F8 boot menu

Rene Lamontagne wrote:
On 2019-11-12 2:36 p.m., Paul wrote:
Rene Lamontagne wrote:
More out of curiosity than anything.
When I insert a bootable USB stick in my system such as a Linux Live
distro or my Kaspersky Rescue stick I get 2 entries in the F8 boot
menu for instance.

SMI USB Disk 1100 (15000MB)
UEFI: SMI USB Disk 1100, Partition 1 (15000MB)

This on an Asus B 450F Strix motorboard with UEFI bios.

Rene

You have UEFI+CSM enabled, so both boot modes are available.

If you plan on *installing* from a USB stick, then the mode
selected is important, as it triggers "install in a matching mode".
If you want the hard drive boot mode to be UEFI, you boot
the USB flash in UEFI too.

I've been playing with a ChromeOS USB stick, and it actually
fails to work properly in UEFI mode, and only CSM mode works
right. I've never seen that happen on a Linux one.

Paul

Thanks both Mike and Paul, First Yes, I use Rufus 3.5 to create my USB
bootable sticks, Looking in the Bios I find CSM is enabled and it has
many options, tried Auto and disabled then it leads to 4 more options so
I left it at Legacy and UEFI, it has UEFI only, Legacy only and a couple
others.
So my question is answered as to why I have two entries.

As Paul noted on his Chrome stick I see the same result on my MX Linux
stick, It boots fine in Legacy mode but goes squirrley if I try UEFI mode.

Thanks for the explanations.

Rene

Since the UEFI keeps state information in NVRAM,
there could come a day when a UEFI based computer
tips over while POSTing. And I don't know how you
fix that, either... (The Flash chip is soldered to
the motherboard.)

My newest machine, has an automated hardware flasher
in it. To recover the machine, present a USB stick with
a named file on it, and you can reload the firmware.
And that motherboard feature works, even if a CPU
is not installed in the socket! Which I thought was
pretty neat.

There's some kind of microcontroller next to the
USB socket, that works the magic. Some day, I may get
to find out just how well that works.

Paul