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
;
46 /* The singleton target ops object. */
48 static riscv_target the_riscv_target
;
50 /* Implementation of linux target ops method "low_arch_setup". */
53 riscv_target::low_arch_setup ()
55 static const char *expedite_regs
[] = { "sp", "pc", NULL
};
57 const riscv_gdbarch_features features
58 = riscv_linux_read_features (lwpid_of (current_thread
));
59 target_desc
*tdesc
= riscv_create_target_description (features
);
61 if (!tdesc
->expedite_regs
)
62 init_target_desc (tdesc
, expedite_regs
);
63 current_process ()->tdesc
= tdesc
;
66 /* Collect GPRs from REGCACHE into BUF. */
69 riscv_fill_gregset (struct regcache
*regcache
, void *buf
)
71 const struct target_desc
*tdesc
= regcache
->tdesc
;
72 elf_gregset_t
*regset
= (elf_gregset_t
*) buf
;
73 int regno
= find_regno (tdesc
, "zero");
76 collect_register_by_name (regcache
, "pc", *regset
);
77 for (i
= 1; i
< ARRAY_SIZE (*regset
); i
++)
78 collect_register (regcache
, regno
+ i
, *regset
+ i
);
81 /* Supply GPRs from BUF into REGCACHE. */
84 riscv_store_gregset (struct regcache
*regcache
, const void *buf
)
86 const elf_gregset_t
*regset
= (const elf_gregset_t
*) buf
;
87 const struct target_desc
*tdesc
= regcache
->tdesc
;
88 int regno
= find_regno (tdesc
, "zero");
91 supply_register_by_name (regcache
, "pc", *regset
);
92 supply_register_zeroed (regcache
, regno
);
93 for (i
= 1; i
< ARRAY_SIZE (*regset
); i
++)
94 supply_register (regcache
, regno
+ i
, *regset
+ i
);
97 /* Collect FPRs from REGCACHE into BUF. */
100 riscv_fill_fpregset (struct regcache
*regcache
, void *buf
)
102 const struct target_desc
*tdesc
= regcache
->tdesc
;
103 int regno
= find_regno (tdesc
, "ft0");
104 int flen
= register_size (regcache
->tdesc
, regno
);
105 gdb_byte
*regbuf
= (gdb_byte
*) buf
;
108 for (i
= 0; i
< ELF_NFPREG
- 1; i
++, regbuf
+= flen
)
109 collect_register (regcache
, regno
+ i
, regbuf
);
110 collect_register_by_name (regcache
, "fcsr", regbuf
);
113 /* Supply FPRs from BUF into REGCACHE. */
116 riscv_store_fpregset (struct regcache
*regcache
, const void *buf
)
118 const struct target_desc
*tdesc
= regcache
->tdesc
;
119 int regno
= find_regno (tdesc
, "ft0");
120 int flen
= register_size (regcache
->tdesc
, regno
);
121 const gdb_byte
*regbuf
= (const gdb_byte
*) buf
;
124 for (i
= 0; i
< ELF_NFPREG
- 1; i
++, regbuf
+= flen
)
125 supply_register (regcache
, regno
+ i
, regbuf
);
126 supply_register_by_name (regcache
, "fcsr", regbuf
);
129 /* RISC-V/Linux regsets. FPRs are optional and come in different sizes,
130 so define multiple regsets for them marking them all as OPTIONAL_REGS
131 rather than FP_REGS, so that "regsets_fetch_inferior_registers" picks
132 the right one according to size. */
133 static struct regset_info riscv_regsets
[] = {
134 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_PRSTATUS
,
135 sizeof (elf_gregset_t
), GENERAL_REGS
,
136 riscv_fill_gregset
, riscv_store_gregset
},
137 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_FPREGSET
,
138 sizeof (struct __riscv_mc_q_ext_state
), OPTIONAL_REGS
,
139 riscv_fill_fpregset
, riscv_store_fpregset
},
140 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_FPREGSET
,
141 sizeof (struct __riscv_mc_d_ext_state
), OPTIONAL_REGS
,
142 riscv_fill_fpregset
, riscv_store_fpregset
},
143 { PTRACE_GETREGSET
, PTRACE_SETREGSET
, NT_FPREGSET
,
144 sizeof (struct __riscv_mc_f_ext_state
), OPTIONAL_REGS
,
145 riscv_fill_fpregset
, riscv_store_fpregset
},
149 /* RISC-V/Linux regset information. */
150 static struct regsets_info riscv_regsets_info
=
152 riscv_regsets
, /* regsets */
154 NULL
, /* disabled_regsets */
157 /* Definition of linux_target_ops data member "regs_info". */
158 static struct regs_info riscv_regs
=
160 NULL
, /* regset_bitmap */
165 /* Implementation of linux target ops method "get_regs_info". */
168 riscv_target::get_regs_info ()
173 /* Implementation of linux_target_ops method "fetch_register". */
176 riscv_fetch_register (struct regcache
*regcache
, int regno
)
178 const struct target_desc
*tdesc
= regcache
->tdesc
;
180 if (regno
!= find_regno (tdesc
, "zero"))
182 supply_register_zeroed (regcache
, regno
);
186 /* Implementation of linux_target_ops method "get_pc". */
189 riscv_get_pc (struct regcache
*regcache
)
191 elf_gregset_t regset
;
193 if (sizeof (regset
[0]) == 8)
194 return linux_get_pc_64bit (regcache
);
196 return linux_get_pc_32bit (regcache
);
199 /* Implementation of linux_target_ops method "set_pc". */
202 riscv_set_pc (struct regcache
*regcache
, CORE_ADDR newpc
)
204 elf_gregset_t regset
;
206 if (sizeof (regset
[0]) == 8)
207 linux_set_pc_64bit (regcache
, newpc
);
209 linux_set_pc_32bit (regcache
, newpc
);
212 /* Correct in either endianness. */
213 static const uint16_t riscv_ibreakpoint
[] = { 0x0073, 0x0010 };
214 static const uint16_t riscv_cbreakpoint
= 0x9002;
216 /* Implementation of linux_target_ops method "breakpoint_kind_from_pc". */
219 riscv_breakpoint_kind_from_pc (CORE_ADDR
*pcptr
)
228 if (target_read_memory (*pcptr
, buf
.bytes
, sizeof (buf
.insn
)) == 0
229 && riscv_insn_length (buf
.insn
== sizeof (riscv_ibreakpoint
)))
230 return sizeof (riscv_ibreakpoint
);
232 return sizeof (riscv_cbreakpoint
);
235 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind". */
237 static const gdb_byte
*
238 riscv_sw_breakpoint_from_kind (int kind
, int *size
)
243 case sizeof (riscv_ibreakpoint
):
244 return (const gdb_byte
*) &riscv_ibreakpoint
;
246 return (const gdb_byte
*) &riscv_cbreakpoint
;
250 /* Implementation of linux_target_ops method "breakpoint_at". */
253 riscv_breakpoint_at (CORE_ADDR pc
)
262 if (target_read_memory (pc
, buf
.bytes
, sizeof (buf
.insn
)) == 0
263 && (buf
.insn
== riscv_cbreakpoint
264 || (buf
.insn
== riscv_ibreakpoint
[0]
265 && target_read_memory (pc
+ sizeof (buf
.insn
), buf
.bytes
,
266 sizeof (buf
.insn
)) == 0
267 && buf
.insn
== riscv_ibreakpoint
[1])))
273 /* RISC-V/Linux target operations. */
274 struct linux_target_ops the_low_target
=
276 NULL
, /* cannot_fetch_register */
277 NULL
, /* cannot_store_register */
278 riscv_fetch_register
,
281 riscv_breakpoint_kind_from_pc
,
282 riscv_sw_breakpoint_from_kind
,
283 NULL
, /* get_next_pcs */
284 0, /* decr_pc_after_break */
288 /* The linux target ops object. */
290 linux_process_target
*the_linux_target
= &the_riscv_target
;
292 /* Initialize the RISC-V/Linux target. */
295 initialize_low_arch ()
297 initialize_regsets_info (&riscv_regsets_info
);