CHECKFLAGS += -D__sparc__ -D__sparc_v9__ -m64
-CPPFLAGS_vmlinux.lds += -Usparc
+# Undefine sparc when processing vmlinux.lds - it is used
+# And teach CPP we are doing 64 bit builds (for this case)
+CPPFLAGS_vmlinux.lds += -m64 -Usparc
LDFLAGS := -m elf64_sparc