linux-user/riscv/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-common.h"
  22 #include "qemu/error-report.h"
  23 #include "qemu.h"
  24 #include "cpu_loop-common.h"
  25 #include "elf.h"
  26 #include "semihosting/common-semi.h"
  27
  28 void cpu_loop(CPURISCVState *env)
  29 {
  30     CPUState *cs = env_cpu(env);
  31     int trapnr, signum, sigcode;
  32     target_ulong sigaddr;
  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         signum = 0;
  42         sigcode = 0;
  43         sigaddr = 0;
  44
  45         switch (trapnr) {
  46         case EXCP_INTERRUPT:
  47             /* just indicate that signals should be handled asap */
  48             break;
  49         case EXCP_ATOMIC:
  50             cpu_exec_step_atomic(cs);
  51             break;
  52         case RISCV_EXCP_U_ECALL:
  53             env->pc += 4;
  54             if (env->gpr[xA7] == TARGET_NR_arch_specific_syscall + 15) {
  55                 /* riscv_flush_icache_syscall is a no-op in QEMU as
  56                    self-modifying code is automatically detected */
  57                 ret = 0;
  58             } else {
  59                 ret = do_syscall(env,
  60                                  env->gpr[(env->elf_flags & EF_RISCV_RVE)
  61                                     ? xT0 : xA7],
  62                                  env->gpr[xA0],
  63                                  env->gpr[xA1],
  64                                  env->gpr[xA2],
  65                                  env->gpr[xA3],
  66                                  env->gpr[xA4],
  67                                  env->gpr[xA5],
  68                                  0, 0);
  69             }
  70             if (ret == -TARGET_ERESTARTSYS) {
  71                 env->pc -= 4;
  72             } else if (ret != -TARGET_QEMU_ESIGRETURN) {
  73                 env->gpr[xA0] = ret;
  74             }
  75             if (cs->singlestep_enabled) {
  76                 goto gdbstep;
  77             }
  78             break;
  79         case RISCV_EXCP_ILLEGAL_INST:
  80             signum = TARGET_SIGILL;
  81             sigcode = TARGET_ILL_ILLOPC;
  82             break;
  83         case RISCV_EXCP_BREAKPOINT:
  84             signum = TARGET_SIGTRAP;
  85             sigcode = TARGET_TRAP_BRKPT;
  86             sigaddr = env->pc;
  87             break;
  88         case RISCV_EXCP_INST_PAGE_FAULT:
  89         case RISCV_EXCP_LOAD_PAGE_FAULT:
  90         case RISCV_EXCP_STORE_PAGE_FAULT:
  91             signum = TARGET_SIGSEGV;
  92             sigcode = TARGET_SEGV_MAPERR;
  93             sigaddr = env->badaddr;
  94             break;
  95         case RISCV_EXCP_SEMIHOST:
  96             env->gpr[xA0] = do_common_semihosting(cs);
  97             env->pc += 4;
  98             break;
  99         case EXCP_DEBUG:
 100         gdbstep:
 101             signum = TARGET_SIGTRAP;
 102             sigcode = TARGET_TRAP_BRKPT;
 103             break;
 104         default:
 105             EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
 106                      trapnr);
 107             exit(EXIT_FAILURE);
 108         }
 109
 110         if (signum) {
 111             target_siginfo_t info = {
 112                 .si_signo = signum,
 113                 .si_errno = 0,
 114                 .si_code = sigcode,
 115                 ._sifields._sigfault._addr = sigaddr
 116             };
 117             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
 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     CPUState *cpu = env_cpu(env);
 127     TaskState *ts = cpu->opaque;
 128     struct image_info *info = ts->info;
 129
 130     env->pc = regs->sepc;
 131     env->gpr[xSP] = regs->sp;
 132     env->elf_flags = info->elf_flags;
 133
 134     if ((env->misa & RVE) && !(env->elf_flags & EF_RISCV_RVE)) {
 135         error_report("Incompatible ELF: RVE cpu requires RVE ABI binary");
 136         exit(EXIT_FAILURE);
 137     }
 138
 139     ts->stack_base = info->start_stack;
 140     ts->heap_base = info->brk;
 141     /* This will be filled in on the first SYS_HEAPINFO call.  */
 142     ts->heap_limit = 0;
 143 }