build-vm, kernel, uboot: setup /etc/fstab for build-vm

The entry in /etc/fstab about the mount parameters of the root
partition needs to be done not only for builds with u-boot.
But, if the record already exists, then it will not be added.
The file system type is set by the variable VM_FSTYPE.

features.in/build-vm/image-scripts.d/50-fstab

@@ -0,0 +1,4 @@
+#!/bin/sh
+
+grep -qe "[[:space:]]/[[:space:]]" /etc/fstab ||
+  printf "LABEL=ROOT\t/\t$GLOBAL_VM_FSTYPE\tdefaults\t1 1\n" >> /etc/fstab

features.in/kernel/config.mk

@@ -75,3 +75,4 @@ ifeq (,$(filter-out armh,$(ARCH)))
 endif
 	@$(call xport,VM_INITRDMODULES)
 	@$(call xport,VM_INITRDFEATURES)
+	@$(call xport,VM_FSTYPE)

features.in/uboot/image-scripts.d/90-uboot-config-install

@@ -16,4 +16,3 @@ done
 for KVER in $kver; do
 	/sbin/installkernel --uboot --keep-initrd "$KVER"
 done
-printf 'LABEL=ROOT\t/\text4\tdefaults\t1 1\n' >> /etc/fstab