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 "cpu_loop-common.h"
23 
cpu_loop(CPUNios2State * env)24 void cpu_loop(CPUNios2State *env)
25 {
26     CPUState *cs = env_cpu(env);
27     Nios2CPU *cpu = NIOS2_CPU(cs);
28     target_siginfo_t info;
29     int trapnr, ret;
30 
31     for (;;) {
32         cpu_exec_start(cs);
33         trapnr = cpu_exec(cs);
34         cpu_exec_end(cs);
35 
36         switch (trapnr) {
37         case EXCP_INTERRUPT:
38             /* just indicate that signals should be handled asap */
39             break;
40         case EXCP_TRAP:
41             if (env->regs[R_AT] == 0) {
42                 abi_long ret;
43                 qemu_log_mask(CPU_LOG_INT, "\nSyscall\n");
44 
45                 ret = do_syscall(env, env->regs[2],
46                                  env->regs[4], env->regs[5], env->regs[6],
47                                  env->regs[7], env->regs[8], env->regs[9],
48                                  0, 0);
49 
50                 if (env->regs[2] == 0) {    /* FIXME: syscall 0 workaround */
51                     ret = 0;
52                 }
53 
54                 env->regs[2] = abs(ret);
55                 /* Return value is 0..4096 */
56                 env->regs[7] = (ret > 0xfffffffffffff000ULL);
57                 env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
58                 env->regs[CR_STATUS] &= ~0x3;
59                 env->regs[R_EA] = env->regs[R_PC] + 4;
60                 env->regs[R_PC] += 4;
61                 break;
62             } else {
63                 qemu_log_mask(CPU_LOG_INT, "\nTrap\n");
64 
65                 env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
66                 env->regs[CR_STATUS] &= ~0x3;
67                 env->regs[R_EA] = env->regs[R_PC] + 4;
68                 env->regs[R_PC] = cpu->exception_addr;
69 
70                 info.si_signo = TARGET_SIGTRAP;
71                 info.si_errno = 0;
72                 info.si_code = TARGET_TRAP_BRKPT;
73                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
74                 break;
75             }
76         case EXCP_DEBUG:
77             info.si_signo = TARGET_SIGTRAP;
78             info.si_errno = 0;
79             info.si_code = TARGET_TRAP_BRKPT;
80             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
81             break;
82         case 0xaa:
83             switch (env->regs[R_PC]) {
84             /*case 0x1000:*/  /* TODO:__kuser_helper_version */
85             case 0x1004:      /* __kuser_cmpxchg */
86                 start_exclusive();
87                 if (env->regs[4] & 0x3) {
88                     goto kuser_fail;
89                 }
90                 ret = get_user_u32(env->regs[2], env->regs[4]);
91                 if (ret) {
92                     end_exclusive();
93                     goto kuser_fail;
94                 }
95                 env->regs[2] -= env->regs[5];
96                 if (env->regs[2] == 0) {
97                     put_user_u32(env->regs[6], env->regs[4]);
98                 }
99                 end_exclusive();
100                 env->regs[R_PC] = env->regs[R_RA];
101                 break;
102             /*case 0x1040:*/  /* TODO:__kuser_sigtramp */
103             default:
104                 ;
105 kuser_fail:
106                 info.si_signo = TARGET_SIGSEGV;
107                 info.si_errno = 0;
108                 /* TODO: check env->error_code */
109                 info.si_code = TARGET_SEGV_MAPERR;
110                 info._sifields._sigfault._addr = env->regs[R_PC];
111                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
112             }
113             break;
114         default:
115             EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
116                      trapnr);
117             abort();
118         }
119 
120         process_pending_signals(env);
121     }
122 }
123 
target_cpu_copy_regs(CPUArchState * env,struct target_pt_regs * regs)124 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
125 {
126     env->regs[0] = 0;
127     env->regs[1] = regs->r1;
128     env->regs[2] = regs->r2;
129     env->regs[3] = regs->r3;
130     env->regs[4] = regs->r4;
131     env->regs[5] = regs->r5;
132     env->regs[6] = regs->r6;
133     env->regs[7] = regs->r7;
134     env->regs[8] = regs->r8;
135     env->regs[9] = regs->r9;
136     env->regs[10] = regs->r10;
137     env->regs[11] = regs->r11;
138     env->regs[12] = regs->r12;
139     env->regs[13] = regs->r13;
140     env->regs[14] = regs->r14;
141     env->regs[15] = regs->r15;
142     /* TODO: unsigned long  orig_r2; */
143     env->regs[R_RA] = regs->ra;
144     env->regs[R_FP] = regs->fp;
145     env->regs[R_SP] = regs->sp;
146     env->regs[R_GP] = regs->gp;
147     env->regs[CR_ESTATUS] = regs->estatus;
148     env->regs[R_EA] = regs->ea;
149     /* TODO: unsigned long  orig_r7; */
150 
151     /* Emulate eret when starting thread. */
152     env->regs[R_PC] = regs->ea;
153 }
154