Arch Linux

darkjh

Member

Registered: 2011-10-21

Posts: 33

[Solved] How Windows 10 detect EFI partition?

Hello,

I plan to install archlinux on dual boot with an existing Windows 10 on my new PC and I've used systemd-boot for a while for boot loader.
The problem is that the EFI partition created by windows is too small: ~100MB.

nvme0n1      259:0    0 953.9G  0 disk 
├─nvme0n1p1  259:1    0   100M  0 part  (EFI)
├─nvme0n1p2  259:2    0   16M  0 part  (Windows reserved)
├─nvme0n1p3  259:3    0 692.1G  0 part  (C:)
├─nvme0n1p4  259:4    0   500M  0 part (Windows boot partition)

So I tried
1. create a new partition nvme0n1p5 with the correct type EFI system using fdisk
2. copied all files of the existing EFI partition
3. delete the first EFI partition and then reboot

But Windows cannot boot. Seems it cannot find the new EFI partition.

To fix this, I re-create the first partition with 100MB size and put back the files, Windows boot correctly even if I have 2 EFI partitions ..., like below

nvme0n1      259:0    0 953.9G  0 disk 
├─nvme0n1p1  259:1    0   100M  0 part  (EFI)
├─nvme0n1p2  259:2    0   16M  0 part  (Windows reserved)
├─nvme0n1p3  259:3    0 692.1G  0 part  (C:)
├─nvme0n1p4  259:4    0   500M  0 part (Windows boot partition)
├─nvme0n1p5  259:4    0   1G  0 part (new EFI)

My question is: Is it possible to let Windows read the new bigger EFI partition?
Thanks!

Last edited by darkjh (2022-03-03 09:04:51)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,668

Re: [Solved] How Windows 10 detect EFI partition?

There's a windows cmdline tool to install the boot loader to a "new" ESP, should be googleable, or ask on a Windows support board.

Maniaxx

Member

Registered: 2014-05-14

Posts: 738

Re: [Solved] How Windows 10 detect EFI partition?

You can "outsource" kernel and initramfs to a different partition.
https://wiki.archlinux.org/title/System … g_XBOOTLDR

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sys2064

darkjh

Member

Registered: 2011-10-21

Posts: 33

Re: [Solved] How Windows 10 detect EFI partition?

Thanks I've solve this by using the extended boot partition.