| /* GNU/Linux/Nios II specific low level interface, for the remote server for |
| GDB. |
| Copyright (C) 2008-2024 Free Software Foundation, Inc. |
| |
| Contributed by Mentor Graphics, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "linux-low.h" |
| #include "elf/common.h" |
| #include "nat/gdb_ptrace.h" |
| #include <endian.h> |
| #include "gdb_proc_service.h" |
| #include <asm/ptrace.h> |
| |
| #ifndef PTRACE_GET_THREAD_AREA |
| #define PTRACE_GET_THREAD_AREA 25 |
| #endif |
| |
| /* Linux target op definitions for the NIOS II architecture. */ |
| |
| class nios2_target : public linux_process_target |
| { |
| public: |
| |
| const regs_info *get_regs_info () override; |
| |
| const gdb_byte *sw_breakpoint_from_kind (int kind, int *size) override; |
| |
| protected: |
| |
| void low_arch_setup () override; |
| |
| bool low_cannot_fetch_register (int regno) override; |
| |
| bool low_cannot_store_register (int regno) override; |
| |
| bool low_supports_breakpoints () override; |
| |
| CORE_ADDR low_get_pc (regcache *regcache) override; |
| |
| void low_set_pc (regcache *regcache, CORE_ADDR newpc) override; |
| |
| bool low_breakpoint_at (CORE_ADDR pc) override; |
| }; |
| |
| /* The singleton target ops object. */ |
| |
| static nios2_target the_nios2_target; |
| |
| bool |
| nios2_target::low_supports_breakpoints () |
| { |
| return true; |
| } |
| |
| CORE_ADDR |
| nios2_target::low_get_pc (regcache *regcache) |
| { |
| return linux_get_pc_32bit (regcache); |
| } |
| |
| void |
| nios2_target::low_set_pc (regcache *regcache, CORE_ADDR pc) |
| { |
| linux_set_pc_32bit (regcache, pc); |
| } |
| |
| /* The following definition must agree with the number of registers |
| defined in "struct user_regs" in GLIBC |
| (sysdeps/unix/sysv/linux/nios2/sys/user.h), and also with |
| NIOS2_NUM_REGS in GDB proper. */ |
| |
| #define nios2_num_regs 49 |
| |
| /* Defined in auto-generated file nios2-linux.c. */ |
| |
| void init_registers_nios2_linux (void); |
| extern const struct target_desc *tdesc_nios2_linux; |
| |
| /* This union is used to convert between int and byte buffer |
| representations of register contents. */ |
| |
| union nios2_register |
| { |
| unsigned char buf[4]; |
| int reg32; |
| }; |
| |
| /* Return the ptrace ``address'' of register REGNO. */ |
| |
| static int nios2_regmap[] = { |
| -1, 1, 2, 3, 4, 5, 6, 7, |
| 8, 9, 10, 11, 12, 13, 14, 15, |
| 16, 17, 18, 19, 20, 21, 22, 23, |
| 24, 25, 26, 27, 28, 29, 30, 31, |
| 32, 33, 34, 35, 36, 37, 38, 39, |
| 40, 41, 42, 43, 44, 45, 46, 47, |
| 48, |
| 0 |
| }; |
| |
| /* Implement the low_arch_setup linux target ops method. */ |
| |
| void |
| nios2_target::low_arch_setup () |
| { |
| current_process ()->tdesc = tdesc_nios2_linux; |
| } |
| |
| /* Implement the low_cannot_fetch_register linux target ops method. */ |
| |
| bool |
| nios2_target::low_cannot_fetch_register (int regno) |
| { |
| return (nios2_regmap[regno] == -1); |
| } |
| |
| /* Implement the low_cannot_store_register linux target ops method. */ |
| |
| bool |
| nios2_target::low_cannot_store_register (int regno) |
| { |
| return (nios2_regmap[regno] == -1); |
| } |
| |
| /* Breakpoint support. Also see comments on nios2_breakpoint_from_pc |
| in nios2-tdep.c. */ |
| |
| #if defined(__nios2_arch__) && __nios2_arch__ == 2 |
| #define NIOS2_BREAKPOINT 0xb7fd0020 |
| #define CDX_BREAKPOINT 0xd7c9 |
| #else |
| #define NIOS2_BREAKPOINT 0x003b6ffa |
| #endif |
| |
| /* We only register the 4-byte breakpoint, even on R2 targets which also |
| support 2-byte breakpoints. Since there is no supports_z_point_type |
| function provided, gdbserver never inserts software breakpoints itself |
| and instead relies on GDB to insert the breakpoint of the correct length |
| via a memory write. */ |
| static const unsigned int nios2_breakpoint = NIOS2_BREAKPOINT; |
| #define nios2_breakpoint_len 4 |
| |
| /* Implementation of target ops method "sw_breakpoint_from_kind". */ |
| |
| const gdb_byte * |
| nios2_target::sw_breakpoint_from_kind (int kind, int *size) |
| { |
| *size = nios2_breakpoint_len; |
| return (const gdb_byte *) &nios2_breakpoint; |
| } |
| |
| /* Implement the low_breakpoint_at linux target ops method. */ |
| |
| bool |
| nios2_target::low_breakpoint_at (CORE_ADDR where) |
| { |
| unsigned int insn; |
| |
| /* For R2, first check for the 2-byte CDX trap.n breakpoint encoding. */ |
| #if defined(__nios2_arch__) && __nios2_arch__ == 2 |
| read_memory (where, (unsigned char *) &insn, 2); |
| if (insn == CDX_BREAKPOINT) |
| return true; |
| #endif |
| |
| read_memory (where, (unsigned char *) &insn, 4); |
| if (insn == nios2_breakpoint) |
| return true; |
| return false; |
| } |
| |
| /* Fetch the thread-local storage pointer for libthread_db. */ |
| |
| ps_err_e |
| ps_get_thread_area (struct ps_prochandle *ph, |
| lwpid_t lwpid, int idx, void **base) |
| { |
| if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0) |
| return PS_ERR; |
| |
| /* IDX is the bias from the thread pointer to the beginning of the |
| thread descriptor. It has to be subtracted due to implementation |
| quirks in libthread_db. */ |
| *base = (void *) ((char *) *base - idx); |
| |
| return PS_OK; |
| } |
| |
| /* Helper functions to collect/supply a single register REGNO. */ |
| |
| static void |
| nios2_collect_register (struct regcache *regcache, int regno, |
| union nios2_register *reg) |
| { |
| union nios2_register tmp_reg; |
| |
| collect_register (regcache, regno, &tmp_reg.reg32); |
| reg->reg32 = tmp_reg.reg32; |
| } |
| |
| static void |
| nios2_supply_register (struct regcache *regcache, int regno, |
| const union nios2_register *reg) |
| { |
| supply_register (regcache, regno, reg->buf); |
| } |
| |
| /* We have only a single register set on Nios II. */ |
| |
| static void |
| nios2_fill_gregset (struct regcache *regcache, void *buf) |
| { |
| union nios2_register *regset = (union nios2_register *) buf; |
| int i; |
| |
| for (i = 1; i < nios2_num_regs; i++) |
| nios2_collect_register (regcache, i, regset + i); |
| } |
| |
| static void |
| nios2_store_gregset (struct regcache *regcache, const void *buf) |
| { |
| const union nios2_register *regset = (union nios2_register *) buf; |
| int i; |
| |
| for (i = 0; i < nios2_num_regs; i++) |
| nios2_supply_register (regcache, i, regset + i); |
| } |
| |
| static struct regset_info nios2_regsets[] = |
| { |
| { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PRSTATUS, |
| nios2_num_regs * 4, GENERAL_REGS, |
| nios2_fill_gregset, nios2_store_gregset }, |
| NULL_REGSET |
| }; |
| |
| static struct regsets_info nios2_regsets_info = |
| { |
| nios2_regsets, /* regsets */ |
| 0, /* num_regsets */ |
| NULL, /* disabled_regsets */ |
| }; |
| |
| static struct usrregs_info nios2_usrregs_info = |
| { |
| nios2_num_regs, |
| nios2_regmap, |
| }; |
| |
| static struct regs_info myregs_info = |
| { |
| NULL, /* regset_bitmap */ |
| &nios2_usrregs_info, |
| &nios2_regsets_info |
| }; |
| |
| const regs_info * |
| nios2_target::get_regs_info () |
| { |
| return &myregs_info; |
| } |
| |
| /* The linux target ops object. */ |
| |
| linux_process_target *the_linux_target = &the_nios2_target; |
| |
| void |
| initialize_low_arch (void) |
| { |
| init_registers_nios2_linux (); |
| |
| initialize_regsets_info (&nios2_regsets_info); |
| } |