1 /*
2  *  qemu user cpu loop
3  *
4  *  Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program 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
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "qemu.h"
22 #include "user-internals.h"
23 #include "cpu_loop-common.h"
24 #include "signal-common.h"
25 
26 void cpu_loop(CPUMBState *env)
27 {
28     int trapnr, ret, si_code, sig;
29     CPUState *cs = env_cpu(env);
30 
31     while (1) {
32         cpu_exec_start(cs);
33         trapnr = cpu_exec(cs);
34         cpu_exec_end(cs);
35         process_queued_cpu_work(cs);
36 
37         switch (trapnr) {
38         case EXCP_INTERRUPT:
39             /* just indicate that signals should be handled asap */
40             break;
41         case EXCP_SYSCALL:
42             /* Return address is 4 bytes after the call.  */
43             env->regs[14] += 4;
44             env->pc = env->regs[14];
45             ret = do_syscall(env,
46                              env->regs[12],
47                              env->regs[5],
48                              env->regs[6],
49                              env->regs[7],
50                              env->regs[8],
51                              env->regs[9],
52                              env->regs[10],
53                              0, 0);
54             if (ret == -QEMU_ERESTARTSYS) {
55                 /* Wind back to before the syscall. */
56                 env->pc -= 4;
57             } else if (ret != -QEMU_ESIGRETURN) {
58                 env->regs[3] = ret;
59             }
60             /* All syscall exits result in guest r14 being equal to the
61              * PC we return to, because the kernel syscall exit "rtbd" does
62              * this. (This is true even for sigreturn(); note that r14 is
63              * not a userspace-usable register, as the kernel may clobber it
64              * at any point.)
65              */
66             env->regs[14] = env->pc;
67             break;
68 
69         case EXCP_HW_EXCP:
70             env->regs[17] = env->pc + 4;
71             if (env->iflags & D_FLAG) {
72                 env->esr |= 1 << 12;
73                 env->pc -= 4;
74                 /* FIXME: if branch was immed, replay the imm as well.  */
75             }
76             env->iflags &= ~(IMM_FLAG | D_FLAG);
77             switch (env->esr & 31) {
78             case ESR_EC_DIVZERO:
79                 sig = TARGET_SIGFPE;
80                 si_code = TARGET_FPE_INTDIV;
81                 break;
82             case ESR_EC_FPU:
83                 /*
84                  * Note that the kernel passes along fsr as si_code
85                  * if there's no recognized bit set.  Possibly this
86                  * implies that si_code is 0, but follow the structure.
87                  */
88                 sig = TARGET_SIGFPE;
89                 si_code = env->fsr;
90                 if (si_code & FSR_IO) {
91                     si_code = TARGET_FPE_FLTINV;
92                 } else if (si_code & FSR_OF) {
93                     si_code = TARGET_FPE_FLTOVF;
94                 } else if (si_code & FSR_UF) {
95                     si_code = TARGET_FPE_FLTUND;
96                 } else if (si_code & FSR_DZ) {
97                     si_code = TARGET_FPE_FLTDIV;
98                 } else if (si_code & FSR_DO) {
99                     si_code = TARGET_FPE_FLTRES;
100                 }
101                 break;
102             case ESR_EC_PRIVINSN:
103                 sig = SIGILL;
104                 si_code = ILL_PRVOPC;
105                 break;
106             default:
107                 fprintf(stderr, "Unhandled hw-exception: 0x%x\n",
108                         env->esr & ESR_EC_MASK);
109                 cpu_dump_state(cs, stderr, 0);
110                 exit(EXIT_FAILURE);
111             }
112             force_sig_fault(sig, si_code, env->pc);
113             break;
114 
115         case EXCP_DEBUG:
116             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
117             break;
118         case EXCP_ATOMIC:
119             cpu_exec_step_atomic(cs);
120             break;
121         default:
122             fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
123             cpu_dump_state(cs, stderr, 0);
124             exit(EXIT_FAILURE);
125         }
126         process_pending_signals (env);
127     }
128 }
129 
130 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
131 {
132     env->regs[0] = regs->r0;
133     env->regs[1] = regs->r1;
134     env->regs[2] = regs->r2;
135     env->regs[3] = regs->r3;
136     env->regs[4] = regs->r4;
137     env->regs[5] = regs->r5;
138     env->regs[6] = regs->r6;
139     env->regs[7] = regs->r7;
140     env->regs[8] = regs->r8;
141     env->regs[9] = regs->r9;
142     env->regs[10] = regs->r10;
143     env->regs[11] = regs->r11;
144     env->regs[12] = regs->r12;
145     env->regs[13] = regs->r13;
146     env->regs[14] = regs->r14;
147     env->regs[15] = regs->r15;
148     env->regs[16] = regs->r16;
149     env->regs[17] = regs->r17;
150     env->regs[18] = regs->r18;
151     env->regs[19] = regs->r19;
152     env->regs[20] = regs->r20;
153     env->regs[21] = regs->r21;
154     env->regs[22] = regs->r22;
155     env->regs[23] = regs->r23;
156     env->regs[24] = regs->r24;
157     env->regs[25] = regs->r25;
158     env->regs[26] = regs->r26;
159     env->regs[27] = regs->r27;
160     env->regs[28] = regs->r28;
161     env->regs[29] = regs->r29;
162     env->regs[30] = regs->r30;
163     env->regs[31] = regs->r31;
164     env->pc = regs->pc;
165 }
166