Index: kernel/arch/amd64/Makefile.inc
===================================================================
--- kernel/arch/amd64/Makefile.inc	(revision 34ae0a59ac38f9f0c42422df75a6ae4d5337dde5)
+++ kernel/arch/amd64/Makefile.inc	(revision 1f7753ac3caad5c5c1e675848e8770f3dcb74bbe)
@@ -33,24 +33,5 @@
 
 FPU_NO_CFLAGS = -mno-sse -mno-sse2
-
-#
-# FIXME:
-#
-# The -fno-optimize-sibling-calls should be removed as soon as a bug
-# in GCC concerning the "large" memory model and tail call optimization
-# is fixed.
-#
-# When GCC generates a code for tail call, instead of generating ..
-#
-#   jmp *fnc
-#
-# it generates an assembly code with an illegal immediate prefix:
-#
-#   jmp *$fnc
-#
-# See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48385 for reference.
-#
-
-CMN1 = -m64 -mcmodel=large -mno-red-zone -fno-unwind-tables -fno-omit-frame-pointer -fno-optimize-sibling-calls
+CMN1 = -m64 -mcmodel=large -mno-red-zone -fno-unwind-tables -fno-omit-frame-pointer
 GCC_CFLAGS += $(CMN1)
 ICC_CFLAGS += $(CMN1)
Index: kernel/arch/ppc32/src/ppc32.c
===================================================================
--- kernel/arch/ppc32/src/ppc32.c	(revision 34ae0a59ac38f9f0c42422df75a6ae4d5337dde5)
+++ kernel/arch/ppc32/src/ppc32.c	(revision 1f7753ac3caad5c5c1e675848e8770f3dcb74bbe)
@@ -103,4 +103,5 @@
 }
 
+#ifdef CONFIG_FB
 static bool display_register(ofw_tree_node_t *node, void *arg)
 {
@@ -169,4 +170,5 @@
 	return true;
 }
+#endif
 
 void arch_post_mm_init(void)