ADDR arm_hwcap = 0; 181 182 if (target_auxv_search (target, AT_FREEBSD_HWCAP, &arm_hwcap) != 1) 183 return nullptr; 184 185 if (arm_hwcap & HWCAP_VFP) 186 { 187 if (arm_hwcap & HWCAP_NEON) 188 return aarch32_read_description (); 189 else if ((arm_hwcap & (HWCAP_VFPv3 | HWCAP_VFPD32)) 190 == (HWCAP_VFPv3 | HWCAP_VFPD32)) 191 return arm_read_description (ARM_FP_TYPE_VFPV3); 192 else 193 return arm_read_description (ARM_FP_TYPE_VFPV2); 194 } 195 196 return nullptr; 197 } 198 199 /* Implement the "core_read_description" gdbarch method. */ 200 201 static const struct target_desc * 202 arm_fbsd_core_read_description (struct gdbarch *gdbarch, 203 struct target_ops *target, 204 bfd *abfd) 205 { 206 return arm_fbsd_read_description_auxv (target); 207 } 208 209 /* Implement the 'init_osabi' method of struct gdb_osabi_handler. */ 210 211 static void 212 arm_fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) 213 { 214 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 215 216 /* Generic FreeBSD support. */ 217 fbsd_init_abi (info, gdbarch); 218 219 if (tdep->fp_model == ARM_FLOAT_AUTO) 220 tdep->fp_model = ARM_FLOAT_SOFT_VFP; 221 222 tramp_frame_prepend_unwinder (gdbarch, &arm_fbsd_sigframe); 223 224 set_solib_svr4_fetch_link_map_offsets 225 (gdbarch, svr4_ilp32_fetch_link_map_offsets); 226 227 tdep->jb_pc = 24; 228 tdep->jb_elt_size = 4; 229 230 set_gdbarch_iterate_over_regset_sections 231 (gdbarch, arm_fbsd_iterate_over_regset_sections); 232 set_gdbarch_core_read_description (gdbarch, arm_fbsd_core_read_description); 233 234 /* Single stepping. */ 235 set_gdbarch_software_single_step (gdbarch, arm_software_single_step); 236 } 237 238 void _initialize_arm_fbsd_tdep (); 239 void 240 _initialize_arm_fbsd_tdep () 241 { 242 gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_FREEBSD, 243 arm_fbsd_init_abi); 244 } 245