recipes-google/boot/gbmc-no-initrd/usr.mount

[Unit]
Wants=mnt.mount run-initramfs-ro.mount
After=mnt.mount run-initramfs-ro.mount

[Mount]
What=overlay
Where=/usr
Type=overlay
Options=lowerdir=/run/initramfs/ro/usr,upperdir=/mnt/usr-cow,workdir=/mnt/usr-work