Sharing EFI in dual boot

[tulip lance]

After successfully, failing to install Arch, I am now following these instructions: https://gist.github.com/ginolhac/314acfbe116afc81a60cbbcce7a34ef2 However, it looks like the author is using multiple disks, so naturally, he is using multiple EFI partitions.

I have Windows 11 installed with a 100 MB EFI partition. From various online posts, I’ve read that you should use a single EFI partition per disk. My system came with the default 100 MB EFI and one SSD, and resizing the EFI would be risky and complicated.

I would like to use systemd-boot instead of GRUB. I’m not sure what I’m supposed to do. I want a safe, recommended method that won’t overwrite or break Windows.

Which parts of the instructions do I need to modify in order to use systemd-boot and potentially share the EFI partition? I’m looking for more of a spoon-fed answer.

[opaque warren]

Systemd-boot can boot from other esp

https://wiki.archlinux.org/title/Systemd-boot#Boot_from_another_disk

[tulip lance]

can i have multiple efi system partation in a single ssd disk?

[opaque warren]

Yes

[tulip lance]

which would be better, to share EFI or create separate new one, considering i have to setup secure boot and TMP module for release disk encryption keys later?

[opaque warren]

With a 100M your only option is a new esp

[tulip lance]

It seems like seprate is a bad choice

[opaque warren]

I don't share the esp with windows even if it's large enough

[tulip lance]

Can't i just extend the current esp.

[tulip lance]

why ?

you haven't faced any problems yet?

[opaque warren]

Because windows at least used to touch it sometimes

[opaque warren]

No issues, there's no limit to esp amount

[opaque warren]

Might have so sign the efi shell binary the same way you'll sign the kernel and initramfs

[tulip lance]

btw, I am thinking of expanding efi

should i extend or ??

actually, nvm i will just create a new efi

btw, @opaque warren do you use multiple disk for window and linux or are they in a single same disk

[opaque warren]

Multiple

[tulip lance]

then, ofc you wouldn't have faced the issue, I have single ssd, who knows i might do 😭

[opaque warren]

You can have issues with partitioning if you don't do it right but there's no issue with multiple esp on one drive

[tulip lance]

Then, i will trsut your word, but can systemd-boot detect that there is a separate EFI system and able to chain load windows??

[opaque warren]

https://wiki.archlinux.org/title/Systemd-boot#Boot_from_another_disk

[tulip lance]

Someone suggest me this on reddit

@opaque warren

[opaque warren]

https://wiki.archlinux.org/title/Systemd-boot#Installation_using_XBOOTLDR

[opaque warren]

You can do that

[tulip lance]

Is there any risk/cons in this approach, since i don't see many ppl using it?

I just asked gpt and with this method the arch will only use "less than" 10Mib storage, which seems like a great deal.

[opaque warren]

The bootloader file will be in the esp

Which is only like a few bytes

And the entries

Maybe a few kib in total

[tulip lance]

so, no cons with this setup?

@opaque warren

[opaque warren]

Yeah