MFC:

If the user did not chose a distribution from the menu, a sensible
  default distribution (user) will be installed, however, no kernel
  will be installed.  Fix this by installing a sensible default kernel,
  SMP/GENERIC, depending on WITH_SMP and number of CPUS found.

Approved by:    re (hrs)

usr.sbin/sysinstall/dist.c

@@ -210,7 +210,7 @@ distSetX(void)
     return distSetXOrg(NULL);
 }
 
-static int
+int
 selectKernel(void)
 {
 #ifdef WITH_SMP

usr.sbin/sysinstall/install.c

@@ -785,6 +785,8 @@ installCommit(dialogMenuItem *self)
 	/* select reasonable defaults if necessary */
 	if (!Dists)
 	    Dists = _DIST_USER;
+	if (!KernelDists)
+	    KernelDists = selectKernel();
     }
 
     if (!mediaVerify())

usr.sbin/sysinstall/sysinstall.h

@@ -613,6 +613,7 @@ extern int	distSetSrc(dialogMenuItem *self);
 extern int	distSetXOrg(dialogMenuItem *self);
 extern int	distSetKernel(dialogMenuItem *self);
 extern int	distExtractAll(dialogMenuItem *self);
+extern int	selectKernel(void);
 
 /* dmenu.c */
 extern int	dmenuDisplayFile(dialogMenuItem *tmp);