qemu

FORK: QEMU emulator
git clone https://git.neptards.moe/neptards/qemu.git
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cpu_loop.c (3771B)

      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/error-report.h"
     22 #include "qemu.h"
     23 #include "user-internals.h"
     24 #include "cpu_loop-common.h"
     25 #include "signal-common.h"
     26 #include "elf.h"
     27 #include "semihosting/common-semi.h"
     28 
     29 void cpu_loop(CPURISCVState *env)
     30 {
     31     CPUState *cs = env_cpu(env);
     32     int trapnr;
     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 EXCP_ATOMIC:
     46             cpu_exec_step_atomic(cs);
     47             break;
     48         case RISCV_EXCP_U_ECALL:
     49             env->pc += 4;
     50             if (env->gpr[xA7] == TARGET_NR_arch_specific_syscall + 15) {
     51                 /* riscv_flush_icache_syscall is a no-op in QEMU as
     52                    self-modifying code is automatically detected */
     53                 ret = 0;
     54             } else {
     55                 ret = do_syscall(env,
     56                                  env->gpr[(env->elf_flags & EF_RISCV_RVE)
     57                                     ? xT0 : xA7],
     58                                  env->gpr[xA0],
     59                                  env->gpr[xA1],
     60                                  env->gpr[xA2],
     61                                  env->gpr[xA3],
     62                                  env->gpr[xA4],
     63                                  env->gpr[xA5],
     64                                  0, 0);
     65             }
     66             if (ret == -QEMU_ERESTARTSYS) {
     67                 env->pc -= 4;
     68             } else if (ret != -QEMU_ESIGRETURN) {
     69                 env->gpr[xA0] = ret;
     70             }
     71             if (cs->singlestep_enabled) {
     72                 goto gdbstep;
     73             }
     74             break;
     75         case RISCV_EXCP_ILLEGAL_INST:
     76             force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPC, env->pc);
     77             break;
     78         case RISCV_EXCP_BREAKPOINT:
     79         case EXCP_DEBUG:
     80         gdbstep:
     81             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
     82             break;
     83         case RISCV_EXCP_SEMIHOST:
     84             do_common_semihosting(cs);
     85             env->pc += 4;
     86             break;
     87         default:
     88             EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
     89                      trapnr);
     90             exit(EXIT_FAILURE);
     91         }
     92 
     93         process_pending_signals(env);
     94     }
     95 }
     96 
     97 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
     98 {
     99     CPUState *cpu = env_cpu(env);
    100     TaskState *ts = cpu->opaque;
    101     struct image_info *info = ts->info;
    102 
    103     env->pc = regs->sepc;
    104     env->gpr[xSP] = regs->sp;
    105     env->elf_flags = info->elf_flags;
    106 
    107     if ((env->misa_ext & RVE) && !(env->elf_flags & EF_RISCV_RVE)) {
    108         error_report("Incompatible ELF: RVE cpu requires RVE ABI binary");
    109         exit(EXIT_FAILURE);
    110     }
    111 
    112     ts->stack_base = info->start_stack;
    113     ts->heap_base = info->brk;
    114     /* This will be filled in on the first SYS_HEAPINFO call.  */
    115     ts->heap_limit = 0;
    116 }