diff --git a/rootf-kernel/Makefile b/rootf-kernel/Makefile
index b3c3599..2b359a3 100644
--- a/rootf-kernel/Makefile
+++ b/rootf-kernel/Makefile
@@ -1,5 +1,8 @@
 .PHONY: use-alpine use-arch use-ubuntu
 
+# aarch64
+# x86_64
+ARCH=x86_64
 
 use-arch: ../out/arch-rootfs.ext4
 	ln -s $< ../out/rootfs.ext4
@@ -11,10 +14,10 @@ use-ubuntu: ../out/ubuntu-22.04.ext4 ../out/ubuntu-22.04.id_rsa
 	ln -s $< ../out/rootfs.ext4
 
 kernel: ../out/vmlinux-5.10.204
-
+	@echo "linux kernel retrieve"
 
 ../out/vmlinux-5.10.204:
-	wget -O $@ https://s3.amazonaws.com/spec.ccfc.min/firecracker-ci/v1.7/${ARCH}/vmlinux-5.10.204
+	wget -O $@ https://s3.amazonaws.com/spec.ccfc.min/firecracker-ci/v1.7/$(ARCH)/vmlinux-5.10.204
 
 ../out/arch-rootfs.ext4:
 	bash ./arch-rootf.sh
@@ -23,8 +26,8 @@ kernel: ../out/vmlinux-5.10.204
 	bash ./alpine-rootf.sh
 
 ../out/ubuntu-22.04.ext4:
-	wget -O $@ https://s3.amazonaws.com/spec.ccfc.min/firecracker-ci/v1.7/$$(uname -m)/ubuntu-22.04.ext4
+	wget -O $@ https://s3.amazonaws.com/spec.ccfc.min/firecracker-ci/v1.7/$(ARCH)/ubuntu-22.04.ext4
 
 ../out/ubuntu-22.04.id_rsa:
-	wget -O $@ https://s3.amazonaws.com/spec.ccfc.min/firecracker-ci/v1.7/$$(uname -m)/ubuntu-22.04.id_rsa
+	wget -O $@ https://s3.amazonaws.com/spec.ccfc.min/firecracker-ci/v1.7/$(ARCH)/ubuntu-22.04.id_rsa
 	chmod 400 $@