Initial step towards factoring out command line configuration

This commit defines a "cfg_t" structure, which currently just holds
the initrd address range. It will be augmented in future commits to
hold other configuration arguments as well.

To represent a configuration argument, we define an arg_t base class.
This holds a current value, together with a flag that tells us whether
the value has been updated from the default. The idea is that in
future we're going to use that flag when reading a DTB file: if an
argument has actually been specified on the command line, we need to
take it into account; if not, we can ignore the default and use the
DTB file's supplied value.

1 files changed, 6 insertions, 5 deletions

diff --git a/riscv/sim.h b/riscv/sim.h
index 518d75e..31c9254 100644
--- a/riscv/sim.h
+++ b/riscv/sim.h
@@ -11,6 +11,7 @@
 #include <boost/asio.hpp>
 #endif
 
+#include "cfg.h"
 #include "debug_module.h"
 #include "devices.h"
 #include "log_file.h"
@@ -31,9 +32,9 @@ class remote_bitbang_t;
 class sim_t : public htif_t, public simif_t
 {
 public:
-  sim_t(const char* isa, const char* priv, const char* varch, size_t _nprocs,
-        bool halted, bool real_time_clint,
-        reg_t initrd_start, reg_t initrd_end, const char* bootargs,
+  sim_t(const cfg_t *cfg,
+        const char* isa, const char* priv, const char* varch, size_t _nprocs,
+        bool halted, bool real_time_clint, const char* bootargs,
         reg_t start_pc, 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,
@@ -71,12 +72,12 @@ public:
 
 private:
   isa_parser_t isa;
+  const cfg_t * const cfg;
   std::vector<std::pair<reg_t, mem_t*>> mems;
   std::vector<std::pair<reg_t, abstract_device_t*>> plugin_devices;
   mmu_t* debug_mmu;  // debug port into main memory
   std::vector<processor_t*> procs;
-  reg_t initrd_start;
-  reg_t initrd_end;
+  std::pair<reg_t, reg_t> initrd_range;
   const char* bootargs;
   reg_t start_pc;
   std::string dts;