UEFI Boot fails if legacy mode is disabled completely in settings on ASUS Z87 board

Michelle Sullivan michelle at sorbs.net
Thu Nov 20 18:59:43 UTC 2014

Dominik Zajac wrote:
> Hi,
> on an ASUS Z87 Pro board, the UEFI boot media only work if the CSM mode
> in the Settings of the UEFI are set to "both". This means it is using
> UEFI boot and CSM mode for legacy booting.
> If I disable the legacy CSM and configure "UEFI only", the UEFI loader
> still loads but when it comes to load the kernel it just stops and the
> system is frozen at that point. Same with 10.1 and 11-current USB
> install media.
> The system now has FreeBSD 10.1 on one disc installed with UEFI mode and
> boots with it as long as the CSM compatibility mode is enabled.
> Has someone a similar problem or behaviour?

Same Mobo, same problem here.
> This leads me to the next question. How can I debug or get more
> information what fails at this stage of the boot process? I would like
> to provide more detailed information and help to debug to hunt this bug
> down.
Sorry - I can't help here, I don't have time to debug as too busy fixing
broken systems from Sept 1 changes.

Michelle Sullivan

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