1/*
2 * QEMU Nios II CPU
3 *
4 * Copyright (c) 2012 Chris Wulff <crwulff@gmail.com>
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see
18 * <http://www.gnu.org/licenses/lgpl-2.1.html>
19 */
20
21#include "qemu/osdep.h"
22#include "qemu/module.h"
23#include "qapi/error.h"
24#include "cpu.h"
25#include "exec/log.h"
26#include "exec/gdbstub.h"
27#include "hw/qdev-properties.h"
28
29static void nios2_cpu_set_pc(CPUState *cs, vaddr value)
30{
31 Nios2CPU *cpu = NIOS2_CPU(cs);
32 CPUNios2State *env = &cpu->env;
33
34 env->regs[R_PC] = value;
35}
36
37static bool nios2_cpu_has_work(CPUState *cs)
38{
39 return cs->interrupt_request & (CPU_INTERRUPT_HARD | CPU_INTERRUPT_NMI);
40}
41
42/* CPUClass::reset() */
43static void nios2_cpu_reset(CPUState *cs)
44{
45 Nios2CPU *cpu = NIOS2_CPU(cs);
46 Nios2CPUClass *ncc = NIOS2_CPU_GET_CLASS(cpu);
47 CPUNios2State *env = &cpu->env;
48
49 if (qemu_loglevel_mask(CPU_LOG_RESET)) {
50 qemu_log("CPU Reset (CPU %d)\n", cs->cpu_index);
51 log_cpu_state(cs, 0);
52 }
53
54 ncc->parent_reset(cs);
55
56 memset(env->regs, 0, sizeof(uint32_t) * NUM_CORE_REGS);
57 env->regs[R_PC] = cpu->reset_addr;
58
59#if defined(CONFIG_USER_ONLY)
60 /* Start in user mode with interrupts enabled. */
61 env->regs[CR_STATUS] = CR_STATUS_U | CR_STATUS_PIE;
62#else
63 env->regs[CR_STATUS] = 0;
64#endif
65}
66
67static void nios2_cpu_initfn(Object *obj)
68{
69 Nios2CPU *cpu = NIOS2_CPU(obj);
70
71 cpu_set_cpustate_pointers(cpu);
72
73#if !defined(CONFIG_USER_ONLY)
74 mmu_init(&cpu->env);
75#endif
76}
77
78static ObjectClass *nios2_cpu_class_by_name(const char *cpu_model)
79{
80 return object_class_by_name(TYPE_NIOS2_CPU);
81}
82
83static void nios2_cpu_realizefn(DeviceState *dev, Error **errp)
84{
85 CPUState *cs = CPU(dev);
86 Nios2CPUClass *ncc = NIOS2_CPU_GET_CLASS(dev);
87 Error *local_err = NULL;
88
89 cpu_exec_realizefn(cs, &local_err);
90 if (local_err != NULL) {
91 error_propagate(errp, local_err);
92 return;
93 }
94
95 qemu_init_vcpu(cs);
96 cpu_reset(cs);
97
98 ncc->parent_realize(dev, errp);
99}
100
101static bool nios2_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
102{
103 Nios2CPU *cpu = NIOS2_CPU(cs);
104 CPUNios2State *env = &cpu->env;
105
106 if ((interrupt_request & CPU_INTERRUPT_HARD) &&
107 (env->regs[CR_STATUS] & CR_STATUS_PIE)) {
108 cs->exception_index = EXCP_IRQ;
109 nios2_cpu_do_interrupt(cs);
110 return true;
111 }
112 return false;
113}
114
115
116static void nios2_cpu_disas_set_info(CPUState *cpu, disassemble_info *info)
117{
118 /* NOTE: NiosII R2 is not supported yet. */
119 info->mach = bfd_arch_nios2;
120#ifdef TARGET_WORDS_BIGENDIAN
121 info->print_insn = print_insn_big_nios2;
122#else
123 info->print_insn = print_insn_little_nios2;
124#endif
125}
126
127static int nios2_cpu_gdb_read_register(CPUState *cs, uint8_t *mem_buf, int n)
128{
129 Nios2CPU *cpu = NIOS2_CPU(cs);
130 CPUClass *cc = CPU_GET_CLASS(cs);
131 CPUNios2State *env = &cpu->env;
132
133 if (n > cc->gdb_num_core_regs) {
134 return 0;
135 }
136
137 if (n < 32) { /* GP regs */
138 return gdb_get_reg32(mem_buf, env->regs[n]);
139 } else if (n == 32) { /* PC */
140 return gdb_get_reg32(mem_buf, env->regs[R_PC]);
141 } else if (n < 49) { /* Status regs */
142 return gdb_get_reg32(mem_buf, env->regs[n - 1]);
143 }
144
145 /* Invalid regs */
146 return 0;
147}
148
149static int nios2_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
150{
151 Nios2CPU *cpu = NIOS2_CPU(cs);
152 CPUClass *cc = CPU_GET_CLASS(cs);
153 CPUNios2State *env = &cpu->env;
154
155 if (n > cc->gdb_num_core_regs) {
156 return 0;
157 }
158
159 if (n < 32) { /* GP regs */
160 env->regs[n] = ldl_p(mem_buf);
161 } else if (n == 32) { /* PC */
162 env->regs[R_PC] = ldl_p(mem_buf);
163 } else if (n < 49) { /* Status regs */
164 env->regs[n - 1] = ldl_p(mem_buf);
165 }
166
167 return 4;
168}
169
170static Property nios2_properties[] = {
171 DEFINE_PROP_BOOL("mmu_present", Nios2CPU, mmu_present, true),
172 /* ALTR,pid-num-bits */
173 DEFINE_PROP_UINT32("mmu_pid_num_bits", Nios2CPU, pid_num_bits, 8),
174 /* ALTR,tlb-num-ways */
175 DEFINE_PROP_UINT32("mmu_tlb_num_ways", Nios2CPU, tlb_num_ways, 16),
176 /* ALTR,tlb-num-entries */
177 DEFINE_PROP_UINT32("mmu_pid_num_entries", Nios2CPU, tlb_num_entries, 256),
178 DEFINE_PROP_END_OF_LIST(),
179};
180
181
182static void nios2_cpu_class_init(ObjectClass *oc, void *data)
183{
184 DeviceClass *dc = DEVICE_CLASS(oc);
185 CPUClass *cc = CPU_CLASS(oc);
186 Nios2CPUClass *ncc = NIOS2_CPU_CLASS(oc);
187
188 device_class_set_parent_realize(dc, nios2_cpu_realizefn,
189 &ncc->parent_realize);
190 dc->props = nios2_properties;
191 ncc->parent_reset = cc->reset;
192 cc->reset = nios2_cpu_reset;
193
194 cc->class_by_name = nios2_cpu_class_by_name;
195 cc->has_work = nios2_cpu_has_work;
196 cc->do_interrupt = nios2_cpu_do_interrupt;
197 cc->cpu_exec_interrupt = nios2_cpu_exec_interrupt;
198 cc->dump_state = nios2_cpu_dump_state;
199 cc->set_pc = nios2_cpu_set_pc;
200 cc->disas_set_info = nios2_cpu_disas_set_info;
201 cc->tlb_fill = nios2_cpu_tlb_fill;
202#ifndef CONFIG_USER_ONLY
203 cc->do_unaligned_access = nios2_cpu_do_unaligned_access;
204 cc->get_phys_page_debug = nios2_cpu_get_phys_page_debug;
205#endif
206 cc->gdb_read_register = nios2_cpu_gdb_read_register;
207 cc->gdb_write_register = nios2_cpu_gdb_write_register;
208 cc->gdb_num_core_regs = 49;
209 cc->tcg_initialize = nios2_tcg_init;
210}
211
212static const TypeInfo nios2_cpu_type_info = {
213 .name = TYPE_NIOS2_CPU,
214 .parent = TYPE_CPU,
215 .instance_size = sizeof(Nios2CPU),
216 .instance_init = nios2_cpu_initfn,
217 .class_size = sizeof(Nios2CPUClass),
218 .class_init = nios2_cpu_class_init,
219};
220
221static void nios2_cpu_register_types(void)
222{
223 type_register_static(&nios2_cpu_type_info);
224}
225
226type_init(nios2_cpu_register_types)
227