Improve dts <-> dtb API

Avoid exposing the string args to the API.

Author: aswaterman

riscv/dts.cc

@@ -99,13 +99,10 @@ std::string make_dts(size_t insns_per_rtc_tick, size_t cpu_hz,
   return s.str();
 }
 
-std::string dtc_compile(const std::string& dtc_input, const std::string& input_type, const std::string& output_type)
+static std::string dtc_compile(const std::string& dtc_input, bool compile)
 {
-  if (input_type == output_type)
-    std::cerr << "Must have differing {in,out}put types for running " DTC << std::endl;
-
-  if (!((input_type == "dts" && output_type == "dtb") || (input_type == "dtb" && output_type == "dts")))
-    std::cerr << "Invalid {in,out}put types for running " DTC ": Must convert from 'dts' to 'dtb' (or vice versa)" << std::endl;
+  const std::string input_type = compile ? "dts" : "dtb";
+  const std::string output_type = compile ? "dtb" : "dts";
 
   int dtc_input_pipe[2];
   pid_t dtc_input_pid;
@@ -186,6 +183,16 @@ std::string dtc_compile(const std::string& dtc_input, const std::string& input_t
   return dtc_output.str();
 }
 
+std::string dtb_to_dts(const std::string& dtc_input)
+{
+  return dtc_compile(dtc_input, false);
+}
+
+std::string dts_to_dtb(const std::string& dtc_input)
+{
+  return dtc_compile(dtc_input, true);
+}
+
 int fdt_get_node_addr_size(const void *fdt, int node, reg_t *addr,
                            unsigned long *size, const char *field)
 {

riscv/dts.h

@@ -11,7 +11,8 @@ std::string make_dts(size_t insns_per_rtc_tick, size_t cpu_hz,
                      std::vector<std::pair<reg_t, abstract_mem_t*>> mems,
                      std::string device_nodes);
 
-std::string dtc_compile(const std::string& dtc_input, const std::string& input_type, const std::string& output_type);
+std::string dts_to_dtb(const std::string& dtc_input);
+std::string dtb_to_dts(const std::string& dtc_input);
 
 int fdt_get_node_addr_size(const void *fdt, int node, reg_t *addr,
                            unsigned long *size, const char *field);

riscv/sim.cc

@@ -133,7 +133,7 @@ sim_t::sim_t(const cfg_t *cfg, bool halted,
     std::stringstream strstream;
     strstream << fin.rdbuf();
     dtb = strstream.str();
-    dts = dtc_compile(dtb, "dtb", "dts");
+    dts = dtb_to_dts(dtb);
   } else {
     std::pair<reg_t, reg_t> initrd_bounds = cfg->initrd_bounds;
     std::string device_nodes;
@@ -143,7 +143,7 @@ sim_t::sim_t(const cfg_t *cfg, bool halted,
       device_nodes.append(factory->generate_dts(this, sargs));
     }
     dts = make_dts(INSNS_PER_RTC_TICK, CPU_HZ, cfg, mems, device_nodes);
-    dtb = dtc_compile(dts, "dts", "dtb");
+    dtb = dts_to_dtb(dts);
   }
 
   int fdt_code = fdt_check_header(dtb.c_str());