1 /* GNU/Linux/Nios II specific low level interface, for the remote server for
3 Copyright (C) 2008-2020 Free Software Foundation, Inc.
5 Contributed by Mentor Graphics, Inc.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "linux-low.h"
24 #include "elf/common.h"
25 #include "nat/gdb_ptrace.h"
27 #include "gdb_proc_service.h"
28 #include <asm/ptrace.h>
30 #ifndef PTRACE_GET_THREAD_AREA
31 #define PTRACE_GET_THREAD_AREA 25
34 /* Linux target op definitions for the NIOS II architecture. */
36 class nios2_target
: public linux_process_target
40 const regs_info
*get_regs_info () override
;
44 void low_arch_setup () override
;
47 /* The singleton target ops object. */
49 static nios2_target the_nios2_target
;
51 /* The following definition must agree with the number of registers
52 defined in "struct user_regs" in GLIBC
53 (sysdeps/unix/sysv/linux/nios2/sys/user.h), and also with
54 NIOS2_NUM_REGS in GDB proper. */
56 #define nios2_num_regs 49
58 /* Defined in auto-generated file nios2-linux.c. */
60 void init_registers_nios2_linux (void);
61 extern const struct target_desc
*tdesc_nios2_linux
;
63 /* This union is used to convert between int and byte buffer
64 representations of register contents. */
72 /* Return the ptrace ``address'' of register REGNO. */
74 static int nios2_regmap
[] = {
75 -1, 1, 2, 3, 4, 5, 6, 7,
76 8, 9, 10, 11, 12, 13, 14, 15,
77 16, 17, 18, 19, 20, 21, 22, 23,
78 24, 25, 26, 27, 28, 29, 30, 31,
79 32, 33, 34, 35, 36, 37, 38, 39,
80 40, 41, 42, 43, 44, 45, 46, 47,
85 /* Implement the low_arch_setup linux target ops method. */
88 nios2_target::low_arch_setup ()
90 current_process ()->tdesc
= tdesc_nios2_linux
;
93 /* Implement the cannot_fetch_register linux_target_ops method. */
96 nios2_cannot_fetch_register (int regno
)
98 if (nios2_regmap
[regno
] == -1)
104 /* Implement the cannot_store_register linux_target_ops method. */
107 nios2_cannot_store_register (int regno
)
109 if (nios2_regmap
[regno
] == -1)
115 /* Breakpoint support. Also see comments on nios2_breakpoint_from_pc
118 #if defined(__nios2_arch__) && __nios2_arch__ == 2
119 #define NIOS2_BREAKPOINT 0xb7fd0020
120 #define CDX_BREAKPOINT 0xd7c9
122 #define NIOS2_BREAKPOINT 0x003b6ffa
125 /* We only register the 4-byte breakpoint, even on R2 targets which also
126 support 2-byte breakpoints. Since there is no supports_z_point_type
127 function provided, gdbserver never inserts software breakpoints itself
128 and instead relies on GDB to insert the breakpoint of the correct length
129 via a memory write. */
130 static const unsigned int nios2_breakpoint
= NIOS2_BREAKPOINT
;
131 #define nios2_breakpoint_len 4
133 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind". */
135 static const gdb_byte
*
136 nios2_sw_breakpoint_from_kind (int kind
, int *size
)
138 *size
= nios2_breakpoint_len
;
139 return (const gdb_byte
*) &nios2_breakpoint
;
142 /* Implement the breakpoint_at linux_target_ops method. */
145 nios2_breakpoint_at (CORE_ADDR where
)
149 /* For R2, first check for the 2-byte CDX trap.n breakpoint encoding. */
150 #if defined(__nios2_arch__) && __nios2_arch__ == 2
151 the_target
->read_memory (where
, (unsigned char *) &insn
, 2);
152 if (insn
== CDX_BREAKPOINT
)
156 the_target
->read_memory (where
, (unsigned char *) &insn
, 4);
157 if (insn
== nios2_breakpoint
)
162 /* Fetch the thread-local storage pointer for libthread_db. */
165 ps_get_thread_area (struct ps_prochandle
*ph
,
166 lwpid_t lwpid
, int idx
, void **base
)
168 if (ptrace (PTRACE_GET_THREAD_AREA
, lwpid
, NULL
, base
) != 0)
171 /* IDX is the bias from the thread pointer to the beginning of the
172 thread descriptor. It has to be subtracted due to implementation
173 quirks in libthread_db. */
174 *base
= (void *) ((char *) *base
- idx
);
179 /* Helper functions to collect/supply a single register REGNO. */
182 nios2_collect_register (struct regcache
*regcache
, int regno
,
183 union nios2_register
*reg
)
185 union nios2_register tmp_reg
;
187 collect_register (regcache
, regno
, &tmp_reg
.reg32
);
188 reg
->reg32
= tmp_reg
.reg32
;
192 nios2_supply_register (struct regcache
*regcache
, int regno
,
193 const union nios2_register
*reg
)
195 supply_register (regcache
, regno
, reg
->buf
);
198 /* We have only a single register set on Nios II. */
201 nios2_fill_gregset (struct regcache
*regcache
, void *buf
)
203 union nios2_register
*regset
= (union nios2_register
*) buf
;
206 for (i
= 1; i
< nios2_num_regs
; i
++)
207 nios2_collect_register (regcache
, i
, regset
+ i
);
211 nios2_store_gregset (struct regcache
*regcache
, const void *buf
)
213 const union nios2_register
*regset
= (union nios2_register
*) buf
;
216 for (i
= 0; i
< nios2_num_regs
; i
++)
217 nios2_supply_register (regcache
, i
, regset
+ i
);
220 static struct regset_info nios2_regsets
[] =
222 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_PRSTATUS
,
223 nios2_num_regs
* 4, GENERAL_REGS
,
224 nios2_fill_gregset
, nios2_store_gregset
},
228 static struct regsets_info nios2_regsets_info
=
230 nios2_regsets
, /* regsets */
232 NULL
, /* disabled_regsets */
235 static struct usrregs_info nios2_usrregs_info
=
241 static struct regs_info myregs_info
=
243 NULL
, /* regset_bitmap */
249 nios2_target::get_regs_info ()
254 struct linux_target_ops the_low_target
=
256 nios2_cannot_fetch_register
,
257 nios2_cannot_store_register
,
261 NULL
, /* breakpoint_kind_from_pc */
262 nios2_sw_breakpoint_from_kind
,
263 NULL
, /* get_next_pcs */
268 /* The linux target ops object. */
270 linux_process_target
*the_linux_target
= &the_nios2_target
;
273 initialize_low_arch (void)
275 init_registers_nios2_linux ();
277 initialize_regsets_info (&nios2_regsets_info
);