A Bash script to rename EFI boot entries
EFI / UEFI, boot configurations
EFI / UEFI is a specification that defines a software interface between an operating system and platform firmware. It is intended by hardware manufacturers to replace the legacy BIOS firmware interface.
In particular this specification allows to define OS boot configurations to be executed upon system power on. These boot configurations specify disk partitions to boot from and are typically identified by their text labels that are listed in "Startup" / "Boot" EFI setup section. These boot configurations may be optionally selectable upon system startup.
Operating system installation routines tend to have these boot configuration entry labels hard-coded and to create them in EFI PROM automatically. So in case a computer has, say, several Ubuntu instances installed, it is also likely to have several identical "ubuntu" boot configuration labels in its EFI menus, causing a kind of confusion.
One might further want to rename boot configurations, so to make them distinguishable, but unfortunately the standard
efibootmgr utility has no option for that. It is only possible to delete a boot
configuration entry and re-create it with a new label. Meanwhile, the data that is necessary for re-creating a boot
configuration entry is not trivial and requires certain inquiries into EFI configuration and disk partition attributes.
rename-efi-entry script is designed to facilitate renaming EFI boot configuration entries using
utility. It automates querying current EFI configuration and bootable partition data, and also shaping command line
sudo ./rename-efi-entry existing_efi_label new_efi_label [bootnum]
existing EFI entry label to be renamed
the new label value to be assigned
sudo ./rename-efi-entry ubuntu 'ubuntu 18.04'
or in case of multiple boot entries labeled as 'ubuntu':
sudo ./rename-efi-entry ubuntu 'ubuntu 18.04' 0001
In case of doubt
bootnum values may be clarified using
efibootmgr --verbose command:
$ efibootmgr --verbose BootCurrent: 0001 Timeout: 0 seconds BootOrder: 0002,0001,0017,001B,0000,0016,0019,001A,0018 Boot0000 Windows Boot Manager HD(1,MBR,0x5092863d,0x3cde8c,0x1340)/File(\EFI\Microsoft\Boot\bootmgfw.efi)WINDOWS... Boot0001* ubuntu HD(1,GPT,2ffcc127-f6ce-40f0-9932-d1dfd14e9462,0x800,0x100000)/File(\EFI\ubuntu\shimx64.efi) Boot0002* ubuntu HD(1,GPT,cba13b09-d754-4d31-9719-369fa60928d1,0x800,0x100000)/File(\EFI\ubuntu\shimx64.efi) Boot0010 ...
bootnum values (e.g.
Boot0001) may be further identified by checking corresponding
2ffcc127-f6ce-40f0-9932-d1dfd14e9462) against values provided by
sfdisk -d command, e.g.:
$ sudo sfdisk -d /dev/sda label: gpt label-id: 0560DAA2-3010-47A2-B083-047C813F0A04 device: /dev/sda unit: sectors first-lba: 34 last-lba: 1953525134 /dev/sda1 : start= 2048, size= 1048576, type=C12A7328-F81F-11D2-BA4B-00A0C93EC93B, uuid=2FFCC127-F6CE-40F0-9932-D1DFD14E9462, name="EFI System Partition" /dev/sda2 : start= 1050624, size= 102400000, type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, uuid=A06790C2-3818-4F57-84EF-4D1B9FFB417E, name="SSD system" /dev/sda3 : start= 103450624, size= 1850073088, type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, uuid=67A374C2-081E-477E-945C-78BE129A2044, name="SSD data"
What the script does under the hood, is:
obtain a list of disk devices using
obtain a list of disk partitions and their
uuidvalues for every disk device using
obtain a list of EFI boot entries using
filter EFI boot entries against
existing_efi_labelvalue, supplied by the user as command line argument;
make sure that this boot entry identification is unique, using
uuidvalue from the EFI boot entry to be renamed, and use it to identify the relevant disk partition and its device name;
verify matching of partition numbers between EFI boot entry and partition device name;
shape the commands for
efibootmgrto delete the existing EFI boot entry and to create a new one with required label;
ask final user consent;
This script can only rename EFI boot entries that are related to Linux. It will most probably ignore the other ones.
Important usage notes
Feel free to use, but do it on your risk :)
It may be wise to review the
efibootmgr commands before final execution…