move user passwd and group to writable partition

recipes-core/base-passwd/base-passwd_%.bbappend

@@ -0,0 +1,10 @@
+
+do_patch_ro_roofs() {
+    install -d ${D}/var/etc
+    install -m 0644 ${D}/etc/passwd ${D}/var/etc/
+    install -m 0644 ${D}/etc/group ${D}/var/etc/
+    rm ${D}/etc/passwd
+    rm ${D}/etc/group
+}
+
+addtask patch_ro_roofs after do_populate_sysroot

recipes-diya/diya-overlay/files/80_diya

@@ -1,3 +1,5 @@
 # d root root 0755 /var/etc/dropbear none
 l root root 0644 /etc/network/interfaces /var/etc/network/itf_diya
 l root root 0644 /etc/dropbear /var/etc/dropbear
+l root root 0644 /etc/passwd /var/etc/passwd
+l root root 0644 /etc/group /var/etc/group