Allow VFPU to save output vcd file

That was amazingly simple.
Can run `gtkwave` on the output vcd file to see all the signals!

diff --git a/src/vfpu.cpp b/src/vfpu.cpp
index 2c6d703..85637ff 100644 (file)
--- a/src/vfpu.cpp
+++ b/src/vfpu.cpp
@@ -32,7 +32,7 @@ static pid_t g_fpu_pid = -1;
  * Starts the VFPU
  * @returns 0 on success, errno of the failing function on failure
  */
-int Start()
+int Start(const char * vcd_output)
 {
        assert(!g_running);
        // create unix socket pair
@@ -59,7 +59,16 @@ int Start()
 
                Debug("Child about to suppress stderr and exec vfpu");
                dup2(open("/dev/null", O_APPEND), fileno(stderr)); //LALALA I AM NOT LISTENING TO YOUR STUPID ERRORS GHDL
-               execl(g_fpu, g_fpu,NULL);
+               if (vcd_output != NULL)
+               {
+                       string s("--vcd=");
+                       s += vcd_output;
+                       execl(g_fpu, g_fpu, s.c_str(), NULL);
+               }
+               else    
+               {
+                       execl(g_fpu, g_fpu,NULL);
+               }
                int err = errno; // Because errno will be set again by the next system call
                Fatal("Uh oh! %s\n", strerror(err)); // We will never see this if something goes wrong... oh dear
                exit(err); // Child exits here.

diff --git a/src/vfpu.h b/src/vfpu.h
index edf471a..12ac9bc 100644 (file)
--- a/src/vfpu.h
+++ b/src/vfpu.h
@@ -9,7 +9,7 @@
 
 namespace VFPU
 {
-       extern int Start(); // Starts the VFPU
+       extern int Start(const char * vcd_output = NULL); // Starts the VFPU
        extern int Halt(); // Halts the VFPU
 
 /**