1 /* GNU/Linux/RISC-V specific low level interface, for the remote server
3 Copyright (C) 2020 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
22 #include "linux-low.h"
24 #include "elf/common.h"
25 #include "nat/riscv-linux-tdesc.h"
26 #include "opcode/riscv.h"
28 /* Work around glibc header breakage causing ELF_NFPREG not to be usable. */
33 /* Linux target op definitions for the RISC-V architecture. */
35 class riscv_target
: public linux_process_target
39 const regs_info
*get_regs_info () override
;
41 int breakpoint_kind_from_pc (CORE_ADDR
*pcptr
) override
;
43 const gdb_byte
*sw_breakpoint_from_kind (int kind
, int *size
) override
;
47 void low_arch_setup () override
;
49 bool low_cannot_fetch_register (int regno
) override
;
51 bool low_cannot_store_register (int regno
) override
;
53 bool low_fetch_register (regcache
*regcache
, int regno
) override
;
55 bool low_supports_breakpoints () override
;
57 CORE_ADDR
low_get_pc (regcache
*regcache
) override
;
59 void low_set_pc (regcache
*regcache
, CORE_ADDR newpc
) override
;
62 /* The singleton target ops object. */
64 static riscv_target the_riscv_target
;
67 riscv_target::low_cannot_fetch_register (int regno
)
69 gdb_assert_not_reached ("linux target op low_cannot_fetch_register "
70 "is not implemented by the target");
74 riscv_target::low_cannot_store_register (int regno
)
76 gdb_assert_not_reached ("linux target op low_cannot_store_register "
77 "is not implemented by the target");
80 /* Implementation of linux target ops method "low_arch_setup". */
83 riscv_target::low_arch_setup ()
85 static const char *expedite_regs
[] = { "sp", "pc", NULL
};
87 const riscv_gdbarch_features features
88 = riscv_linux_read_features (lwpid_of (current_thread
));
89 target_desc
*tdesc
= riscv_create_target_description (features
);
91 if (!tdesc
->expedite_regs
)
92 init_target_desc (tdesc
, expedite_regs
);
93 current_process ()->tdesc
= tdesc
;
96 /* Collect GPRs from REGCACHE into BUF. */
99 riscv_fill_gregset (struct regcache
*regcache
, void *buf
)
101 const struct target_desc
*tdesc
= regcache
->tdesc
;
102 elf_gregset_t
*regset
= (elf_gregset_t
*) buf
;
103 int regno
= find_regno (tdesc
, "zero");
106 collect_register_by_name (regcache
, "pc", *regset
);
107 for (i
= 1; i
< ARRAY_SIZE (*regset
); i
++)
108 collect_register (regcache
, regno
+ i
, *regset
+ i
);
111 /* Supply GPRs from BUF into REGCACHE. */
114 riscv_store_gregset (struct regcache
*regcache
, const void *buf
)
116 const elf_gregset_t
*regset
= (const elf_gregset_t
*) buf
;
117 const struct target_desc
*tdesc
= regcache
->tdesc
;
118 int regno
= find_regno (tdesc
, "zero");
121 supply_register_by_name (regcache
, "pc", *regset
);
122 supply_register_zeroed (regcache
, regno
);
123 for (i
= 1; i
< ARRAY_SIZE (*regset
); i
++)
124 supply_register (regcache
, regno
+ i
, *regset
+ i
);
127 /* Collect FPRs from REGCACHE into BUF. */
130 riscv_fill_fpregset (struct regcache
*regcache
, void *buf
)
132 const struct target_desc
*tdesc
= regcache
->tdesc
;
133 int regno
= find_regno (tdesc
, "ft0");
134 int flen
= register_size (regcache
->tdesc
, regno
);
135 gdb_byte
*regbuf
= (gdb_byte
*) buf
;
138 for (i
= 0; i
< ELF_NFPREG
- 1; i
++, regbuf
+= flen
)
139 collect_register (regcache
, regno
+ i
, regbuf
);
140 collect_register_by_name (regcache
, "fcsr", regbuf
);
143 /* Supply FPRs from BUF into REGCACHE. */
146 riscv_store_fpregset (struct regcache
*regcache
, const void *buf
)
148 const struct target_desc
*tdesc
= regcache
->tdesc
;
149 int regno
= find_regno (tdesc
, "ft0");
150 int flen
= register_size (regcache
->tdesc
, regno
);
151 const gdb_byte
*regbuf
= (const gdb_byte
*) buf
;
154 for (i
= 0; i
< ELF_NFPREG
- 1; i
++, regbuf
+= flen
)
155 supply_register (regcache
, regno
+ i
, regbuf
);
156 supply_register_by_name (regcache
, "fcsr", regbuf
);
159 /* RISC-V/Linux regsets. FPRs are optional and come in different sizes,
160 so define multiple regsets for them marking them all as OPTIONAL_REGS
161 rather than FP_REGS, so that "regsets_fetch_inferior_registers" picks
162 the right one according to size. */
163 static struct regset_info riscv_regsets
[] = {
164 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_PRSTATUS
,
165 sizeof (elf_gregset_t
), GENERAL_REGS
,
166 riscv_fill_gregset
, riscv_store_gregset
},
167 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_FPREGSET
,
168 sizeof (struct __riscv_mc_q_ext_state
), OPTIONAL_REGS
,
169 riscv_fill_fpregset
, riscv_store_fpregset
},
170 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_FPREGSET
,
171 sizeof (struct __riscv_mc_d_ext_state
), OPTIONAL_REGS
,
172 riscv_fill_fpregset
, riscv_store_fpregset
},
173 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_FPREGSET
,
174 sizeof (struct __riscv_mc_f_ext_state
), OPTIONAL_REGS
,
175 riscv_fill_fpregset
, riscv_store_fpregset
},
179 /* RISC-V/Linux regset information. */
180 static struct regsets_info riscv_regsets_info
=
182 riscv_regsets
, /* regsets */
184 NULL
, /* disabled_regsets */
187 /* Definition of linux_target_ops data member "regs_info". */
188 static struct regs_info riscv_regs
=
190 NULL
, /* regset_bitmap */
195 /* Implementation of linux target ops method "get_regs_info". */
198 riscv_target::get_regs_info ()
203 /* Implementation of linux target ops method "low_fetch_register". */
206 riscv_target::low_fetch_register (regcache
*regcache
, int regno
)
208 const struct target_desc
*tdesc
= regcache
->tdesc
;
210 if (regno
!= find_regno (tdesc
, "zero"))
212 supply_register_zeroed (regcache
, regno
);
217 riscv_target::low_supports_breakpoints ()
222 /* Implementation of linux target ops method "low_get_pc". */
225 riscv_target::low_get_pc (regcache
*regcache
)
227 elf_gregset_t regset
;
229 if (sizeof (regset
[0]) == 8)
230 return linux_get_pc_64bit (regcache
);
232 return linux_get_pc_32bit (regcache
);
235 /* Implementation of linux target ops method "low_set_pc". */
238 riscv_target::low_set_pc (regcache
*regcache
, CORE_ADDR newpc
)
240 elf_gregset_t regset
;
242 if (sizeof (regset
[0]) == 8)
243 linux_set_pc_64bit (regcache
, newpc
);
245 linux_set_pc_32bit (regcache
, newpc
);
248 /* Correct in either endianness. */
249 static const uint16_t riscv_ibreakpoint
[] = { 0x0073, 0x0010 };
250 static const uint16_t riscv_cbreakpoint
= 0x9002;
252 /* Implementation of target ops method "breakpoint_kind_from_pc". */
255 riscv_target::breakpoint_kind_from_pc (CORE_ADDR
*pcptr
)
264 if (target_read_memory (*pcptr
, buf
.bytes
, sizeof (buf
.insn
)) == 0
265 && riscv_insn_length (buf
.insn
== sizeof (riscv_ibreakpoint
)))
266 return sizeof (riscv_ibreakpoint
);
268 return sizeof (riscv_cbreakpoint
);
271 /* Implementation of target ops method "sw_breakpoint_from_kind". */
274 riscv_target::sw_breakpoint_from_kind (int kind
, int *size
)
279 case sizeof (riscv_ibreakpoint
):
280 return (const gdb_byte
*) &riscv_ibreakpoint
;
282 return (const gdb_byte
*) &riscv_cbreakpoint
;
286 /* Implementation of linux_target_ops method "breakpoint_at". */
289 riscv_breakpoint_at (CORE_ADDR pc
)
298 if (target_read_memory (pc
, buf
.bytes
, sizeof (buf
.insn
)) == 0
299 && (buf
.insn
== riscv_cbreakpoint
300 || (buf
.insn
== riscv_ibreakpoint
[0]
301 && target_read_memory (pc
+ sizeof (buf
.insn
), buf
.bytes
,
302 sizeof (buf
.insn
)) == 0
303 && buf
.insn
== riscv_ibreakpoint
[1])))
309 /* RISC-V/Linux target operations. */
310 struct linux_target_ops the_low_target
=
312 0, /* decr_pc_after_break */
316 /* The linux target ops object. */
318 linux_process_target
*the_linux_target
= &the_riscv_target
;
320 /* Initialize the RISC-V/Linux target. */
323 initialize_low_arch ()
325 initialize_regsets_info (&riscv_regsets_info
);