busybox-udhcpc: udhcpc.default file for IDU.

Hopefully, this installs a different /etc/default/udhcpc file on
sysmocom-idu machines. Not sure if adding a machine subdir suffices.

The idea is that the machine-specific subdir symocom-idu should replace
the udhcpc.default file used for the idu packages, only, which has both
resolv.conf mods and default route disabled by default.

recipes-core/busybox/busybox_sysmocom.inc

@@ -1,6 +1,6 @@
 SYSMOCOM := "${@os.path.dirname(bb.data.getVar('FILE', d, True))}"
 FILESEXTRAPATHS_prepend := "${SYSMOCOM}/busybox-${SYSMOCOM_ORIG_PV}:${SYSMOCOM}/files:"
-PRINC = "29"
+PRINC = "30"
 
 SRC_URI += "file://udhcpc-ntp.sh \
             file://udhcpc-ntp.default \

recipes-core/busybox/sysmocom-idu/udhcpc.default

@@ -0,0 +1,5 @@
+# Uncomment the following line, if udhcpc should not touch /etc/resolv.conf
+STATIC_DNS="yes"
+
+# Uncomment the following line if udhcpc should not install a default route
+INSTALL_DEFAULT_ROUTE="no"