Arch Linux

ivanoff

Member

Registered: 2012-03-18

Posts: 73

[SOLVED] ArchLinux Live USB UEFi boot impossible on a new PC

Hello all.
I am becoming crazy here. I am trying to install Arch on an ASUS PRIME B850-Plus wifi motherboard, but despite my efforts, my USB drive remains invisible in the boot menu.
The disk works fine in UEFi on my previous computer, though, so I think I created it fine.
It becomes visible when I activate CSM, but of course, then I am no longer in UEFI, but in BIOS.
I have tried to change everything : os type: other OS pr windows
Secure boot mode: custom or standard.
Whatever i do, the disk remains invisible and unbootable.
I have even cleared the boot keys, however I am not sure that was such a good idea.
Does anybody have an idea of what to do next?
Thank you!

Last edited by ivanoff (2025-03-29 09:56:24)

Scimmia

Fellow

Registered: 2012-09-01

Posts: 12,527

Re: [SOLVED] ArchLinux Live USB UEFi boot impossible on a new PC

Secure boot mode: custom or standard.

It needs to be off

cryptearth

Member

Registered: 2024-02-03

Posts: 1,367

Re: [SOLVED] ArchLinux Live USB UEFi boot impossible on a new PC

Secure boot mode: custom or standard.

It needs to be off

well - ASUS has it's own way for "off":

there's an option to enable or disable SecureBoot called "OS Type" - with the two options: "Windows" and "other OS" - with "OS Type: Windows" mean: "load default keys and enable SecureBoot" while "OS Type Other" means "disable SecureBoot and unload keys"
the other option mentioned "SB Type" is to switch between your own keys or the ones the board comes with

so - to disable SB on an ASUS board:
- SB Type: <doesn't matter - but I'd select custom>
- OS Type: Other

@OP
ASUS also has some options for option roms with "uefi only" and "uefi/legacy" for storage, network, and a few others - check that when CSM is disabled the option roms are all on "UEFI only"

ivanoff

Member

Registered: 2012-03-18

Posts: 73

Re: [SOLVED] ArchLinux Live USB UEFi boot impossible on a new PC

Unfortunately, I've already tried that, with no luck.
Os type: other OS
Secure boot mode: standard
Setting it to Custom, doesn't change anything
For the record, it seems i have the latest version of the mobo Bios: 1022
I still see no device to boot into...
CSM is disabled
What did I miss?

Edit: i think I will end-up going with CSM / BIOS / MBR

Last edited by ivanoff (2025-03-26 08:40:33)

ivanoff

Member

Registered: 2012-03-18

Posts: 73

Re: [SOLVED] ArchLinux Live USB UEFi boot impossible on a new PC

I finally solved my issues and managed to boot in UEFI on the live CD with the following :
* Used the manual formatting instead of the ISO formatting, as explained in  https://wiki.archlinux.org/title/USB_fl … #UEFI_only
* Downgraded the liveCD arch iso from 2025.03 to 2025.02. The 03 was crashing after startup (/dev/loop0 mount issue). I lost the ethernet driver (supported in the 2025.03 though), but wifi was alright.
Last info: my mobo is a ASUS PRIME B850-PLUS WIFI.