Arch Linux

esteka3000

Member

Registered: 2020-04-10

Posts: 18

[Solved] Boot mode… Legacy vs UEFI vs UEFI with CSM

Hi there!

I want to install ArchLinux on my brand new laptop… But first, i would like to know which "Boot mode" I should choose…

My motherboard proposes three different ones: Legacy, UEFI, UEFI with CSM. As a newbie — after reading a bit about it — I thought i should go with "UEFI" boot mode. Issue there: that gives me a "Secure Boot Violation : Invalid signature detected. Check Security Boot Policy in Setup" message. If I run it with "UEFI with CSM", the message does not show up.

So my question is the following: what should I do, and why?

Cheers mates!

Last edited by esteka3000 (2020-04-12 08:04:34)

loqs

Member

Registered: 2014-03-06

Posts: 17,890

Re: [Solved] Boot mode… Legacy vs UEFI vs UEFI with CSM

Is there an option in the firmware called Security Boot Policy or similar to disable Secure Boot?

esteka3000

Member

Registered: 2020-04-10

Posts: 18

Re: [Solved] Boot mode… Legacy vs UEFI vs UEFI with CSM

Is there an option in the firmware called Security Boot Policy or similar to disable Secure Boot?

In "Security" there is "Secure Boot", there "System Mode" is User, "Secure Boot Support" is Disable, "Secure Boot" is Not Active and "Secure Boot Mode" is Standard.

Does that answered your question?

loqs

Member

Registered: 2014-03-06

Posts: 17,890

Re: [Solved] Boot mode… Legacy vs UEFI vs UEFI with CSM

Can you boot in UEFI boot mode if you set Secure Boot Support to Disable?

esteka3000

Member

Registered: 2020-04-10

Posts: 18

Re: [Solved] Boot mode… Legacy vs UEFI vs UEFI with CSM

Can you boot in UEFI boot mode if you set Secure Boot Support to Disable?

Indeed, I did not notice that if I change the boot mode, the secure boot mode does change too…
Well, that message does not show up anymore, true. But is UEFI without secure boot mode better that UEFI with CSM with secure boot mode?

loqs

Member

Registered: 2014-03-06

Posts: 17,890

Re: [Solved] Boot mode… Legacy vs UEFI vs UEFI with CSM

UEFI with CSM with secure boot mode will not load the unsigned UEFI boot loader the arch installation media provides.  It will use the CSM compatible BIOS mode boot loader which is also unsigned.
If you want to boot in UEFI mode you need to disable secure boot at least for the installation process.  You can then sign the boot loader and re-enable secure boot.
See Secure Boot.

Last edited by loqs (2020-04-10 15:50:20)

esteka3000

Member

Registered: 2020-04-10

Posts: 18

Re: [Solved] Boot mode… Legacy vs UEFI vs UEFI with CSM

UEFI with CSM with secure boot mode will not load the unsigned UEFI boot loader the arch installation media provides.  It will use the CSM compatible BIOS mode boot loader which is also unsigned.
If you want to boot in UEFI mode you need to disable secure boot at least for the installation process.  You can then sign the boot loader and re-enable secure boot.
See Secure Boot.

Thanks a lot mate!
Cheers!