Hello @INeedMana@piefed.zip! I have decided to not use this OS any longer. Since the EFI entry works, I tried it, and it’s not what I’m looking for. Thank you for all the help, tho.

1. 2. and 3. is all correct.

I use systemd mode in MX. In pmOS’s entries there is no such choice, unless… the 2 dublicate options in the “advanced options” GRUB entry is actually the dual init format specific to MX? Then we can assume this is an incompatibility on MX Linux’s part? I guess I tried booting pmOS in both modes, but I don’t see any difference. All the later tests bellow were done on the main pmOS GRUB entry, not in the “advanced options”.

The strangely named “6969” UUID is real, sda6’s UUID is named like that, and I don’t know why.

All UIIDs in order:

• EFI
  • 13AA-3B2E
• OTHERS
  • 081de505-7ddd-482a-aff8-9403865510d7
  • 829c2c7a-d475-4692-bc78-d8502ded5d3b and LUKS e1bae6b2-c0b7-47de-bb88-3261cf0c83ba
  • 37e894b4-435c-4156-a923-7cfc27b6705f and LUKS f68c92ec-cade-4686-b467-70f4100c36e0
  • 0ba63eb1-ffa9-466c-ab2a-9b29db2882d2
• PMOS
  • 6969-ACCE
  • 791e8d35-d7ec-46ed-9b53-a70a8beebe14

The photo is exactly all the visible text on screen, and nothing else appears bellow the screen.

There is no initrd in sda6, but there is vmlinuz-lts. In pmbootstrap I choose the Alpine LTS kernel, and I don’t know if that’s related to vmlinuz-lts’s naming.

(hd0,gpt7) did not fix anything regarding the line 249 edit.

The line 242 edit produced, just bellow the rdinit error: Skipping autodetection of RAID arrays. (raid=autodetect will force). I later then reverted this edit and added sda7’s UUID to line 249, replacing (hd0,gpt7), and it produces me same RAID array error.

Actually, here’s the grub menu from MX, where pmOS entry was auto-generated.

EDIT: corrected accidental duplication when pasting the config

Ah, no problem! So there is nothing related to grub at all in pmOS_boot… However the system is boot-able through UEFI entries! I don’t know why I didn’t try that earlier.

My workstation’s BIOS is all fancy and let’s you add custom entries, but it was easier to use MX’s UEFI manager. I simply added a new entry to pmOS’s BOOTX64.EFI. I still would like to boot it through my GRUB.

Also thanks for the piece of info and all the interest in helping me so far :)

1. 

2. Bellow all my entries there lies:

• postmarketOS v26 (can’t remember full name)
• advanced settings for postmarketOS v26
  • postmarketOS v26
  • postmarketOS v26 (yes it’s 2 identical in this menu)

And again, I will mention that these entries were automatically generated by # update-grub.

3. Nothing else to the left side of partition 7 & 8 (pmOS boot & root) matters, except EFI, since well it’s the EFI partition. I want to boot pmOS through GRUB. The other boot partition is for my main OS.

thanks