LXR qemu/linux-user/nios2/cpu

   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
  26void cpu_loop(CPUNios2State *env)
  27{
  28    CPUState *cs = env_cpu(env);
  29    Nios2CPU *cpu = NIOS2_CPU(cs);
  30    target_siginfo_t info;
  31    int trapnr, ret;
  32
  33    for (;;) {
  34        cpu_exec_start(cs);
  35        trapnr = cpu_exec(cs);
  36        cpu_exec_end(cs);
  37
  38        switch (trapnr) {
  39        case EXCP_INTERRUPT:
  40            /* just indicate that signals should be handled asap */
  41            break;
  42        case EXCP_TRAP:
  43            if (env->regs[R_AT] == 0) {
  44                abi_long ret;
  45                qemu_log_mask(CPU_LOG_INT, "\nSyscall\n");
  46
  47                ret = do_syscall(env, env->regs[2],
  48                                 env->regs[4], env->regs[5], env->regs[6],
  49                                 env->regs[7], env->regs[8], env->regs[9],
  50                                 0, 0);
  51
  52                if (env->regs[2] == 0) {    /* FIXME: syscall 0 workaround */
  53                    ret = 0;
  54                }
  55
  56                env->regs[2] = abs(ret);
  57                /* Return value is 0..4096 */
  58                env->regs[7] = (ret > 0xfffffffffffff000ULL);
  59                env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
  60                env->regs[CR_STATUS] &= ~0x3;
  61                env->regs[R_EA] = env->regs[R_PC] + 4;
  62                env->regs[R_PC] += 4;
  63                break;
  64            } else {
  65                qemu_log_mask(CPU_LOG_INT, "\nTrap\n");
  66
  67                env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
  68                env->regs[CR_STATUS] &= ~0x3;
  69                env->regs[R_EA] = env->regs[R_PC] + 4;
  70                env->regs[R_PC] = cpu->exception_addr;
  71
  72                info.si_signo = TARGET_SIGTRAP;
  73                info.si_errno = 0;
  74                info.si_code = TARGET_TRAP_BRKPT;
  75                queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
  76                break;
  77            }
  78        case EXCP_DEBUG:
  79            info.si_signo = TARGET_SIGTRAP;
  80            info.si_errno = 0;
  81            info.si_code = TARGET_TRAP_BRKPT;
  82            queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
  83            break;
  84        case 0xaa:
  85            switch (env->regs[R_PC]) {
  86            /*case 0x1000:*/  /* TODO:__kuser_helper_version */
  87            case 0x1004:      /* __kuser_cmpxchg */
  88                start_exclusive();
  89                if (env->regs[4] & 0x3) {
  90                    goto kuser_fail;
  91                }
  92                ret = get_user_u32(env->regs[2], env->regs[4]);
  93                if (ret) {
  94                    end_exclusive();
  95                    goto kuser_fail;
  96                }
  97                env->regs[2] -= env->regs[5];
  98                if (env->regs[2] == 0) {
  99                    put_user_u32(env->regs[6], env->regs[4]);
 100                }
 101                end_exclusive();
 102                env->regs[R_PC] = env->regs[R_RA];
 103                break;
 104            /*case 0x1040:*/  /* TODO:__kuser_sigtramp */
 105            default:
 106                ;
 107kuser_fail:
 108                info.si_signo = TARGET_SIGSEGV;
 109                info.si_errno = 0;
 110                /* TODO: check env->error_code */
 111                info.si_code = TARGET_SEGV_MAPERR;
 112                info._sifields._sigfault._addr = env->regs[R_PC];
 113                queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
 114            }
 115            break;
 116        default:
 117            EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
 118                     trapnr);
 119            abort();
 120        }
 121
 122        process_pending_signals(env);
 123    }
 124}
 125
 126void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
 127{
 128    env->regs[0] = 0;
 129    env->regs[1] = regs->r1;
 130    env->regs[2] = regs->r2;
 131    env->regs[3] = regs->r3;
 132    env->regs[4] = regs->r4;
 133    env->regs[5] = regs->r5;
 134    env->regs[6] = regs->r6;
 135    env->regs[7] = regs->r7;
 136    env->regs[8] = regs->r8;
 137    env->regs[9] = regs->r9;
 138    env->regs[10] = regs->r10;
 139    env->regs[11] = regs->r11;
 140    env->regs[12] = regs->r12;
 141    env->regs[13] = regs->r13;
 142    env->regs[14] = regs->r14;
 143    env->regs[15] = regs->r15;
 144    /* TODO: unsigned long  orig_r2; */
 145    env->regs[R_RA] = regs->ra;
 146    env->regs[R_FP] = regs->fp;
 147    env->regs[R_SP] = regs->sp;
 148    env->regs[R_GP] = regs->gp;
 149    env->regs[CR_ESTATUS] = regs->estatus;
 150    env->regs[R_EA] = regs->ea;
 151    /* TODO: unsigned long  orig_r7; */
 152
 153    /* Emulate eret when starting thread. */
 154    env->regs[R_PC] = regs->ea;
 155}
 156