| 1 | /* Target-dependent code for NetBSD/arm. |
| 2 | |
| 3 | Copyright (C) 2002-2020 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 | #include "osabi.h" |
| 22 | |
| 23 | #include "arch/arm.h" |
| 24 | #include "arm-nbsd-tdep.h" |
| 25 | #include "arm-tdep.h" |
| 26 | #include "regset.h" |
| 27 | #include "solib-svr4.h" |
| 28 | |
| 29 | /* Description of the longjmp buffer. */ |
| 30 | #define ARM_NBSD_JB_PC 24 |
| 31 | #define ARM_NBSD_JB_ELEMENT_SIZE ARM_INT_REGISTER_SIZE |
| 32 | |
| 33 | /* For compatibility with previous implementations of GDB on arm/NetBSD, |
| 34 | override the default little-endian breakpoint. */ |
| 35 | static const gdb_byte arm_nbsd_arm_le_breakpoint[] = {0x11, 0x00, 0x00, 0xe6}; |
| 36 | static const gdb_byte arm_nbsd_arm_be_breakpoint[] = {0xe6, 0x00, 0x00, 0x11}; |
| 37 | static const gdb_byte arm_nbsd_thumb_le_breakpoint[] = {0xfe, 0xde}; |
| 38 | static const gdb_byte arm_nbsd_thumb_be_breakpoint[] = {0xde, 0xfe}; |
| 39 | |
| 40 | /* This matches struct reg from NetBSD's sys/arch/arm/include/reg.h: |
| 41 | https://github.com/NetBSD/src/blob/7c13e6e6773bb171f4ed3ed53013e9d24b3c1eac/sys/arch/arm/include/reg.h#L39 |
| 42 | */ |
| 43 | struct arm_nbsd_reg |
| 44 | { |
| 45 | uint32_t reg[13]; |
| 46 | uint32_t sp; |
| 47 | uint32_t lr; |
| 48 | uint32_t pc; |
| 49 | uint32_t cpsr; |
| 50 | }; |
| 51 | |
| 52 | void |
| 53 | arm_nbsd_supply_gregset (const struct regset *regset, struct regcache *regcache, |
| 54 | int regnum, const void *gregs, size_t len) |
| 55 | { |
| 56 | const arm_nbsd_reg *gregset = static_cast<const arm_nbsd_reg *>(gregs); |
| 57 | gdb_assert (len >= sizeof (arm_nbsd_reg)); |
| 58 | |
| 59 | /* Integer registers. */ |
| 60 | for (int i = ARM_A1_REGNUM; i < ARM_SP_REGNUM; i++) |
| 61 | if (regnum == -1 || regnum == i) |
| 62 | regcache->raw_supply (i, (char *) &gregset->reg[i]); |
| 63 | |
| 64 | if (regnum == -1 || regnum == ARM_SP_REGNUM) |
| 65 | regcache->raw_supply (ARM_SP_REGNUM, (char *) &gregset->sp); |
| 66 | |
| 67 | if (regnum == -1 || regnum == ARM_LR_REGNUM) |
| 68 | regcache->raw_supply (ARM_LR_REGNUM, (char *) &gregset->lr); |
| 69 | |
| 70 | if (regnum == -1 || regnum == ARM_PC_REGNUM) |
| 71 | { |
| 72 | CORE_ADDR r_pc = gdbarch_addr_bits_remove (regcache->arch (), gregset->pc); |
| 73 | regcache->raw_supply (ARM_PC_REGNUM, (char *) &r_pc); |
| 74 | } |
| 75 | |
| 76 | if (regnum == -1 || regnum == ARM_PS_REGNUM) |
| 77 | { |
| 78 | if (arm_apcs_32) |
| 79 | regcache->raw_supply (ARM_PS_REGNUM, (char *) &gregset->cpsr); |
| 80 | else |
| 81 | regcache->raw_supply (ARM_PS_REGNUM, (char *) &gregset->pc); |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | static const struct regset arm_nbsd_regset = { |
| 86 | nullptr, |
| 87 | arm_nbsd_supply_gregset, |
| 88 | /* We don't need a collect function because we only use this reading registers |
| 89 | (via iterate_over_regset_sections and fetch_regs/fetch_register). */ |
| 90 | nullptr, |
| 91 | 0 |
| 92 | }; |
| 93 | |
| 94 | static void |
| 95 | arm_nbsd_iterate_over_regset_sections (struct gdbarch *gdbarch, |
| 96 | iterate_over_regset_sections_cb *cb, |
| 97 | void *cb_data, |
| 98 | const struct regcache *regcache) |
| 99 | { |
| 100 | cb (".reg", sizeof (arm_nbsd_reg), sizeof (arm_nbsd_reg), &arm_nbsd_regset, |
| 101 | NULL, cb_data); |
| 102 | /* cbiesinger/2020-02-12 -- as far as I can tell, ARM/NetBSD does |
| 103 | not write any floating point registers into the core file (tested |
| 104 | with NetBSD 9.1_RC1). When it does, this function will need to read them, |
| 105 | and the arm-netbsd gdbarch will need a core_read_description function |
| 106 | to return the right description for them. */ |
| 107 | } |
| 108 | |
| 109 | static void |
| 110 | arm_netbsd_init_abi_common (struct gdbarch_info info, |
| 111 | struct gdbarch *gdbarch) |
| 112 | { |
| 113 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 114 | |
| 115 | tdep->lowest_pc = 0x8000; |
| 116 | switch (info.byte_order) |
| 117 | { |
| 118 | case BFD_ENDIAN_LITTLE: |
| 119 | tdep->arm_breakpoint = arm_nbsd_arm_le_breakpoint; |
| 120 | tdep->thumb_breakpoint = arm_nbsd_thumb_le_breakpoint; |
| 121 | tdep->arm_breakpoint_size = sizeof (arm_nbsd_arm_le_breakpoint); |
| 122 | tdep->thumb_breakpoint_size = sizeof (arm_nbsd_thumb_le_breakpoint); |
| 123 | break; |
| 124 | |
| 125 | case BFD_ENDIAN_BIG: |
| 126 | tdep->arm_breakpoint = arm_nbsd_arm_be_breakpoint; |
| 127 | tdep->thumb_breakpoint = arm_nbsd_thumb_be_breakpoint; |
| 128 | tdep->arm_breakpoint_size = sizeof (arm_nbsd_arm_be_breakpoint); |
| 129 | tdep->thumb_breakpoint_size = sizeof (arm_nbsd_thumb_be_breakpoint); |
| 130 | break; |
| 131 | |
| 132 | default: |
| 133 | internal_error (__FILE__, __LINE__, |
| 134 | _("arm_gdbarch_init: bad byte order for float format")); |
| 135 | } |
| 136 | |
| 137 | tdep->jb_pc = ARM_NBSD_JB_PC; |
| 138 | tdep->jb_elt_size = ARM_NBSD_JB_ELEMENT_SIZE; |
| 139 | |
| 140 | set_gdbarch_iterate_over_regset_sections |
| 141 | (gdbarch, arm_nbsd_iterate_over_regset_sections); |
| 142 | /* Single stepping. */ |
| 143 | set_gdbarch_software_single_step (gdbarch, arm_software_single_step); |
| 144 | } |
| 145 | |
| 146 | static void |
| 147 | arm_netbsd_elf_init_abi (struct gdbarch_info info, |
| 148 | struct gdbarch *gdbarch) |
| 149 | { |
| 150 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 151 | |
| 152 | arm_netbsd_init_abi_common (info, gdbarch); |
| 153 | if (tdep->fp_model == ARM_FLOAT_AUTO) |
| 154 | tdep->fp_model = ARM_FLOAT_SOFT_VFP; |
| 155 | |
| 156 | /* NetBSD ELF uses SVR4-style shared libraries. */ |
| 157 | set_solib_svr4_fetch_link_map_offsets |
| 158 | (gdbarch, svr4_ilp32_fetch_link_map_offsets); |
| 159 | } |
| 160 | |
| 161 | void _initialize_arm_netbsd_tdep (); |
| 162 | void |
| 163 | _initialize_arm_netbsd_tdep () |
| 164 | { |
| 165 | gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_NETBSD, |
| 166 | arm_netbsd_elf_init_abi); |
| 167 | } |