Resize EFI partition

When installing respun Ubuntu or similar distros on Intel Apollo Lake devices using the '-b Linuxium'  option (or '--apollo') one issue that might be encountered is where the EFI partition isn't large enough to store the bootable EFI file. Some Windows installations only create a 60MB partition which after installing the Windows EFI files leaves only around 30MB free. With the later Linux kernel releases the size and number of modules have increased and the generated bootable EFI file is now quite large (over 50MB) and if there is insufficient space for it the resultant installation will not boot.

The solution is to increase the size of the EFI partition. Unfortunately this cannot be achieved through a simple command so I've written some instructions that whilst appearing somewhat complicated will achieve the required result.

Before embarking on using the instructions I highly recommend creating a backup image of your eMMC to use as recovery should the need arise.

The resizing process involves creating a 'Windows 10 installation and repair' USB, removing the existing EFI partition and then creating a new one using the 'repair' USB. If Ubuntu or similar was previously installed then additional steps are required to save and then restore the Ubuntu EFI files and to update the GRUB bootloader if used. You will need a working internet connection and two USBs (both minimum 8GB) and start by 'dd'ing an Ubuntu ISO to one of them.

Then to increase the EFI partition when only Windows is installed use the following instructions:

1. Boot Windows
REM right-click the Windows icon (bottom-left corner on the desktop) and select 'Disk Management'
REM right-click the Windows volume and then click 'Shrink Volume'
REM assume new EFI partition will be 150MB so enter '150' in the 'Enter the amount of space to shrink in MB' box and click 'Shrink'
REM when the shrink operation has completed an area of '150 MB Unallocated' space should appear

2. Boot from Ubuntu LiveUSB
# remove NVRAM entries for Windows
sudo efibootmgr -b $(efibootmgr -v | grep Windows | sed 's/\*.*//' | sed 's/Boot//' | head -1) -B
# delete EFI partition
DISK=$(blkid | grep -i "EFI System Partition" | sed 's/p.*//')
sudo sgdisk --delete=$(sudo gdisk -l ${DISK} | grep -i "EFI System Partition" | awk '{print $1}') ${DISK}

3. Still in Ubuntu create a 'Windows 10 installation and repair' USB
# go to 'https://www.microsoft.com/en-au/software-download/windows10ISO' in a browser
select 'Windows 10' and click 'Confirm'
select 'English International' and click 'Confirm'
select '64-bit Download' and click 'Confirm'
# wait for ISO to download
# confirm ISO has successfully downloaded
ls -ltr ~/Downloads | tail -1
# insert the other the USB
USB=$(ll /dev/disk/by-id/ | grep usb | head -1 | sed 's?.*/??')
# unmount any mounted partitions
sudo umount /dev/${USB}*
# initialize the USB
sudo sgdisk -Z /dev/${USB}
# create a single partition on the USB
sudo sgdisk --new=0:0:0 /dev/${USB}
# create a FAT32 file system on the USB
sudo mkfs.vfat /dev/${USB}1
# copy the Windows 10 ISO to the USB
sudo rm -rf /mnt/usb
sudo rm -rf /mnt/iso
sudo mkdir /mnt/iso /mnt/usb
sudo mount ~/Downloads/Win10_1709_EnglishInternational_x64.iso /mnt/iso
sudo mount /dev/${USB}1 /mnt/usb
sudo cp -dR --preserve=all --no-preserve=ownership /mnt/iso/* /mnt/usb
sudo sync
sudo sync
sudo umount /mnt/iso /mnt/usb
sudo rmdir /mnt/iso /mnt/usb

4. Boot from 'Windows 10 installation and repair' USB
REM choose 'Time and currency format'
REM select next
REM click 'Repair your computer'
REM click 'Troubleshoot'
REM click 'Advanced options'
REM click 'Command Prompt'
diskpart
list disk
REM select disk number of device (the other will be the USB)
sel disk 0
REM create new EFI partition (size 150MB)
REM if amount of space is not known simply enter 'create part efi' to use all available space
create part efi size=150
format quick fs=fat32
assign
list vol
REM note the drive letter for Wndows (e.g. C:) and the new EFI partition (e.g. F:)
exit
REM install Windows bootloader to new EFI partition
bcdboot C:\Windows /s F: /f UEFI
exit
REM click 'Turn off your PC'

You can now reboot into Windows to view the resized EFI partition or boot from the Ubuntu LiveUSB and install Ubuntu.

To increase the EFI partition when both Windows and Ubuntu or similar are installed use these instructions:

1. Boot from Ubuntu LiveUSB

# assumes Ubuntu partition is automatically loaded under '/media/<user name>/<UUID of Ubuntu partition>' where <user name> will be 'ubuntu' on a LiveUSB

cd /media/$(whoami)/$(blkid | grep ext4 | awk '{print $2}' | sed 's/^UUID="//' | sed 's/"$//')/boot

# save /boot/efi/EFI/ubuntu

sudo mount $(blkid | grep -i "EFI System Partition" | sed 's/:.*//') /mnt

sudo cp -a /mnt/EFI .

sudo umount /mnt

# remove NVRAM entries for Ubuntu and Windows

sudo efibootmgr -b $(efibootmgr -v | grep -i ubuntu | sed 's/\*.*//' | sed 's/Boot//' | head -1) -B

sudo efibootmgr -b $(efibootmgr -v | grep Windows | sed 's/\*.*//' | sed 's/Boot//' | head -1) -B

# delete EFI partition

DISK=$(blkid | grep -i "EFI System Partition" | sed 's/p.*//')

sudo sgdisk --delete=$(sudo gdisk -l ${DISK} | grep -i "EFI System Partition" | awk '{print $1}') ${DISK}

# shrink Ubuntu partition to allocate as new EFI partition

# click 'ignore' for any 'The driver descriptor says the physical block size is 2048 bytes, but Linux says it is 512 bytes' warnings

# for example new EFI partition will be 150MB so shrink Ubuntu partition by 150MB

sudo gparted

# note the amount of free space created

2. Still in Ubuntu create a 'Windows 10 installation and repair' USB

# go to 'https://www.microsoft.com/en-au/software-download/windows10ISO' in a browser

select 'Windows 10' and click 'Confirm'

select 'English International' and click 'Confirm'

select '64-bit Download' and click 'Confirm'

# wait for ISO to download

# confirm ISO has successfully downloaded

ls -ltr ~/Downloads | tail -1

# insert the other USB

USB=$(ll /dev/disk/by-id/ | grep usb | head -1 | sed 's?.*/??')

# unmount any mounted partitions

sudo umount /dev/${USB}*

# initialize the USB

sudo sgdisk -Z /dev/${USB}

# create a single partition on the USB

sudo sgdisk --new=0:0:0 /dev/${USB}

# create a FAT32 file system on the USB

sudo mkfs.vfat /dev/${USB}1

# copy the Windows 10 ISO to the USB

sudo rm -rf /mnt/usb

sudo rm -rf /mnt/iso

sudo mkdir /mnt/iso /mnt/usb

sudo mount ~/Downloads/Win10_1709_EnglishInternational_x64.iso /mnt/iso

sudo mount /dev/${USB}1 /mnt/usb

sudo cp -dR --preserve=all --no-preserve=ownership /mnt/iso/* /mnt/usb

sudo sync

sudo sync

sudo umount /mnt/iso /mnt/usb

sudo rmdir /mnt/iso /mnt/usb

3. Boot from 'Windows 10 installation and repair' USB

REM choose 'Time and currency format'

REM select next

REM click 'Repair your computer'

REM click 'Troubleshoot'

REM click 'Advanced options'

REM click 'Command Prompt'

diskpart

list disk

REM select disk number of device (the other will be the USB)

sel disk 0

REM create new EFI partition (size 150MB)

REM if amount of space is not known simply enter 'create part efi' to use all available space

create part efi size=150

format quick fs=fat32

assign

list vol

REM note the drive letter for Wndows (e.g. C:) and the new EFI partition (e.g. F:)

exit

REM install Windows bootloader to new EFI partition

bcdboot C:\Windows /s F: /f UEFI

exit

REM click 'Turn off your PC'

4. Boot from Ubuntu LiveUSB

# assumes Ubuntu partition is automatically loaded under '/media/<user name>/<UUID of Ubuntu partition>' where <user name> will be 'ubuntu' on a LiveUSB

cd /media/$(whoami)/$(blkid | grep ext4 | awk '{print $2}' | sed 's/^UUID="//' | sed 's/"$//')/boot

# restore /boot/efi/EFI/ubuntu

sudo mount $(blkid | grep -i "EFI System Partition" | sed 's/:.*//') /mnt

sudo cp -a EFI/ubuntu /mnt/EFI

sudo umount /mnt

# add NVRAM entry for Ubuntu

DISK=$(blkid | grep -i "EFI System Partition" | sed 's/p.*//')

sudo efibootmgr -c -d ${DISK} -p $(sudo gdisk -l ${DISK} | grep -i "EFI System Partition" | awk '{print $1}') -l \\EFI\\ubuntu\\shimx64.efi -L ubuntu

# update /etc/fstab

sudo sed -i "s/$(grep '^UUID' ../etc/fstab | grep '/boot/efi' | awk '{print $1}' | sed 's/UUID=//')/$(blkid | grep -i 'EFI System Partition' | awk '{print $2}' | sed 's/"$//' | sed 's/.*"//')/" ../etc/fstab

5. Boot from Ubuntu

# update GRUB if used as a boot loader

sudo update-grub

Note that if a different distro to Ubuntu (or Ubuntu flavour) was previously installed then the above instructions might need to be modified to change the restore from 'EFI/ubuntu' to whatever directory is relevant and to create the label for the NVRAM entry that reflects the distro installed.  

If Ubuntu previously wasn't booting because the EFI partition was too small simply reboot from the Ubuntu LiveUSB and reinstall Ubuntu.

Both sets of instructions can be downloaded from:

• resize-efi-with-only-windows-installed.txt
• resize-efi-with-both-windows-and-ubuntu-installed.txt  

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