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
41 /* The singleton target ops object. */
43 static riscv_target the_riscv_target
;
45 /* Implementation of linux_target_ops method "arch_setup". */
50 static const char *expedite_regs
[] = { "sp", "pc", NULL
};
52 const riscv_gdbarch_features features
53 = riscv_linux_read_features (lwpid_of (current_thread
));
54 target_desc
*tdesc
= riscv_create_target_description (features
);
56 if (!tdesc
->expedite_regs
)
57 init_target_desc (tdesc
, expedite_regs
);
58 current_process ()->tdesc
= tdesc
;
61 /* Collect GPRs from REGCACHE into BUF. */
64 riscv_fill_gregset (struct regcache
*regcache
, void *buf
)
66 const struct target_desc
*tdesc
= regcache
->tdesc
;
67 elf_gregset_t
*regset
= (elf_gregset_t
*) buf
;
68 int regno
= find_regno (tdesc
, "zero");
71 collect_register_by_name (regcache
, "pc", *regset
);
72 for (i
= 1; i
< ARRAY_SIZE (*regset
); i
++)
73 collect_register (regcache
, regno
+ i
, *regset
+ i
);
76 /* Supply GPRs from BUF into REGCACHE. */
79 riscv_store_gregset (struct regcache
*regcache
, const void *buf
)
81 const elf_gregset_t
*regset
= (const elf_gregset_t
*) buf
;
82 const struct target_desc
*tdesc
= regcache
->tdesc
;
83 int regno
= find_regno (tdesc
, "zero");
86 supply_register_by_name (regcache
, "pc", *regset
);
87 supply_register_zeroed (regcache
, regno
);
88 for (i
= 1; i
< ARRAY_SIZE (*regset
); i
++)
89 supply_register (regcache
, regno
+ i
, *regset
+ i
);
92 /* Collect FPRs from REGCACHE into BUF. */
95 riscv_fill_fpregset (struct regcache
*regcache
, void *buf
)
97 const struct target_desc
*tdesc
= regcache
->tdesc
;
98 int regno
= find_regno (tdesc
, "ft0");
99 int flen
= register_size (regcache
->tdesc
, regno
);
100 gdb_byte
*regbuf
= (gdb_byte
*) buf
;
103 for (i
= 0; i
< ELF_NFPREG
- 1; i
++, regbuf
+= flen
)
104 collect_register (regcache
, regno
+ i
, regbuf
);
105 collect_register_by_name (regcache
, "fcsr", regbuf
);
108 /* Supply FPRs from BUF into REGCACHE. */
111 riscv_store_fpregset (struct regcache
*regcache
, const void *buf
)
113 const struct target_desc
*tdesc
= regcache
->tdesc
;
114 int regno
= find_regno (tdesc
, "ft0");
115 int flen
= register_size (regcache
->tdesc
, regno
);
116 const gdb_byte
*regbuf
= (const gdb_byte
*) buf
;
119 for (i
= 0; i
< ELF_NFPREG
- 1; i
++, regbuf
+= flen
)
120 supply_register (regcache
, regno
+ i
, regbuf
);
121 supply_register_by_name (regcache
, "fcsr", regbuf
);
124 /* RISC-V/Linux regsets. FPRs are optional and come in different sizes,
125 so define multiple regsets for them marking them all as OPTIONAL_REGS
126 rather than FP_REGS, so that "regsets_fetch_inferior_registers" picks
127 the right one according to size. */
128 static struct regset_info riscv_regsets
[] = {
129 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_PRSTATUS
,
130 sizeof (elf_gregset_t
), GENERAL_REGS
,
131 riscv_fill_gregset
, riscv_store_gregset
},
132 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_FPREGSET
,
133 sizeof (struct __riscv_mc_q_ext_state
), OPTIONAL_REGS
,
134 riscv_fill_fpregset
, riscv_store_fpregset
},
135 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_FPREGSET
,
136 sizeof (struct __riscv_mc_d_ext_state
), OPTIONAL_REGS
,
137 riscv_fill_fpregset
, riscv_store_fpregset
},
138 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_FPREGSET
,
139 sizeof (struct __riscv_mc_f_ext_state
), OPTIONAL_REGS
,
140 riscv_fill_fpregset
, riscv_store_fpregset
},
144 /* RISC-V/Linux regset information. */
145 static struct regsets_info riscv_regsets_info
=
147 riscv_regsets
, /* regsets */
149 NULL
, /* disabled_regsets */
152 /* Definition of linux_target_ops data member "regs_info". */
153 static struct regs_info riscv_regs
=
155 NULL
, /* regset_bitmap */
160 /* Implementation of linux_target_ops method "regs_info". */
162 static const struct regs_info
*
168 /* Implementation of linux_target_ops method "fetch_register". */
171 riscv_fetch_register (struct regcache
*regcache
, int regno
)
173 const struct target_desc
*tdesc
= regcache
->tdesc
;
175 if (regno
!= find_regno (tdesc
, "zero"))
177 supply_register_zeroed (regcache
, regno
);
181 /* Implementation of linux_target_ops method "get_pc". */
184 riscv_get_pc (struct regcache
*regcache
)
186 elf_gregset_t regset
;
188 if (sizeof (regset
[0]) == 8)
189 return linux_get_pc_64bit (regcache
);
191 return linux_get_pc_32bit (regcache
);
194 /* Implementation of linux_target_ops method "set_pc". */
197 riscv_set_pc (struct regcache
*regcache
, CORE_ADDR newpc
)
199 elf_gregset_t regset
;
201 if (sizeof (regset
[0]) == 8)
202 linux_set_pc_64bit (regcache
, newpc
);
204 linux_set_pc_32bit (regcache
, newpc
);
207 /* Correct in either endianness. */
208 static const uint16_t riscv_ibreakpoint
[] = { 0x0073, 0x0010 };
209 static const uint16_t riscv_cbreakpoint
= 0x9002;
211 /* Implementation of linux_target_ops method "breakpoint_kind_from_pc". */
214 riscv_breakpoint_kind_from_pc (CORE_ADDR
*pcptr
)
223 if (target_read_memory (*pcptr
, buf
.bytes
, sizeof (buf
.insn
)) == 0
224 && riscv_insn_length (buf
.insn
== sizeof (riscv_ibreakpoint
)))
225 return sizeof (riscv_ibreakpoint
);
227 return sizeof (riscv_cbreakpoint
);
230 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind". */
232 static const gdb_byte
*
233 riscv_sw_breakpoint_from_kind (int kind
, int *size
)
238 case sizeof (riscv_ibreakpoint
):
239 return (const gdb_byte
*) &riscv_ibreakpoint
;
241 return (const gdb_byte
*) &riscv_cbreakpoint
;
245 /* Implementation of linux_target_ops method "breakpoint_at". */
248 riscv_breakpoint_at (CORE_ADDR pc
)
257 if (target_read_memory (pc
, buf
.bytes
, sizeof (buf
.insn
)) == 0
258 && (buf
.insn
== riscv_cbreakpoint
259 || (buf
.insn
== riscv_ibreakpoint
[0]
260 && target_read_memory (pc
+ sizeof (buf
.insn
), buf
.bytes
,
261 sizeof (buf
.insn
)) == 0
262 && buf
.insn
== riscv_ibreakpoint
[1])))
268 /* RISC-V/Linux target operations. */
269 struct linux_target_ops the_low_target
=
273 NULL
, /* cannot_fetch_register */
274 NULL
, /* cannot_store_register */
275 riscv_fetch_register
,
278 riscv_breakpoint_kind_from_pc
,
279 riscv_sw_breakpoint_from_kind
,
280 NULL
, /* get_next_pcs */
281 0, /* decr_pc_after_break */
285 /* The linux target ops object. */
287 linux_process_target
*the_linux_target
= &the_riscv_target
;
289 /* Initialize the RISC-V/Linux target. */
292 initialize_low_arch ()
294 initialize_regsets_info (&riscv_regsets_info
);