Move hartids into cfg_t

The only slightly difficult thing here is that hartids will always
be considered "overridden" by the time we get to sim_t::sim_t (either
overridden by a command line argument, or overridden when we set
default hartids just before the constructor). To allow downstream code
to distinguish between "I picked IDs 0, 1, 2, 3 because the user asked
for 4 processors" and "The user explicitly asked for IDs 0, 1, 2, 3",
we have an extra explicit_hartids field.

4 files changed, 28 insertions, 18 deletions

diff --git a/riscv/cfg.h b/riscv/cfg.h
index 1e08f80..6410c81 100644
--- a/riscv/cfg.h
+++ b/riscv/cfg.h
@@ -56,13 +56,16 @@ public:
   cfg_t(std::pair<reg_t, reg_t> default_initrd_bounds,
         const char *default_bootargs, size_t default_nprocs,
         const char *default_isa, const char *default_priv,
-        const std::vector<mem_cfg_t> &default_mem_layout)
+        const std::vector<mem_cfg_t> &default_mem_layout,
+        const std::vector<int> default_hartids)
     : initrd_bounds(default_initrd_bounds),
       bootargs(default_bootargs),
       nprocs(default_nprocs),
       isa(default_isa),
       priv(default_priv),
-      mem_layout(default_mem_layout)
+      mem_layout(default_mem_layout),
+      hartids(default_hartids),
+      explicit_hartids(false)
   {}
 
   cfg_arg_t<std::pair<reg_t, reg_t>> initrd_bounds;
@@ -72,6 +75,8 @@ public:
   cfg_arg_t<const char *>            priv;
   cfg_arg_t<std::vector<mem_cfg_t>>  mem_layout;
   std::optional<reg_t>               start_pc;
+  cfg_arg_t<std::vector<int>>        hartids;
+  bool                               explicit_hartids;
 };
 
 #endif
diff --git a/riscv/sim.cc b/riscv/sim.cc
index d285183..d7585ca 100644
--- a/riscv/sim.cc
+++ b/riscv/sim.cc
@@ -32,7 +32,6 @@ sim_t::sim_t(const cfg_t *cfg, const char* varch, bool halted, bool real_time_cl
              std::vector<std::pair<reg_t, mem_t*>> mems,
              std::vector<std::pair<reg_t, abstract_device_t*>> plugin_devices,
              const std::vector<std::string>& args,
-             std::vector<int> const hartids,
              const debug_module_config_t &dm_config,
              const char *log_path,
              bool dtb_enabled, const char *dtb_file,
@@ -63,7 +62,7 @@ sim_t::sim_t(const cfg_t *cfg, const char* varch, bool halted, bool real_time_cl
     remote_bitbang(NULL),
     debug_module(this, dm_config)
 {
-  assert(hartids.size() == cfg->nprocs());
+  assert(cfg->hartids().size() == cfg->nprocs());
 
   signal(SIGINT, &handle_signal);
 
@@ -79,8 +78,8 @@ sim_t::sim_t(const cfg_t *cfg, const char* varch, bool halted, bool real_time_cl
 
   debug_mmu = new mmu_t(this, NULL);
 
-  for (size_t i = 0; i < nprocs(); i++) {
-    procs[i] = new processor_t(&isa, varch, this, hartids[i], halted,
+  for (size_t i = 0; i < cfg->nprocs(); i++) {
+    procs[i] = new processor_t(&isa, varch, this, cfg->hartids()[i], halted,
                                log_file.get(), sout_);
   }
 
diff --git a/riscv/sim.h b/riscv/sim.h
index 6acc440..de82ccd 100644
--- a/riscv/sim.h
+++ b/riscv/sim.h
@@ -35,7 +35,7 @@ public:
   sim_t(const cfg_t *cfg, const char* varch, bool halted, bool real_time_clint,
         std::vector<std::pair<reg_t, mem_t*>> mems,
         std::vector<std::pair<reg_t, abstract_device_t*>> plugin_devices,
-        const std::vector<std::string>& args, const std::vector<int> hartids,
+        const std::vector<std::string>& args,
         const debug_module_config_t &dm_config, const char *log_path,
         bool dtb_enabled, const char *dtb_file,
 #ifdef HAVE_BOOST_ASIO
diff --git a/spike_main/spike.cc b/spike_main/spike.cc
index a3c18d1..12b8dc0 100644
--- a/spike_main/spike.cc
+++ b/spike_main/spike.cc
@@ -272,13 +272,13 @@ int main(int argc, char** argv)
     .support_haltgroups = true,
     .support_impebreak = true
   };
-  std::vector<int> hartids;
   cfg_t cfg(/*default_initrd_bounds=*/std::make_pair((reg_t)0, (reg_t)0),
             /*default_bootargs=*/nullptr,
             /*default_nprocs=*/1,
             /*default_isa=*/DEFAULT_ISA,
             /*default_priv=*/DEFAULT_PRIV,
-            /*default_mem_layout=*/parse_mem_layout("2048"));
+            /*default_mem_layout=*/parse_mem_layout("2048"),
+            /*default_hartids=*/std::vector<int>());
 
   auto const device_parser = [&plugin_devices](const char *s) {
     const std::string str(s);
@@ -338,7 +338,10 @@ int main(int argc, char** argv)
   parser.option('H', 0, 0, [&](const char* s){halted = true;});
   parser.option(0, "rbb-port", 1, [&](const char* s){use_rbb = true; rbb_port = atoul_safe(s);});
   parser.option(0, "pc", 1, [&](const char* s){cfg.start_pc = strtoull(s, 0, 0);});
-  parser.option(0, "hartids", 1, [&](const char* s){hartids = parse_hartids(s);});
+  parser.option(0, "hartids", 1, [&](const char* s){
+    cfg.hartids = parse_hartids(s);
+    cfg.explicit_hartids = true;
+  });
   parser.option(0, "ic", 1, [&](const char* s){ic.reset(new icache_sim_t(s));});
   parser.option(0, "dc", 1, [&](const char* s){dc.reset(new dcache_sim_t(s));});
   parser.option(0, "l2", 1, [&](const char* s){l2.reset(cache_sim_t::construct(s, "L2$"));});
@@ -458,25 +461,28 @@ int main(int argc, char** argv)
   }
 #endif
 
-  if (!hartids.empty()) {
-    if (cfg.nprocs.overridden() && (cfg.nprocs() != hartids.size())) {
+  if (cfg.explicit_hartids) {
+    if (cfg.nprocs.overridden() && (cfg.nprocs() != cfg.hartids().size())) {
       std::cerr << "Number of specified hartids ("
-                << hartids.size()
+                << cfg.hartids().size()
                 << ") doesn't match specified number of processors ("
                 << cfg.nprocs() << ").\n";
       exit(1);
     }
   } else {
-    // Set default set of hartids based on nprocs
-    hartids.reserve(cfg.nprocs());
+    // Set default set of hartids based on nprocs, but don't set the
+    // explicit_hartids flag (which means that downstream code can know that
+    // we've only set the number of harts, not explicitly chosen their IDs).
+    std::vector<int> default_hartids;
+    default_hartids.reserve(cfg.nprocs());
     for (size_t i = 0; i < cfg.nprocs(); ++i) {
-      hartids.push_back(i);
+      default_hartids.push_back(i);
     }
+    cfg.hartids = default_hartids;
   }
 
   sim_t s(&cfg, varch, halted, real_time_clint,
-      mems, plugin_devices, htif_args,
-      std::move(hartids), dm_config, log_path, dtb_enabled, dtb_file,
+      mems, plugin_devices, htif_args, dm_config, log_path, dtb_enabled, dtb_file,
 #ifdef HAVE_BOOST_ASIO
       io_service_ptr, acceptor_ptr,
 #endif