1 /* Native-dependent code for GNU/Linux RISC-V.
2 Copyright (C) 2018 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "linux-nat.h"
23 #include "riscv-tdep.h"
25 #include "elf/common.h"
27 #include <sys/ptrace.h>
29 /* RISC-V Linux native additions to the default linux support. */
31 class riscv_linux_nat_target final
: public linux_nat_target
34 /* Add our register access methods. */
35 void fetch_registers (struct regcache
*regcache
, int regnum
) override
;
36 void store_registers (struct regcache
*regcache
, int regnum
) override
;
39 static riscv_linux_nat_target the_riscv_linux_nat_target
;
41 /* Copy general purpose register REGNUM (or all gp regs if REGNUM == -1)
42 from regset GREGS into REGCACHE. */
45 supply_gregset_regnum (struct regcache
*regcache
, const prgregset_t
*gregs
,
49 const elf_greg_t
*regp
= *gregs
;
53 /* We only support the integer registers and PC here. */
54 for (i
= RISCV_ZERO_REGNUM
+ 1; i
< RISCV_PC_REGNUM
; i
++)
55 regcache
->raw_supply (i
, regp
+ i
);
57 /* GDB stores PC in reg 32. Linux kernel stores it in reg 0. */
58 regcache
->raw_supply (32, regp
+ 0);
60 /* Fill the inaccessible zero register with zero. */
61 regcache
->raw_supply_zeroed (0);
63 else if (regnum
== RISCV_ZERO_REGNUM
)
64 regcache
->raw_supply_zeroed (0);
65 else if (regnum
> RISCV_ZERO_REGNUM
&& regnum
< RISCV_PC_REGNUM
)
66 regcache
->raw_supply (regnum
, regp
+ regnum
);
67 else if (regnum
== RISCV_PC_REGNUM
)
68 regcache
->raw_supply (32, regp
+ 0);
71 /* Copy all general purpose registers from regset GREGS into REGCACHE. */
74 supply_gregset (struct regcache
*regcache
, const prgregset_t
*gregs
)
76 supply_gregset_regnum (regcache
, gregs
, -1);
79 /* Copy floating point register REGNUM (or all fp regs if REGNUM == -1)
80 from regset FPREGS into REGCACHE. */
83 supply_fpregset_regnum (struct regcache
*regcache
, const prfpregset_t
*fpregs
,
90 /* We only support the FP registers and FCSR here. */
91 for (i
= RISCV_FIRST_FP_REGNUM
; i
<= RISCV_LAST_FP_REGNUM
; i
++)
92 regcache
->raw_supply (i
, &fpregs
->__d
.__f
[i
- RISCV_FIRST_FP_REGNUM
]);
94 regcache
->raw_supply (RISCV_CSR_FCSR_REGNUM
, &fpregs
->__d
.__fcsr
);
96 else if (regnum
>= RISCV_FIRST_FP_REGNUM
&& regnum
<= RISCV_LAST_FP_REGNUM
)
97 regcache
->raw_supply (regnum
,
98 &fpregs
->__d
.__f
[regnum
- RISCV_FIRST_FP_REGNUM
]);
99 else if (regnum
== RISCV_CSR_FCSR_REGNUM
)
100 regcache
->raw_supply (RISCV_CSR_FCSR_REGNUM
, &fpregs
->__d
.__fcsr
);
103 /* Copy all floating point registers from regset FPREGS into REGCACHE. */
106 supply_fpregset (struct regcache
*regcache
, const prfpregset_t
*fpregs
)
108 supply_fpregset_regnum (regcache
, fpregs
, -1);
111 /* Copy general purpose register REGNUM (or all gp regs if REGNUM == -1)
112 from REGCACHE into regset GREGS. */
115 fill_gregset (const struct regcache
*regcache
, prgregset_t
*gregs
, int regnum
)
117 elf_greg_t
*regp
= *gregs
;
121 /* We only support the integer registers and PC here. */
122 for (int i
= RISCV_ZERO_REGNUM
+ 1; i
< RISCV_PC_REGNUM
; i
++)
123 regcache
->raw_collect (i
, regp
+ i
);
125 regcache
->raw_collect (32, regp
+ 0);
127 else if (regnum
== RISCV_ZERO_REGNUM
)
128 /* Nothing to do here. */
130 else if (regnum
> RISCV_ZERO_REGNUM
&& regnum
< RISCV_PC_REGNUM
)
131 regcache
->raw_collect (regnum
, regp
+ regnum
);
132 else if (regnum
== RISCV_PC_REGNUM
)
133 regcache
->raw_collect (32, regp
+ 0);
136 /* Copy floating point register REGNUM (or all fp regs if REGNUM == -1)
137 from REGCACHE into regset FPREGS. */
140 fill_fpregset (const struct regcache
*regcache
, prfpregset_t
*fpregs
,
145 /* We only support the FP registers and FCSR here. */
146 for (int i
= RISCV_FIRST_FP_REGNUM
; i
<= RISCV_LAST_FP_REGNUM
; i
++)
147 regcache
->raw_collect (i
, &fpregs
->__d
.__f
[i
- RISCV_FIRST_FP_REGNUM
]);
149 regcache
->raw_collect (RISCV_CSR_FCSR_REGNUM
, &fpregs
->__d
.__fcsr
);
151 else if (regnum
>= RISCV_FIRST_FP_REGNUM
&& regnum
<= RISCV_LAST_FP_REGNUM
)
152 regcache
->raw_collect (regnum
,
153 &fpregs
->__d
.__f
[regnum
- RISCV_FIRST_FP_REGNUM
]);
154 else if (regnum
== RISCV_CSR_FCSR_REGNUM
)
155 regcache
->raw_collect (RISCV_CSR_FCSR_REGNUM
, &fpregs
->__d
.__fcsr
);
158 /* Fetch REGNUM (or all registers if REGNUM == -1) from the target
159 into REGCACHE using PTRACE_GETREGSET. */
162 riscv_linux_nat_target::fetch_registers (struct regcache
*regcache
, int regnum
)
166 tid
= get_ptrace_pid (regcache
->ptid());
168 if ((regnum
>= RISCV_ZERO_REGNUM
&& regnum
<= RISCV_PC_REGNUM
)
174 iov
.iov_base
= ®s
;
175 iov
.iov_len
= sizeof (regs
);
177 if (ptrace (PTRACE_GETREGSET
, tid
, NT_PRSTATUS
,
178 (PTRACE_TYPE_ARG3
) &iov
) == -1)
179 perror_with_name (_("Couldn't get registers"));
181 supply_gregset_regnum (regcache
, ®s
, regnum
);
184 if ((regnum
>= RISCV_FIRST_FP_REGNUM
185 && regnum
<= RISCV_LAST_FP_REGNUM
)
186 || (regnum
== RISCV_CSR_FCSR_REGNUM
)
192 iov
.iov_base
= ®s
;
193 iov
.iov_len
= sizeof (regs
);
195 if (ptrace (PTRACE_GETREGSET
, tid
, NT_FPREGSET
,
196 (PTRACE_TYPE_ARG3
) &iov
) == -1)
197 perror_with_name (_("Couldn't get registers"));
199 supply_fpregset_regnum (regcache
, ®s
, regnum
);
202 if ((regnum
== RISCV_CSR_MISA_REGNUM
)
205 /* TODO: Need to add a ptrace call for this. */
206 regcache
->raw_supply_zeroed (regnum
);
209 /* Access to other CSRs has potential security issues, don't support them for
213 /* Store REGNUM (or all registers if REGNUM == -1) to the target
214 from REGCACHE using PTRACE_SETREGSET. */
217 riscv_linux_nat_target::store_registers (struct regcache
*regcache
, int regnum
)
221 tid
= get_ptrace_pid (regcache
->ptid ());
223 if ((regnum
>= RISCV_ZERO_REGNUM
&& regnum
<= RISCV_PC_REGNUM
)
229 iov
.iov_base
= ®s
;
230 iov
.iov_len
= sizeof (regs
);
232 if (ptrace (PTRACE_GETREGSET
, tid
, NT_PRSTATUS
,
233 (PTRACE_TYPE_ARG3
) &iov
) == -1)
234 perror_with_name (_("Couldn't get registers"));
237 fill_gregset (regcache
, ®s
, regnum
);
239 if (ptrace (PTRACE_SETREGSET
, tid
, NT_PRSTATUS
,
240 (PTRACE_TYPE_ARG3
) &iov
) == -1)
241 perror_with_name (_("Couldn't set registers"));
245 if ((regnum
>= RISCV_FIRST_FP_REGNUM
246 && regnum
<= RISCV_LAST_FP_REGNUM
)
247 || (regnum
== RISCV_CSR_FCSR_REGNUM
)
253 iov
.iov_base
= ®s
;
254 iov
.iov_len
= sizeof (regs
);
256 if (ptrace (PTRACE_GETREGSET
, tid
, NT_FPREGSET
,
257 (PTRACE_TYPE_ARG3
) &iov
) == -1)
258 perror_with_name (_("Couldn't get registers"));
261 fill_fpregset (regcache
, ®s
, regnum
);
263 if (ptrace (PTRACE_SETREGSET
, tid
, NT_FPREGSET
,
264 (PTRACE_TYPE_ARG3
) &iov
) == -1)
265 perror_with_name (_("Couldn't set registers"));
269 /* Access to CSRs has potential security issues, don't support them for
273 /* Initialize RISC-V Linux native support. */
276 _initialize_riscv_linux_nat (void)
278 /* Register the target. */
279 linux_target
= &the_riscv_linux_nat_target
;
280 add_inf_child_target (&the_riscv_linux_nat_target
);