diff --git a/layers/meta-belden-coreos-bsp/conf/machine/beaglebone.conf b/layers/meta-belden-coreos-bsp/conf/machine/beaglebone.conf
index c294280..8ada8b7 100644
--- a/layers/meta-belden-coreos-bsp/conf/machine/beaglebone.conf
+++ b/layers/meta-belden-coreos-bsp/conf/machine/beaglebone.conf
@@ -58,5 +58,11 @@ QB_TCPSERIAL_OPT = "-device virtio-serial-device -chardev socket,id=virtcon,port
 # No watchdog available yet
 EFIBOOTGUARD_TIMEOUT ?= "0"
 
+# MBR disk can't select the root device by partition label as MBR doesn't have
+# a partition label. Using filesystem label only work with an initramfs and we
+# don't support it yet.
+COREOS_PLATFORM0_ROOT ?= "/dev/mmcblk0p3"
+COREOS_PLATFORM1_ROOT ?= "/dev/mmcblk0p4"
+
 require conf/machine/include/coreos-generic-features/efi.inc
 require conf/machine/include/coreos-generic-features/legacy-mbr-disk.inc
diff --git a/layers/meta-belden-coreos-bsp/conf/machine/include/coreos-generic-features/legacy-mbr-disk.inc b/layers/meta-belden-coreos-bsp/conf/machine/include/coreos-generic-features/legacy-mbr-disk.inc
index a20b26e..9997044 100644
--- a/layers/meta-belden-coreos-bsp/conf/machine/include/coreos-generic-features/legacy-mbr-disk.inc
+++ b/layers/meta-belden-coreos-bsp/conf/machine/include/coreos-generic-features/legacy-mbr-disk.inc
@@ -6,6 +6,10 @@
 # a GPT disk instead
 COREOS_DISK_PARTLABEL_LOOKUP_DIRECTORY ?= "/dev/disk/by-label"
 
+# MBR can't disk can't use partition label, but may use filesystem label
+# This will only work with an initramfs. If no initramfs is used, this will
+# have to be set to the right disk device inside the machine configuration
+# like that COREOS_PLATFORMx_ROOT = "/dev/mmcblk<DISK>p<PART>"
 COREOS_PLATFORM0_ROOT ?= "LABEL=platform0"
 COREOS_PLATFORM1_ROOT ?= "LABEL=platform1"