vt/sc: retire logic to select vt(4) by default for UEFI boot

We previously defaulted to using sc(4) with a special case to prefer
vt(4) when booted via UEFI.  As vt(4) is now always the default we can
simplify this.

Reviewed by:	imp, kevans
Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D45356

sys/amd64/amd64/machdep.c

@@ -1464,15 +1464,6 @@ hammer_time(u_int64_t modulep, u_int64_t physfree)
 	r_idt.rd_base = (long) idt;
 	lidt(&r_idt);
 
-	/*
-	 * Use vt(4) by default for UEFI boot (during the sc(4)/vt(4)
-	 * transition).
-	 * Once bootblocks have updated, we can test directly for
-	 * efi_systbl != NULL here...
-	 */
-	if (efi_boot)
-		vty_set_preferred(VTY_VT);
-
 	TUNABLE_INT_FETCH("hw.ibrs_disable", &hw_ibrs_disable);
 	TUNABLE_INT_FETCH("machdep.mitigations.ibrs.disable", &hw_ibrs_disable);
 

sys/kern/kern_cons.c

@@ -737,7 +737,6 @@ sysbeep(int pitch __unused, sbintime_t duration __unused)
 /*
  * Temporary support for sc(4) to vt(4) transition.
  */
-static unsigned vty_prefer;
 static char vty_name[16];
 SYSCTL_STRING(_kern, OID_AUTO, vty, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, vty_name,
     0, "Console vty driver");
@@ -762,10 +761,6 @@ vty_enabled(unsigned vty)
 				break;
 			}
 #endif
-			if (vty_prefer != 0) {
-				vty_selected = vty_prefer;
-				break;
-			}
 #if defined(DEV_VT)
 			vty_selected = VTY_VT;
 #elif defined(DEV_SC)
@@ -780,16 +775,3 @@ vty_enabled(unsigned vty)
 	}
 	return ((vty_selected & vty) != 0);
 }
-
-void
-vty_set_preferred(unsigned vty)
-{
-
-	vty_prefer = vty;
-#if !defined(DEV_SC)
-	vty_prefer &= ~VTY_SC;
-#endif
-#if !defined(DEV_VT)
-	vty_prefer &= ~VTY_VT;
-#endif
-}

sys/sys/cons.h

@@ -145,7 +145,6 @@ int	constty_clear(struct tty *tp);
 #define	VTY_SC 0x01
 #define	VTY_VT 0x02
 int	vty_enabled(unsigned int);
-void	vty_set_preferred(unsigned int);
 
 #endif /* _KERNEL */