Mount of filesystem fails (MNT_DEVICE)

[jussihyva]

I have an issue related to mount of devices.
This because of subname is not p1 and p2 but just 1 and 2. Refer lsblk print below.

LSBLK Printout

sdb 8:16 1 29,7G 0 disk
├─sdb1 8:17 1 256M 0 part /media/juhani/boot
└─sdb2 8:18 1 29,5G 0 part /media/juhani/rootfs

Could is be possible to add additional parameter (MNT_DEVICE_SUB or just SUB)?
I'm using external conf file with export commands and mount and umount issues
are only reasons why I have to modify the Makefile.

Content of the Makefile

mount: ## Mount the current SD device
sudo mount $(MNT_DEVICE)p1 $(MNT_BOOT)
sudo mount $(MNT_DEVICE)p2 $(MNT_ROOT)

.PHONY: unmount
unmount: ## Unmount the current SD device
sudo umount $(MNT_DEVICE)p1 || true
sudo umount $(MNT_DEVICE)p2 || true

[jussihyva]

Its here as well:
.PHONY: clean
clean: ## Unmount and delete all temporary mount directories
sudo umount $(MNT_DEVICE)p1 || true
sudo umount $(MNT_DEVICE)p2 || true
sudo rm -rf $(MNT_BOOT)
sudo rm -rf $(MNT_ROOT)