riscv/sim.cc

   1 // See LICENSE for license details.
   2
   3 #include "sim.h"
   4 #include "htif.h"
   5 #include <map>
   6 #include <iostream>
   7 #include <climits>
   8 #include <cstdlib>
   9 #include <cassert>
  10 #include <signal.h>
  11
  12 volatile bool ctrlc_pressed = false;
  13 static void handle_signal(int sig)
  14 {
  15   if (ctrlc_pressed)
  16     exit(-1);
  17   ctrlc_pressed = true;
  18   signal(sig, &handle_signal);
  19 }
  20
  21 sim_t::sim_t(size_t nprocs, size_t mem_mb, const std::vector<std::string>& args)
  22   : htif(new htif_isasim_t(this, args)), procs(std::max(nprocs, size_t(1))),
  23     current_step(0), current_proc(0), debug(false)
  24 {
  25   signal(SIGINT, &handle_signal);
  26   // allocate target machine's memory, shrinking it as necessary
  27   // until the allocation succeeds
  28   size_t memsz0 = (size_t)mem_mb << 20;
  29   size_t quantum = 1L << 20;
  30   if (memsz0 == 0)
  31     memsz0 = 1L << (sizeof(size_t) == 8 ? 32 : 30);
  32
  33   memsz = memsz0;
  34   while ((mem = (char*)calloc(1, memsz)) == NULL)
  35     memsz = memsz*10/11/quantum*quantum;
  36
  37   if (memsz != memsz)
  38     fprintf(stderr, "warning: only got %lu bytes of target mem (wanted %lu)\n",
  39             (unsigned long)memsz, (unsigned long)memsz0);
  40
  41   debug_mmu = new mmu_t(mem, memsz);
  42
  43   for (size_t i = 0; i < procs.size(); i++)
  44     procs[i] = new processor_t(this, new mmu_t(mem, memsz), i);
  45 }
  46
  47 sim_t::~sim_t()
  48 {
  49   for (size_t i = 0; i < procs.size(); i++)
  50   {
  51     mmu_t* pmmu = procs[i]->get_mmu();
  52     delete procs[i];
  53     delete pmmu;
  54   }
  55   delete debug_mmu;
  56   free(mem);
  57 }
  58
  59 void sim_t::send_ipi(reg_t who)
  60 {
  61   if (who < procs.size())
  62     procs[who]->deliver_ipi();
  63 }
  64
  65 reg_t sim_t::get_scr(int which)
  66 {
  67   switch (which)
  68   {
  69     case 0: return procs.size();
  70     case 1: return memsz >> 20;
  71     default: return -1;
  72   }
  73 }
  74
  75 void sim_t::run()
  76 {
  77   while (!htif->done())
  78   {
  79     if (debug || ctrlc_pressed)
  80       interactive();
  81     else
  82       step(INTERLEAVE, false);
  83   }
  84 }
  85
  86 void sim_t::step(size_t n, bool noisy)
  87 {
  88   for (size_t i = 0, steps = 0; i < n; i += steps)
  89   {
  90     steps = std::min(n - i, INTERLEAVE - current_step);
  91     procs[current_proc]->step(steps, noisy);
  92
  93     current_step += steps;
  94     if (current_step == INTERLEAVE)
  95     {
  96       current_step = 0;
  97       procs[current_proc]->yield_load_reservation();
  98       if (++current_proc == procs.size())
  99         current_proc = 0;
 100
 101       htif->tick();
 102       if (!running())
 103         break;
 104     }
 105   }
 106 }
 107
 108 bool sim_t::running()
 109 {
 110   for (size_t i = 0; i < procs.size(); i++)
 111     if (procs[i]->running())
 112       return true;
 113   return false;
 114 }
 115
 116 void sim_t::stop()
 117 {
 118   procs[0]->state.tohost = 1;
 119   while (!htif->done())
 120     htif->tick();
 121 }