xref: /openbmc/qemu/target/loongarch/gdbstub.c (revision 542b10bd)
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 #include "vec.h"
15 
16 uint64_t read_fcc(CPULoongArchState *env)
17 {
18     uint64_t ret = 0;
19 
20     for (int i = 0; i < 8; ++i) {
21         ret |= (uint64_t)env->cf[i] << (i * 8);
22     }
23 
24     return ret;
25 }
26 
27 void write_fcc(CPULoongArchState *env, uint64_t val)
28 {
29     for (int i = 0; i < 8; ++i) {
30         env->cf[i] = (val >> (i * 8)) & 1;
31     }
32 }
33 
34 int loongarch_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
35 {
36     LoongArchCPU *cpu = LOONGARCH_CPU(cs);
37     CPULoongArchState *env = &cpu->env;
38     uint64_t val;
39 
40     if (0 <= n && n < 32) {
41         val = env->gpr[n];
42     } else if (n == 32) {
43         /* orig_a0 */
44         val = 0;
45     } else if (n == 33) {
46         val = env->pc;
47     } else if (n == 34) {
48         val = env->CSR_BADV;
49     }
50 
51     if (0 <= n && n <= 34) {
52         if (is_la64(env)) {
53             return gdb_get_reg64(mem_buf, val);
54         } else {
55             return gdb_get_reg32(mem_buf, val);
56         }
57     }
58     return 0;
59 }
60 
61 int loongarch_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
62 {
63     LoongArchCPU *cpu = LOONGARCH_CPU(cs);
64     CPULoongArchState *env = &cpu->env;
65     target_ulong tmp;
66     int read_length;
67     int length = 0;
68 
69     if (is_la64(env)) {
70         tmp = ldq_p(mem_buf);
71         read_length = 8;
72     } else {
73         tmp = ldl_p(mem_buf);
74         read_length = 4;
75     }
76 
77     if (0 <= n && n < 32) {
78         env->gpr[n] = tmp;
79         length = read_length;
80     } else if (n == 33) {
81         set_pc(env, tmp);
82         length = read_length;
83     }
84     return length;
85 }
86 
87 static int loongarch_gdb_get_fpu(CPULoongArchState *env,
88                                  GByteArray *mem_buf, int n)
89 {
90     if (0 <= n && n < 32) {
91         return gdb_get_reg64(mem_buf, env->fpr[n].vreg.D(0));
92     } else if (32 <= n && n < 40) {
93         return gdb_get_reg8(mem_buf, env->cf[n - 32]);
94     } else if (n == 40) {
95         return gdb_get_reg32(mem_buf, env->fcsr0);
96     }
97     return 0;
98 }
99 
100 static int loongarch_gdb_set_fpu(CPULoongArchState *env,
101                                  uint8_t *mem_buf, int n)
102 {
103     int length = 0;
104 
105     if (0 <= n && n < 32) {
106         env->fpr[n].vreg.D(0) = ldq_p(mem_buf);
107         length = 8;
108     } else if (32 <= n && n < 40) {
109         env->cf[n - 32] = ldub_p(mem_buf);
110         length = 1;
111     } else if (n == 40) {
112         env->fcsr0 = ldl_p(mem_buf);
113         length = 4;
114     }
115     return length;
116 }
117 
118 void loongarch_cpu_register_gdb_regs_for_features(CPUState *cs)
119 {
120     gdb_register_coprocessor(cs, loongarch_gdb_get_fpu, loongarch_gdb_set_fpu,
121                              41, "loongarch-fpu.xml", 0);
122 }
123