xref: /openbmc/qemu/target/loongarch/gdbstub.c (revision 243975c0)
1 /*
2  * LOONGARCH gdb server stub
3  *
4  * Copyright (c) 2021 Loongson Technology Corporation Limited
5  *
6  * SPDX-License-Identifier: LGPL-2.1+
7  */
8 
9 #include "qemu/osdep.h"
10 #include "cpu.h"
11 #include "internals.h"
12 #include "exec/gdbstub.h"
13 #include "gdbstub/helpers.h"
14 
15 uint64_t read_fcc(CPULoongArchState *env)
16 {
17     uint64_t ret = 0;
18 
19     for (int i = 0; i < 8; ++i) {
20         ret |= (uint64_t)env->cf[i] << (i * 8);
21     }
22 
23     return ret;
24 }
25 
26 void write_fcc(CPULoongArchState *env, uint64_t val)
27 {
28     for (int i = 0; i < 8; ++i) {
29         env->cf[i] = (val >> (i * 8)) & 1;
30     }
31 }
32 
33 int loongarch_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
34 {
35     LoongArchCPU *cpu = LOONGARCH_CPU(cs);
36     CPULoongArchState *env = &cpu->env;
37     uint64_t val;
38 
39     if (0 <= n && n < 32) {
40         val = env->gpr[n];
41     } else if (n == 32) {
42         /* orig_a0 */
43         val = 0;
44     } else if (n == 33) {
45         val = env->pc;
46     } else if (n == 34) {
47         val = env->CSR_BADV;
48     }
49 
50     if (0 <= n && n <= 34) {
51         if (is_la64(env)) {
52             return gdb_get_reg64(mem_buf, val);
53         } else {
54             return gdb_get_reg32(mem_buf, val);
55         }
56     }
57     return 0;
58 }
59 
60 int loongarch_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
61 {
62     LoongArchCPU *cpu = LOONGARCH_CPU(cs);
63     CPULoongArchState *env = &cpu->env;
64     target_ulong tmp;
65     int read_length;
66     int length = 0;
67 
68     if (is_la64(env)) {
69         tmp = ldq_p(mem_buf);
70         read_length = 8;
71     } else {
72         tmp = ldl_p(mem_buf);
73         read_length = 4;
74     }
75 
76     if (0 <= n && n < 32) {
77         env->gpr[n] = tmp;
78         length = read_length;
79     } else if (n == 33) {
80         set_pc(env, tmp);
81         length = read_length;
82     }
83     return length;
84 }
85 
86 static int loongarch_gdb_get_fpu(CPULoongArchState *env,
87                                  GByteArray *mem_buf, int n)
88 {
89     if (0 <= n && n < 32) {
90         return gdb_get_reg64(mem_buf, env->fpr[n].vreg.D(0));
91     } else if (32 <= n && n < 40) {
92         return gdb_get_reg8(mem_buf, env->cf[n - 32]);
93     } else if (n == 40) {
94         return gdb_get_reg32(mem_buf, env->fcsr0);
95     }
96     return 0;
97 }
98 
99 static int loongarch_gdb_set_fpu(CPULoongArchState *env,
100                                  uint8_t *mem_buf, int n)
101 {
102     int length = 0;
103 
104     if (0 <= n && n < 32) {
105         env->fpr[n].vreg.D(0) = ldq_p(mem_buf);
106         length = 8;
107     } else if (32 <= n && n < 40) {
108         env->cf[n - 32] = ldub_p(mem_buf);
109         length = 1;
110     } else if (n == 40) {
111         env->fcsr0 = ldl_p(mem_buf);
112         length = 4;
113     }
114     return length;
115 }
116 
117 void loongarch_cpu_register_gdb_regs_for_features(CPUState *cs)
118 {
119     gdb_register_coprocessor(cs, loongarch_gdb_get_fpu, loongarch_gdb_set_fpu,
120                              41, "loongarch-fpu.xml", 0);
121 }
122