makefiles tested on fresh system

Makefile

@@ -1,27 +1,30 @@
 .PHONY: .FORCE
 
-files: files/pxelinux.0 files/initrd.img files/vmlinuz files/pxelinux.cfg/default files/ldlinux.c32 files/root.squashfs
+all: files/pxelinux.0 files/initrd.img files/vmlinuz files/pxelinux.cfg/default files/ldlinux.c32 files/root.squashfs
 
-files/pxelinux.0: syslinux
+files/pxelinux.0: syslinux | files
 	cp syslinux/bios/core/pxelinux.0 files/pxelinux.0
 
-files/initrd.img: linux/build/rootfs/initrd.img
+files/initrd.img: linux/build/rootfs/initrd.img | files
 	cp linux/build/rootfs/initrd.img files/initrd.img
 
-files/vmlinuz: linux/build/rootfs/vmlinuz
+files/vmlinuz: linux/build/rootfs/vmlinuz | files
 	cp linux/build/rootfs/vmlinuz files/vmlinuz
 
-files/pxelinux.cfg/default: pxelinux.cfg
+files/pxelinux.cfg/default: pxelinux.cfg | files
 	mkdir -p files/pxelinux.cfg
 	cp pxelinux.cfg files/pxelinux.cfg/default
 
-files/ldlinux.c32: syslinux
+files/ldlinux.c32: syslinux | files
 	cp syslinux/bios/com32/elflink/ldlinux/ldlinux.c32 files/ldlinux.c32
 
-files/root.squashfs: .FORCE
+files/root.squashfs: .FORCE | files
 	rm files/root.squashfs || true
 	mksquashfs linux/build/rootfs files/root.squashfs
 
+files:
+	mkdir -p files
+
 syslinux:
 	rm -r syslinux || true
 	rm syslinux-6.03.tar.gz|| true

linux/Makefile

@@ -3,38 +3,39 @@ CHROOT_CMD := chroot build/rootfs /bin/bash -c
 FILES = $(shell find src/ -type f -print | sed -e 's|^src/|build/rootfs/|')
 FILES_SRC = $(shell find src/ -type f -print)
 
-.PHONY: .FORCE
-
-all: build/rootfs $(FILES) menu images build/rootfs/initrd.img
+all: $(FILES) menu images build/rootfs/initrd.img
 
 clean:
 	rm -rf build/rootfs
 
-menu:
+menu: build/rootfs | build
 	$(CHROOT_CMD) "apt install dialog"
 	$(CHROOT_CMD) "chmod +x /scripts/menu.sh"
 	$(CHROOT_CMD) "usermod -s /scripts/menu.sh root"
 
-images:
+images: build/rootfs | build
 	$(CHROOT_CMD) "apt install -y udpcast"
 	$(CHROOT_CMD) "apt install -y partclone"
 	$(CHROOT_CMD) "apt install -y lzop strace"
 	$(CHROOT_CMD) "touch /etc/mtab"
 
-build/rootfs/initrd.img: $(FILES)
+build/rootfs/initrd.img: build/rootfs $(FILES) | build
 	chmod +x build/rootfs/etc/initramfs-tools/scripts/local-top/download.sh
-	$(CHROOT_CMD) "apt update && apt install -y linux-image-4.19.0-6-amd64"
+	$(CHROOT_CMD) "apt update && apt install -y linux-image-4.19.0-*-amd64"
 	$(CHROOT_CMD) "update-initramfs -c -kall"
 
-$(FILES): .FORCE
+$(FILES): build/rootfs | build
 	mkdir -p $(@D)
 	cp $(shell echo $@ | sed -e 's|^build/rootfs/|src/|') $@
 
-build/rootfs: build/cache
+build/rootfs: build/cache | build
 	rm -rf build/rootfs
 	cp -r build/cache build/rootfs
 	rm -rf $(FILES)
 
-build/cache:
+build/cache: | build
 	rm -rf build/cache || true
 	debootstrap buster build/cache
+
+build:
+	mkdir -p build