emu: output coverage to coverage.dat.

Makefile

@@ -69,7 +69,7 @@ EMU_CXXFLAGS += -std=c++11 -static -Wall -I$(EMU_CSRC_DIR)
 EMU_CXXFLAGS += -DVERILATOR -Wno-maybe-uninitialized
 EMU_LDFLAGS  += -lpthread -lSDL2 -ldl -lz
 
-VEXTRA_FLAGS  = -I$(abspath $(BUILD_DIR)) --x-assign unique -O3 -CFLAGS "$(EMU_CXXFLAGS)" -LDFLAGS "$(EMU_LDFLAGS)"
+VEXTRA_FLAGS  = -I$(abspath $(BUILD_DIR)) --x-assign unique -O3 -CFLAGS "$(EMU_CXXFLAGS)" -LDFLAGS "$(EMU_LDFLAGS)" --coverage-line
 
 # Verilator trace support
 EMU_TRACE ?=

src/test/csrc/emu.cpp

@@ -329,6 +329,7 @@ uint64_t Emulator::execute(uint64_t max_cycle, uint64_t max_instr) {
 #if VM_TRACE == 1
   if (enable_waveform) tfp->close();
 #endif
+  save_coverage();
   display_trapinfo();
   return cycles;
 }
@@ -358,6 +359,19 @@ inline char* Emulator::waveform_filename(time_t t) {
   return buf;
 }
 
+
+inline void Emulator::save_coverage(void) {
+  char *noop_home = getenv("NOOP_HOME");
+  assert(noop_home != NULL);
+
+  char buf[1024];
+  snprintf(buf, 1024, "%s/build/logs", noop_home);
+  Verilated::mkdir(buf);
+  snprintf(buf, 1024, "%s/build/logs/coverage.dat", noop_home);
+  VerilatedCov::write(buf);
+}
+
+
 void Emulator::display_trapinfo() {
   uint64_t pc = dut_ptr->io_trap_pc;
   uint64_t instrCnt = dut_ptr->io_trap_instrCnt;

src/test/csrc/emu.h

@@ -59,6 +59,7 @@ class Emulator {
   void snapshot_save(const char *filename);
   void snapshot_load(const char *filename);
   inline char* waveform_filename(time_t t);
+  inline void save_coverage(void);
 
 public:
   Emulator(int argc, const char *argv[]);