1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
|
/*
* M68K helper routines
*
* Copyright (c) 2007 CodeSourcery
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "exec.h"
#include "helpers.h"
#if defined(CONFIG_USER_ONLY)
void do_interrupt(int is_hw)
{
env->exception_index = -1;
}
#else
extern int semihosting_enabled;
#define MMUSUFFIX _mmu
#define SHIFT 0
#include "softmmu_template.h"
#define SHIFT 1
#include "softmmu_template.h"
#define SHIFT 2
#include "softmmu_template.h"
#define SHIFT 3
#include "softmmu_template.h"
/* Try to fill the TLB and return an exception if error. If retaddr is
NULL, it means that the function was called in C code (i.e. not
from generated code or from helper.c) */
/* XXX: fix it to restore all registers */
void tlb_fill (target_ulong addr, int is_write, int mmu_idx, void *retaddr)
{
TranslationBlock *tb;
CPUState *saved_env;
unsigned long pc;
int ret;
/* XXX: hack to restore env in all cases, even if not called from
generated code */
saved_env = env;
env = cpu_single_env;
ret = cpu_m68k_handle_mmu_fault(env, addr, is_write, mmu_idx, 1);
if (unlikely(ret)) {
if (retaddr) {
/* now we have a real cpu fault */
pc = (unsigned long)retaddr;
tb = tb_find_pc(pc);
if (tb) {
/* the PC is inside the translated code. It means that we have
a virtual CPU fault */
cpu_restore_state(tb, env, pc);
}
}
cpu_loop_exit();
}
env = saved_env;
}
static void do_rte(void)
{
uint32_t sp;
uint32_t fmt;
sp = env->aregs[7];
fmt = ldl_kernel(sp);
env->pc = ldl_kernel(sp + 4);
sp |= (fmt >> 28) & 3;
env->sr = fmt & 0xffff;
m68k_switch_sp(env);
env->aregs[7] = sp + 8;
}
void do_interrupt(int is_hw)
{
uint32_t sp;
uint32_t fmt;
uint32_t retaddr;
uint32_t vector;
fmt = 0;
retaddr = env->pc;
if (!is_hw) {
switch (env->exception_index) {
case EXCP_RTE:
/* Return from an exception. */
do_rte();
return;
case EXCP_HALT_INSN:
if (semihosting_enabled
&& (env->sr & SR_S) != 0
&& (env->pc & 3) == 0
&& lduw_code(env->pc - 4) == 0x4e71
&& ldl_code(env->pc) == 0x4e7bf000) {
env->pc += 4;
do_m68k_semihosting(env, env->dregs[0]);
return;
}
env->halted = 1;
env->exception_index = EXCP_HLT;
cpu_loop_exit();
return;
}
if (env->exception_index >= EXCP_TRAP0
&& env->exception_index <= EXCP_TRAP15) {
/* Move the PC after the trap instruction. */
retaddr += 2;
}
}
vector = env->exception_index << 2;
sp = env->aregs[7];
fmt |= 0x40000000;
fmt |= (sp & 3) << 28;
fmt |= vector << 16;
fmt |= env->sr;
env->sr |= SR_S;
if (is_hw) {
env->sr = (env->sr & ~SR_I) | (env->pending_level << SR_I_SHIFT);
env->sr &= ~SR_M;
}
m68k_switch_sp(env);
/* ??? This could cause MMU faults. */
sp &= ~3;
sp -= 4;
stl_kernel(sp, retaddr);
sp -= 4;
stl_kernel(sp, fmt);
env->aregs[7] = sp;
/* Jump to vector. */
env->pc = ldl_kernel(env->vbr + vector);
}
#endif
static void raise_exception(int tt)
{
env->exception_index = tt;
cpu_loop_exit();
}
void HELPER(raise_exception)(uint32_t tt)
{
raise_exception(tt);
}
void HELPER(divu)(CPUState *env, uint32_t word)
{
uint32_t num;
uint32_t den;
uint32_t quot;
uint32_t rem;
uint32_t flags;
num = env->div1;
den = env->div2;
/* ??? This needs to make sure the throwing location is accurate. */
if (den == 0)
raise_exception(EXCP_DIV0);
quot = num / den;
rem = num % den;
flags = 0;
/* Avoid using a PARAM1 of zero. This breaks dyngen because it uses
the address of a symbol, and gcc knows symbols can't have address
zero. */
if (word && quot > 0xffff)
flags |= CCF_V;
if (quot == 0)
flags |= CCF_Z;
else if ((int32_t)quot < 0)
flags |= CCF_N;
env->div1 = quot;
env->div2 = rem;
env->cc_dest = flags;
}
void HELPER(divs)(CPUState *env, uint32_t word)
{
int32_t num;
int32_t den;
int32_t quot;
int32_t rem;
int32_t flags;
num = env->div1;
den = env->div2;
if (den == 0)
raise_exception(EXCP_DIV0);
quot = num / den;
rem = num % den;
flags = 0;
if (word && quot != (int16_t)quot)
flags |= CCF_V;
if (quot == 0)
flags |= CCF_Z;
else if (quot < 0)
flags |= CCF_N;
env->div1 = quot;
env->div2 = rem;
env->cc_dest = flags;
}
|
