From 970466e6ebcf4957f131fde8b62ca10fb70b2bd6 Mon Sep 17 00:00:00 2001
From: Rupert Swarbrick <rswarbrick@lowrisc.org>
Date: Thu, 24 Mar 2022 22:00:46 +0000
Subject: [PATCH] Move start_pc into cfg_t

---
 riscv/cfg.h         | 2 ++
 riscv/sim.cc        | 5 ++---
 riscv/sim.h         | 3 +--
 spike_main/spike.cc | 5 ++---
 4 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/riscv/cfg.h b/riscv/cfg.h
index e844738b..1e08f80e 100644
--- a/riscv/cfg.h
+++ b/riscv/cfg.h
@@ -2,6 +2,7 @@
 #ifndef _RISCV_CFG_H
 #define _RISCV_CFG_H
 
+#include <optional>
 #include "decode.h"
 #include "mmu.h"
 #include <cassert>
@@ -70,6 +71,7 @@ public:
   cfg_arg_t<const char *>            isa;
   cfg_arg_t<const char *>            priv;
   cfg_arg_t<std::vector<mem_cfg_t>>  mem_layout;
+  std::optional<reg_t>               start_pc;
 };
 
 #endif
diff --git a/riscv/sim.cc b/riscv/sim.cc
index 90fa210a..4e3dd409 100644
--- a/riscv/sim.cc
+++ b/riscv/sim.cc
@@ -29,7 +29,7 @@ static void handle_signal(int sig)
 }
 
 sim_t::sim_t(const cfg_t *cfg, const char* varch, bool halted, bool real_time_clint,
-             reg_t start_pc, std::vector<std::pair<reg_t, mem_t*>> mems,
+             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,
@@ -46,7 +46,6 @@ sim_t::sim_t(const cfg_t *cfg, const char* varch, bool halted, bool real_time_cl
     mems(mems),
     plugin_devices(plugin_devices),
     procs(std::max(cfg->nprocs(), size_t(1))),
-    start_pc(start_pc),
     dtb_file(dtb_file ? dtb_file : ""),
     dtb_enabled(dtb_enabled),
     log_file(log_path),
@@ -334,7 +333,7 @@ void sim_t::set_rom()
 {
   const int reset_vec_size = 8;
 
-  start_pc = start_pc == reg_t(-1) ? get_entry_point() : start_pc;
+  reg_t start_pc = cfg->start_pc.value_or(get_entry_point());
 
   uint32_t reset_vec[reset_vec_size] = {
     0x297,                                      // auipc  t0,0x0
diff --git a/riscv/sim.h b/riscv/sim.h
index fc20a2c8..6acc4409 100644
--- a/riscv/sim.h
+++ b/riscv/sim.h
@@ -33,7 +33,7 @@ class sim_t : public htif_t, public simif_t
 {
 public:
   sim_t(const cfg_t *cfg, const char* varch, bool halted, bool real_time_clint,
-        reg_t start_pc, std::vector<std::pair<reg_t, mem_t*>> mems,
+        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 debug_module_config_t &dm_config, const char *log_path,
@@ -76,7 +76,6 @@ private:
   mmu_t* debug_mmu;  // debug port into main memory
   std::vector<processor_t*> procs;
   std::pair<reg_t, reg_t> initrd_range;
-  reg_t start_pc;
   std::string dts;
   std::string dtb;
   std::string dtb_file;
diff --git a/spike_main/spike.cc b/spike_main/spike.cc
index 3080efbd..7791fbfc 100644
--- a/spike_main/spike.cc
+++ b/spike_main/spike.cc
@@ -232,7 +232,6 @@ int main(int argc, char** argv)
   bool real_time_clint = false;
   const char* kernel = NULL;
   reg_t kernel_offset, kernel_size;
-  reg_t start_pc = reg_t(-1);
   std::vector<std::pair<reg_t, abstract_device_t*>> plugin_devices;
   std::unique_ptr<icache_sim_t> ic;
   std::unique_ptr<dcache_sim_t> dc;
@@ -335,7 +334,7 @@ int main(int argc, char** argv)
   // I wanted to use --halted, but for some reason that doesn't work.
   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){start_pc = strtoull(s, 0, 0);});
+  parser.option(0, "pc", 1, [&](const char* s){cfg.start_pc = strtoull(s, 0, 0);});
   parser.option(0, "hartids", 1, hartids_parser);
   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));});
@@ -457,7 +456,7 @@ int main(int argc, char** argv)
 #endif
 
   sim_t s(&cfg, varch, halted, real_time_clint,
-      start_pc, mems, plugin_devices, htif_args,
+      mems, plugin_devices, htif_args,
       std::move(hartids), dm_config, log_path, dtb_enabled, dtb_file,
 #ifdef HAVE_BOOST_ASIO
       io_service_ptr, acceptor_ptr,