xref: /openbmc/qemu/linux-user/hexagon/cpu_loop.c (revision 4921d0a7)
1 /*
2  *  qemu user cpu loop
3  *
4  *  Copyright (c) 2003-2008 Fabrice Bellard
5  *  Copyright(c) 2019-2021 Qualcomm Innovation Center, Inc. All Rights Reserved.
6  *
7  *  This program is free software; you can redistribute it and/or modify
8  *  it under the terms of the GNU General Public License as published by
9  *  the Free Software Foundation; either version 2 of the License, or
10  *  (at your option) any later version.
11  *
12  *  This program 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
15  *  GNU General Public License for more details.
16  *
17  *  You should have received a copy of the GNU General Public License
18  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include "qemu/osdep.h"
22 #include "qemu.h"
23 #include "user-internals.h"
24 #include "cpu_loop-common.h"
25 #include "signal-common.h"
26 #include "internal.h"
27 
28 void cpu_loop(CPUHexagonState *env)
29 {
30     CPUState *cs = env_cpu(env);
31     int trapnr;
32     target_ulong syscallnum;
33     target_ulong ret;
34 
35     for (;;) {
36         cpu_exec_start(cs);
37         trapnr = cpu_exec(cs);
38         cpu_exec_end(cs);
39         process_queued_cpu_work(cs);
40 
41         switch (trapnr) {
42         case EXCP_INTERRUPT:
43             /* just indicate that signals should be handled asap */
44             break;
45         case HEX_EXCP_TRAP0:
46             syscallnum = env->gpr[6];
47             env->gpr[HEX_REG_PC] += 4;
48             ret = do_syscall(env,
49                              syscallnum,
50                              env->gpr[0],
51                              env->gpr[1],
52                              env->gpr[2],
53                              env->gpr[3],
54                              env->gpr[4],
55                              env->gpr[5],
56                              0, 0);
57             if (ret == -QEMU_ERESTARTSYS) {
58                 env->gpr[HEX_REG_PC] -= 4;
59             } else if (ret != -QEMU_ESIGRETURN) {
60                 env->gpr[0] = ret;
61             }
62             break;
63         case EXCP_ATOMIC:
64             cpu_exec_step_atomic(cs);
65             break;
66         case EXCP_DEBUG:
67             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, 0);
68             break;
69         default:
70             EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
71                      trapnr);
72             exit(EXIT_FAILURE);
73         }
74         process_pending_signals(env);
75     }
76 }
77 
78 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
79 {
80     env->gpr[HEX_REG_PC] = regs->sepc;
81     env->gpr[HEX_REG_SP] = regs->sp;
82     env->gpr[HEX_REG_USR] = 0x56000;
83 }
84