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 "cpu_loop-common.h"
  23
  24void 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, 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                ;
 105kuser_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
 124void 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