xref: /openbmc/qemu/target/xtensa/gdbstub.c (revision 966f2ec3)
1 /*
2  * Xtensa 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 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 "qemu-common.h"
22 #include "cpu.h"
23 #include "exec/gdbstub.h"
24 #include "qemu/log.h"
25 
26 enum {
27   xtRegisterTypeArRegfile = 1,  /* Register File ar0..arXX.  */
28   xtRegisterTypeSpecialReg,     /* CPU states, such as PS, Booleans, (rsr).  */
29   xtRegisterTypeUserReg,        /* User defined registers (rur).  */
30   xtRegisterTypeTieRegfile,     /* User define register files.  */
31   xtRegisterTypeTieState,       /* TIE States (mapped on user regs).  */
32   xtRegisterTypeMapped,         /* Mapped on Special Registers.  */
33   xtRegisterTypeUnmapped,       /* Special case of masked registers.  */
34   xtRegisterTypeWindow,         /* Live window registers (a0..a15).  */
35   xtRegisterTypeVirtual,        /* PC, FP.  */
36   xtRegisterTypeUnknown
37 };
38 
39 #define XTENSA_REGISTER_FLAGS_PRIVILEGED        0x0001
40 #define XTENSA_REGISTER_FLAGS_READABLE          0x0002
41 #define XTENSA_REGISTER_FLAGS_WRITABLE          0x0004
42 #define XTENSA_REGISTER_FLAGS_VOLATILE          0x0008
43 
44 void xtensa_count_regs(const XtensaConfig *config,
45                        unsigned *n_regs, unsigned *n_core_regs)
46 {
47     unsigned i;
48 
49     for (i = 0; config->gdb_regmap.reg[i].targno >= 0; ++i) {
50         if (config->gdb_regmap.reg[i].type != xtRegisterTypeTieState &&
51             config->gdb_regmap.reg[i].type != xtRegisterTypeMapped &&
52             config->gdb_regmap.reg[i].type != xtRegisterTypeUnmapped) {
53             ++*n_regs;
54             if ((config->gdb_regmap.reg[i].flags &
55                  XTENSA_REGISTER_FLAGS_PRIVILEGED) == 0) {
56                 ++*n_core_regs;
57             }
58         }
59     }
60 }
61 
62 int xtensa_cpu_gdb_read_register(CPUState *cs, uint8_t *mem_buf, int n)
63 {
64     XtensaCPU *cpu = XTENSA_CPU(cs);
65     CPUXtensaState *env = &cpu->env;
66     const XtensaGdbReg *reg = env->config->gdb_regmap.reg + n;
67 #ifdef CONFIG_USER_ONLY
68     int num_regs = env->config->gdb_regmap.num_core_regs;
69 #else
70     int num_regs = env->config->gdb_regmap.num_regs;
71 #endif
72     unsigned i;
73 
74     if (n < 0 || n >= num_regs) {
75         return 0;
76     }
77 
78     switch (reg->type) {
79     case xtRegisterTypeVirtual: /*pc*/
80         return gdb_get_reg32(mem_buf, env->pc);
81 
82     case xtRegisterTypeArRegfile: /*ar*/
83         xtensa_sync_phys_from_window(env);
84         return gdb_get_reg32(mem_buf, env->phys_regs[(reg->targno & 0xff)
85                                                      % env->config->nareg]);
86 
87     case xtRegisterTypeSpecialReg: /*SR*/
88         return gdb_get_reg32(mem_buf, env->sregs[reg->targno & 0xff]);
89 
90     case xtRegisterTypeUserReg: /*UR*/
91         return gdb_get_reg32(mem_buf, env->uregs[reg->targno & 0xff]);
92 
93     case xtRegisterTypeTieRegfile: /*f*/
94         i = reg->targno & 0x0f;
95         switch (reg->size) {
96         case 4:
97             return gdb_get_reg32(mem_buf,
98                                  float32_val(env->fregs[i].f32[FP_F32_LOW]));
99         case 8:
100             return gdb_get_reg64(mem_buf, float64_val(env->fregs[i].f64));
101         default:
102             qemu_log_mask(LOG_UNIMP, "%s from reg %d of unsupported size %d\n",
103                           __func__, n, reg->size);
104             memset(mem_buf, 0, reg->size);
105             return reg->size;
106         }
107 
108     case xtRegisterTypeWindow: /*a*/
109         return gdb_get_reg32(mem_buf, env->regs[reg->targno & 0x0f]);
110 
111     default:
112         qemu_log_mask(LOG_UNIMP, "%s from reg %d of unsupported type %d\n",
113                       __func__, n, reg->type);
114         memset(mem_buf, 0, reg->size);
115         return reg->size;
116     }
117 }
118 
119 int xtensa_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
120 {
121     XtensaCPU *cpu = XTENSA_CPU(cs);
122     CPUXtensaState *env = &cpu->env;
123     uint32_t tmp;
124     const XtensaGdbReg *reg = env->config->gdb_regmap.reg + n;
125 #ifdef CONFIG_USER_ONLY
126     int num_regs = env->config->gdb_regmap.num_core_regs;
127 #else
128     int num_regs = env->config->gdb_regmap.num_regs;
129 #endif
130 
131     if (n < 0 || n >= num_regs) {
132         return 0;
133     }
134 
135     tmp = ldl_p(mem_buf);
136 
137     switch (reg->type) {
138     case xtRegisterTypeVirtual: /*pc*/
139         env->pc = tmp;
140         break;
141 
142     case xtRegisterTypeArRegfile: /*ar*/
143         env->phys_regs[(reg->targno & 0xff) % env->config->nareg] = tmp;
144         xtensa_sync_window_from_phys(env);
145         break;
146 
147     case xtRegisterTypeSpecialReg: /*SR*/
148         env->sregs[reg->targno & 0xff] = tmp;
149         break;
150 
151     case xtRegisterTypeUserReg: /*UR*/
152         env->uregs[reg->targno & 0xff] = tmp;
153         break;
154 
155     case xtRegisterTypeTieRegfile: /*f*/
156         switch (reg->size) {
157         case 4:
158             env->fregs[reg->targno & 0x0f].f32[FP_F32_LOW] = make_float32(tmp);
159             return 4;
160         case 8:
161             env->fregs[reg->targno & 0x0f].f64 = make_float64(tmp);
162             return 8;
163         default:
164             qemu_log_mask(LOG_UNIMP, "%s to reg %d of unsupported size %d\n",
165                           __func__, n, reg->size);
166             return reg->size;
167         }
168 
169     case xtRegisterTypeWindow: /*a*/
170         env->regs[reg->targno & 0x0f] = tmp;
171         break;
172 
173     default:
174         qemu_log_mask(LOG_UNIMP, "%s to reg %d of unsupported type %d\n",
175                       __func__, n, reg->type);
176         return reg->size;
177     }
178 
179     return 4;
180 }
181