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
;
52 /* The singleton target ops object. */
54 static riscv_target the_riscv_target
;
57 riscv_target::low_cannot_fetch_register (int regno
)
59 gdb_assert_not_reached ("linux target op low_cannot_fetch_register "
60 "is not implemented by the target");
64 riscv_target::low_cannot_store_register (int regno
)
66 gdb_assert_not_reached ("linux target op low_cannot_store_register "
67 "is not implemented by the target");
70 /* Implementation of linux target ops method "low_arch_setup". */
73 riscv_target::low_arch_setup ()
75 static const char *expedite_regs
[] = { "sp", "pc", NULL
};
77 const riscv_gdbarch_features features
78 = riscv_linux_read_features (lwpid_of (current_thread
));
79 target_desc
*tdesc
= riscv_create_target_description (features
);
81 if (!tdesc
->expedite_regs
)
82 init_target_desc (tdesc
, expedite_regs
);
83 current_process ()->tdesc
= tdesc
;
86 /* Collect GPRs from REGCACHE into BUF. */
89 riscv_fill_gregset (struct regcache
*regcache
, void *buf
)
91 const struct target_desc
*tdesc
= regcache
->tdesc
;
92 elf_gregset_t
*regset
= (elf_gregset_t
*) buf
;
93 int regno
= find_regno (tdesc
, "zero");
96 collect_register_by_name (regcache
, "pc", *regset
);
97 for (i
= 1; i
< ARRAY_SIZE (*regset
); i
++)
98 collect_register (regcache
, regno
+ i
, *regset
+ i
);
101 /* Supply GPRs from BUF into REGCACHE. */
104 riscv_store_gregset (struct regcache
*regcache
, const void *buf
)
106 const elf_gregset_t
*regset
= (const elf_gregset_t
*) buf
;
107 const struct target_desc
*tdesc
= regcache
->tdesc
;
108 int regno
= find_regno (tdesc
, "zero");
111 supply_register_by_name (regcache
, "pc", *regset
);
112 supply_register_zeroed (regcache
, regno
);
113 for (i
= 1; i
< ARRAY_SIZE (*regset
); i
++)
114 supply_register (regcache
, regno
+ i
, *regset
+ i
);
117 /* Collect FPRs from REGCACHE into BUF. */
120 riscv_fill_fpregset (struct regcache
*regcache
, void *buf
)
122 const struct target_desc
*tdesc
= regcache
->tdesc
;
123 int regno
= find_regno (tdesc
, "ft0");
124 int flen
= register_size (regcache
->tdesc
, regno
);
125 gdb_byte
*regbuf
= (gdb_byte
*) buf
;
128 for (i
= 0; i
< ELF_NFPREG
- 1; i
++, regbuf
+= flen
)
129 collect_register (regcache
, regno
+ i
, regbuf
);
130 collect_register_by_name (regcache
, "fcsr", regbuf
);
133 /* Supply FPRs from BUF into REGCACHE. */
136 riscv_store_fpregset (struct regcache
*regcache
, const void *buf
)
138 const struct target_desc
*tdesc
= regcache
->tdesc
;
139 int regno
= find_regno (tdesc
, "ft0");
140 int flen
= register_size (regcache
->tdesc
, regno
);
141 const gdb_byte
*regbuf
= (const gdb_byte
*) buf
;
144 for (i
= 0; i
< ELF_NFPREG
- 1; i
++, regbuf
+= flen
)
145 supply_register (regcache
, regno
+ i
, regbuf
);
146 supply_register_by_name (regcache
, "fcsr", regbuf
);
149 /* RISC-V/Linux regsets. FPRs are optional and come in different sizes,
150 so define multiple regsets for them marking them all as OPTIONAL_REGS
151 rather than FP_REGS, so that "regsets_fetch_inferior_registers" picks
152 the right one according to size. */
153 static struct regset_info riscv_regsets
[] = {
154 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_PRSTATUS
,
155 sizeof (elf_gregset_t
), GENERAL_REGS
,
156 riscv_fill_gregset
, riscv_store_gregset
},
157 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_FPREGSET
,
158 sizeof (struct __riscv_mc_q_ext_state
), OPTIONAL_REGS
,
159 riscv_fill_fpregset
, riscv_store_fpregset
},
160 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_FPREGSET
,
161 sizeof (struct __riscv_mc_d_ext_state
), OPTIONAL_REGS
,
162 riscv_fill_fpregset
, riscv_store_fpregset
},
163 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_FPREGSET
,
164 sizeof (struct __riscv_mc_f_ext_state
), OPTIONAL_REGS
,
165 riscv_fill_fpregset
, riscv_store_fpregset
},
169 /* RISC-V/Linux regset information. */
170 static struct regsets_info riscv_regsets_info
=
172 riscv_regsets
, /* regsets */
174 NULL
, /* disabled_regsets */
177 /* Definition of linux_target_ops data member "regs_info". */
178 static struct regs_info riscv_regs
=
180 NULL
, /* regset_bitmap */
185 /* Implementation of linux target ops method "get_regs_info". */
188 riscv_target::get_regs_info ()
193 /* Implementation of linux target ops method "low_fetch_register". */
196 riscv_target::low_fetch_register (regcache
*regcache
, int regno
)
198 const struct target_desc
*tdesc
= regcache
->tdesc
;
200 if (regno
!= find_regno (tdesc
, "zero"))
202 supply_register_zeroed (regcache
, regno
);
206 /* Implementation of linux_target_ops method "get_pc". */
209 riscv_get_pc (struct regcache
*regcache
)
211 elf_gregset_t regset
;
213 if (sizeof (regset
[0]) == 8)
214 return linux_get_pc_64bit (regcache
);
216 return linux_get_pc_32bit (regcache
);
219 /* Implementation of linux_target_ops method "set_pc". */
222 riscv_set_pc (struct regcache
*regcache
, CORE_ADDR newpc
)
224 elf_gregset_t regset
;
226 if (sizeof (regset
[0]) == 8)
227 linux_set_pc_64bit (regcache
, newpc
);
229 linux_set_pc_32bit (regcache
, newpc
);
232 /* Correct in either endianness. */
233 static const uint16_t riscv_ibreakpoint
[] = { 0x0073, 0x0010 };
234 static const uint16_t riscv_cbreakpoint
= 0x9002;
236 /* Implementation of linux_target_ops method "breakpoint_kind_from_pc". */
239 riscv_breakpoint_kind_from_pc (CORE_ADDR
*pcptr
)
248 if (target_read_memory (*pcptr
, buf
.bytes
, sizeof (buf
.insn
)) == 0
249 && riscv_insn_length (buf
.insn
== sizeof (riscv_ibreakpoint
)))
250 return sizeof (riscv_ibreakpoint
);
252 return sizeof (riscv_cbreakpoint
);
255 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind". */
257 static const gdb_byte
*
258 riscv_sw_breakpoint_from_kind (int kind
, int *size
)
263 case sizeof (riscv_ibreakpoint
):
264 return (const gdb_byte
*) &riscv_ibreakpoint
;
266 return (const gdb_byte
*) &riscv_cbreakpoint
;
270 /* Implementation of linux_target_ops method "breakpoint_at". */
273 riscv_breakpoint_at (CORE_ADDR pc
)
282 if (target_read_memory (pc
, buf
.bytes
, sizeof (buf
.insn
)) == 0
283 && (buf
.insn
== riscv_cbreakpoint
284 || (buf
.insn
== riscv_ibreakpoint
[0]
285 && target_read_memory (pc
+ sizeof (buf
.insn
), buf
.bytes
,
286 sizeof (buf
.insn
)) == 0
287 && buf
.insn
== riscv_ibreakpoint
[1])))
293 /* RISC-V/Linux target operations. */
294 struct linux_target_ops the_low_target
=
298 riscv_breakpoint_kind_from_pc
,
299 riscv_sw_breakpoint_from_kind
,
300 NULL
, /* get_next_pcs */
301 0, /* decr_pc_after_break */
305 /* The linux target ops object. */
307 linux_process_target
*the_linux_target
= &the_riscv_target
;
309 /* Initialize the RISC-V/Linux target. */
312 initialize_low_arch ()
314 initialize_regsets_info (&riscv_regsets_info
);