xref: /openbmc/qemu/target/riscv/gdbstub.c (revision 3ae8a100)
1 /*
2  * RISC-V GDB Server Stub
3  *
4  * Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2 or later, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License along with
16  * this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include "qemu/osdep.h"
20 #include "qemu-common.h"
21 #include "exec/gdbstub.h"
22 #include "cpu.h"
23 
24 int riscv_cpu_gdb_read_register(CPUState *cs, uint8_t *mem_buf, int n)
25 {
26     RISCVCPU *cpu = RISCV_CPU(cs);
27     CPURISCVState *env = &cpu->env;
28 
29     if (n < 32) {
30         return gdb_get_regl(mem_buf, env->gpr[n]);
31     } else if (n == 32) {
32         return gdb_get_regl(mem_buf, env->pc);
33     } else if (n < 65) {
34         return gdb_get_reg64(mem_buf, env->fpr[n - 33]);
35     } else if (n < 4096 + 65) {
36         return gdb_get_regl(mem_buf, csr_read_helper(env, n - 65));
37     }
38     return 0;
39 }
40 
41 int riscv_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
42 {
43     RISCVCPU *cpu = RISCV_CPU(cs);
44     CPURISCVState *env = &cpu->env;
45 
46     if (n == 0) {
47         /* discard writes to x0 */
48         return sizeof(target_ulong);
49     } else if (n < 32) {
50         env->gpr[n] = ldtul_p(mem_buf);
51         return sizeof(target_ulong);
52     } else if (n == 32) {
53         env->pc = ldtul_p(mem_buf);
54         return sizeof(target_ulong);
55     } else if (n < 65) {
56         env->fpr[n - 33] = ldq_p(mem_buf); /* always 64-bit */
57         return sizeof(uint64_t);
58     } else if (n < 4096 + 65) {
59         csr_write_helper(env, ldtul_p(mem_buf), n - 65);
60     }
61     return 0;
62 }
63