sims/e1000_gem5: support enabling debug messages dynamically

experiments/simbricks/simulators.py

@@ -387,12 +387,15 @@ class I40eNIC(NICSim):
         return self.basic_run_cmd(env, '/i40e_bm/i40e_bm')
 
 class E1000NIC(NICSim):
+    debug = False
     def __init__(self):
         super().__init__()
 
     def run_cmd(self, env):
-        #return 'valgrind -v -v -v ' + self.basic_run_cmd(env, '/e1000_gem5/e1000_gem5')
-        return self.basic_run_cmd(env, '/e1000_gem5/e1000_gem5')
+        cmd = self.basic_run_cmd(env, '/e1000_gem5/e1000_gem5')
+        if self.debug:
+            cmd = 'env E1000_DEBUG=1 ' + cmd
+        return cmd
 
 class MultiSubNIC(NICSim):
     name = ''

sims/nic/e1000_gem5/e1000_gem5.cc

@@ -5,6 +5,7 @@
 #include "sims/nic/e1000_gem5/i8254xGBe.h"
 
 static nicbm::Runner *runner;
+static bool debug_enable = false;
 
 class Gem5DMAOp : public nicbm::DMAOp, public nicbm::TimedEvent {
   public:
@@ -195,19 +196,38 @@ void panic(const char *fmt, ...)
     abort();
 }
 
+static void debug_init()
+{
+#ifdef DEBUG_E1000
+    char *debug_env = getenv("E1000_DEBUG");
+    if (debug_env &&
+        (!strcmp(debug_env, "1") ||
+         !strcmp(debug_env, "y") ||
+         !strcmp(debug_env, "Y")))
+    {
+        warn("enabling debug messages because E1000_DEBUG envar set\n");
+        debug_enable = true;
+    }
+#endif
+}
+
 void debug_printf(const char *fmt, ...)
 {
+    if (debug_enable) {
         va_list val;
         va_start(val, fmt);
         fprintf(stderr, "%lu: ", runner->TimePs());
         vfprintf(stderr, fmt, val);
         va_end(val);
+    }
 }
 
 /******************************************************************************/
 
 int main(int argc, char *argv[])
 {
+    debug_init();
+
     IGbEParams params;
     params.rx_fifo_size = 384 * 1024;
     params.tx_fifo_size = 384 * 1024;

sims/nic/e1000_gem5/support.h

@@ -12,7 +12,7 @@
 
 void debug_printf(const char *fmt, ...);
 
-//#define DEBUG_E1000
+#define DEBUG_E1000
 #ifdef DEBUG_E1000
 #   define DPRINTF(x,y...) debug_printf(#x ": " y)
 #else