Installing a Grub distro next to UEFI-installed Endeavour: what do I need to know?

saw no topic in search re: efi bootloader distro and grub distro living happily ever after on same HDD.

I want to install a grub distro next to Endeavour for the halibut. Have the GPT partition ready.

I think I have to switch my bios back to legacy+uefi instead of uefi for the install.

I have to remember update-grub and it’s similar commands if Alpine knocks out Endeavour boot.

Anything to be mindful of?

(this is tiny Alpine, open-RC, no systemd, and basically a variant of LFS since, evidently, I can’t get enough self-torture.?

thanks for any insight.

When you say “grub distro” do you mean a distro without UEFI support? Because grub also supports UEFI.

Yes, I meant one with no uefi support.

The first question is does your bios/firmware support legacy booting from a GPT disk. Some do, some don’t.

Even if it does, it usually requires some special handling.

Other than that, they can co-exist but legacy grub can’t boot uefi and vice-versa.

that’s a great question. I do not no. It’s an older MSI board but I think I have done it before.

I may have tried this once in my linux lifetime. I reached perfection once: booting while tapping a key and bringing up a menu with a grub loader and a an efi bootloader together.

But about 8 other times this didn’t work at all since grub usually clubs the bootloader over the head and leaves it on the sidewalk and then update-grub never works so I have to delete the distro I just installed to get the efi distro back.

That said, I was hoping to get lucky again. I had this magic scenario once.

If I remember correctly, you need to leave some empty space at the beginning of the disk when legacy booting off a GPT disk. I haven’t tried this in many years though so that is just from memory.

thank you