xref: /openbmc/qemu/target/mips/gdbstub.c (revision df1f50c3)
1 /*
2  * MIPS gdb server stub
3  *
4  * Copyright (c) 2003-2005 Fabrice Bellard
5  * Copyright (c) 2013 SUSE LINUX Products GmbH
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * This library 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 GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
19  */
20 #include "qemu/osdep.h"
21 #include "cpu.h"
22 #include "internal.h"
23 #include "gdbstub/helpers.h"
24 #include "fpu_helper.h"
25 
26 int mips_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
27 {
28     MIPSCPU *cpu = MIPS_CPU(cs);
29     CPUMIPSState *env = &cpu->env;
30 
31     if (n < 32) {
32         return gdb_get_regl(mem_buf, env->active_tc.gpr[n]);
33     }
34     if (env->CP0_Config1 & (1 << CP0C1_FP) && n >= 38 && n < 72) {
35         switch (n) {
36         case 70:
37             return gdb_get_regl(mem_buf, (int32_t)env->active_fpu.fcr31);
38         case 71:
39             return gdb_get_regl(mem_buf, (int32_t)env->active_fpu.fcr0);
40         default:
41             if (env->CP0_Status & (1 << CP0St_FR)) {
42                 return gdb_get_regl(mem_buf,
43                     env->active_fpu.fpr[n - 38].d);
44             } else {
45                 return gdb_get_regl(mem_buf,
46                     env->active_fpu.fpr[n - 38].w[FP_ENDIAN_IDX]);
47             }
48         }
49     }
50     switch (n) {
51     case 32:
52         return gdb_get_regl(mem_buf, (int32_t)env->CP0_Status);
53     case 33:
54         return gdb_get_regl(mem_buf, env->active_tc.LO[0]);
55     case 34:
56         return gdb_get_regl(mem_buf, env->active_tc.HI[0]);
57     case 35:
58         return gdb_get_regl(mem_buf, env->CP0_BadVAddr);
59     case 36:
60         return gdb_get_regl(mem_buf, (int32_t)env->CP0_Cause);
61     case 37:
62         return gdb_get_regl(mem_buf, env->active_tc.PC |
63                                      !!(env->hflags & MIPS_HFLAG_M16));
64     case 72:
65         return gdb_get_regl(mem_buf, 0); /* fp */
66     case 89:
67         return gdb_get_regl(mem_buf, (int32_t)env->CP0_PRid);
68     default:
69         if (n > 89) {
70             return 0;
71         }
72         /* 16 embedded regs.  */
73         return gdb_get_regl(mem_buf, 0);
74     }
75 
76     return 0;
77 }
78 
79 int mips_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
80 {
81     MIPSCPU *cpu = MIPS_CPU(cs);
82     CPUMIPSState *env = &cpu->env;
83     target_ulong tmp;
84 
85     tmp = ldtul_p(mem_buf);
86 
87     if (n < 32) {
88         env->active_tc.gpr[n] = tmp;
89         return sizeof(target_ulong);
90     }
91     if (env->CP0_Config1 & (1 << CP0C1_FP) && n >= 38 && n < 72) {
92         switch (n) {
93         case 70:
94             env->active_fpu.fcr31 = (tmp & env->active_fpu.fcr31_rw_bitmask) |
95                   (env->active_fpu.fcr31 & ~(env->active_fpu.fcr31_rw_bitmask));
96             restore_fp_status(env);
97             break;
98         case 71:
99             /* FIR is read-only.  Ignore writes.  */
100             break;
101         default:
102             if (env->CP0_Status & (1 << CP0St_FR)) {
103                 env->active_fpu.fpr[n - 38].d = tmp;
104             } else {
105                 env->active_fpu.fpr[n - 38].w[FP_ENDIAN_IDX] = tmp;
106             }
107             break;
108         }
109         return sizeof(target_ulong);
110     }
111     switch (n) {
112     case 32:
113 #ifndef CONFIG_USER_ONLY
114         cpu_mips_store_status(env, tmp);
115 #endif
116         break;
117     case 33:
118         env->active_tc.LO[0] = tmp;
119         break;
120     case 34:
121         env->active_tc.HI[0] = tmp;
122         break;
123     case 35:
124         env->CP0_BadVAddr = tmp;
125         break;
126     case 36:
127 #ifndef CONFIG_USER_ONLY
128         cpu_mips_store_cause(env, tmp);
129 #endif
130         break;
131     case 37:
132         env->active_tc.PC = tmp & ~(target_ulong)1;
133         if (tmp & 1) {
134             env->hflags |= MIPS_HFLAG_M16;
135         } else {
136             env->hflags &= ~(MIPS_HFLAG_M16);
137         }
138         break;
139     case 72: /* fp, ignored */
140         break;
141     default:
142         if (n > 89) {
143             return 0;
144         }
145         /* Other registers are readonly.  Ignore writes.  */
146         break;
147     }
148 
149     return sizeof(target_ulong);
150 }
151