I did not specify the partition correctly I have FDE, so I don't use "/dev/mmcblk${linux_mmcdev}p${rootpart}" but "/dev/mapper/root":
cat /boot/boot.txt
[...]
setenv bootargs loglevel=4 console=${console} console=tty0 root=/dev/mmcblk${linux_mmcdev}p${rootpart} rw rootwait quiet bootsplash.bootfile=bootsplash-themes/danctnix/bootsplash resume=/dev/mapper/root resume_offset=266240
[...]
To rebuild image:
cd /boot
mkimage -A arm -O linux -T script -C none -n "U-Boot boot script" -d boot.txt boot.scr
Hooks:
HOOKS=(base udev autodetect modconf kms keyboard keymap consolefont block filesystems unl0kr resume fsck)