| /* GNU/Linux/Nios II specific low level interface, for the remote server for |
| GDB. |
| Copyright (C) 2008-2015 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 "server.h" |
| #include "linux-low.h" |
| #include "elf/common.h" |
| #include <sys/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 |
| |
| /* 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 arch_setup linux_target_ops method. */ |
| |
| static void |
| nios2_arch_setup (void) |
| { |
| current_process ()->tdesc = tdesc_nios2_linux; |
| } |
| |
| /* Implement the cannot_fetch_register linux_target_ops method. */ |
| |
| static int |
| nios2_cannot_fetch_register (int regno) |
| { |
| if (nios2_regmap[regno] == -1) |
| return 1; |
| |
| return 0; |
| } |
| |
| /* Implement the cannot_store_register linux_target_ops method. */ |
| |
| static int |
| nios2_cannot_store_register (int regno) |
| { |
| if (nios2_regmap[regno] == -1) |
| return 1; |
| |
| return 0; |
| } |
| |
| /* Implement the get_pc linux_target_ops method. */ |
| |
| static CORE_ADDR |
| nios2_get_pc (struct regcache *regcache) |
| { |
| union nios2_register pc; |
| |
| collect_register_by_name (regcache, "pc", pc.buf); |
| return pc.reg32; |
| } |
| |
| /* Implement the set_pc linux_target_ops method. */ |
| |
| static void |
| nios2_set_pc (struct regcache *regcache, CORE_ADDR pc) |
| { |
| union nios2_register newpc; |
| |
| newpc.reg32 = pc; |
| supply_register_by_name (regcache, "pc", newpc.buf); |
| } |
| |
| /* Breakpoint support. */ |
| |
| static const unsigned int nios2_breakpoint = 0x003b6ffa; |
| #define nios2_breakpoint_len 4 |
| |
| /* Implement the breakpoint_reinsert_addr linux_target_ops method. */ |
| |
| static CORE_ADDR |
| nios2_reinsert_addr (void) |
| { |
| union nios2_register ra; |
| struct regcache *regcache = get_thread_regcache (current_thread, 1); |
| |
| collect_register_by_name (regcache, "ra", ra.buf); |
| return ra.reg32; |
| } |
| |
| /* Implement the breakpoint_at linux_target_ops method. */ |
| |
| static int |
| nios2_breakpoint_at (CORE_ADDR where) |
| { |
| unsigned int insn; |
| |
| (*the_target->read_memory) (where, (unsigned char *) &insn, 4); |
| if (insn == nios2_breakpoint) |
| return 1; |
| return 0; |
| } |
| |
| /* Fetch the thread-local storage pointer for libthread_db. */ |
| |
| ps_err_e |
| ps_get_thread_area (const 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 = 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 = 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 }, |
| { 0, 0, 0, -1, -1, NULL, NULL } |
| }; |
| |
| 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 regs_info = |
| { |
| NULL, /* regset_bitmap */ |
| &nios2_usrregs_info, |
| &nios2_regsets_info |
| }; |
| |
| static const struct regs_info * |
| nios2_regs_info (void) |
| { |
| return ®s_info; |
| } |
| |
| struct linux_target_ops the_low_target = |
| { |
| nios2_arch_setup, |
| nios2_regs_info, |
| nios2_cannot_fetch_register, |
| nios2_cannot_store_register, |
| NULL, |
| nios2_get_pc, |
| nios2_set_pc, |
| (const unsigned char *) &nios2_breakpoint, |
| nios2_breakpoint_len, |
| nios2_reinsert_addr, |
| 0, |
| nios2_breakpoint_at, |
| }; |
| |
| void |
| initialize_low_arch (void) |
| { |
| init_registers_nios2_linux (); |
| |
| initialize_regsets_info (&nios2_regsets_info); |
| } |