and lower case also works. $ cat /proc/cmdline BOOT_IMAGE=/EFI/BOOT/vmlinuz-4.3.0-8-generic boot=local earlycon=pl011,0x3ced1000 console=ttyAMA1 debug user_debug=31 loglevel=9 uefi_debug e1000e.IntMode=1 pci=pcie_bus_safe acpi=force cpuidle.off=1 usb-storage.delay_use=1 rootwait rw root=PARTUUID=81780ad9-068c-4a80-a795-56856973b8f9 rootfstype=ext4
and lower case also works. /EFI/BOOT/ vmlinuz- 4.3.0-8- generic boot=local earlycon= pl011,0x3ced100 0 console=ttyAMA1 debug user_debug=31 loglevel=9 uefi_debug e1000e.IntMode=1 pci=pcie_bus_safe acpi=force cpuidle.off=1 usb-storage. delay_use= 1 rootwait rw root=PARTUUID= 81780ad9- 068c-4a80- a795-56856973b8 f9 rootfstype=ext4
$ cat /proc/cmdline
BOOT_IMAGE=