linux-user/nios2/cpu_loop.c

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