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_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
 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 }