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
;
43 void low_arch_setup () override
;
45 bool low_cannot_fetch_register (int regno
) override
;
47 bool low_cannot_store_register (int regno
) override
;
49 bool low_fetch_register (regcache
*regcache
, int regno
) override
;
51 bool low_supports_breakpoints () override
;
53 CORE_ADDR
low_get_pc (regcache
*regcache
) override
;
55 void low_set_pc (regcache
*regcache
, CORE_ADDR newpc
) override
;
58 /* The singleton target ops object. */
60 static riscv_target the_riscv_target
;
63 riscv_target::low_cannot_fetch_register (int regno
)
65 gdb_assert_not_reached ("linux target op low_cannot_fetch_register "
66 "is not implemented by the target");
70 riscv_target::low_cannot_store_register (int regno
)
72 gdb_assert_not_reached ("linux target op low_cannot_store_register "
73 "is not implemented by the target");
76 /* Implementation of linux target ops method "low_arch_setup". */
79 riscv_target::low_arch_setup ()
81 static const char *expedite_regs
[] = { "sp", "pc", NULL
};
83 const riscv_gdbarch_features features
84 = riscv_linux_read_features (lwpid_of (current_thread
));
85 target_desc
*tdesc
= riscv_create_target_description (features
);
87 if (!tdesc
->expedite_regs
)
88 init_target_desc (tdesc
, expedite_regs
);
89 current_process ()->tdesc
= tdesc
;
92 /* Collect GPRs from REGCACHE into BUF. */
95 riscv_fill_gregset (struct regcache
*regcache
, void *buf
)
97 const struct target_desc
*tdesc
= regcache
->tdesc
;
98 elf_gregset_t
*regset
= (elf_gregset_t
*) buf
;
99 int regno
= find_regno (tdesc
, "zero");
102 collect_register_by_name (regcache
, "pc", *regset
);
103 for (i
= 1; i
< ARRAY_SIZE (*regset
); i
++)
104 collect_register (regcache
, regno
+ i
, *regset
+ i
);
107 /* Supply GPRs from BUF into REGCACHE. */
110 riscv_store_gregset (struct regcache
*regcache
, const void *buf
)
112 const elf_gregset_t
*regset
= (const elf_gregset_t
*) buf
;
113 const struct target_desc
*tdesc
= regcache
->tdesc
;
114 int regno
= find_regno (tdesc
, "zero");
117 supply_register_by_name (regcache
, "pc", *regset
);
118 supply_register_zeroed (regcache
, regno
);
119 for (i
= 1; i
< ARRAY_SIZE (*regset
); i
++)
120 supply_register (regcache
, regno
+ i
, *regset
+ i
);
123 /* Collect FPRs from REGCACHE into BUF. */
126 riscv_fill_fpregset (struct regcache
*regcache
, void *buf
)
128 const struct target_desc
*tdesc
= regcache
->tdesc
;
129 int regno
= find_regno (tdesc
, "ft0");
130 int flen
= register_size (regcache
->tdesc
, regno
);
131 gdb_byte
*regbuf
= (gdb_byte
*) buf
;
134 for (i
= 0; i
< ELF_NFPREG
- 1; i
++, regbuf
+= flen
)
135 collect_register (regcache
, regno
+ i
, regbuf
);
136 collect_register_by_name (regcache
, "fcsr", regbuf
);
139 /* Supply FPRs from BUF into REGCACHE. */
142 riscv_store_fpregset (struct regcache
*regcache
, const void *buf
)
144 const struct target_desc
*tdesc
= regcache
->tdesc
;
145 int regno
= find_regno (tdesc
, "ft0");
146 int flen
= register_size (regcache
->tdesc
, regno
);
147 const gdb_byte
*regbuf
= (const gdb_byte
*) buf
;
150 for (i
= 0; i
< ELF_NFPREG
- 1; i
++, regbuf
+= flen
)
151 supply_register (regcache
, regno
+ i
, regbuf
);
152 supply_register_by_name (regcache
, "fcsr", regbuf
);
155 /* RISC-V/Linux regsets. FPRs are optional and come in different sizes,
156 so define multiple regsets for them marking them all as OPTIONAL_REGS
157 rather than FP_REGS, so that "regsets_fetch_inferior_registers" picks
158 the right one according to size. */
159 static struct regset_info riscv_regsets
[] = {
160 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_PRSTATUS
,
161 sizeof (elf_gregset_t
), GENERAL_REGS
,
162 riscv_fill_gregset
, riscv_store_gregset
},
163 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_FPREGSET
,
164 sizeof (struct __riscv_mc_q_ext_state
), OPTIONAL_REGS
,
165 riscv_fill_fpregset
, riscv_store_fpregset
},
166 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_FPREGSET
,
167 sizeof (struct __riscv_mc_d_ext_state
), OPTIONAL_REGS
,
168 riscv_fill_fpregset
, riscv_store_fpregset
},
169 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_FPREGSET
,
170 sizeof (struct __riscv_mc_f_ext_state
), OPTIONAL_REGS
,
171 riscv_fill_fpregset
, riscv_store_fpregset
},
175 /* RISC-V/Linux regset information. */
176 static struct regsets_info riscv_regsets_info
=
178 riscv_regsets
, /* regsets */
180 NULL
, /* disabled_regsets */
183 /* Definition of linux_target_ops data member "regs_info". */
184 static struct regs_info riscv_regs
=
186 NULL
, /* regset_bitmap */
191 /* Implementation of linux target ops method "get_regs_info". */
194 riscv_target::get_regs_info ()
199 /* Implementation of linux target ops method "low_fetch_register". */
202 riscv_target::low_fetch_register (regcache
*regcache
, int regno
)
204 const struct target_desc
*tdesc
= regcache
->tdesc
;
206 if (regno
!= find_regno (tdesc
, "zero"))
208 supply_register_zeroed (regcache
, regno
);
213 riscv_target::low_supports_breakpoints ()
218 /* Implementation of linux target ops method "low_get_pc". */
221 riscv_target::low_get_pc (regcache
*regcache
)
223 elf_gregset_t regset
;
225 if (sizeof (regset
[0]) == 8)
226 return linux_get_pc_64bit (regcache
);
228 return linux_get_pc_32bit (regcache
);
231 /* Implementation of linux target ops method "low_set_pc". */
234 riscv_target::low_set_pc (regcache
*regcache
, CORE_ADDR newpc
)
236 elf_gregset_t regset
;
238 if (sizeof (regset
[0]) == 8)
239 linux_set_pc_64bit (regcache
, newpc
);
241 linux_set_pc_32bit (regcache
, newpc
);
244 /* Correct in either endianness. */
245 static const uint16_t riscv_ibreakpoint
[] = { 0x0073, 0x0010 };
246 static const uint16_t riscv_cbreakpoint
= 0x9002;
248 /* Implementation of linux_target_ops method "breakpoint_kind_from_pc". */
251 riscv_breakpoint_kind_from_pc (CORE_ADDR
*pcptr
)
260 if (target_read_memory (*pcptr
, buf
.bytes
, sizeof (buf
.insn
)) == 0
261 && riscv_insn_length (buf
.insn
== sizeof (riscv_ibreakpoint
)))
262 return sizeof (riscv_ibreakpoint
);
264 return sizeof (riscv_cbreakpoint
);
267 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind". */
269 static const gdb_byte
*
270 riscv_sw_breakpoint_from_kind (int kind
, int *size
)
275 case sizeof (riscv_ibreakpoint
):
276 return (const gdb_byte
*) &riscv_ibreakpoint
;
278 return (const gdb_byte
*) &riscv_cbreakpoint
;
282 /* Implementation of linux_target_ops method "breakpoint_at". */
285 riscv_breakpoint_at (CORE_ADDR pc
)
294 if (target_read_memory (pc
, buf
.bytes
, sizeof (buf
.insn
)) == 0
295 && (buf
.insn
== riscv_cbreakpoint
296 || (buf
.insn
== riscv_ibreakpoint
[0]
297 && target_read_memory (pc
+ sizeof (buf
.insn
), buf
.bytes
,
298 sizeof (buf
.insn
)) == 0
299 && buf
.insn
== riscv_ibreakpoint
[1])))
305 /* RISC-V/Linux target operations. */
306 struct linux_target_ops the_low_target
=
308 riscv_breakpoint_kind_from_pc
,
309 riscv_sw_breakpoint_from_kind
,
310 NULL
, /* get_next_pcs */
311 0, /* decr_pc_after_break */
315 /* The linux target ops object. */
317 linux_process_target
*the_linux_target
= &the_riscv_target
;
319 /* Initialize the RISC-V/Linux target. */
322 initialize_low_arch ()
324 initialize_regsets_info (&riscv_regsets_info
);