feat: added some comments to command.c

kernel/command.c

@@ -49,10 +49,10 @@ void help(const char *args);
 
 void shutdown(const char *args);
 
-void explode(const char *args);
-
 #ifdef ENABLE_SELF_TEST
 
+void explode(const char *args);
+
 void exec_self_test(const char *args);
 
 void smash(const char *args);
@@ -67,11 +67,11 @@ cmd_handler cmd_handlers[] = {
         {"print", print},
         {"ide", ide},
         {"shutdown", shutdown},
-        {"explode", explode},
         {"slingurl", slingurl},
 #ifdef ENABLE_SELF_TEST
         {"self-test", exec_self_test},
         {"smash", smash},
+        {"explode", explode},
 #endif
         {NULL, NULL},
 };
@@ -80,23 +80,30 @@ void slingurl(const char* args) {
     slingurl_decompose(args);
 }
 
+#ifdef ENABLE_SELF_TEST
+
 void smash(const char *args) {
+    // smash the stack, should trigger the stack protector
     char data[16];
     memset(data, 'A', 32);
 }
 
 void exec_self_test(const char *args) {
+    // unit tests
     self_test();
 }
 
 
 void explode(const char *args) {
+    // trigger a divide by zero exception
     uint32_t x = 0;
     uint32_t y = 0;
     __asm__("div %%ebx" :
     "=a" (x), "=b" (y));
 }
 
+#endif
+
 void shutdown(const char *args) {
     power_shutdown();
 }