1# Extract UUID from ${ROOTFS}, which must have been built 2# by the time that this function gets called. Only works 3# on ext file systems and depends on tune2fs. 4def get_rootfs_uuid(d): 5 import subprocess 6 rootfs = d.getVar('ROOTFS') 7 output = subprocess.check_output(['tune2fs', '-l', rootfs], text=True) 8 for line in output.split('\n'): 9 if line.startswith('Filesystem UUID:'): 10 uuid = line.split()[-1] 11 bb.note('UUID of %s: %s' % (rootfs, uuid)) 12 return uuid 13 bb.fatal('Could not determine filesystem UUID of %s' % rootfs) 14 15# Replace the special <<uuid-of-rootfs>> inside a string (like the 16# root= APPEND string in a syslinux.cfg or systemd-boot entry) with the 17# actual UUID of the rootfs. Does nothing if the special string 18# is not used. 19def replace_rootfs_uuid(d, string): 20 UUID_PLACEHOLDER = '<<uuid-of-rootfs>>' 21 if UUID_PLACEHOLDER in string: 22 uuid = get_rootfs_uuid(d) 23 string = string.replace(UUID_PLACEHOLDER, uuid) 24 return string 25